An online operational rainfall-monitoring resource for epidemic malaria early warning systems in Africa

USGS Publications Warehouse

Grover-Kopec, Emily; Kawano, Mika; Klaver, Robert W.; Blumenthal, Benno; Ceccato, Pietro; Connor, Stephen J.

2005-01-01

Periodic epidemics of malaria are a major public health problem for many sub-Saharan African countries. Populations in epidemic prone areas have a poorly developed immunity to malaria and the disease remains life threatening to all age groups. The impact of epidemics could be minimized by prediction and improved prevention through timely vector control and deployment of appropriate drugs. Malaria Early Warning Systems are advocated as a means of improving the opportunity for preparedness and timely response.Rainfall is one of the major factors triggering epidemics in warm semi-arid and desert-fringe areas. Explosive epidemics often occur in these regions after excessive rains and, where these follow periods of drought and poor food security, can be especially severe. Consequently, rainfall monitoring forms one of the essential elements for the development of integrated Malaria Early Warning Systems for sub-Saharan Africa, as outlined by the World Health Organization.The Roll Back Malaria Technical Resource Network on Prevention and Control of Epidemics recommended that a simple indicator of changes in epidemic risk in regions of marginal transmission, consisting primarily of rainfall anomaly maps, could provide immediate benefit to early warning efforts. In response to these recommendations, the Famine Early Warning Systems Network produced maps that combine information about dekadal rainfall anomalies, and epidemic malaria risk, available via their Africa Data Dissemination Service. These maps were later made available in a format that is directly compatible with HealthMapper, the mapping and surveillance software developed by the WHO's Communicable Disease Surveillance and Response Department. A new monitoring interface has recently been developed at the International Research Institute for Climate Prediction (IRI) that enables the user to gain a more contextual perspective of the current rainfall estimates by comparing them to previous seasons and climatological averages. These resources are available at no cost to the user and are updated on a routine basis.

Impact of constrained rewiring on network structure and node dynamics

NASA Astrophysics Data System (ADS)

Rattana, P.; Berthouze, L.; Kiss, I. Z.

2014-11-01

In this paper, we study an adaptive spatial network. We consider a susceptible-infected-susceptible (SIS) epidemic on the network, with a link or contact rewiring process constrained by spatial proximity. In particular, we assume that susceptible nodes break links with infected nodes independently of distance and reconnect at random to susceptible nodes available within a given radius. By systematically manipulating this radius we investigate the impact of rewiring on the structure of the network and characteristics of the epidemic. We adopt a step-by-step approach whereby we first study the impact of rewiring on the network structure in the absence of an epidemic, then with nodes assigned a disease status but without disease dynamics, and finally running network and epidemic dynamics simultaneously. In the case of no labeling and no epidemic dynamics, we provide both analytic and semianalytic formulas for the value of clustering achieved in the network. Our results also show that the rewiring radius and the network's initial structure have a pronounced effect on the endemic equilibrium, with increasingly large rewiring radiuses yielding smaller disease prevalence.

The HIV Epidemic: High-Income Countries

PubMed Central

Vermund, Sten H.; Leigh-Brown, Andrew J.

2012-01-01

The HIV epidemic in higher-income nations is driven by receptive anal intercourse, injection drug use through needle/syringe sharing, and, less efficiently, vaginal intercourse. Alcohol and noninjecting drug use increase sexual HIV vulnerability. Appropriate diagnostic screening has nearly eliminated blood/blood product-related transmissions and, with antiretroviral therapy, has reduced mother-to-child transmission radically. Affected subgroups have changed over time (e.g., increasing numbers of Black and minority ethnic men who have sex with men). Molecular phylogenetic approaches have established historical links between HIV strains from central Africa to those in the United States and thence to Europe. However, Europe did not just receive virus from the United States, as it was also imported from Africa directly. Initial introductions led to epidemics in different risk groups in Western Europe distinguished by viral clades/sequences, and likewise, more recent explosive epidemics linked to injection drug use in Eastern Europe are associated with specific strains. Recent developments in phylodynamic approaches have made it possible to obtain estimates of sequence evolution rates and network parameters for epidemics. PMID:22553497

Epidemic spreading in metapopulation networks with heterogeneous infection rates

NASA Astrophysics Data System (ADS)

Gong, Yong-Wang; Song, Yu-Rong; Jiang, Guo-Ping

2014-12-01

In this paper, we study epidemic spreading in metapopulation networks wherein each node represents a subpopulation symbolizing a city or an urban area and links connecting nodes correspond to the human traveling routes among cities. Differently from previous studies, we introduce a heterogeneous infection rate to characterize the effect of nodes' local properties, such as population density, individual health habits, and social conditions, on epidemic infectivity. By means of a mean-field approach and Monte Carlo simulations, we explore how the heterogeneity of the infection rate affects the epidemic dynamics, and find that large fluctuations of the infection rate have a profound impact on the epidemic threshold as well as the temporal behavior of the prevalence above the epidemic threshold. This work can refine our understanding of epidemic spreading in metapopulation networks with the effect of nodes' local properties.

Leveraging hospital big data to monitor flu epidemics.

PubMed

Bouzillé, Guillaume; Poirier, Canelle; Campillo-Gimenez, Boris; Aubert, Marie-Laure; Chabot, Mélanie; Chazard, Emmanuel; Lavenu, Audrey; Cuggia, Marc

2018-02-01

Influenza epidemics are a major public health concern and require a costly and time-consuming surveillance system at different geographical scales. The main challenge is being able to predict epidemics. Besides traditional surveillance systems, such as the French Sentinel network, several studies proposed prediction models based on internet-user activity. Here, we assessed the potential of hospital big data to monitor influenza epidemics. We used the clinical data warehouse of the Academic Hospital of Rennes (France) and then built different queries to retrieve relevant information from electronic health records to gather weekly influenza-like illness activity. We found that the query most highly correlated with Sentinel network estimates was based on emergency reports concerning discharged patients with a final diagnosis of influenza (Pearson's correlation coefficient (PCC) of 0.931). The other tested queries were based on structured data (ICD-10 codes of influenza in Diagnosis-related Groups, and influenza PCR tests) and performed best (PCC of 0.981 and 0.953, respectively) during the flu season 2014-15. This suggests that both ICD-10 codes and PCR results are associated with severe epidemics. Finally, our approach allowed us to obtain additional patients' characteristics, such as the sex ratio or age groups, comparable with those from the Sentinel network. Conclusions: Hospital big data seem to have a great potential for monitoring influenza epidemics in near real-time. Such a method could constitute a complementary tool to standard surveillance systems by providing additional characteristics on the concerned population or by providing information earlier. This system could also be easily extended to other diseases with possible activity changes. Additional work is needed to assess the real efficacy of predictive models based on hospital big data to predict flu epidemics. Copyright © 2017 Elsevier B.V. All rights reserved.

Is the New Heroin Epidemic Really New? Racializing Heroin.

PubMed

Bowser, Benjamin; Fullilove, Robert; Word, Carl

2017-01-01

Heroin abuse as an outcome of the prior use of painkillers increased rapidly over the past decade. This "new epidemic" is unique because the new heroin users are primarily young White Americans in rural areas of virtually every state. This commentary argues that the painkiller-to-heroin transition could not be the only cause of heroin use on such a scale and that the new and old heroin epidemics are linked. The social marketing that so successfully drove the old heroin epidemic has innovated and expanded due to the use of cell-phones, text messaging and the "dark web" which requires a Tor browser, and software that allows one to communicate with encrypted sites without detection. Central city gentrification has forced traffickers to take advantage of larger and more lucrative markets. A second outcome is that urban black and Latino communities are no longer needed as heroin stages areas for suburban and exurban illicit drug distribution. Drug dealing can be done directly in predominantly white suburbs and rural areas without the accompanying violence associated with the old epidemic. Denial of the link between the new and old heroin epidemics racially segregates heroin users and more proactive prevention and treatment in the new epidemic than in the old. It also cuts off a half-century of knowledge about the supply-side of heroin drug dealing and the inevitable public policy measures that will have to be implemented to effectively slow and stop both the old and new epidemic. Copyright © 2016 National Medical Association. Published by Elsevier Inc. All rights reserved.

Canine distemper virus infection among wildlife before and after the epidemic.

PubMed

Suzuki, Junko; Nishio, Yohei; Kameo, Yuki; Terada, Yutaka; Kuwata, Ryusei; Shimoda, Hiroshi; Suzuki, Kazuo; Maeda, Ken

2015-11-01

In 2007-2008, a canine distemper virus (CDV) epidemic occurred among wild animals in Wakayama Prefecture, Japan, and many mammals, including the wild boar and deer, were infected. In this study, CDV prevalence among wild animals was surveyed before and after the epidemic. At first, an enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase-conjugated protein A/G was established to detect CDV antibodies in many mammalian species. This established ELISA was available for testing dogs, raccoons and raccoon dogs as well as virus-neutralization test. Next, a serological survey of wild mammalians was conducted, and it was indicated that many wild mammalians, particularly raccoons, were infected with CDV during the epidemic, but few were infected before and after the epidemic. On the other hand, many raccoon dogs died during the epidemic, but CDV remained prevalent in the remaining population, and a small epidemic occurred in raccoon dogs in 2012-2013. These results indicated that the epidemic of 2007-2008 may have been intensified by transmission to raccoons.

Roles of the spreading scope and effectiveness in spreading dynamics on multiplex networks

NASA Astrophysics Data System (ADS)

Li, Ming; Liu, Run-Ran; Peng, Dan; Jia, Chun-Xiao; Wang, Bing-Hong

2018-02-01

Comparing with single networks, the multiplex networks bring two main effects on the spreading process among individuals. First, the pathogen or information can be transmitted to more individuals through different layers at one time, which enlarges the spreading scope. Second, through different layers, an individual can also transmit the pathogen or information to the same individuals more than once at one time, which makes the spreading more effective. To understand the different roles of the spreading scope and effectiveness, we propose an epidemic model on multiplex networks with link overlapping, where the spreading effectiveness of each interaction as well as the variety of channels (spreading scope) can be controlled by the number of overlapping links. We find that for Poisson degree distribution, increasing the epidemic scope (the first effect) is more efficient than enhancing epidemic probability (the second effect) to facilitate the spreading process. However, for power-law degree distribution, the effects of the two factors on the spreading dynamics become complicated. Enhancing epidemic probability makes pathogen or rumor easier to outbreak in a finite system. But after that increasing epidemic scopes is still more effective for a wide spreading. Theoretical results along with reasonable explanation for these phenomena are all given in this paper, which indicates that the epidemic scope could play an important role in the spreading dynamics.

User's guide to the douglas-fir beetle impact model. Forest Service general technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marsden, M.A.; Eav, B.B.; Thompson, M.K.

1994-09-01

Douglas-fir beetle occurs throughout the range of its principal host, Douglas-fir. At epidemic levels, the beetle causes considerable mortality in large-diameter Douglas-fir trees. Wind storms, drought, fire, and other factors have been reported as precendent conditions for epidemics of Douglas-fir beetle. An impact model has been developed to simulate tree mortality during such epidemics. The model has been linked to the Stand Prognosis Model (Forest Vegetation Simulator). This is a guide for using the model.

A Bayesian method for inferring transmission chains in a partially observed epidemic.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marzouk, Youssef M.; Ray, Jaideep

2008-10-01

We present a Bayesian approach for estimating transmission chains and rates in the Abakaliki smallpox epidemic of 1967. The epidemic affected 30 individuals in a community of 74; only the dates of appearance of symptoms were recorded. Our model assumes stochastic transmission of the infections over a social network. Distinct binomial random graphs model intra- and inter-compound social connections, while disease transmission over each link is treated as a Poisson process. Link probabilities and rate parameters are objects of inference. Dates of infection and recovery comprise the remaining unknowns. Distributions for smallpox incubation and recovery periods are obtained from historicalmore » data. Using Markov chain Monte Carlo, we explore the joint posterior distribution of the scalar parameters and provide an expected connectivity pattern for the social graph and infection pathway.« less

Optimal Link Removal for Epidemic Mitigation: A Two-Way Partitioning Approach

PubMed Central

Enns, Eva A.; Mounzer, Jeffrey J.; Brandeau, Margaret L.

2011-01-01

The structure of the contact network through which a disease spreads may influence the optimal use of resources for epidemic control. In this work, we explore how to minimize the spread of infection via quarantining with limited resources. In particular, we examine which links should be removed from the contact network, given a constraint on the number of removable links, such that the number of nodes which are no longer at risk for infection is maximized. We show how this problem can be posed as a non-convex quadratically constrained quadratic program (QCQP), and we use this formulation to derive a link removal algorithm. The performance of our QCQP-based algorithm is validated on small Erdős-Renyi and small-world random graphs, and then tested on larger, more realistic networks, including a real-world network of injection drug use. We show that our approach achieves near optimal performance and out-perform so ther intuitive link removal algorithms, such as removing links in order of edge centrality. PMID:22115862

Reverse-feeding effect of epidemic by propagators in two-layered networks

NASA Astrophysics Data System (ADS)

Dayu, Wu; Yanping, Zhao; Muhua, Zheng; Jie, Zhou; Zonghua, Liu

2016-02-01

Epidemic spreading has been studied for a long time and is currently focused on the spreading of multiple pathogens, especially in multiplex networks. However, little attention has been paid to the case where the mutual influence between different pathogens comes from a fraction of epidemic propagators, such as bisexual people in two separated groups of heterosexual and homosexual people. We here study this topic by presenting a network model of two layers connected by impulsive links, in contrast to the persistent links in each layer. We let each layer have a distinct pathogen and their interactive infection is implemented by a fraction of propagators jumping between the corresponding pairs of nodes in the two layers. By this model we show that (i) the propagators take the key role to transmit pathogens from one layer to the other, which significantly influences the stabilized epidemics; (ii) the epidemic thresholds will be changed by the propagators; and (iii) a reverse-feeding effect can be expected when the infective rate is smaller than its threshold of isolated spreading. A theoretical analysis is presented to explain the numerical results. Project supported by the National Natural Science Foundation of China (Grant Nos. 11135001, 11375066, and 11405059) and the National Basic Key Program of China (Grant No. 2013CB834100).

Identifying Potential Norovirus Epidemics in China via Internet Surveillance

PubMed Central

Chen, Bin; Jiang, Tao; Cai, Gaofeng; Jiang, Zhenggang; Chen, Yongdi; Wang, Zhengting; Gu, Hua; Chai, Chengliang

2017-01-01

Background Norovirus is a common virus that causes acute gastroenteritis worldwide, but a monitoring system for norovirus is unavailable in China. Objective We aimed to identify norovirus epidemics through Internet surveillance and construct an appropriate model to predict potential norovirus infections. Methods The norovirus-related data of a selected outbreak in Jiaxing Municipality, Zhejiang Province of China, in 2014 were collected from immediate epidemiological investigation, and the Internet search volume, as indicated by the Baidu Index, was acquired from the Baidu search engine. All correlated search keywords in relation to norovirus were captured, screened, and composited to establish the composite Baidu Index at different time lags by Spearman rank correlation. The optimal model was chosen and possibly predicted maps in Zhejiang Province were presented by ArcGIS software. Results The combination of two vital keywords at a time lag of 1 day was ultimately identified as optimal (ρ=.924, P<.001). The exponential curve model was constructed to fit the trend of this epidemic, suggesting that a one-unit increase in the mean composite Baidu Index contributed to an increase of norovirus infections by 2.15 times during the outbreak. In addition to Jiaxing Municipality, Hangzhou Municipality might have had some potential epidemics in the study time from the predicted model. Conclusions Although there are limitations with early warning and unavoidable biases, Internet surveillance may be still useful for the monitoring of norovirus epidemics when a monitoring system is unavailable. PMID:28790023

Suppressed epidemics in multirelational networks

NASA Astrophysics Data System (ADS)

Xu, Elvis H. W.; Wang, Wei; Xu, C.; Tang, Ming; Do, Younghae; Hui, P. M.

2015-08-01

A two-state epidemic model in networks with links mimicking two kinds of relationships between connected nodes is introduced. Links of weights w1 and w0 occur with probabilities p and 1 -p , respectively. The fraction of infected nodes ρ (p ) shows a nonmonotonic behavior, with ρ drops with p for small p and increases for large p . For small to moderate w1/w0 ratios, ρ (p ) exhibits a minimum that signifies an optimal suppression. For large w1/w0 ratios, the suppression leads to an absorbing phase consisting only of healthy nodes within a range pL≤p ≤pR , and an active phase with mixed infected and healthy nodes for p pR . A mean field theory that ignores spatial correlation is shown to give qualitative agreement and capture all the key features. A physical picture that emphasizes the intricate interplay between infections via w0 links and within clusters formed by nodes carrying the w1 links is presented. The absorbing state at large w1/w0 ratios results when the clusters are big enough to disrupt the spread via w0 links and yet small enough to avoid an epidemic within the clusters. A theory that uses the possible local environments of a node as variables is formulated. The theory gives results in good agreement with simulation results, thereby showing the necessity of including longer spatial correlations.

Influenza surveillance in Europe: establishing epidemic thresholds by the Moving Epidemic Method

PubMed Central

Vega, Tomás; Lozano, Jose Eugenio; Meerhoff, Tamara; Snacken, René; Mott, Joshua; Ortiz de Lejarazu, Raul; Nunes, Baltazar

2012-01-01

Please cite this paper as: Vega et al. (2012) Influenza surveillance in Europe: establishing epidemic thresholds by the moving epidemic method. Influenza and Other Respiratory Viruses 7(4), 546–558. Background  Timely influenza surveillance is important to monitor influenza epidemics. Objectives  (i) To calculate the epidemic threshold for influenza‐like illness (ILI) and acute respiratory infections (ARI) in 19 countries, as well as the thresholds for different levels of intensity. (ii) To evaluate the performance of these thresholds. Methods  The moving epidemic method (MEM) has been developed to determine the baseline influenza activity and an epidemic threshold. False alerts, detection lags and timeliness of the detection of epidemics were calculated. The performance was evaluated using a cross‐validation procedure. Results  The overall sensitivity of the MEM threshold was 71·8% and the specificity was 95·5%. The median of the timeliness was 1 week (range: 0–4·5). Conclusions  The method produced a robust and specific signal to detect influenza epidemics. The good balance between the sensitivity and specificity of the epidemic threshold to detect seasonal epidemics and avoid false alerts has advantages for public health purposes. This method may serve as standard to define the start of the annual influenza epidemic in countries in Europe. PMID:22897919

Effects of active links on epidemic transmission over social networks

NASA Astrophysics Data System (ADS)

Zhu, Guanghu; Chen, Guanrong; Fu, Xinchu

2017-02-01

A new epidemic model with two infection periods is developed to account for the human behavior in social network, where newly infected individuals gradually restrict most of future contacts or are quarantined, causing infectivity change from a degree-dependent form to a constant. The corresponding dynamics are formulated by a set of ordinary differential equations (ODEs) via mean-field approximation. The effects of diverse infectivity on the epidemic dynamics ​are examined, with a behavioral interpretation of the basic reproduction number. Results show that such simple adaptive reactions largely determine the impact of network structure on epidemics. Particularly, a theorem proposed by Lajmanovich and Yorke in 1976 is generalized, so that it can be applied for the analysis of the epidemic models with multi-compartments especially network-coupled ODE systems.

Canine distemper virus infection among wildlife before and after the epidemic

PubMed Central

SUZUKI, Junko; NISHIO, Yohei; KAMEO, Yuki; TERADA, Yutaka; KUWATA, Ryusei; SHIMODA, Hiroshi; SUZUKI, Kazuo; MAEDA, Ken

2015-01-01

In 2007–2008, a canine distemper virus (CDV) epidemic occurred among wild animals in Wakayama Prefecture, Japan, and many mammals, including the wild boar and deer, were infected. In this study, CDV prevalence among wild animals was surveyed before and after the epidemic. At first, an enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase-conjugated protein A/G was established to detect CDV antibodies in many mammalian species. This established ELISA was available for testing dogs, raccoons and raccoon dogs as well as virus-neutralization test. Next, a serological survey of wild mammalians was conducted, and it was indicated that many wild mammalians, particularly raccoons, were infected with CDV during the epidemic, but few were infected before and after the epidemic. On the other hand, many raccoon dogs died during the epidemic, but CDV remained prevalent in the remaining population, and a small epidemic occurred in raccoon dogs in 2012–2013. These results indicated that the epidemic of 2007–2008 may have been intensified by transmission to raccoons. PMID:26074342

Addressing knowledge gaps in molecular, sero-surveillance and monitoring approaches on Zika epidemics and other arbovirus co-infections: A structured review.

PubMed

Tambo, Ernest; Khayeka-Wandabwa, Christopher; Olalubi, Oluwasogo A; Adedeji, Ahmed A; Ngogang, Jeanne Y; Khater, Emad Im

2017-05-01

Globalization, with consequent increased travel and trade, rapid urbanization and growing weather variation events due to climate change has contributed to the recent unprecedented Zika virus (ZIKV) pandemic. This has emphasized the pressing need for local, national, regional and global community collaborative proactiveness, leadership and financial investment resilience in research and development. This paper addresses the potential knowledge gaps and impact of early detection and monitoring approaches on ZIKV epidemics and related arboviral infections steered towards effective prevention and smart response strategies. We advocate for the development and validation of robust field and point of care diagnostic tools that are more sensitive, specific and cost effective for use in ZIKV epidemics and routine pathophysiology surveillance and monitoring systems as an imperative avenue in understanding Zika-related and other arbovirus trends and apply genomic and proteomic characterisation approaches in guiding annotation efforts in order to design and implement public health burden mitigation and adaptation strategies.

Linked Outbreaks of Hepatitis A in Homosexual Men and in Food Service Patrons and Employees

PubMed Central

Kosatsky, Tom; Middaugh, John P.

1986-01-01

Outbreaks of hepatitis A among patrons and employees of two food service establishments in Anchorage, Alaska, in November 1982 and April 1983 were linked to male food handlers infected with the virus. By case finding and contact tracing, we established that the food handlers in both outbreaks were associated with an epidemic of hepatitis A that was transmitted among Anchorage homosexual men for more than six months. Lacking specific serologic findings, physicians treating several of these homosexual men had incorrectly diagnosed the illness as hepatitis B, delaying recognition of the epidemic. ImagesFigure 3. PMID:3962292

On extinction time of a generalized endemic chain-binomial model.

PubMed

Aydogmus, Ozgur

2016-09-01

We considered a chain-binomial epidemic model not conferring immunity after infection. Mean field dynamics of the model has been analyzed and conditions for the existence of a stable endemic equilibrium are determined. The behavior of the chain-binomial process is probabilistically linked to the mean field equation. As a result of this link, we were able to show that the mean extinction time of the epidemic increases at least exponentially as the population size grows. We also present simulation results for the process to validate our analytical findings. Copyright © 2016 Elsevier Inc. All rights reserved.

Optimal control of epidemic information dissemination over networks.

PubMed

Chen, Pin-Yu; Cheng, Shin-Ming; Chen, Kwang-Cheng

2014-12-01

Information dissemination control is of crucial importance to facilitate reliable and efficient data delivery, especially in networks consisting of time-varying links or heterogeneous links. Since the abstraction of information dissemination much resembles the spread of epidemics, epidemic models are utilized to characterize the collective dynamics of information dissemination over networks. From a systematic point of view, we aim to explore the optimal control policy for information dissemination given that the control capability is a function of its distribution time, which is a more realistic model in many applications. The main contributions of this paper are to provide an analytically tractable model for information dissemination over networks, to solve the optimal control signal distribution time for minimizing the accumulated network cost via dynamic programming, and to establish a parametric plug-in model for information dissemination control. In particular, we evaluate its performance in mobile and generalized social networks as typical examples.

Monitoring an epidemic of Theileria-associated bovine anaemia (Ikeda) in cattle herds in New Zealand.

PubMed

McFadden, A M J; Vink, D; Pulford, D J; Lawrence, K; Gias, E; Heath, A C G; McFadden, C B; Bingham, P

2016-03-01

Monitoring an epidemic of an emerging vector-borne disease can be problematic; particularly in a country where vector-borne disease has previously had minimal impact on livestock. This paper describes methods of past and current surveillance of the Theileria-associated bovine anaemia (Ikeda; TABA) epidemic in New Zealand, and the resulting inferences made. Over the three year period of the TABA epidemic a portfolio of surveillance methods has been used: case reporting (with subsidised PCR testing), syndromic surveillance, sentinel surveillance, testing convenience samples for herd infection, as well as specific active surveillance initiatives to understand the tick vector distribution. Surveillance data have shown that the number of affected cattle herds has continued to increase over time with seasonal peaks in spring and autumn coinciding with peak activity of nymph and adult ticks respectively. In spring 2014, the epidemic extended south into areas that were previously considered to be unsuitable for the tick vector. As a result a survey was initiated that showed that ticks were present in areas outside of the known distribution. Testing pooled blood samples from cattle herds across New Zealand showed there still remained a significant percentage of herds where only non-Ikeda type infections were present, indicating that these herds were at risk of future TABA (Ikeda) outbreaks. For some regions there had been a noticeable increase in the percentage of herds infected, yet with only a small increase in the number of outbreaks compared with the previous year. Thus, outbreaks had either gone unobserved or had not been confirmed by testing. In these regions extensive low-input beef farming could explain the non-detection observed. There was a close relationship between the number of syndromic reports of anaemia and the number of confirmed cases of TABA (Ikeda), (P<0.01, adjusted R-squared=0.74). Active monitoring of the epidemic for a three year period has provided valuable insight into seasonal nature of the disease and its continuing impact. Information from multiple surveillance sources can help build up an understanding of the epidemiology, even when data from each individual surveillance stream are limited. The TABA (Ikeda) epidemic in New Zealand represents a useful case study of long term monitoring where disease is caused by an emerging pathogen. Copyright © 2015 Elsevier B.V. All rights reserved.

Phenotypic Analysis Reveals that the 2010 Haiti Cholera Epidemic Is Linked to a Hypervirulent Strain

PubMed Central

Jones, Christopher J.; Wong, Jennifer; Queen, Jessica; Agarwal, Shivani; Yildiz, Fitnat H.

2016-01-01

Vibrio cholerae O1 El Tor strains have been responsible for pandemic cholera since 1961. These strains have evolved over time, spreading globally in three separate waves. Wave 3 is caused by altered El Tor (AET) variant strains, which include the strain with the signature ctxB7 allele that was introduced in 2010 into Haiti, where it caused a devastating epidemic. In this study, we used phenotypic analysis to compare an early isolate from the Haiti epidemic to wave 1 El Tor isolates commonly used for research. It is demonstrated that the Haiti isolate has increased production of cholera toxin (CT) and hemolysin, increased motility, and a reduced ability to form biofilms. This strain also outcompetes common wave 1 El Tor isolates for colonization of infant mice, indicating that it has increased virulence. Monitoring of CT production and motility in additional wave 3 isolates revealed that this phenotypic variation likely evolved over time rather than in a single genetic event. Analysis of available whole-genome sequences and phylogenetic analyses suggested that increased virulence arose from positive selection for mutations found in known and putative regulatory genes, including hns and vieA, diguanylate cyclase genes, and genes belonging to the lysR and gntR regulatory families. Overall, the studies presented here revealed that V. cholerae virulence potential can evolve and that the currently prevalent wave 3 AET strains are both phenotypically distinct from and more virulent than many El Tor isolates. PMID:27297393

Second-generation HIV surveillance: better data for decision-making.

PubMed Central

Rehle, Thomas; Lazzari, Stefano; Dallabetta, Gina; Asamoah-Odei, Emil

2004-01-01

This paper seeks to outline the key elements of the expanded surveillance efforts recommended by the second-generation HIV surveillance approach. Second-generation systems focus on improving and expanding existing surveillance methods and combine them in ways that have the greatest explanatory power. The main elements of this approach include: considering biological surveillance - HIV, AIDS, sexually transmitted infections (STIs) - and behavioural surveillance as integral components, targeting surveillance efforts at segments of the population where most new infections are concentrated - which might differ depending on the stage and type of the epidemic - and providing the rationale for the optimal use of data generated for monitoring the HIV epidemic and evaluating national AIDS control programmes. The paper emphasizes improvements in existing surveillance methodologies and discusses in detail crucial issues such as the validity of HIV prevalence data measured in pregnant women and linking HIV surveillance and behavioural data collection. In addition, a strategic partnership between second-generation surveillance and AIDS programme evaluation is proposed that stresses the complementary roles of these data collection activities in determining the effectiveness of prevention and care programmes and explaining the epidemiological trend data collected by sentinel serosurveillance systems. In conclusion, second-generation HIV surveillance systems provide a comprehensive, cost-effective and appropriate response to the information needs of AIDS control programmes. The implementation of such systems, including a better use of the data generated by the system, will ensure that national programmes are in the best possible position to respond to the challenges of the epidemic. PMID:15042234

Second-generation HIV surveillance: better data for decision-making.

PubMed

Rehle, Thomas; Lazzari, Stefano; Dallabetta, Gina; Asamoah-Odei, Emil

2004-02-01

This paper seeks to outline the key elements of the expanded surveillance efforts recommended by the second-generation HIV surveillance approach. Second-generation systems focus on improving and expanding existing surveillance methods and combine them in ways that have the greatest explanatory power. The main elements of this approach include: considering biological surveillance - HIV, AIDS, sexually transmitted infections (STIs) - and behavioural surveillance as integral components, targeting surveillance efforts at segments of the population where most new infections are concentrated - which might differ depending on the stage and type of the epidemic - and providing the rationale for the optimal use of data generated for monitoring the HIV epidemic and evaluating national AIDS control programmes. The paper emphasizes improvements in existing surveillance methodologies and discusses in detail crucial issues such as the validity of HIV prevalence data measured in pregnant women and linking HIV surveillance and behavioural data collection. In addition, a strategic partnership between second-generation surveillance and AIDS programme evaluation is proposed that stresses the complementary roles of these data collection activities in determining the effectiveness of prevention and care programmes and explaining the epidemiological trend data collected by sentinel serosurveillance systems. In conclusion, second-generation HIV surveillance systems provide a comprehensive, cost-effective and appropriate response to the information needs of AIDS control programmes. The implementation of such systems, including a better use of the data generated by the system, will ensure that national programmes are in the best possible position to respond to the challenges of the epidemic.

International Spread of MDR TB from Tugela Ferry, South Africa

PubMed Central

Beaton, R. Kate; Lessells, Richard J.; John, Laurence; Ashworth, Simon; Kon, Onn Min; Williams, O. Martin; Supply, P.; Moodley, P.; Pym, Alexander S.

2011-01-01

We describe a death associated with multidrug-resistant tuberculosis and HIV infection outside Africa that can be linked to Tugela Ferry (KwaZulu-Natal, South Africa), the town most closely associated with the regional epidemic of drug-resistant tuberculosis. This case underscores the international relevance of this regional epidemic, particularly among health care workers. PMID:22099091

The Curse of Frybread: The Diabetes Epidemic in Indian Country.

ERIC Educational Resources Information Center

Hill, Mary Anne

1997-01-01

Diabetes among American Indians has become epidemic since World War II, due to dietary changes and a possible genetic predisposition. Innovative community-based programs teach prevention and management of diabetes through exercise, diet, and blood sugar monitoring. Traditional American Indian lifestyles and diets prevented diabetes. Sidebars…

Design and Implementation of Integrated Surveillance and Modeling Systems for Climate-Sensitive Diseases

NASA Astrophysics Data System (ADS)

Wimberly, M. C.; Merkord, C. L.; Davis, J. K.; Liu, Y.; Henebry, G. M.; Hildreth, M. B.

2016-12-01

Climatic variations have a multitude of effects on human health, ranging from the direct impacts of extreme heat events to indirect effects on the vectors and hosts that transmit infectious diseases. Disease surveillance has traditionally focused on monitoring human cases, and in some instances tracking populations sizes and infection rates of arthropod vectors and zoonotic hosts. For climate-sensitive diseases, there is a potential to strengthen surveillance and obtain early indicators of future outbreaks by monitoring environmental risk factors using broad-scale sensor networks that include earth-observing satellites as well as ground stations. We highlight the opportunities and challenges of this integration by presenting modeling results and discussing lessons learned from two projects focused on surveillance and forecasting of mosquito-borne diseases. The Epidemic Prognosis Incorporating Disease and Environmental Monitoring for Integrated Assessement (EPIDEMIA) project integrates malaria case surveillance with remotely-sensed environmental data for early detection of malaria epidemics in the Amhara region of Ethiopia and has been producing weekly forecast reports since 2015. The South Dakota Mosquito Information System (SDMIS) project similarly combines entomological surveillance with environmental monitoring to generate weekly maps for West Nile virus (WNV) in the north-central United States. We are currently implementing a new disease forecasting and risk reporting framework for the state of South Dakota during the 2016 WNV transmission season. Despite important differences in disease ecology and geographic setting, our experiences with these projects highlight several important lessons learned that can inform future efforts at disease early warning based on climatic predictors. These include the need to engage end users in system design from the outset, the critical role of automated workflows to facilitate the timely integration of multiple data streams, the importance of focused visualizations that synthesize modeling results, and the challenge of linking risk indicators and forecasts to specific public health responses.

Remote sensing of desert dust aerosols over the Sahel : potential use for health impact studies

NASA Astrophysics Data System (ADS)

Deroubaix, A. D.; Martiny, N. M.; Chiapello, I. C.; Marticorena, B. M.

2012-04-01

Since the end of the 70's, remote sensing monitors the desert dust aerosols due to their absorption and scattering properties and allows to make long time series which are necessary for air quality or health impact studies. In the Sahel, a huge health problem is the Meningitis Meningococcal (MM) epidemics that occur during the dry season : the dust has been suspected to be crucial to understand their onsets and dynamics. The Aerosol absorption Index (AI) is a semi-quantitative index derived from TOMS and OMI observations in the UV available at a spatial resolution of 1° (1979-2005) and 0.25° (2005-today) respectively. The comparison of the OMI-AI and AERONET Aerosol Optical thickness (AOT) shows a good agreement at a daily time-step (correlation ~0.7). The comparison of the OMI-AI with the Particle Matter (PM) measurement of the Sahelian Dust Transect is lower (~0.4) at a daily time-step but it increases at a weekly time-step (~0.6). The OMI-AI reproduces the dust seasonal cycle over the Sahel and we conclude that the OMI-AI product at a 0.25° spatial resolution is suitable for health impact studies, especially at a weekly epidemiological time-step. Despite the AI is sensitive to the aerosol altitude, it provides a daily spatial information on dust. A preliminary investigation analysis of the link between weekly OMI AI and weekly WHO epidemiological data sets is presented in Mali and Niger, showing a good agreement between the AI and the onset of the MM epidemics with a constant lag (between 1 and 2 week). The next of this study is to analyse a deeper AI time series constituted by TOMS and OMI data sets. Based on the weekly ratios PM/AI at 2 stations of the Sahelian Dust Transect, a spatialized proxy for PM from the AI has been developed. The AI as a proxy for PM and other climate variables such as Temperature (T°), Relative Humidity (RH%) and the wind (intensity and direction) could then be used to analyze the link between those variables and the MM epidemics in the most concerned countries in Western Africa, which would be an important step towards a forecasting tool for the epidemics risks in Western Africa.

Suppressing epidemic spreading by risk-averse migration in dynamical networks

NASA Astrophysics Data System (ADS)

Yang, Han-Xin; Tang, Ming; Wang, Zhen

2018-01-01

In this paper, we study the interplay between individual behaviors and epidemic spreading in a dynamical network. We distribute agents on a square-shaped region with periodic boundary conditions. Every agent is regarded as a node of the network and a wireless link is established between two agents if their geographical distance is less than a certain radius. At each time, every agent assesses the epidemic situation and make decisions on whether it should stay in or leave its current place. An agent will leave its current place with a speed if the number of infected neighbors reaches or exceeds a critical value E. Owing to the movement of agents, the network's structure is dynamical. Interestingly, we find that there exists an optimal value of E leading to the maximum epidemic threshold. This means that epidemic spreading can be effectively controlled by risk-averse migration. Besides, we find that the epidemic threshold increases as the recovering rate increases, decreases as the contact radius increases, and is maximized by an optimal moving speed. Our findings offer a deeper understanding of epidemic spreading in dynamical networks.

Integrated travel network model for studying epidemics: Interplay between journeys and epidemic

PubMed Central

Ruan, Zhongyuan; Wang, Chaoqing; Ming Hui, Pak; Liu, Zonghua

2015-01-01

The ease of travelling between cities has contributed much to globalization. Yet, it poses a threat on epidemic outbreaks. It is of great importance for network science and health control to understand the impact of frequent journeys on epidemics. We stress that a new framework of modelling that takes a traveller’s viewpoint is needed. Such integrated travel network (ITN) model should incorporate the diversity among links as dictated by the distances between cities and different speeds of different modes of transportation, diversity among nodes as dictated by the population and the ease of travelling due to infrastructures and economic development of a city, and round-trip journeys to targeted destinations via the paths of shortest travel times typical of human journeys. An example is constructed for 116 cities in China with populations over one million that are connected by high-speed train services and highways. Epidemic spread on the constructed network is studied. It is revealed both numerically and theoretically that the traveling speed and frequency are important factors of epidemic spreading. Depending on the infection rate, increasing the traveling speed would result in either an enhanced or suppressed epidemic, while increasing the traveling frequency enhances the epidemic spreading. PMID:26073191

Integrated travel network model for studying epidemics: Interplay between journeys and epidemic

NASA Astrophysics Data System (ADS)

Ruan, Zhongyuan; Wang, Chaoqing; Ming Hui, Pak; Liu, Zonghua

2015-06-01

The ease of travelling between cities has contributed much to globalization. Yet, it poses a threat on epidemic outbreaks. It is of great importance for network science and health control to understand the impact of frequent journeys on epidemics. We stress that a new framework of modelling that takes a traveller’s viewpoint is needed. Such integrated travel network (ITN) model should incorporate the diversity among links as dictated by the distances between cities and different speeds of different modes of transportation, diversity among nodes as dictated by the population and the ease of travelling due to infrastructures and economic development of a city, and round-trip journeys to targeted destinations via the paths of shortest travel times typical of human journeys. An example is constructed for 116 cities in China with populations over one million that are connected by high-speed train services and highways. Epidemic spread on the constructed network is studied. It is revealed both numerically and theoretically that the traveling speed and frequency are important factors of epidemic spreading. Depending on the infection rate, increasing the traveling speed would result in either an enhanced or suppressed epidemic, while increasing the traveling frequency enhances the epidemic spreading.

Integrated travel network model for studying epidemics: Interplay between journeys and epidemic.

PubMed

Ruan, Zhongyuan; Wang, Chaoqing; Hui, Pak Ming; Liu, Zonghua

2015-06-15

The ease of travelling between cities has contributed much to globalization. Yet, it poses a threat on epidemic outbreaks. It is of great importance for network science and health control to understand the impact of frequent journeys on epidemics. We stress that a new framework of modelling that takes a traveller's viewpoint is needed. Such integrated travel network (ITN) model should incorporate the diversity among links as dictated by the distances between cities and different speeds of different modes of transportation, diversity among nodes as dictated by the population and the ease of travelling due to infrastructures and economic development of a city, and round-trip journeys to targeted destinations via the paths of shortest travel times typical of human journeys. An example is constructed for 116 cities in China with populations over one million that are connected by high-speed train services and highways. Epidemic spread on the constructed network is studied. It is revealed both numerically and theoretically that the traveling speed and frequency are important factors of epidemic spreading. Depending on the infection rate, increasing the traveling speed would result in either an enhanced or suppressed epidemic, while increasing the traveling frequency enhances the epidemic spreading.

An interdependent analytic approach to explaining the evolution of NGOs, social movements, and biased government response to AIDS and tuberculosis in Brazil.

PubMed

Gómez, Eduardo J

2013-02-01

The politics of government response to health epidemics is a new area of scholarly research. Nevertheless, to date scholars have not considered how social science theory can be used and interdependently linked to provide a more thorough discussion of civil societal and national government response to different types of health epidemics. Introducing what I call an interdependent analytic framework of government response to epidemics, this article illustrates how social science theories can be interdependently linked and applied to help explain the evolutionary role of interest groups and social movements in response to AIDS and tuberculosis in Brazil, and when and why the government eventually responded more aggressively to AIDS but not tuberculosis. Evidence from Brazil suggests that the policy influence of interest groups and social movements evolves over time and is more influential after the national government implements new policies; moreover, this response is triggered by the rise of international pressures and government reputation building, not civil society. I highlight new areas of research that the framework provides and provide examples of how this approach can help explain civil societal and biased government responses to different types of epidemics in other nations.

Detection of severe respiratory disease epidemic outbreaks by CUSUM-based overcrowd-severe-respiratory-disease-index model.

PubMed

Polanco, Carlos; Castañón-González, Jorge Alberto; Macías, Alejandro E; Samaniego, José Lino; Buhse, Thomas; Villanueva-Martínez, Sebastián

2013-01-01

A severe respiratory disease epidemic outbreak correlates with a high demand of specific supplies and specialized personnel to hold it back in a wide region or set of regions; these supplies would be beds, storage areas, hemodynamic monitors, and mechanical ventilators, as well as physicians, respiratory technicians, and specialized nurses. We describe an online cumulative sum based model named Overcrowd-Severe-Respiratory-Disease-Index based on the Modified Overcrowd Index that simultaneously monitors and informs the demand of those supplies and personnel in a healthcare network generating early warnings of severe respiratory disease epidemic outbreaks through the interpretation of such variables. A post hoc historical archive is generated, helping physicians in charge to improve the transit and future allocation of supplies in the entire hospital network during the outbreak. The model was thoroughly verified in a virtual scenario, generating multiple epidemic outbreaks in a 6-year span for a 13-hospital network. When it was superimposed over the H1N1 influenza outbreak census (2008-2010) taken by the National Institute of Medical Sciences and Nutrition Salvador Zubiran in Mexico City, it showed that it is an effective algorithm to notify early warnings of severe respiratory disease epidemic outbreaks with a minimal rate of false alerts.

Detection of Severe Respiratory Disease Epidemic Outbreaks by CUSUM-Based Overcrowd-Severe-Respiratory-Disease-Index Model

PubMed Central

Castañón-González, Jorge Alberto; Macías, Alejandro E.; Samaniego, José Lino; Buhse, Thomas; Villanueva-Martínez, Sebastián

2013-01-01

A severe respiratory disease epidemic outbreak correlates with a high demand of specific supplies and specialized personnel to hold it back in a wide region or set of regions; these supplies would be beds, storage areas, hemodynamic monitors, and mechanical ventilators, as well as physicians, respiratory technicians, and specialized nurses. We describe an online cumulative sum based model named Overcrowd-Severe-Respiratory-Disease-Index based on the Modified Overcrowd Index that simultaneously monitors and informs the demand of those supplies and personnel in a healthcare network generating early warnings of severe respiratory disease epidemic outbreaks through the interpretation of such variables. A post hoc historical archive is generated, helping physicians in charge to improve the transit and future allocation of supplies in the entire hospital network during the outbreak. The model was thoroughly verified in a virtual scenario, generating multiple epidemic outbreaks in a 6-year span for a 13-hospital network. When it was superimposed over the H1N1 influenza outbreak census (2008–2010) taken by the National Institute of Medical Sciences and Nutrition Salvador Zubiran in Mexico City, it showed that it is an effective algorithm to notify early warnings of severe respiratory disease epidemic outbreaks with a minimal rate of false alerts. PMID:24069063

Social influence and obesity.

PubMed

Hammond, Ross A

2010-10-01

To review a selection of research published in the last 12 months on the role of social influence in the obesity epidemic. Recent papers add evidence to previous work linking social network structures and obesity. Social norms, both eating norms and body image norms, are identified as one major source of social influence through networks. Social capital and social stress are additional types of social influence. There is increasing evidence that social influence and social network structures are significant factors in obesity. Deeper understanding of the mechanisms of action and dynamics of social influence, and its link with other factors involved in the obesity epidemic, is an important goal for further research.

Global warming and obesity: a systematic review.

PubMed

An, R; Ji, M; Zhang, S

2018-02-01

Global warming and the obesity epidemic are two unprecedented challenges mankind faces today. A literature search was conducted in the PubMed, Web of Science, EBSCO and Scopus for articles published until July 2017 that reported findings on the relationship between global warming and the obesity epidemic. Fifty studies were identified. Topic-wise, articles were classified into four relationships - global warming and the obesity epidemic are correlated because of common drivers (n = 21); global warming influences the obesity epidemic (n = 13); the obesity epidemic influences global warming (n = 13); and global warming and the obesity epidemic influence each other (n = 3). We constructed a conceptual model linking global warming and the obesity epidemic - the fossil fuel economy, population growth and industrialization impact land use and urbanization, motorized transportation and agricultural productivity and consequently influences global warming by excess greenhouse gas emission and the obesity epidemic by nutrition transition and physical inactivity; global warming also directly impacts obesity by food supply/price shock and adaptive thermogenesis, and the obesity epidemic impacts global warming by the elevated energy consumption. Policies that endorse deployment of clean and sustainable energy sources, and urban designs that promote active lifestyles, are likely to alleviate the societal burden of global warming and obesity. © 2017 World Obesity Federation.

Phylogenetic Analysis of Enterovirus 71 Strains Isolated during Linked Epidemics in Malaysia, Singapore, and Western Australia

PubMed Central

McMinn, Peter; Lindsay, Katie; Perera, David; Chan, Hung Ming; Chan, Kwai Peng; Cardosa, Mary Jane

2001-01-01

Enterovirus 71 (EV71) is a frequent cause of hand, foot, and mouth disease (HFMD) epidemics associated with severe neurological sequelae in a small proportion of cases. There has been a significant increase in EV71 epidemic activity throughout the Asia-Pacific region since 1997. Recent HFMD epidemics in this region have been associated with a severe form of brainstem encephalitis associated with pulmonary edema and high case fatality rates. In this study, we show that four genetic lineages of EV71 have been prevalent in the Asia-Pacific region since 1997, including two previously undescribed genogroups (B3 and B4). Furthermore, we show that viruses belonging to genogroups B3 and B4 have circulated endemically in Southeast Asia during this period and have been the primary cause of several large HFMD or encephalitis epidemics in Malaysia, Singapore, and Western Australia. PMID:11462047

El Niño, Climate, and Cholera Associations in Piura, Peru, 1991-2001: A Wavelet Analysis.

PubMed

Ramírez, Iván J; Grady, Sue C

2016-03-01

In Peru, it was hypothesized that epidemic cholera in 1991 was linked to El Niño, the warm phase of El Niño-Southern Oscillation. While previous studies demonstrated an association in 1997-1998, using cross-sectional data, they did not assess the consistency of this relationship across the decade. Thus, how strong or variable an El Niño-cholera relationship was in Peru or whether El Niño triggered epidemic cholera early in the decade remains unknown. In this study, wavelet and mediation analyses were used to characterize temporal patterns among El Niño, local climate variables (rainfall, river discharge, and air temperature), and cholera incidence in Piura, Peru from 1991 to 2001 and to estimate the mediating effects of local climate on El Niño-cholera relationships. The study hypothesis is that El Niño-related connections with cholera in Piura were transient and interconnected via local climate pathways. Overall, our findings provide evidence that a strong El Niño-cholera link, mediated by local hydrology, existed in the latter part of the 1990s but found no evidence of an El Niño association in the earlier part of the decade, suggesting that El Niño may not have precipitated cholera emergence in Piura. Further examinations of cholera epicenters in Peru are recommended to support these results in Piura. For public health planning, the results may improve existing efforts that utilize El Niño monitoring for preparedness during future climate-related extremes in the region.

Intercontinental dispersal of HIV-1 subtype B associated with transmission among men who have sex with men in Japan.

PubMed

Takebe, Yutaka; Naito, Yuki; Raghwani, Jayna; Fearnhill, Esther; Sano, Takako; Kusagawa, Shigeru; Mbisa, Jean L; Zhang, Hongyi; Matano, Tetsuro; Brown, Andrew J Leigh; Pybus, Oliver G; Dunn, David; Kondo, Makiko

2014-09-01

Transmission clusters of HIV-1 subtype B uniquely associated with the epidemic among men who have sex with men (MSM) in East Asia have recently been identified. Using the Los Alamos HIV sequence database and the UK HIV drug resistance database, we explored possible links between HIV MSM epidemics in East Asia and the rest of the world by using phylogenetic and molecular clock analyses. We found that JP.MSM.B-1, a subtype B MSM variant that accounts for approximately one-third of the infections among Japanese MSM, was detected worldwide, in the United Kingdom (n=13), mainland China (n=3), the United States, Germany, Canada, and Taiwan (n=1 each). Interestingly, 10 United Kingdom samples plus two from Germany and the United States formed a distinct monophyletic subgroup within JP.MSM.B-1. The estimated divergence times of JP.MSM.B-1 and the latter subgroup were ∼1989 and ∼1999, respectively. These dates suggest that JP.MSM.B-1 was circulating for many years in Japan among MSM before disseminating to other countries, most likely through global MSM networks. A significant number of other Asian MSM HIV lineages were also detected in the UK HIV drug resistance database. Our study provides insight into the regional and global dispersal of Asian MSM HIV lineages. Further study of these strains is warranted to elucidate viral migration and the interrelationship of HIV epidemics on a global scale. We previously identified several transmission clusters of HIV-1 subtype B uniquely associated with the epidemic among men who have sex with men (MSM) in East Asia. Using the Los Alamos HIV sequence database and the UK HIV drug resistance database, we explored the possible interplay of HIV MSM epidemics in the different geographic regions and found previously unrecognized interrelationships among the HIV-1 epidemics in East Asia, the United Kingdom, and the rest of the world. Our study provides insight into the regional and global dispersal of Asian MSM HIV lineages and highlights the importance of strengthening HIV monitoring efforts and the need for implementing effective control measures to reduce HIV transmission on a global scale. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Clustering model for transmission of the SARS virus: application to epidemic control and risk assessment

NASA Astrophysics Data System (ADS)

Small, Michael; Tse, C. K.

2005-06-01

We propose a new four state model for disease transmission and illustrate the model with data from the 2003 SARS epidemic in Hong Kong. The critical feature of this model is that the community is modelled as a small-world network of interconnected nodes. Each node is linked to a fixed number of immediate neighbors and a random number of geographically remote nodes. Transmission can only propagate between linked nodes. This model exhibits two features typical of SARS transmission: geographically localized outbreaks and “super-spreaders”. Neither of these features are evident in standard susceptible-infected-removed models of disease transmission. Our analysis indicates that “super-spreaders” may occur even if the infectiousness of all infected individuals is constant. Moreover, we find that nosocomial transmission in Hong Kong directly contributed to the severity of the outbreak and that by limiting individual exposure time to 3-5 days the extent of the SARS epidemic would have been minimal.

Scarlet fever epidemic, Hong Kong, 2011.

PubMed

Luk, Emma Y Y; Lo, Janice Y C; Li, Amy Z L; Lau, Michael C K; Cheung, Terence K M; Wong, Alice Y M; Wong, Monica M H; Wong, Christine W; Chuang, Shuk-kwan; Tsang, Thomas

2012-10-01

More than 900 cases of scarlet fever were recorded in Hong Kong during January-July, 2011. Six cases were complicated by toxic shock syndrome, of which 2 were fatal. Pulsed-field gel electrophoresis patterns suggested a multiclonal epidemic; emm12 was the predominant circulating type. We recommend genetic testing of and antimicrobial resistance monitoring for this reportable disease.

Scarlet Fever Epidemic, Hong Kong, 2011

PubMed Central

Lo, Janice Y.C.; Li, Amy Z.L.; Lau, Michael C.K.; Cheung, Terence K.M.; Wong, Alice Y.M.; Wong, Monica M.H.; Wong, Christine W.; Chuang, Shuk-kwan; Tsang, Thomas

2012-01-01

More than 900 cases of scarlet fever were recorded in Hong Kong during January–July, 2011. Six cases were complicated by toxic shock syndrome, of which 2 were fatal. Pulsed-field gel electrophoresis patterns suggested a multiclonal epidemic; emm12 was the predominant circulating type. We recommend genetic testing of and antimicrobial resistance monitoring for this reportable disease. PMID:23018120

Comparing nonpharmaceutical interventions for containing emerging epidemics.

PubMed

Peak, Corey M; Childs, Lauren M; Grad, Yonatan H; Buckee, Caroline O

2017-04-11

Strategies for containing an emerging infectious disease outbreak must be nonpharmaceutical when drugs or vaccines for the pathogen do not yet exist or are unavailable. The success of these nonpharmaceutical strategies will depend on not only the effectiveness of isolation measures but also the epidemiological characteristics of the infection. However, there is currently no systematic framework to assess the relationship between different containment strategies and the natural history and epidemiological dynamics of the pathogen. Here, we compare the effectiveness of quarantine and symptom monitoring, implemented via contact tracing, in controlling epidemics using an agent-based branching model. We examine the relationship between epidemic containment and the disease dynamics of symptoms and infectiousness for seven case-study diseases with diverse natural histories, including Ebola, influenza A, and severe acute respiratory syndrome (SARS). We show that the comparative effectiveness of symptom monitoring and quarantine depends critically on the natural history of the infectious disease, its inherent transmissibility, and the intervention feasibility in the particular healthcare setting. The benefit of quarantine over symptom monitoring is generally maximized for fast-course diseases, but we show the conditions under which symptom monitoring alone can control certain outbreaks. This quantitative framework can guide policymakers on how best to use nonpharmaceutical interventions and prioritize research during an outbreak of an emerging pathogen.

Epidemic spreading on preferred degree adaptive networks.

PubMed

Jolad, Shivakumar; Liu, Wenjia; Schmittmann, B; Zia, R K P

2012-01-01

We study the standard SIS model of epidemic spreading on networks where individuals have a fluctuating number of connections around a preferred degree κ. Using very simple rules for forming such preferred degree networks, we find some unusual statistical properties not found in familiar Erdös-Rényi or scale free networks. By letting κ depend on the fraction of infected individuals, we model the behavioral changes in response to how the extent of the epidemic is perceived. In our models, the behavioral adaptations can be either 'blind' or 'selective'--depending on whether a node adapts by cutting or adding links to randomly chosen partners or selectively, based on the state of the partner. For a frozen preferred network, we find that the infection threshold follows the heterogeneous mean field result λ(c)/μ = <κ>/<κ2> and the phase diagram matches the predictions of the annealed adjacency matrix (AAM) approach. With 'blind' adaptations, although the epidemic threshold remains unchanged, the infection level is substantially affected, depending on the details of the adaptation. The 'selective' adaptive SIS models are most interesting. Both the threshold and the level of infection changes, controlled not only by how the adaptations are implemented but also how often the nodes cut/add links (compared to the time scales of the epidemic spreading). A simple mean field theory is presented for the selective adaptations which capture the qualitative and some of the quantitative features of the infection phase diagram.

Effects of epidemic threshold definition on disease spread statistics

NASA Astrophysics Data System (ADS)

Lagorio, C.; Migueles, M. V.; Braunstein, L. A.; López, E.; Macri, P. A.

2009-03-01

We study the statistical properties of SIR epidemics in random networks, when an epidemic is defined as only those SIR propagations that reach or exceed a minimum size sc. Using percolation theory to calculate the average fractional size of an epidemic, we find that the strength of the spanning link percolation cluster P∞ is an upper bound to . For small values of sc, P∞ is no longer a good approximation, and the average fractional size has to be computed directly. We find that the choice of sc is generally (but not always) guided by the network structure and the value of T of the disease in question. If the goal is to always obtain P∞ as the average epidemic size, one should choose sc to be the typical size of the largest percolation cluster at the critical percolation threshold for the transmissibility. We also study Q, the probability that an SIR propagation reaches the epidemic mass sc, and find that it is well characterized by percolation theory. We apply our results to real networks (DIMES and Tracerouter) to measure the consequences of the choice sc on predictions of average outcome sizes of computer failure epidemics.

Analysis of nonlinear relationships in dual epidemics, and its application to the management of grapevine downy and powdery mildews.

PubMed

Savary, Serge; Delbac, Lionel; Rochas, Amélie; Taisant, Guillaume; Willocquet, Laetitia

2009-08-01

Dual epidemics are defined as epidemics developing on two or several plant organs in the course of a cropping season. Agricultural pathosystems where such epidemics develop are often very important, because the harvestable part is one of the organs affected. These epidemics also are often difficult to manage, because the linkage between epidemiological components occurring on different organs is poorly understood, and because prediction of the risk toward the harvestable organs is difficult. In the case of downy mildew (DM) and powdery mildew (PM) of grapevine, nonlinear modeling and logistic regression indicated nonlinearity in the foliage-cluster relationships. Nonlinear modeling enabled the parameterization of a transmission coefficient that numerically links the two components, leaves and clusters, in DM and PM epidemics. Logistic regression analysis yielded a series of probabilistic models that enabled predicting preset levels of cluster infection risks based on DM and PM severities on the foliage at successive crop stages. The usefulness of this framework for tactical decision-making for disease control is discussed.

Model-based time-series analysis of FIA panel data absent re-measurements

Treesearch

Raymond L. Czaplewski; Mike T. Thompson

2013-01-01

An epidemic of lodgepole pine (Pinus contorta) mortality from the mountain pine beetle (Dendroctonus ponderosae) has swept across the Interior West. Aerial surveys monitor the areal extent of the epidemic, but only Forest Inventory and Analysis (FIA) field data support a detailed assessment at the tree level. Dynamics of the lodgepole pine population occur at a more...

A vectorial capacity product to monitor changing malaria transmission potential in epidemic regions of Africa

USGS Publications Warehouse

Ceccato, Pietro; Vancutsem, Christelle; Klaver, Robert; Rowland, James; Connor, Stephen J.

2012-01-01

Rainfall and temperature are two of the major factors triggering malaria epidemics in warm semi-arid (desert-fringe) and high altitude (highland-fringe) epidemic risk areas. The ability of the mosquitoes to transmit Plasmodium spp. is dependent upon a series of biological features generally referred to as vectorial capacity. In this study, the vectorial capacity model (VCAP) was expanded to include the influence of rainfall and temperature variables on malaria transmission potential. Data from two remote sensing products were used to monitor rainfall and temperature and were integrated into the VCAP model. The expanded model was tested in Eritrea and Madagascar to check the viability of the approach. The analysis of VCAP in relation to rainfall, temperature and malaria incidence data in these regions shows that the expanded VCAP correctly tracks the risk of malaria both in regions where rainfall is the limiting factor and in regions where temperature is the limiting factor. The VCAP maps are currently offered as an experimental resource for testing within Malaria Early Warning applications in epidemic prone regions of sub-Saharan Africa. User feedback is currently being collected in preparation for further evaluation and refinement of the VCAP model.

Emergence and global spread of epidemic healthcare-associated Clostridium difficile

PubMed Central

He, Miao; Miyajima, Fabio; Roberts, Paul; Ellison, Louise; Pickard, Derek J.; Martin, Melissa J.; Connor, Thomas R.; Harris, Simon R.; Fairley, Derek; Bamford, Kathleen B.; D’Arc, Stephanie; Brazier, Jon; Brown, Derek; Coia, John E.; Douce, Gill; Gerding, Dale; Kim, Hee Jung; Koh, Tse Hsien; Kato, Haru; Senoh, Mitsutoshi; Louie, Tom; Michell, Stephen; Butt, Emma; Peacock, Sharon J.; Brown, Nick M.; Riley, Tom; Songer, Glen; Wilcox, Mark; Pirmohamed, Munir; Kuijper, Ed; Hawkey, Peter; Wren, Brendan W.; Dougan, Gordon; Parkhill, Julian; Lawley, Trevor D.

2012-01-01

Epidemic Clostridium difficile (027/BI/NAP1) rapidly emerged in the past decade as the leading cause of antibiotic-associated diarrhea worldwide. However, the key moments in the evolutionary history leading to its emergence and subsequent patterns of global spread remain unknown. Here we define the global population structure of C. difficile 027/BI/NAP1 based on whole-genome sequencing and phylogenetic analysis. We demonstrate that two distinct epidemic lineages, FQR1 and FQR2, not one as previously thought, emerged in North America within a relatively short period after acquiring the same fluoroquinolone resistance mutation and a highly-related conjugative transposon. The two epidemic lineages displayed distinct patterns of global spread, and the FQR2 lineage spread more widely leading to healthcare outbreaks in the UK, continental Europe and Australia. Our analysis identifies key genetic changes linked to the rapid trans-continental dissemination of epidemic C. difficile 027/BI/NAP1 and highlights the routes by which it spreads through the global healthcare system. PMID:23222960

Phylodynamic and Phylogeographic Patterns of the HIV Type 1 Subtype F1 Parenteral Epidemic in Romania

PubMed Central

Hué, Stéphane; Buckton, Andrew J.; Myers, Richard E.; Duiculescu, Dan; Ene, Luminita; Oprea, Cristiana; Tardei, Gratiela; Rugina, Sorin; Mardarescu, Mariana; Floch, Corinne; Notheis, Gundula; Zöhrer, Bettina; Cane, Patricia A.; Pillay, Deenan

2012-01-01

Abstract In the late 1980s an HIV-1 epidemic emerged in Romania that was dominated by subtype F1. The main route of infection is believed to be parenteral transmission in children. We sequenced partial pol coding regions of 70 subtype F1 samples from children and adolescents from the PENTA-EPPICC network of which 67 were from Romania. Phylogenetic reconstruction using the sequences and other publically available global subtype F sequences showed that 79% of Romanian F1 sequences formed a statistically robust monophyletic cluster. The monophyletic cluster was epidemiologically linked to parenteral transmission in children. Coalescent-based analysis dated the origins of the parenteral epidemic to 1983 [1981–1987; 95% HPD]. The analysis also shows that the epidemic's effective population size has remained fairly constant since the early 1990s suggesting limited onward spread of the virus within the population. Furthermore, phylogeographic analysis suggests that the root location of the parenteral epidemic was Bucharest. PMID:22251065

An Agent-Based Epidemic Simulation of Social Behaviors Affecting HIV Transmission among Taiwanese Homosexuals

PubMed Central

2015-01-01

Computational simulations are currently used to identify epidemic dynamics, to test potential prevention and intervention strategies, and to study the effects of social behaviors on HIV transmission. The author describes an agent-based epidemic simulation model of a network of individuals who participate in high-risk sexual practices, using number of partners, condom usage, and relationship length to distinguish between high- and low-risk populations. Two new concepts—free links and fixed links—are used to indicate tendencies among individuals who either have large numbers of short-term partners or stay in long-term monogamous relationships. An attempt was made to reproduce epidemic curves of reported HIV cases among male homosexuals in Taiwan prior to using the agent-based model to determine the effects of various policies on epidemic dynamics. Results suggest that when suitable adjustments are made based on available social survey statistics, the model accurately simulates real-world behaviors on a large scale. PMID:25815047

Epidemic spreading on contact networks with adaptive weights.

PubMed

Zhu, Guanghu; Chen, Guanrong; Xu, Xin-Jian; Fu, Xinchu

2013-01-21

The heterogeneous patterns of interactions within a population are often described by contact networks, but the variety and adaptivity of contact strengths are usually ignored. This paper proposes a modified epidemic SIS model with a birth-death process and nonlinear infectivity on an adaptive and weighted contact network. The links' weights, named as 'adaptive weights', which indicate the intimacy or familiarity between two connected individuals, will reduce as the disease develops. Through mathematical and numerical analyses, conditions are established for population extermination, disease extinction and infection persistence. Particularly, it is found that the fixed weights setting can trigger the epidemic incidence, and that the adaptivity of weights cannot change the epidemic threshold but it can accelerate the disease decay and lower the endemic level. Finally, some corresponding control measures are suggested. Copyright © 2012 Elsevier Ltd. All rights reserved.

Vector-borne diseases and climate change: a European perspective

PubMed Central

Suk, Jonathan E

2017-01-01

Abstract Climate change has already impacted the transmission of a wide range of vector-borne diseases in Europe, and it will continue to do so in the coming decades. Climate change has been implicated in the observed shift of ticks to elevated altitudes and latitudes, notably including the Ixodes ricinus tick species that is a vector for Lyme borreliosis and tick-borne encephalitis. Climate change is also thought to have been a factor in the expansion of other important disease vectors in Europe: Aedes albopictus (the Asian tiger mosquito), which transmits diseases such as Zika, dengue and chikungunya, and Phlebotomus sandfly species, which transmits diseases including Leishmaniasis. In addition, highly elevated temperatures in the summer of 2010 have been associated with an epidemic of West Nile Fever in Southeast Europe and subsequent outbreaks have been linked to summer temperature anomalies. Future climate-sensitive health impacts are challenging to project quantitatively, in part due to the intricate interplay between non-climatic and climatic drivers, weather-sensitive pathogens and climate-change adaptation. Moreover, globalisation and international air travel contribute to pathogen and vector dispersion internationally. Nevertheless, monitoring forecasts of meteorological conditions can help detect epidemic precursors of vector-borne disease outbreaks and serve as early warning systems for risk reduction. PMID:29149298

Vector-borne diseases and climate change: a European perspective.

PubMed

Semenza, Jan C; Suk, Jonathan E

2018-02-01

Climate change has already impacted the transmission of a wide range of vector-borne diseases in Europe, and it will continue to do so in the coming decades. Climate change has been implicated in the observed shift of ticks to elevated altitudes and latitudes, notably including the Ixodes ricinus tick species that is a vector for Lyme borreliosis and tick-borne encephalitis. Climate change is also thought to have been a factor in the expansion of other important disease vectors in Europe: Aedes albopictus (the Asian tiger mosquito), which transmits diseases such as Zika, dengue and chikungunya, and Phlebotomus sandfly species, which transmits diseases including Leishmaniasis. In addition, highly elevated temperatures in the summer of 2010 have been associated with an epidemic of West Nile Fever in Southeast Europe and subsequent outbreaks have been linked to summer temperature anomalies. Future climate-sensitive health impacts are challenging to project quantitatively, in part due to the intricate interplay between non-climatic and climatic drivers, weather-sensitive pathogens and climate-change adaptation. Moreover, globalisation and international air travel contribute to pathogen and vector dispersion internationally. Nevertheless, monitoring forecasts of meteorological conditions can help detect epidemic precursors of vector-borne disease outbreaks and serve as early warning systems for risk reduction. © FEMS 2017.

Monitoring the Environment using High-Spatial Resolution Remote Sensing: Contribution to Health Information Systems

NASA Astrophysics Data System (ADS)

Tourre, Y. M.; Lacaux, J.

2007-12-01

Presence (density) of mosquitoes linked to Rift Valley Fever (RVF) epidemics in the Ferlo (Senegal) is evaluated by monitoring the environment from space. Using five SPOT-5 high-resolution images (~10m spatial resolution, on August 17th, 2006) a meridional transect of 290 x 60 km2 is analyzed for the first time. Four major ecozones are thus identified: Senegal River valley; sandy Ferlo; sandy-clayey Ferlo; and steppe/cultivated areas, from north to south, respectively. An integrated/multidisciplinary approach using remote-sensing leads to a composited Zones Potentially Occupied by Mosquitoes (or ZPOMs, with extrema). It is found that at the peak of the rainy season, the area occupied by ponds is of 12,817 ha ± 10% (i.e., ~ 0.8 % of the transect) with a mean ZPOM 17 times larger i.e.: 212,813 ha ± 10 % (or ~14 % of the transect). ZPOMs characteristics (minimum and maximum) at the ecozones levels with different hydrological mechanisms, are presented. Ponds and ZPOMs inter-annual variabilities and RVF risks, are subsequently highlighted by comparing statistics in the so-called Barkedji zone (sandy-clayey Ferlo with a hydrofossil riverbed), for the very humid year of 2003, and the near normal rainfall year of 2006. It is shown that at the end of August 2003/2006, ponds (ZPOMs) areas, were already ~22 (~5) times larger. The key roles played by isolated ponds for animals' exposure to RVF risks are thus identified. These results highlight the importance of monitoring the changing environment when linkages with public health exist. The ZPOM approach is to be adapted for other vector-borne diseases such as malaria, dengue fever, in different places of the world. Results are meant to be included into Health Information Systems (HIS) on an operational basis, in order to minimize socio-economical impacts from epidemics.

Time series analysis of RSV and bronchiolitis seasonality in temperate and tropical Western Australia.

PubMed

Hogan, Alexandra B; Anderssen, Robert S; Davis, Stephanie; Moore, Hannah C; Lim, Faye J; Fathima, Parveen; Glass, Kathryn

2016-09-01

Respiratory syncytial virus (RSV) causes respiratory illness in young children and is most commonly associated with bronchiolitis. RSV typically occurs as annual or biennial winter epidemics in temperate regions, with less pronounced seasonality in the tropics. We sought to characterise and compare the seasonality of RSV and bronchiolitis in temperate and tropical Western Australia. We examined over 13 years of RSV laboratory identifications and bronchiolitis hospitalisations in children, using an extensive linked dataset from Western Australia. We applied mathematical time series analyses to identify the dominant seasonal cycle, and changes in epidemic size and timing over this period. Both the RSV and bronchiolitis data showed clear winter epidemic peaks in July or August in the southern Western Australia regions, but less identifiable seasonality in the northern regions. Use of complex demodulation proved very effective at comparing disease epidemics. The timing of RSV and bronchiolitis epidemics coincided well, but the size of the epidemics differed, with more consistent peak sizes for bronchiolitis than for RSV. Our results show that bronchiolitis hospitalisations are a reasonable proxy for the timing of RSV detections, but may not fully capture the magnitude of RSV epidemics. Copyright © 2016 The Author(s). Published by Elsevier B.V. All rights reserved.

Importance of exfoliatin toxin A production by Staphylococcus aureus strains isolated from clustered epidemics of neonatal pustulosis.

PubMed Central

Kaplan, M H; Chmel, H; Hsieh, H C; Stephens, A; Brinsko, V

1986-01-01

Clustered epidemics of pustulosis due to Staphylococcus aureus occurred in two geographically distant newborn nurseries. In nurseries A and B an attack rate of pustulosis of 0.8 and 2.0 cases per 100 live births occurred, respectively. Experimental phage type 1046/1116 belonging to phage group II dominated clustered epidemics in nursery A, while group II phage type 3A/3C/55/71 and 3A/3C/55 occurred in nursery B. Other group II strains also occasionally produced clustered epidemics. These epidemic strains were found to be making heat-stable dermal exfoliatin toxin A (ETA) which had a pI of 6.8 and a molecular weight of 32,000 and 33,000. ETA-bearing strains did not make bacteriocin. Children infected with ETA-producing strains developed extensive bullous pustulosis. Surveillance cultures of personnel revealed an ETA-bearing strain in only one person. This strain was not the same phage type as the epidemic cluster. In contrast, ETA-bearing epidemic strains were found in the inanimate environment of both nurseries. ETA protein acts as an important virulence factor in the production of neonatal pustulosis infection and appears to be linked with the ability of S. aureus organisms to stick to the inanimate environment. Images PMID:3700612

The epidemiology of obesity: the size of the problem.

PubMed

James, W P T

2008-04-01

The epidemic of obesity took off from about 1980 and in almost all countries has been rising inexorably ever since. Only in 1997 did WHO accept that this was a major public health problem and, even then, there was no accepted method for monitoring the problem in children. It was soon evident, however, that the optimum population body mass index is about 21 and this is particularly true in Asia and Latin America where the populations are very prone to developing abdominal obesity, type 2 diabetes and hypertension. These features are now being increasingly linked to epigenetic programming of gene expression and body composition in utero and early childhood, both in terms of fat/lean tissue ratios and also in terms of organ size and metabolic pathway regulation. New Indian evidence suggests that insulin resistance at birth seems linked to low birth weight and a higher proportion of body fat with selective B12 deficiency and abnormalities of one carbon pool metabolism potentially responsible and affecting 75% of Indians and many populations in the developing world. Biologically there are also adaptive biological mechanisms which limit weight loss after weight gain and thereby in part account for the continuing epidemic despite the widespread desire to slim. Logically, the burden of disease induced by inappropriate diets and widespread physical inactivity can be addressed by increasing physical activity (PA), but simply advocating more leisure time activity is unrealistic. Substantial changes in urban planning and diet are needed to counter the removal of any every day need for PA and the decades of misdirected food policies which with free market forces have induced our current 'toxic environment'. Counteracting this requires unusual policy initiatives.

Information spreading in complex networks with participation of independent spreaders

NASA Astrophysics Data System (ADS)

Ma, Kun; Li, Weihua; Guo, Quantong; Zheng, Xiaoqi; Zheng, Zhiming; Gao, Chao; Tang, Shaoting

2018-02-01

Information diffusion dynamics in complex networks is often modeled as a contagion process among neighbors which is analogous to epidemic diffusion. The attention of previous literature is mainly focused on epidemic diffusion within one network, which, however neglects the possible interactions between nodes beyond the underlying network. The disease can be transmitted to other nodes by other means without following the links in the focal network. Here we account for this phenomenon by introducing the independent spreaders in a susceptible-infectious-recovered contagion process. We derive the critical epidemic thresholds on Erdős-Rényi and scale-free networks as a function of infectious rate, recovery rate and the activeness of independent spreaders. We also present simulation results on ER and SF networks, as well as on a real-world email network. The result shows that the extent to which a disease can infect might be more far-reaching, than we can explain in terms of link contagion only. Besides, these results also help to explain how activeness of independent spreaders can affect the diffusion process, which can be used to explore many other dynamical processes.

Women and the AIDS epidemic: no longer hidden.

PubMed

Williams, A B

1992-07-01

1. Women acquire HIV infection along one of three routes: parenteral, sexual, or vertical (perinatal). The HIV/AIDS epidemic among women in the US is growing primarily through parenteral and heterosexual exposures, which are tightly linked to social issues of substance abuse. 2. The majority of AIDS clinical trial participants have been white men. Differences in male and female physiology, hormonal influences on drug pharmacokinetics, and the social context of disease may render protocols ineffective or even harmful for women. 3. To respond effectively to the AIDS epidemic among women in the US, major public health issues, such as access to care, availability of family planning and drug treatment services, and racial discrimination, must be addressed.

Sudden increase in human infection with avian influenza A(H7N9) virus in China, September–December 2016

PubMed Central

Zhou, Lei; Ren, Ruiqi; Yang, Lei; Bao, Changjun; Wu, Jiabing; Wang, Dayan; Li, Chao; Xiang, Nijuan; Wang, Yali; Li, Dan; Sui, Haitian; Shu, Yuelong; Feng, Zijian; Li, Qun

2017-01-01

Since the first outbreak of avian influenza A(H7N9) virus in humans was identified in 2013, there have been five seasonal epidemics observed in China. An earlier start and a steep increase in the number of humans infected with H7N9 virus was observed between September and December 2016, raising great public concern in domestic and international societies. The epidemiological characteristics of the recently reported confirmed H7N9 cases were analysed. The results suggested that although more cases were reported recently, most cases in the fifth epidemic were still highly sporadically distributed without any epidemiology links; the main characteristics remained unchanged and the genetic characteristics of virus strains that were isolated in this epidemic remained similar to earlier epidemics. Interventions included live poultry market closures in several cities that reported more H7N9 cases recently. PMID:28409054

Etiologic agent of an epidemic of cutaneous leishmaniasis in Tolima, Colombia.

PubMed

Rodríguez-Barraquer, Isabel; Góngora, Rafael; Prager, Martín; Pacheco, Robinson; Montero, Luz Mery; Navas, Adriana; Ferro, Cristina; Miranda, Maria Consuelo; Saravia, Nancy G

2008-02-01

American cutaneous leishmaniasis (ACL) has been characterized as a zoonotic disease. However, peridomestic and domestic transmission have been recorded in at least nine countries in Central and South America. The present study was undertaken to identify the etiologic agent of a peridomestic epidemic of ACL in the Department of Tolima, Colombia. Leishmania isolates were obtained during the diagnosis of 56 patients with ACL who consulted the local leishmaniasis control program in three municipalities in Tolima. Species were identified using monoclonal antibodies and isoenzyme electrophoresis. A total of 53 (94.6%) of 56 isolates were identified as Leishmania (Viannia) guyanensis. Three isolates (5.4%) were identified as L. (V.) panamensis. Leishmania (V.) guyanensis is the probable etiologic agent of the largest epidemic of cutaneous leishmaniasis recorded in Colombia. This species has not previously been reported outside the Amazon and southeastern regions of Colombia, and has not been described in the peridomestic setting or linked with an epidemic.

Genome-Based Infection Tracking Reveals Dynamics of Clostridium difficile Transmission and Disease Recurrence.

PubMed

Kumar, Nitin; Miyajima, Fabio; He, Miao; Roberts, Paul; Swale, Andrew; Ellison, Louise; Pickard, Derek; Smith, Godfrey; Molyneux, Rebecca; Dougan, Gordon; Parkhill, Julian; Wren, Brendan W; Parry, Christopher M; Pirmohamed, Munir; Lawley, Trevor D

2016-03-15

Accurate tracking of Clostridium difficile transmission within healthcare settings is key to its containment but is hindered by the lack of discriminatory power of standard genotyping methods. We describe a whole-genome phylogenetic-based method to track the transmission of individual clones in infected hospital patients from the epidemic C. difficile 027/ST1 lineage, and to distinguish between the 2 causes of recurrent disease, relapse (same strain), or reinfection (different strain). We monitored patients with C. difficile infection in a UK hospital over a 2-year period. We performed whole-genome sequencing and phylogenetic analysis of 108 strains isolated from symptomatic patients. High-resolution phylogeny was integrated with in-hospital transfers and contact data to create an infection network linking individual patients and specific hospital wards. Epidemic C. difficile 027/ST1 caused the majority of infections during our sampling period. Integration of whole-genome single nucleotide polymorphism (SNP) phylogenetic analysis, which accurately discriminated between 27 distinct SNP genotypes, with patient movement and contact data identified 32 plausible transmission events, including ward-based contamination (66%) or direct donor-recipient contact (34%). Highly contagious donors were identified who contributed to the persistence of clones within distinct hospital wards and the spread of clones between wards, especially in areas of intense turnover. Recurrent cases were identified between 4 and 26 weeks, highlighting the limitation of the standard <8-week cutoff used for patient diagnosis and management. Genome-based infection tracking to monitor the persistence and spread of C. difficile within healthcare facilities could inform infection control and patient management. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America.

Post-marketing safety monitoring of a new group B meningococcal vaccine in New Zealand, 2004-2006.

PubMed

McNicholas, Anne; Galloway, Yvonne; Stehr-Green, Paul; Reid, Stewart; Radke, Sarah; Sexton, Kerry; Kieft, Charlotte; Macdonald, Claire; Neutze, Jocelyn; Drake, Ross; Isaac, Dorothy; O'Donnell, Mary; Tatley, Michael; Oster, Philipp; O'Hallahan, Jane

2007-01-01

New Zealand introduced a new outer membrane vesicle vaccine in 2004 to combat an epidemic of group B meningococcal disease. An Independent Safety Monitoring Board oversaw intensive safety monitoring, which included hospital surveillance, health professional reporting (passive and active) and mortality monitoring. With over three million doses administered to individuals aged under 20 years, the monitoring results provide consistent evidence supporting the vaccine's safety.

Epidemic characterization and modeling within herd transmission dynamics of an "emerging trans-boundary" camel disease epidemic in Ethiopia.

PubMed

Megersa, Bekele; Biffa, Demelash; Abunna, Fufa; Regassa, Alemayehu; Bohlin, Jon; Skjerve, Eystein

2012-10-01

A highly acute and contagious camel disease, an epidemic wave of unknown etiology, referred to here as camel sudden death syndrome, has plagued camel population in countries in the Horn of Africa. To better understand its epidemic patterns and transmission dynamics, we used epidemiologic parameters and differential equation deterministic modeling (SEIR/D-model) to predict the outcome likelihood following an exposure of susceptible camel population. Our results showed 45.7, 17.6, and 38.6 % overall morbidity, mortality, and case fatality rates of the epidemic, respectively. Pregnant camels had the highest mortality and case fatality rates, followed by breeding males, and lactating females, implying serious socioeconomic consequences. Disease dynamics appeared to be linked to livestock trade route and animal movements. The epidemic exhibited a strong basic reproductive number (R (0)) with an average of 16 camels infected by one infectious case during the entire infectious period. The epidemic curve suggested that the critical moment of the disease development is approximately between 30 and 40 days, where both infected/exposed and infectious camels are at their highest numbers. The lag between infected/infectious curves indicates a time-shift of approximately 3-5 days from when a camel is infected and until it becomes infectious. According to this predictive model, of all animals exposed to the infection, 66.8 % (n = 868) and 33.2 % (n = 431) had recovered and died, respectively, at the end of epidemic period. Hence, if early measures are not taken, such an epidemic could cause a much more devastative effect, within short period of time than the anticipated proportion.

[A prognostic model of a cholera epidemic].

PubMed

Boev, B V; Bondarenko, V M; Prokop'eva, N V; San Román, R T; Raygoza-Anaya, M; García de Alba, R

1994-01-01

A new model for the prognostication of cholera epidemic on the territory of a large city is proposed. This model reflects the characteristic feature of contacting infection by sensitive individuals due to the preservation of Vibrio cholerae in their water habitat. The mathematical model of the epidemic quantitatively reflects the processes of the spread of infection by kinetic equations describing the interaction of the streams of infected persons, the causative agents and susceptible persons. The functions and parameters of the model are linked with the distribution of individuals according to the duration of the incubation period and infectious process, as well as the period of asymptomatic carrier state. The computer realization of the model by means of IBM PC/AT made it possible to study the cholera epidemic which took place in Mexico in 1833. The verified model of the cholera epidemic was used for the prognostication of the possible spread of this infection in Guadalajara, taking into account changes in the epidemiological situation and the size of the population, as well as improvements in sanitary and hygienic conditions, in the city.

On Spatially Explicit Models of Cholera Epidemics: Hydrologic controls, environmental drivers, human-mediated transmissions (Invited)

NASA Astrophysics Data System (ADS)

Rinaldo, A.; Bertuzzo, E.; Mari, L.; Righetto, L.; Gatto, M.; Casagrandi, R.; Rodriguez-Iturbe, I.

2010-12-01

A recently proposed model for cholera epidemics is examined. The model accounts for local communities of susceptibles and infectives in a spatially explicit arrangement of nodes linked by networks having different topologies. The vehicle of infection (Vibrio cholerae) is transported through the network links which are thought of as hydrological connections among susceptible communities. The mathematical tools used are borrowed from general schemes of reactive transport on river networks acting as the environmental matrix for the circulation and mixing of water-borne pathogens. The results of a large-scale application to the Kwa Zulu (Natal) epidemics of 2001-2002 will be discussed. Useful theoretical results derived in the spatially-explicit context will also be reviewed (like e.g. the exact derivation of the speed of propagation for traveling fronts of epidemics on regular lattices endowed with uniform population density). Network effects will be discussed. The analysis of the limit case of uniformly distributed population density proves instrumental in establishing the overall conditions for the relevance of spatially explicit models. To that extent, it is shown that the ratio between spreading and disease outbreak timescales proves the crucial parameter. The relevance of our results lies in the major differences potentially arising between the predictions of spatially explicit models and traditional compartmental models of the SIR-like type. Our results suggest that in many cases of real-life epidemiological interest timescales of disease dynamics may trigger outbreaks that significantly depart from the predictions of compartmental models. Finally, a view on further developments includes: hydrologically improved aquatic reservoir models for pathogens; human mobility patterns affecting disease propagation; double-peak emergence and seasonality in the spatially explicit epidemic context.

CLON: Overlay Networks and Gossip Protocols for Cloud Environments

NASA Astrophysics Data System (ADS)

Matos, Miguel; Sousa, António; Pereira, José; Oliveira, Rui; Deliot, Eric; Murray, Paul

Although epidemic or gossip-based multicast is a robust and scalable approach to reliable data dissemination, its inherent redundancy results in high resource consumption on both links and nodes. This problem is aggravated in settings that have costlier or resource constrained links as happens in Cloud Computing infrastructures composed by several interconnected data centers across the globe.

Global AIDS Reporting-2001 to 2015: Lessons for Monitoring the Sustainable Development Goals.

PubMed

Alfvén, T; Erkkola, T; Ghys, P D; Padayachy, J; Warner-Smith, M; Rugg, D; de Lay, P

2017-07-01

Since 2001 the UNAIDS Secretariat has retained the responsibility for monitoring progress towards global commitments on HIV/AIDS. Key critical characteristics of the reporting system were assessed for the reporting period from 2004 to 2014 and analyses were undertaken of response rates and core indicator performance. Country submission rates ranged from 102 (53%) Member States in 2004 to 186 (96%) in 2012. There was great variance in response rates for specific indicators, with the highest response rates for treatment-related indicators. The Global AIDS reporting system has improved substantially over time and has provided key trend data on responses to the HIV epidemic, serving as the global accountability mechanism and providing reference data on the global AIDS response. It will be critical that reporting systems continue to evolve to support the monitoring of the Sustainable Development Goals, in view of ending the AIDS epidemic as a public health threat by 2030.

Monitoring sudden oak death in California using high-resolution imagery

Treesearch

Nina Maggi Kelly

2002-01-01

The Sudden Oak Death (SOD) epidemic in California is alarming for those living with, and adjacent to, the complex of oak and tanoak woodland that exist in patches along the coast. Monitoring SOD occurrence and spread is an on-going necessity. Remote sensing methods have proved to be successful in mapping and monitoring forest health and distribution when a sufficiently...

Constructing the effect of alternative intervention strategies on historic epidemics.

PubMed

Cook, A R; Gibson, G J; Gottwald, T R; Gilligan, C A

2008-10-06

Data from historical epidemics provide a vital and sometimes under-used resource from which to devise strategies for future control of disease. Previous methods for retrospective analysis of epidemics, in which alternative interventions are compared, do not make full use of the information; by using only partial information on the historical trajectory, augmentation of control may lead to predictions of a paradoxical increase in disease. Here we introduce a novel statistical approach that takes full account of the available information in constructing the effect of alternative intervention strategies in historic epidemics. The key to the method lies in identifying a suitable mapping between the historic and notional outbreaks, under alternative control strategies. We do this by using the Sellke construction as a latent process linking epidemics. We illustrate the application of the method with two examples. First, using temporal data for the common human cold, we show the improvement under the new method in the precision of predictions for different control strategies. Second, we show the generality of the method for retrospective analysis of epidemics by applying it to a spatially extended arboreal epidemic in which we demonstrate the relative effectiveness of host culling strategies that differ in frequency and spatial extent. Some of the inferential and philosophical issues that arise are discussed along with the scope of potential application of the new method.

A network model for the propagation of Hepatitis C with HIV co-infection

NASA Astrophysics Data System (ADS)

Nucit, Arnaud; Randon-Furling, Julien

2017-05-01

We define and examine a model of epidemic propagation for a virus such as Hepatitis C (with HIV co-infection) on a network of networks, namely the network of French urban areas. One network level is that of the individual interactions inside each urban area. The second level is that of the areas themselves, linked by individuals travelling between these areas and potentially helping the epidemic spread from one city to another. We choose to encode the second level of the network as extra, special nodes in the first level. We observe that such an encoding leads to sensible results in terms of the extent and speed of propagation of an epidemic, depending on its source point.

Epidemic Kaposi Sarcoma

MedlinePlus

... to boost, direct, or restore the body's natural defenses against cancer. This type of cancer treatment is ... Security Reuse & Copyright Syndication Services Website Linking U.S. Department of Health and Human Services National Institutes of ...

Secondary Bacterial Infections Associated with Influenza Pandemics

PubMed Central

Morris, Denise E.; Cleary, David W.; Clarke, Stuart C.

2017-01-01

Lower and upper respiratory infections are the fourth highest cause of global mortality (Lozano et al., 2012). Epidemic and pandemic outbreaks of respiratory infection are a major medical concern, often causing considerable disease and a high death toll, typically over a relatively short period of time. Influenza is a major cause of epidemic and pandemic infection. Bacterial co/secondary infection further increases morbidity and mortality of influenza infection, with Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus reported as the most common causes. With increased antibiotic resistance and vaccine evasion it is important to monitor the epidemiology of pathogens in circulation to inform clinical treatment and development, particularly in the setting of an influenza epidemic/pandemic. PMID:28690590

Prostitution, AIDS, and preventive health behavior.

PubMed

Campbell, C A

1991-01-01

Although considerable attention has been placed on the role of prostitutes in the AIDS epidemic, little attention has been directed to features of prostitutes' work lives which are relevant to the control of AIDS. This article reviews several aspects of prostitution in the United States which have implications for control of the epidemic. The article first reviews the epidemiology of human immunodeficiency virus (HIV) infection among prostitutes. The legalized system of prostitution in Nevada serves as a basis for comparison to illegal prostitution. This article examines the effectiveness of mandatory testing of prostitutes for monitoring and controlling the epidemic. And finally, a peer education approach as a means to control HIV infection among prostitutes is explored.

Skip the trip: air travelers' behavioral responses to pandemic influenza.

PubMed

Fenichel, Eli P; Kuminoff, Nicolai V; Chowell, Gerardo

2013-01-01

Theory suggests that human behavior has implications for disease spread. We examine the hypothesis that individuals engage in voluntary defensive behavior during an epidemic. We estimate the number of passengers missing previously purchased flights as a function of concern for swine flu or A/H1N1 influenza using 1.7 million detailed flight records, Google Trends, and the World Health Organization's FluNet data. We estimate that concern over "swine flu," as measured by Google Trends, accounted for 0.34% of missed flights during the epidemic. The Google Trends data correlates strongly with media attention, but poorly (at times negatively) with reported cases in FluNet. Passengers show no response to reported cases. Passengers skipping their purchased trips forwent at least $50 M in travel related benefits. Responding to actual cases would have cut this estimate in half. Thus, people appear to respond to an epidemic by voluntarily engaging in self-protection behavior, but this behavior may not be responsive to objective measures of risk. Clearer risk communication could substantially reduce epidemic costs. People undertaking costly risk reduction behavior, for example, forgoing nonrefundable flights, suggests they may also make less costly behavior adjustments to avoid infection. Accounting for defensive behaviors may be important for forecasting epidemics, but linking behavior with epidemics likely requires consideration of risk communication.

The role of the intensive care unit in real-time surveillance of emerging pandemics: the Italian GiViTI experience.

PubMed

Bertolini, G; Nattino, G; Langer, M; Tavola, M; Crespi, D; Mondini, M; Rossi, C; Previtali, C; Marshall, J; Poole, D

2016-01-01

The prompt availability of reliable epidemiological information on emerging pandemics is crucial for public health policy-makers. Early in 2013, a possible new H1N1 epidemic notified by an intensive care unit (ICU) to GiViTI, the Italian ICU network, prompted the re-activation of the real-time monitoring system developed during the 2009-2010 pandemic. Based on data from 216 ICUs, we were able to detect and monitor an outbreak of severe H1N1 infection, and to compare the situation with previous years. The timely and correct assessment of the severity of an epidemic can be obtained by investigating ICU admissions, especially when historical comparisons can be made.

SARS Grid--an AG-based disease management and collaborative platform.

PubMed

Hung, Shu-Hui; Hung, Tsung-Chieh; Juang, Jer-Nan

2006-01-01

This paper describes the development of the NCHC's Severe Acute Respiratory Syndrome (SARS) Grid project-An Access Grid (AG)-based disease management and collaborative platform that allowed for SARS patient's medical data to be dynamically shared and discussed between hospitals and doctors using AG's video teleconferencing (VTC) capabilities. During the height of the SARS epidemic in Asia, SARS Grid and the SARShope website significantly curved the spread of SARS by helping doctors manage the in-hospital and in-home care of quarantined SARS patients through medical data exchange and the monitoring of the patient's symptoms. Now that the SARS epidemic has ended, the primary function of the SARS Grid project is that of a web-based informatics tool to increase pubic awareness of SARS and other epidemic diseases. Additionally, the SARS Grid project can be viewed and further studied as an outstanding model of epidemic disease prevention and/or containment.

Climate Change and the Emergent Epidemic of CKD from Heat Stress in Rural Communities: The Case for Heat Stress Nephropathy

PubMed Central

Glaser, Jason; Lemery, Jay; Rajagopalan, Balaji; Diaz, Henry F.; García-Trabanino, Ramón; Taduri, Gangadhar; Madero, Magdalena; Amarasinghe, Mala; Abraham, Georgi; Anutrakulchai, Sirirat; Jha, Vivekanand; Stenvinkel, Peter; Roncal-Jimenez, Carlos; Lanaspa, Miguel A.; Correa-Rotter, Ricardo; Sheikh-Hamad, David; Burdmann, Emmanuel A.; Andres-Hernando, Ana; Milagres, Tamara; Weiss, Ilana; Kanbay, Mehmet; Wesseling, Catharina; Sánchez-Lozada, Laura Gabriela

2016-01-01

Climate change has led to significant rise of 0.8°C–0.9°C in global mean temperature over the last century and has been linked with significant increases in the frequency and severity of heat waves (extreme heat events). Climate change has also been increasingly connected to detrimental human health. One of the consequences of climate-related extreme heat exposure is dehydration and volume loss, leading to acute mortality from exacerbations of pre-existing chronic disease, as well as from outright heat exhaustion and heat stroke. Recent studies have also shown that recurrent heat exposure with physical exertion and inadequate hydration can lead to CKD that is distinct from that caused by diabetes, hypertension, or GN. Epidemics of CKD consistent with heat stress nephropathy are now occurring across the world. Here, we describe this disease, discuss the locations where it appears to be manifesting, link it with increasing temperatures, and discuss ongoing attempts to prevent the disease. Heat stress nephropathy may represent one of the first epidemics due to global warming. Government, industry, and health policy makers in the impacted regions should place greater emphasis on occupational and community interventions. PMID:27151892

Epidemic dynamics on a risk-based evolving social network

NASA Astrophysics Data System (ADS)

Antwi, Shadrack; Shaw, Leah

2013-03-01

Social network models have been used to study how behavior affects the dynamics of an infection in a population. Motivated by HIV, we consider how a trade-off between benefits and risks of sexual connections determine network structure and disease prevalence. We define a stochastic network model with formation and breaking of links as changes in sexual contacts. Each node has an intrinsic benefit its neighbors derive from connecting to it. Nodes' infection status is not apparent to others, but nodes with more connections (higher degree) are assumed more likely to be infected. The probability to form and break links is determined by a payoff computed from the benefit and degree-dependent risk. The disease is represented by a SI (susceptible-infected) model. We study network and epidemic evolution via Monte Carlo simulation and analytically predict the behavior with a heterogeneous mean field approach. The dependence of network connectivity and infection threshold on parameters is determined, and steady state degree distribution and epidemic levels are obtained. We also study a situation where system-wide infection levels alter perception of risk and cause nodes to adjust their behavior. This is a case of an adaptive network, where node status feeds back to change network geometry.

Descriptive epidemiology of typhoid fever during an epidemic in Harare, Zimbabwe, 2012.

PubMed

Polonsky, Jonathan A; Martínez-Pino, Isabel; Nackers, Fabienne; Chonzi, Prosper; Manangazira, Portia; Van Herp, Michel; Maes, Peter; Porten, Klaudia; Luquero, Francisco J

2014-01-01

Typhoid fever remains a significant public health problem in developing countries. In October 2011, a typhoid fever epidemic was declared in Harare, Zimbabwe - the fourth enteric infection epidemic since 2008. To orient control activities, we described the epidemiology and spatiotemporal clustering of the epidemic in Dzivaresekwa and Kuwadzana, the two most affected suburbs of Harare. A typhoid fever case-patient register was analysed to describe the epidemic. To explore clustering, we constructed a dataset comprising GPS coordinates of case-patient residences and randomly sampled residential locations (spatial controls). The scale and significance of clustering was explored with Ripley K functions. Cluster locations were determined by a random labelling technique and confirmed using Kulldorff's spatial scan statistic. We analysed data from 2570 confirmed and suspected case-patients, and found significant spatiotemporal clustering of typhoid fever in two non-overlapping areas, which appeared to be linked to environmental sources. Peak relative risk was more than six times greater than in areas lying outside the cluster ranges. Clusters were identified in similar geographical ranges by both random labelling and Kulldorff's spatial scan statistic. The spatial scale at which typhoid fever clustered was highly localised, with significant clustering at distances up to 4.5 km and peak levels at approximately 3.5 km. The epicentre of infection transmission shifted from one cluster to the other during the course of the epidemic. This study demonstrated highly localised clustering of typhoid fever during an epidemic in an urban African setting, and highlights the importance of spatiotemporal analysis for making timely decisions about targetting prevention and control activities and reinforcing treatment during epidemics. This approach should be integrated into existing surveillance systems to facilitate early detection of epidemics and identify their spatial range.

Descriptive Epidemiology of Typhoid Fever during an Epidemic in Harare, Zimbabwe, 2012

PubMed Central

Polonsky, Jonathan A.; Martínez-Pino, Isabel; Nackers, Fabienne; Chonzi, Prosper; Manangazira, Portia; Van Herp, Michel; Maes, Peter; Porten, Klaudia; Luquero, Francisco J.

2014-01-01

Background Typhoid fever remains a significant public health problem in developing countries. In October 2011, a typhoid fever epidemic was declared in Harare, Zimbabwe - the fourth enteric infection epidemic since 2008. To orient control activities, we described the epidemiology and spatiotemporal clustering of the epidemic in Dzivaresekwa and Kuwadzana, the two most affected suburbs of Harare. Methods A typhoid fever case-patient register was analysed to describe the epidemic. To explore clustering, we constructed a dataset comprising GPS coordinates of case-patient residences and randomly sampled residential locations (spatial controls). The scale and significance of clustering was explored with Ripley K functions. Cluster locations were determined by a random labelling technique and confirmed using Kulldorff's spatial scan statistic. Principal Findings We analysed data from 2570 confirmed and suspected case-patients, and found significant spatiotemporal clustering of typhoid fever in two non-overlapping areas, which appeared to be linked to environmental sources. Peak relative risk was more than six times greater than in areas lying outside the cluster ranges. Clusters were identified in similar geographical ranges by both random labelling and Kulldorff's spatial scan statistic. The spatial scale at which typhoid fever clustered was highly localised, with significant clustering at distances up to 4.5 km and peak levels at approximately 3.5 km. The epicentre of infection transmission shifted from one cluster to the other during the course of the epidemic. Conclusions This study demonstrated highly localised clustering of typhoid fever during an epidemic in an urban African setting, and highlights the importance of spatiotemporal analysis for making timely decisions about targetting prevention and control activities and reinforcing treatment during epidemics. This approach should be integrated into existing surveillance systems to facilitate early detection of epidemics and identify their spatial range. PMID:25486292

Genetic shifts in methicillin-resistant Staphylococcus aureus epidemic clones and toxin gene profiles in Japan: comparative analysis among pre-epidemic, epidemic and post-epidemic phases.

PubMed

Osaka, Shunsuke; Okuzumi, Katsuko; Koide, Shota; Tamai, Kiyoko; Sato, Tomoaki; Tanimoto, Koichi; Tomita, Haruyoshi; Suzuki, Masahiro; Nagano, Yukiko; Shibayama, Keigo; Arakawa, Yoshichika; Nagano, Noriyuki

2018-03-01

The decline in methicillin-resistant Staphylococcus aureus (MRSA) isolation rates has become a general observation worldwide, including Japan. We hypothesized that some genetic shift in MRSA might cause this phenomenon, and therefore we investigated the genetic profiles among MRSA clinical isolates obtained from three different epidemic phases in Japan. A total of 353 MRSA isolates were selected from 202 medical facilities in 1990 (pre-epidemic phase), 2004 (epidemic phase) and 2016 (post-epidemic phase). Molecular typing was performed by PCR detection of 22 genes using the polymerase chain reaction (PCR)-based ORF typing (POT) system, including an additional eight genes including small genomic islets and seven toxin genes. Isolates with a POT1 of score 93, identified as presumed clonal complex (pCC)5-staphylococcal cassette chromosome mec (SCCmec) type II including ST5-SCCmec type II New York/Japan clone, represented the major epidemic MRSA lineage in 1990 and 2004. In 2016, however, a marked decrease in isolates with a POT1 score of 93, along with changes in the epidemiology of toxin genes carried, was noted, where the carriers of tst genes including the tst-sec combination were markedly reduced, and those possessing the seb gene alone were markedly increased. Rather, isolates with a POT1 score of 106, including pCC1 or pCC8 among the isolates with SCCmec type IV, which often links to community-associated MRSA, were predominant. Interestingly, the pCC1 and pCC8 lineages were related to sea and tst-sec carriage, respectively. Over time, a transition in MRSA genetic profiles from a POT1 score of 93 in 1990 and 2004 to 106 in 2014 was found in Japan.

Introduction of Mobile Health Tools to Support Ebola Surveillance and Contact Tracing in Guinea.

PubMed

Sacks, Jilian A; Zehe, Elizabeth; Redick, Cindil; Bah, Alhoussaine; Cowger, Kai; Camara, Mamady; Diallo, Aboubacar; Gigo, Abdel Nasser Iro; Dhillon, Ranu S; Liu, Anne

2015-11-12

Challenges in data availability and quality have contributed to the longest and deadliest Ebola epidemic in history that began in December 2013. Accurate surveillance data, in particular, has been difficult to access, as it is often collected in remote communities. We describe the design, implementation, and challenges of implementing a smartphone-based contact tracing system that is linked to analytics and data visualization software as part of the Ebola response in Guinea. The system, built on the mobile application CommCare and business intelligence software Tableau, allows for real-time identification of contacts who have not been visited and strong accountability of contact tracers through timestamps and collection of GPS points with their surveillance data. Deployment of this system began in November 2014 in Conakry, Guinea, and was expanded to a total of 5 prefectures by April 2015. To date, the mobile system has not replaced the paper-based system in the 5 prefectures where the program is active. However, as of April 30, 2015, 210 contact tracers in the 5 prefectures were actively using the mobile system to collectively monitor 9,162 contacts. With proper training, some investment in technical hardware, and adequate managerial oversight, there is opportunity to improve access to surveillance data from difficult-to-reach communities in order to inform epidemic control strategies while strengthening health systems to reduce risk of future disease outbreaks. © Liu et al.

Introduction of Mobile Health Tools to Support Ebola Surveillance and Contact Tracing in Guinea

PubMed Central

Sacks, Jilian A; Zehe, Elizabeth; Redick, Cindil; Bah, Alhoussaine; Cowger, Kai; Camara, Mamady; Diallo, Aboubacar; Gigo, Abdel Nasser Iro; Dhillon, Ranu S; Liu, Anne

2015-01-01

Challenges in data availability and quality have contributed to the longest and deadliest Ebola epidemic in history that began in December 2013. Accurate surveillance data, in particular, has been difficult to access, as it is often collected in remote communities. We describe the design, implementation, and challenges of implementing a smartphone-based contact tracing system that is linked to analytics and data visualization software as part of the Ebola response in Guinea. The system, built on the mobile application CommCare and business intelligence software Tableau, allows for real-time identification of contacts who have not been visited and strong accountability of contact tracers through timestamps and collection of GPS points with their surveillance data. Deployment of this system began in November 2014 in Conakry, Guinea, and was expanded to a total of 5 prefectures by April 2015. To date, the mobile system has not replaced the paper-based system in the 5 prefectures where the program is active. However, as of April 30, 2015, 210 contact tracers in the 5 prefectures were actively using the mobile system to collectively monitor 9,162 contacts. With proper training, some investment in technical hardware, and adequate managerial oversight, there is opportunity to improve access to surveillance data from difficult-to-reach communities in order to inform epidemic control strategies while strengthening health systems to reduce risk of future disease outbreaks. PMID:26681710

The SPINDLE Disruption-Tolerant Networking System

DTIC Science & Technology

2007-11-01

average availability ( AA ). The AA metric attempts to measure the average fraction of time in the near future that the link will be available for use...Each link’s AA is epidemically disseminated to all nodes. Path costs are computed using the topology learned through this dissemination, with cost of a...link l set to (1 − AA (l)) + c (a small constant factor that makes routing favor fewer number of hops when all links have AA of 1). Additional details

Development of an Antigen Capture Enzyme-Linked Immunosorbent Assay for Virus Detection Based on Porcine Epidemic Diarrhea Virus Monoclonal Antibodies

PubMed Central

Wang, Zanyu; Jiyuan, Yin; Su, Chen; Xinyuan, Qiao

2015-01-01

Abstract Porcine epidemic diarrhea virus (PEDV), a coronavirus, can cause acute diarrhea and dehydration in pigs. In the current study, two positive monoclonal cell lines (5D7 and 3H4) specific for PEDV were established, and the immunoreactivity of the monoclonal antibodies was confirmed by immunofluorescence and dot-immunobinding assays. A method, termed antigen capture enzyme-linked immunosorbent assay (AC-ELISA), which used the monoclonal antibody 5D7 as the detecting antibody and rabbit antiserum of PEDV protein S as the capture antibody, was developed. Compared with the reverse transcription polymerase chain reaction method of detecting PEDV in fecal samples, AC-ELISA showed similar sensitivity and specificity. These results suggested that AC-ELISA would be useful for the diagnosis and epidemiological studies of PEDV. PMID:25658793

[Hepatitis: a longstanding companion in human history].

PubMed

Craxi, Lucia

2012-03-01

Hepatitis has gone along with human history since its origins, due to its prompt identifiability linked to jaundice as a symptom. Written evidence of outbreaks of epidemic jaundice can be tracked back a few millenniums before Christ. Unavoidable confusion arises due to the overlap of different sources possibly linked to different aetiologies, identified over time as epidemic jaundice (HAV or HEV hepatitis?) and serum hepatitis (HBV or HCV hepatitis?). The journey that brought to recognize viruses as the main cause of jaundice was long and started midway during the last century, when the infectious hypothesis, which had taken place step by step, was finally confirmed by epidemiological investigations of an outbreak occurring in the US army in 1942, after a yellow fever immunization campaign. Further research identified two clinically different types of hepatitis, called for the first time hepatitis A and hepatitis B.

Congenital microcephaly: A diagnostic challenge during Zika epidemics.

PubMed

Alvarado-Socarras, Jorge L; Idrovo, Álvaro J; Contreras-García, Gustavo A; Rodriguez-Morales, Alfonso J; Audcent, Tobey A; Mogollon-Mendoza, Adriana C; Paniz-Mondolfi, Alberto

2018-02-19

The multiple, wide and diverse etiologies of congenital microcephaly are complex and multifactorial. Recent advances in genetic testing have improved understanding of novel genetic causes of congenital microcephaly. The recent Zika virus (ZIKV) epidemic in Latin America has highlighted the need for a better understanding of the underlying pathological mechanisms of microcephaly including both infectious and non-infectious causes. The diagnostic approach to microcephaly needs to include potential infectious and genetic etiologies, as well as environmental in-utero exposures such as alcohol, toxins, and medications. Emerging genetic alterations linked to microcephaly include abnormal mitotic microtubule spindle structure and abnormal function of centrosomes. We discuss the diagnostic challenge of congenital microcephaly in the context of understanding the links with ZIKV emergence as a new etiological factor involved in this birth defect. Copyright © 2018 Elsevier Ltd. All rights reserved.

Epidemic spreading and immunization strategy in multiplex networks

NASA Astrophysics Data System (ADS)

Alvarez Zuzek, Lucila G.; Buono, Camila; Braunstein, Lidia A.

2015-09-01

A more connected world has brought major consequences such as facilitate the spread of diseases all over the world to quickly become epidemics, reason why researchers are concentrated in modeling the propagation of epidemics and outbreaks in multilayer networks. In this networks all nodes interact in different layers with different type of links. However, in many scenarios such as in the society, a multiplex network framework is not completely suitable since not all individuals participate in all layers. In this paper, we use a partially overlapped, multiplex network where only a fraction of the individuals are shared by the layers. We develop a mitigation strategy for stopping a disease propagation, considering the Susceptible-Infected- Recover model, in a system consisted by two layers. We consider a random immunization in one of the layers and study the effect of the overlapping fraction in both, the propagation of the disease and the immunization strategy. Using branching theory, we study this scenario theoretically and via simulations and find a lower epidemic threshold than in the case without strategy.

Social Distancing Strategies against Disease Spreading

NASA Astrophysics Data System (ADS)

Valdez, L. D.; Buono, C.; Macri, P. A.; Braunstein, L. A.

2013-12-01

The recurrent infectious diseases and their increasing impact on the society has promoted the study of strategies to slow down the epidemic spreading. In this review we outline the applications of percolation theory to describe strategies against epidemic spreading on complex networks. We give a general outlook of the relation between link percolation and the susceptible-infected-recovered model, and introduce the node void percolation process to describe the dilution of the network composed by healthy individual, i.e., the network that sustain the functionality of a society. Then, we survey two strategies: the quenched disorder strategy where an heterogeneous distribution of contact intensities is induced in society, and the intermittent social distancing strategy where health individuals are persuaded to avoid contact with their neighbors for intermittent periods of time. Using percolation tools, we show that both strategies may halt the epidemic spreading. Finally, we discuss the role of the transmissibility, i.e., the effective probability to transmit a disease, on the performance of the strategies to slow down the epidemic spreading.

Epidemic Model with Isolation in Multilayer Networks

NASA Astrophysics Data System (ADS)

Zuzek, L. G. Alvarez; Stanley, H. E.; Braunstein, L. A.

2015-07-01

The Susceptible-Infected-Recovered (SIR) model has successfully mimicked the propagation of such airborne diseases as influenza A (H1N1). Although the SIR model has recently been studied in a multilayer networks configuration, in almost all the research the isolation of infected individuals is disregarded. Hence we focus our study in an epidemic model in a two-layer network, and we use an isolation parameter w to measure the effect of quarantining infected individuals from both layers during an isolation period tw. We call this process the Susceptible-Infected-Isolated-Recovered (SIIR) model. Using the framework of link percolation we find that isolation increases the critical epidemic threshold of the disease because the time in which infection can spread is reduced. In this scenario we find that this threshold increases with w and tw. When the isolation period is maximum there is a critical threshold for w above which the disease never becomes an epidemic. We simulate the process and find an excellent agreement with the theoretical results.

The impact of mass gatherings and holiday traveling on the course of an influenza pandemic: a computational model.

PubMed

Shi, Pengyi; Keskinocak, Pinar; Swann, Julie L; Lee, Bruce Y

2010-12-21

During the 2009 H1N1 influenza pandemic, concerns arose about the potential negative effects of mass public gatherings and travel on the course of the pandemic. Better understanding the potential effects of temporal changes in social mixing patterns could help public officials determine if and when to cancel large public gatherings or enforce regional travel restrictions, advisories, or surveillance during an epidemic. We develop a computer simulation model using detailed data from the state of Georgia to explore how various changes in social mixing and contact patterns, representing mass gatherings and holiday traveling, may affect the course of an influenza pandemic. Various scenarios with different combinations of the length of the mass gatherings or traveling period (range: 0.5 to 5 days), the proportion of the population attending the mass gathering events or on travel (range: 1% to 50%), and the initial reproduction numbers R0 (1.3, 1.5, 1.8) are explored. Mass gatherings that occur within 10 days before the epidemic peak can result in as high as a 10% relative increase in the peak prevalence and the total attack rate, and may have even worse impacts on local communities and travelers' families. Holiday traveling can lead to a second epidemic peak under certain scenarios. Conversely, mass traveling or gatherings may have little effect when occurring much earlier or later than the epidemic peak, e.g., more than 40 days earlier or 20 days later than the peak when the initial R0 = 1.5. Our results suggest that monitoring, postponing, or cancelling large public gatherings may be warranted close to the epidemic peak but not earlier or later during the epidemic. Influenza activity should also be closely monitored for a potential second peak if holiday traveling occurs when prevalence is high.

SARS and population health technology.

PubMed

Eysenbach, Gunther

2003-01-01

The recent global outbreak of SARS (severe acute respiratory syndrome) provides an opportunity to study the use and impact of public health informatics and population health technology to detect and fight a global epidemic. Population health technology is the umbrella term for technology applications that have a population focus and the potential to improve public health. This includes the Internet, but also other technologies such as wireless devices, mobile phones, smart appliances, or smart homes. In the context of an outbreak or bioterrorism attack, such technologies may help to gather intelligence and detect diseases early, and communicate and exchange information electronically worldwide. Some of the technologies brought forward during the SARS epidemic may have been primarily motivated by marketing efforts, or were more directed towards reassuring people that "something is being done," ie, fighting an "epidemic of fear." To understand "fear epidemiology" is important because early warning systems monitoring data from a large number of people may not be able to discriminate between a biological epidemic and an epidemic of fear. The need for critical evaluation of all of these technologies is stressed.

Probing into the effectiveness of self-isolation policies in epidemic control

NASA Astrophysics Data System (ADS)

Crokidakis, Nuno; Duarte Queirós, Sílvio M.

2012-06-01

In this work, we inspect the reliability of controlling and quelling an epidemic disease mimicked by a susceptible-infected-susceptible (SIS) model defined on a complex network by means of current and implementable quarantine and isolation policies. Specifically, we consider that each individual in the network is originally linked to individuals of two types: members of the same household and acquaintances. The topology of this network evolves, taking into account a probability q that aims at representing the quarantine or isolation process in which the connection with acquaintances is severed according to standard policies of control of epidemics. Within current policies of self-isolation and standard infection rates, our results show that the propagation is either only controllable for hypothetical rates of compliance or not controllable at all.

Zika virus infection in Vietnam: current epidemic, strain origin, spreading risk, and perspective.

PubMed

Chu, Dinh-Toi; Ngoc, Vo Truong Nhu; Tao, Yang

2017-11-01

Zika virus infection and its associated microcephaly have being receiving global concern. This infection has spread widely since the first outbreak was recorded in Africa in 1952. Now, it has been reported in over 70 countries on five continents including Africa, North and South America, Asia, and Europe. Vietnam is one of the most recent countries which had cases of Zika virus infection at the end of 2016. This country has also reported the first case of a microcephaly-born baby which was probably linked to Zika virus infection. However, information on the Zika virus epidemic in Vietnam is still limited. This brief report intends to update the current Zika virus epidemic, and to discuss challenges and perspectives in controlling this infection in Vietnam.

Monitoring the tobacco use epidemic IV. The vector: Tobacco industry data sources and recommendations for research and evaluation.

PubMed

Cruz, Tess Boley

2009-01-01

This Vector paper (IV of V on monitoring the tobacco use epidemic) presents the data sources and methods that can be used to monitor tobacco marketing and makes recommendations for creating a national surveillance system. In 2002, the Vector Work Group of the National Tobacco Monitoring, Research and Evaluation Workshop identified priority indicators of tobacco marketing: tobacco brand pricing strategies, retail environment advertising and promotional allowances, gray market or smuggling activities, lobbying, direct mail marketing, tobacco brand placements in films, Internet promotions, and sponsorship at bars and events. This paper reviews and identifies data sources and gaps for these priority indicators and for 12 other indicators of interest. There are 38 commercial data sites and Internet sources, as well as individual research efforts that address the priority indicators. These sources are not integrated, often costly, and limited in standardization. Tobacco marketing could be more effectively monitored with the development of a national research network. Surveillance of the tobacco industry's methods to push tobacco and pull consumers can help the public health community identify new markets and campaigns, justify and tailor effective tobacco control strategies, and evaluate existing counter-marketing efforts.

Politics of Monitoring and Evaluation: Lessons from the AIDS Epidemic

ERIC Educational Resources Information Center

De Lay, Paul; Manda, Valerie

2004-01-01

Conventional monitoring and evaluation (M&E) textbooks rarely address the various political influences exerted on M&E of public health programs. Policymakers are often the largest consumers of M&E information; indeed, the genesis of many public health program evaluation efforts is a need to inform public policy. People define "political…

Controlling epidemic spread by social distancing: Do it well or not at all

PubMed Central

2012-01-01

Background Existing epidemiological models have largely tended to neglect the impact of individual behaviour on the dynamics of diseases. However, awareness of the presence of illness can cause people to change their behaviour by, for example, staying at home and avoiding social contacts. Such changes can be used to control epidemics but they exact an economic cost. Our aim is to study the costs and benefits of using individual-based social distancing undertaken by healthy individuals as a form of control. Methods Our model is a standard SIR model superimposed on a spatial network, without and with addition of small-world interactions. Disease spread is controlled by allowing susceptible individuals to temporarily reduce their social contacts in response to the presence of infection within their local neighbourhood. We ascribe an economic cost to the loss of social contacts, and weigh this against the economic benefit gained by reducing the impact of the epidemic. We study the sensitivity of the results to two key parameters, the individuals’ attitude to risk and the size of the awareness neighbourhood. Results Depending on the characteristics of the epidemic and on the relative economic importance of making contacts versus avoiding infection, the optimal control is one of two extremes: either to adopt a highly cautious control, thereby suppressing the epidemic quickly by drastically reducing contacts as soon as disease is detected; or else to forego control and allow the epidemic to run its course. The worst outcome arises when control is attempted, but not cautiously enough to cause the epidemic to be suppressed. The next main result comes from comparing the size of the neighbourhood of which individuals are aware to that of the neighbourhood within which transmission can occur. The control works best when these sizes match and is particularly ineffective when the awareness neighbourhood is smaller than the infection neighbourhood. The results are robust with respect to inclusion of long-range, small-world links which destroy the spatial structure, regardless of whether individuals can or cannot control them. However, addition of many non-local links eventually makes control ineffective. Conclusions These results have implications for the design of control strategies using social distancing: a control that is too weak or based upon inaccurate knowledge, may give a worse outcome than doing nothing. PMID:22905965

Bottled beverages and typhoid fever: the Mexican epidemic of 1972-73.

PubMed Central

Gonzalez-Cortes, A; Gangarosa, E J; Parrilla, C; Martin, W T; Espinosa-Ayala, A M; Ruiz, L; Bessudo, D; Hernandez-Arreortua, H

1982-01-01

A chloramphenicol resistant strain of S. typhi which caused a very large epidemic of typhoid fever in Mexico in 1972-73 survived in opened bottles of one carbonated drink with a pH of 4.6 for two weeks and in another such drink with a pH of 5.1 for six months. Bottled beverages are potential sources of large outbreaks of enteric disease, and deserve the same type of standards sand monitoring as comparable fluids such as milk. PMID:7091481

Utility and potential of rapid epidemic intelligence from internet-based sources.

PubMed

Yan, S J; Chughtai, A A; Macintyre, C R

2017-10-01

Rapid epidemic detection is an important objective of surveillance to enable timely intervention, but traditional validated surveillance data may not be available in the required timeframe for acute epidemic control. Increasing volumes of data on the Internet have prompted interest in methods that could use unstructured sources to enhance traditional disease surveillance and gain rapid epidemic intelligence. We aimed to summarise Internet-based methods that use freely-accessible, unstructured data for epidemic surveillance and explore their timeliness and accuracy outcomes. Steps outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist were used to guide a systematic review of research related to the use of informal or unstructured data by Internet-based intelligence methods for surveillance. We identified 84 articles published between 2006-2016 relating to Internet-based public health surveillance methods. Studies used search queries, social media posts and approaches derived from existing Internet-based systems for early epidemic alerts and real-time monitoring. Most studies noted improved timeliness compared to official reporting, such as in the 2014 Ebola epidemic where epidemic alerts were generated first from ProMED-mail. Internet-based methods showed variable correlation strength with official datasets, with some methods showing reasonable accuracy. The proliferation of publicly available information on the Internet provided a new avenue for epidemic intelligence. Methodologies have been developed to collect Internet data and some systems are already used to enhance the timeliness of traditional surveillance systems. To improve the utility of Internet-based systems, the key attributes of timeliness and data accuracy should be included in future evaluations of surveillance systems. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Infectious haematopoietic necrosis epidemic (2001 to 2003) in farmed Atlantic salmon Salmo salar in British Columbia.

PubMed

Saksida, S M

2006-10-27

I investigated a recent infectious haematopoietic necrosis disease (IHN) epidemic in farmed Atlantic salmon Salmo salar in British Columbia (BC), Canada. All companies with infected farms (n = 36) participated in the study. Over 12 million Atlantic salmon on infected farms died or were culled during the epidemic with cumulative mortality on the farms averaging 58%. The first reported case of IHN occurred in August 2001 and the last outbreak in June 2003. Outbreaks on the farms lasted between 20 and 22 wk. Genetic sequencing by other researchers, revealed that 2 different IHN isolates contributed to this epidemic, one linked to all cases in 4 areas, the other associated with all cases in a fifth area. Spatial and temporal patterns of the farm outbreaks were examined to determine possible methods of spread between the farms. Evidence presented herein appears to show that farming practices themselves contributed significantly to the spread between farms both within and between areas. Natural waterborne transmission may have played a role in the spread of the virus between farms located in close proximity to each other. The data collected from this epidemic are compared with reports which examined the first reported epidemic in Atlantic salmon in BC (1992 to 1996). Evidence is presented for the hypothesis that wild fish species may have been the source of introduction of the virus into the farmed Atlantic salmon population.

Skip the Trip: Air Travelers' Behavioral Responses to Pandemic Influenza

PubMed Central

Fenichel, Eli P.; Kuminoff, Nicolai V.; Chowell, Gerardo

2013-01-01

Theory suggests that human behavior has implications for disease spread. We examine the hypothesis that individuals engage in voluntary defensive behavior during an epidemic. We estimate the number of passengers missing previously purchased flights as a function of concern for swine flu or A/H1N1 influenza using 1.7 million detailed flight records, Google Trends, and the World Health Organization's FluNet data. We estimate that concern over “swine flu,” as measured by Google Trends, accounted for 0.34% of missed flights during the epidemic. The Google Trends data correlates strongly with media attention, but poorly (at times negatively) with reported cases in FluNet. Passengers show no response to reported cases. Passengers skipping their purchased trips forwent at least $50 M in travel related benefits. Responding to actual cases would have cut this estimate in half. Thus, people appear to respond to an epidemic by voluntarily engaging in self-protection behavior, but this behavior may not be responsive to objective measures of risk. Clearer risk communication could substantially reduce epidemic costs. People undertaking costly risk reduction behavior, for example, forgoing nonrefundable flights, suggests they may also make less costly behavior adjustments to avoid infection. Accounting for defensive behaviors may be important for forecasting epidemics, but linking behavior with epidemics likely requires consideration of risk communication. PMID:23526970

Genomic Dissection of an Icelandic Epidemic of Respiratory Disease in Horses and Associated Zoonotic Cases

PubMed Central

Björnsdóttir, Sigríður; Harris, Simon R.; Svansson, Vilhjálmur; Gunnarsson, Eggert; Sigurðardóttir, Ólöf G.; Gammeljord, Kristina; Steward, Karen F.; Newton, J. Richard; Robinson, Carl; Charbonneau, Amelia R. L.

2017-01-01

ABSTRACT Iceland is free of the major infectious diseases of horses. However, in 2010 an epidemic of respiratory disease of unknown cause spread through the country’s native horse population of 77,000. Microbiological investigations ruled out known viral agents but identified the opportunistic pathogen Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) in diseased animals. We sequenced the genomes of 257 isolates of S. zooepidemicus to differentiate epidemic from endemic strains. We found that although multiple endemic clones of S. zooepidemicus were present, one particular clone, sequence type 209 (ST209), was likely to have been responsible for the epidemic. Concurrent with the epidemic, ST209 was also recovered from a human case of septicemia, highlighting the pathogenic potential of this strain. Epidemiological investigation revealed that the incursion of this strain into one training yard during February 2010 provided a nidus for the infection of multiple horses that then transmitted the strain to farms throughout Iceland. This study represents the first time that whole-genome sequencing has been used to investigate an epidemic on a national scale to identify the likely causative agent and the link to an associated zoonotic infection. Our data highlight the importance of national biosecurity to protect vulnerable populations of animals and also demonstrate the potential impact of S. zooepidemicus transmission to other animals, including humans. PMID:28765219

[THE PRESENT STATE OF EPIZOOTOLOGICAL MONITORING OF THE NATURAL FOCI OF INFECTIONS IN THE RUSSIAN FEDERATION].

PubMed

Trankvilevsky, D V; Tsarenko, V A; Zhukov, V I

2016-01-01

The facilities of the Russian Federal Service for Supervision of Consumer Rights Protection and Human Welfare play a leading role in epizootological monitoring. The specialists (zoologists and entomologists) of Hygiene and Epidemiology Centers do basic work in the subjects of the Russian Federation. The data obtained in the participation of different ministries and departments are used to analyze the results of monitoring. The latter is one of the important steps in the management of the epidemic, process in natural focal infections. In recent years, there has been an unjustified reduction in the volume of studies in the natural foci. This negatively affects the reliability of estimates and predictions of the epidemic activity of the natural foci of infections. Ensuring the national, security of the Russian Federation, epidemiological surveillance, and control of its natural foci requires staffing and appropriate professional training in the zoological and entomological subdivisions of the Russian Federal Service for Supervision of Consumer Rights Protection and Human Welfare.

Epidemics in Adaptive Social Networks with Temporary Link Deactivation

NASA Astrophysics Data System (ADS)

Tunc, Ilker; Shkarayev, Maxim S.; Shaw, Leah B.

2013-04-01

Disease spread in a society depends on the topology of the network of social contacts. Moreover, individuals may respond to the epidemic by adapting their contacts to reduce the risk of infection, thus changing the network structure and affecting future disease spread. We propose an adaptation mechanism where healthy individuals may choose to temporarily deactivate their contacts with sick individuals, allowing reactivation once both individuals are healthy. We develop a mean-field description of this system and find two distinct regimes: slow network dynamics, where the adaptation mechanism simply reduces the effective number of contacts per individual, and fast network dynamics, where more efficient adaptation reduces the spread of disease by targeting dangerous connections. Analysis of the bifurcation structure is supported by numerical simulations of disease spread on an adaptive network. The system displays a single parameter-dependent stable steady state and non-monotonic dependence of connectivity on link deactivation rate.

Reaction-diffusion processes and metapopulation models on duplex networks

NASA Astrophysics Data System (ADS)

Xuan, Qi; Du, Fang; Yu, Li; Chen, Guanrong

2013-03-01

Reaction-diffusion processes, used to model various spatially distributed dynamics such as epidemics, have been studied mostly on regular lattices or complex networks with simplex links that are identical and invariant in transferring different kinds of particles. However, in many self-organized systems, different particles may have their own private channels to keep their purities. Such division of links often significantly influences the underlying reaction-diffusion dynamics and thus needs to be carefully investigated. This article studies a special reaction-diffusion process, named susceptible-infected-susceptible (SIS) dynamics, given by the reaction steps β→α and α+β→2β, on duplex networks where links are classified into two groups: α and β links used to transfer α and β particles, which, along with the corresponding nodes, consist of an α subnetwork and a β subnetwork, respectively. It is found that the critical point of particle density to sustain reaction activity is independent of the network topology if there is no correlation between the degree sequences of the two subnetworks, and this critical value is suppressed or extended if the two degree sequences are positively or negatively correlated, respectively. Based on the obtained results, it is predicted that epidemic spreading may be promoted on positive correlated traffic networks but may be suppressed on networks with modules composed of different types of diffusion links.

Efficient community-based control strategies in adaptive networks

NASA Astrophysics Data System (ADS)

Yang, Hui; Tang, Ming; Zhang, Hai-Feng

2012-12-01

Most studies on adaptive networks concentrate on the properties of steady state, but neglect transient dynamics. In this study, we pay attention to the emergence of community structure in the transient process and the effects of community-based control strategies on epidemic spreading. First, by normalizing the modularity, we investigate the evolution of community structure during the transient process, and find that a strong community structure is induced by the rewiring mechanism in the early stage of epidemic dynamics, which, remarkably, delays the outbreak of disease. We then study the effects of control strategies started at different stages on the prevalence. Both immunization and quarantine strategies indicate that it is not ‘the earlier, the better’ for the implementation of control measures. And the optimal control effect is obtained if control measures can be efficiently implemented in the period of a strong community structure. For the immunization strategy, immunizing the susceptible nodes on susceptible-infected links and immunizing susceptible nodes randomly have similar control effects. However, for the quarantine strategy, quarantining the infected nodes on susceptible-infected links can yield a far better result than quarantining infected nodes randomly. More significantly, the community-based quarantine strategy performs better than the community-based immunization strategy. This study may shed new light on the forecast and the prevention of epidemics among humans.

Climate Change and the Emergent Epidemic of CKD from Heat Stress in Rural Communities: The Case for Heat Stress Nephropathy.

PubMed

Glaser, Jason; Lemery, Jay; Rajagopalan, Balaji; Diaz, Henry F; García-Trabanino, Ramón; Taduri, Gangadhar; Madero, Magdalena; Amarasinghe, Mala; Abraham, Georgi; Anutrakulchai, Sirirat; Jha, Vivekanand; Stenvinkel, Peter; Roncal-Jimenez, Carlos; Lanaspa, Miguel A; Correa-Rotter, Ricardo; Sheikh-Hamad, David; Burdmann, Emmanuel A; Andres-Hernando, Ana; Milagres, Tamara; Weiss, Ilana; Kanbay, Mehmet; Wesseling, Catharina; Sánchez-Lozada, Laura Gabriela; Johnson, Richard J

2016-08-08

Climate change has led to significant rise of 0.8°C-0.9°C in global mean temperature over the last century and has been linked with significant increases in the frequency and severity of heat waves (extreme heat events). Climate change has also been increasingly connected to detrimental human health. One of the consequences of climate-related extreme heat exposure is dehydration and volume loss, leading to acute mortality from exacerbations of pre-existing chronic disease, as well as from outright heat exhaustion and heat stroke. Recent studies have also shown that recurrent heat exposure with physical exertion and inadequate hydration can lead to CKD that is distinct from that caused by diabetes, hypertension, or GN. Epidemics of CKD consistent with heat stress nephropathy are now occurring across the world. Here, we describe this disease, discuss the locations where it appears to be manifesting, link it with increasing temperatures, and discuss ongoing attempts to prevent the disease. Heat stress nephropathy may represent one of the first epidemics due to global warming. Government, industry, and health policy makers in the impacted regions should place greater emphasis on occupational and community interventions. Copyright © 2016 by the American Society of Nephrology.

Surveillance of gastrointestinal disease in France using drug sales data.

PubMed

Pivette, Mathilde; Mueller, Judith E; Crépey, Pascal; Bar-Hen, Avner

2014-09-01

Drug sales data have increasingly been used for disease surveillance during recent years. Our objective was to assess the value of drug sales data as an operational early detection tool for gastroenteritis epidemics at national and regional level in France. For the period 2008-2013, we compared temporal trends of drug sales for the treatment of gastroenteritis with trends of cases reported by a Sentinel Network of general practitioners. We benchmarked detection models to select the one with the best sensitivity, false alert proportion and timeliness, and developed a prospective framework to assess the operational performance of the system. Drug sales data allowed the detection of seasonal gastrointestinal epidemics occurring in winter with a distinction between prescribed and non-prescribed drugs. Sales of non-prescribed drugs allowed epidemic detection on average 2.25 weeks earlier than Sentinel data. These results confirm the value of drug sales data for real-time monitoring of gastroenteritis epidemic activity. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Parasite transmission in social interacting hosts: Monogenean epidemics in guppies

USGS Publications Warehouse

Johnson, M.B.; Lafferty, K.D.; van, Oosterhout C.; Cable, J.

2011-01-01

Background: Infection incidence increases with the average number of contacts between susceptible and infected individuals. Contact rates are normally assumed to increase linearly with host density. However, social species seek out each other at low density and saturate their contact rates at high densities. Although predicting epidemic behaviour requires knowing how contact rates scale with host density, few empirical studies have investigated the effect of host density. Also, most theory assumes each host has an equal probability of transmitting parasites, even though individual parasite load and infection duration can vary. To our knowledge, the relative importance of characteristics of the primary infected host vs. the susceptible population has never been tested experimentally. Methodology/Principal Findings: Here, we examine epidemics using a common ectoparasite, Gyrodactylus turnbulli infecting its guppy host (Poecilia reticulata). Hosts were maintained at different densities (3, 6, 12 and 24 fish in 40 L aquaria), and we monitored gyrodactylids both at a population and individual host level. Although parasite population size increased with host density, the probability of an epidemic did not. Epidemics were more likely when the primary infected fish had a high mean intensity and duration of infection. Epidemics only occurred if the primary infected host experienced more than 23 worm days. Female guppies contracted infections sooner than males, probably because females have a higher propensity for shoaling. Conclusions/Significance: These findings suggest that in social hosts like guppies, the frequency of social contact largely governs disease epidemics independent of host density. ?? 2011 Johnson et al.

Parasite transmission in social interacting hosts: Monogenean epidemics in guppies

USGS Publications Warehouse

Johnson, Mirelle B.; Lafferty, Kevin D.; van Oosterhout, Cock; Cable, Joanne

2011-01-01

Background Infection incidence increases with the average number of contacts between susceptible and infected individuals. Contact rates are normally assumed to increase linearly with host density. However, social species seek out each other at low density and saturate their contact rates at high densities. Although predicting epidemic behaviour requires knowing how contact rates scale with host density, few empirical studies have investigated the effect of host density. Also, most theory assumes each host has an equal probability of transmitting parasites, even though individual parasite load and infection duration can vary. To our knowledge, the relative importance of characteristics of the primary infected host vs. the susceptible population has never been tested experimentally. Methodology/Principal Findings Here, we examine epidemics using a common ectoparasite, Gyrodactylus turnbulli infecting its guppy host (Poecilia reticulata). Hosts were maintained at different densities (3, 6, 12 and 24 fish in 40 L aquaria), and we monitored gyrodactylids both at a population and individual host level. Although parasite population size increased with host density, the probability of an epidemic did not. Epidemics were more likely when the primary infected fish had a high mean intensity and duration of infection. Epidemics only occurred if the primary infected host experienced more than 23 worm days. Female guppies contracted infections sooner than males, probably because females have a higher propensity for shoaling. Conclusions/Significance These findings suggest that in social hosts like guppies, the frequency of social contact largely governs disease epidemics independent of host density.

Establishment and evaluation of a theater influenza monitoring platform.

PubMed

Wang, Jian; Yang, Hui-Suo; Deng, Bing; Shi, Meng-Jing; Li, Xiang-Da; Nian, Qing-Gong; Song, Wen-Jing; Bing, Feng; Li, Qing-Feng

2017-11-20

Influenza is an acute respiratory infectious disease with a high incidence rate in the Chinese army, which directly disturbs military training and affects soldiers' health. Influenza surveillance systems are widely used around the world and play an important role in influenza epidemic prevention and control. As a theater centers for disease prevention and control, we established an influenza monitoring platform (IMP) in 2014 to strengthen the monitoring of influenza-like illness and influenza virus infection. In this study, we introduced the constitution, influenza virus detection, and quality control for an IMP. The monitoring effect was also evaluated by comparing the monitoring data with data from national influenza surveillance systems. The experiences and problems associated with the platform also were summarized. A theater IMP was established based on 3 levels of medical units, including monitoring sites, testing laboratories and a checking laboratory. A series of measures were taken to guarantee the quality of monitoring, such as technical training, a unified process, sufficient supervision and timely communication. The platform has run smoothly for 3 monitoring years to date. In the 2014-2015 and 2016-2017 monitoring years, sample amount coincided with that obtained from the National Influenza Surveillance program. In the 2015-2016 monitoring year, due to the strict prevention and control measures, an influenza epidemic peak was avoided in monitoring units, and the monitoring data did not coincide with that of the National Influenza Surveillance program. Several problems, including insufficient attention, unreasonable administrative intervention or subordination relationships, and the necessity of detection in monitoring sites were still observed. A theater IMP was established rationally and played a deserved role in the prevention and control of influenza. However, several problems remain to be solved.

Outbreaks of Ebola virus disease in Africa: the beginnings of a tragic saga.

PubMed

Chippaux, Jean-Philippe

2014-01-01

The tremendous outbreak of Ebola virus disease occurring in West Africa since the end of 2013 surprises by its remoteness from previous epidemics and dramatic extent. This review aims to describe the 27 manifestations of Ebola virus that arose after its discovery in 1976. It provides an update on research on the ecology of Ebola viruses, modes of contamination and human transmission of the disease that are mainly linked to close contact with an infected animal or a patient suffering from the disease. The recommendations to contain the epidemic and challenges to achieve it are reminded.

"War dysentery" and the limitations of German military hygiene during World War I.

PubMed

Linton, Derek S

2010-01-01

This article examines major epidemics of bacillary dysentery in the German army as well as among civilians in eastern Europe and in Germany during World War I. These epidemics were all the more surprising in light of prewar advances in understanding the disease and limiting dysentery outbreaks. Three major reasons are adduced for the incapacity of German military hygienists to prevent wartime epidemics. First was the difficulty of bacteriological testing at the front, especially early in the war, with negative consequences for diagnosis, therapy, and disease control. Second was inadequate hygiene including major shortcomings in latrine cleanliness and attempts to grapple with the "fly plague." Third was the lack of a Pasteur-type vaccine until late in the war. Susceptibility to dysentery was also heightened by war-related nutritional deficiencies. Taking off from an article by the English medical historian Roger Cooter, this article shows that the concept of "war dysentery" was socially constructed and served a variety of professional interests but at the same time takes issue with Cooter's arguments against linking "war" and "epidemics" pathogenetically.

Eradication of typhus exanthematicus in Bosnia and Herzegovina.

PubMed

Puvacić, Zlatko; Beslagić, Edina; Zvizdić, Sukrija; Puvacić, Sandra; Ravlija, Jelena; Hamzić, Sadeta

2006-02-01

Typhus exanthematicus in Bosnia and Herzegovina held in endemic areas from which especially quickly began spread after 1945. That year, in 1945, one hundred epidemics of typhus fever appeared, with the highest incidence rate in Europe of 215.04 per 1,000. Directions of unique program in the world were to eradicate lice of the body, but also establish monitoring of the recidivism, Brill-Zinsser disease. Since 1971, typhus exanthematicus (classical typhus) hasn't appeared in Bosnia and Herzegovina, so epidemic typhus can considered as an eradicated communicable disease.

Diversity of methicillin-resistant Staphylococcus aureus CC22-MRSA-IV from Saudi Arabia and the Gulf region.

PubMed

Senok, Abiola; Somily, Ali; Raji, Adeola; Gawlik, Darius; Al-Shahrani, Fatimah; Baqi, Shehla; Boswihi, Samar; Skakni, Leila; Udo, Edet E; Weber, Stefan; Ehricht, Ralf; Monecke, Stefan

2016-10-01

CC22-MRSA-IV, UK-EMRSA-15/Barnim EMRSA, is a common and pandemic strain of methicillin-resistant Staphylococcus aureus (MRSA) that has been found mainly in Western Europe, but also in other parts of the world including some Gulf countries. One suspected case of an infection with this strain in a patient who was admitted to the surgical unit in Riyadh, Kingdom of Saudi Arabia (KSA) was investigated in order to check whether this strain has reached KSA. Besides the index isolate, 46 additional isolates of CC22-MRSA-IV from patients from KSA, Abu Dhabi, Kuwait, and Germany (patients with a history of travel in the Middle East), were characterized by microarray hybridization. The study revealed a regional presence of as many as six distinct 'strains' of CC22-MRSA-IV that could be distinguished based on carriage of SCCmec IV subtypes and virulence factors. No true UK-EMRSA-15/Barnim EMRSA was identified in Riyadh; all suspected isolates from Riyadh were assigned to other, albeit related strains. However, this strain was identified in Abu Dhabi and Kuwait. CC22-MRSA-IV from KSA could be linked to other epidemic strains from the Middle East and possibly India, rather than to the Western European UK-EMRSA-15/Barnim EMRSA. High-resolution typing methods, including SCCmec subtyping, might help to differentiate related epidemic strains and to monitor routes of transmission. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

3 CFR 8746 - Proclamation 8746 of November 1, 2011. National Diabetes Month, 2011

Code of Federal Regulations, 2012 CFR

2012-01-01

... diabetes among our Nation’s children is linked to the rise of childhood obesity. To end the epidemic of childhood obesity within a generation, First Lady Michelle Obama’s Let’s Move! initiative is inspiring...

Bayesian hierarchical Poisson models with a hidden Markov structure for the detection of influenza epidemic outbreaks.

PubMed

Conesa, D; Martínez-Beneito, M A; Amorós, R; López-Quílez, A

2015-04-01

Considerable effort has been devoted to the development of statistical algorithms for the automated monitoring of influenza surveillance data. In this article, we introduce a framework of models for the early detection of the onset of an influenza epidemic which is applicable to different kinds of surveillance data. In particular, the process of the observed cases is modelled via a Bayesian Hierarchical Poisson model in which the intensity parameter is a function of the incidence rate. The key point is to consider this incidence rate as a normal distribution in which both parameters (mean and variance) are modelled differently, depending on whether the system is in an epidemic or non-epidemic phase. To do so, we propose a hidden Markov model in which the transition between both phases is modelled as a function of the epidemic state of the previous week. Different options for modelling the rates are described, including the option of modelling the mean at each phase as autoregressive processes of order 0, 1 or 2. Bayesian inference is carried out to provide the probability of being in an epidemic state at any given moment. The methodology is applied to various influenza data sets. The results indicate that our methods outperform previous approaches in terms of sensitivity, specificity and timeliness. © The Author(s) 2011 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Tobacco in the Arab world: old and new epidemics amidst policy paralysis

PubMed Central

Maziak, Wasim; Nakkash, Rima; Bahelah, Raed; Husseini, Abdullatif; Fanous, Nadia; Eissenberg, Thomas

2014-01-01

The Arab world is comprised of 22 countries with a combined population of ∼360 million. The region is still at the initial stages of the tobacco epidemic, where it is expected to witness an increase in smoking levels and mounting tobacco-related morbidity and mortality in the future. Still, the bleak outlook of the tobacco epidemic in the Arab world continues to be faced with complacency in the form of underutilization of surveillance systems to monitor the tobacco epidemic and prioritize action, and failure to implement and enforce effective policies to curb the tobacco epidemic. Understandably, the focus on the Arab world carries the risk of trying to generalize to such a diverse group of countries at different level of economic and political development. Yet, tobacco control in the Arab world faces some shared patterns and common challenges that need to be addressed to advance its cause in this region. In addition, forces that promote tobacco use, such as the tobacco industry, and trends in tobacco use, such as the emerging waterpipe epidemic tend to coalesce around some shared cultural and socio-political features of this region. Generally, available data from Arab countries point at three major trends in the tobacco epidemic: (1) high prevalence of cigarette smoking among Arab men compared with women; (2) the re-emergence of waterpipe (also known as hookah, narghile, shisha, arghile) smoking as a major tobacco use method, especially among youth and (3) the failure of policy to provide an adequate response to the tobacco epidemic. In this review, we will discuss these trends, factors contributing to them, and the way forward for tobacco control in this unstable region. PMID:23958628

Tobacco in the Arab world: old and new epidemics amidst policy paralysis.

PubMed

Maziak, Wasim; Nakkash, Rima; Bahelah, Raed; Husseini, Abdullatif; Fanous, Nadia; Eissenberg, Thomas

2014-09-01

The Arab world is comprised of 22 countries with a combined population of ∼360 million. The region is still at the initial stages of the tobacco epidemic, where it is expected to witness an increase in smoking levels and mounting tobacco-related morbidity and mortality in the future. Still, the bleak outlook of the tobacco epidemic in the Arab world continues to be faced with complacency in the form of underutilization of surveillance systems to monitor the tobacco epidemic and prioritize action, and failure to implement and enforce effective policies to curb the tobacco epidemic. Understandably, the focus on the Arab world carries the risk of trying to generalize to such a diverse group of countries at different level of economic and political development. Yet, tobacco control in the Arab world faces some shared patterns and common challenges that need to be addressed to advance its cause in this region. In addition, forces that promote tobacco use, such as the tobacco industry, and trends in tobacco use, such as the emerging waterpipe epidemic tend to coalesce around some shared cultural and socio-political features of this region. Generally, available data from Arab countries point at three major trends in the tobacco epidemic: (1) high prevalence of cigarette smoking among Arab men compared with women; (2) the re-emergence of waterpipe (also known as hookah, narghile, shisha, arghile) smoking as a major tobacco use method, especially among youth and (3) the failure of policy to provide an adequate response to the tobacco epidemic. In this review, we will discuss these trends, factors contributing to them, and the way forward for tobacco control in this unstable region. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2013; all rights reserved.

Suppressing epidemics with a limited amount of immunization units.

PubMed

Schneider, Christian M; Mihaljev, Tamara; Havlin, Shlomo; Herrmann, Hans J

2011-12-01

The way diseases spread through schools, epidemics through countries, and viruses through the internet is crucial in determining their risk. Although each of these threats has its own characteristics, its underlying network determines the spreading. To restrain the spreading, a widely used approach is the fragmentation of these networks through immunization, so that epidemics cannot spread. Here we develop an immunization approach based on optimizing the susceptible size, which outperforms the best known strategy based on immunizing the highest-betweenness links or nodes. We find that the network's vulnerability can be significantly reduced, demonstrating this on three different real networks: the global flight network, a school friendship network, and the internet. In all cases, we find that not only is the average infection probability significantly suppressed, but also for the most relevant case of a small and limited number of immunization units the infection probability can be reduced by up to 55%.

Labour migration and HIV epidemics in Africa.

PubMed

Decosas, J

1998-10-01

The profile of HIV infection in West Africa is linked to the regional pattern of labor migration. Areas of high HIV prevalence correspond closely to the destination and recruitment points of migrant workers. This correlation suggests that mobile populations have characteristics that make them more susceptible to HIV epidemics. The most plausible explanatory variables for the association of migration and epidemic HIV are deprived living conditions, disruption of social support, and dysfunctional social organization. Migration creates chronic gender imbalances in the reproductive age group. The general excess of females in the recruitment areas and excess of males at the destination erodes traditional community norms of behavior. Health service provision, including health education and condom marketing, does not address these key social factors. Small improvements in the physical and social environment of migrants and their communities of origin may result in greater benefits than any targeted service provision.

Multi-granularity immunization strategy based on SIRS model in scale-free network

NASA Astrophysics Data System (ADS)

Nian, Fuzhong; Wang, Ke

2015-04-01

In this paper, a new immunization strategy was established to prevent the epidemic spreading based on the principle of "Multi-granularity" and "Pre-warning Mechanism", which send different pre-warning signal with the risk rank of the susceptible node to be infected. The pre-warning means there is a higher risk that the susceptible node is more likely to be infected. The multi-granularity means the susceptible node is linked with multi-infected nodes. In our model, the effect of the different situation of the multi-granularity immunizations is compared and different spreading rates are adopted to describe the epidemic behavior of nodes. In addition the threshold value of epidemic outbreak is investigated, which makes the result more convincing. The theoretical analysis and the simulations indicate that the proposed immunization strategy is effective and it is also economic and feasible.

Short-Term Dynamic and Local Epidemiological Trends in the South American HIV-1B Epidemic.

PubMed

Junqueira, Dennis Maletich; de Medeiros, Rubia Marília; Gräf, Tiago; Almeida, Sabrina Esteves de Matos

2016-01-01

The human displacement and sexual behavior are the main factors driving the HIV-1 pandemic to the current profile. The intrinsic structure of the HIV transmission among different individuals has valuable importance for the understanding of the epidemic and for the public health response. The aim of this study was to characterize the HIV-1 subtype B (HIV-1B) epidemic in South America through the identification of transmission links and infer trends about geographical patterns and median time of transmission between individuals. Sequences of the protease and reverse transcriptase coding regions from 4,810 individuals were selected from GenBank. Maximum likelihood phylogenies were inferred and submitted to ClusterPicker to identify transmission links. Bayesian analyses were applied only for clusters including ≥5 dated samples in order to estimate the median maximum inter-transmission interval. This study analyzed sequences sampled from 12 South American countries, from individuals of different exposure categories, under different antiretroviral profiles, and from a wide period of time (1989-2013). Continentally, Brazil, Argentina and Venezuela were revealed important sites for the spread of HIV-1B among countries inside South America. Of note, from all the clusters identified about 70% of the HIV-1B infections are primarily occurring among individuals living in the same geographic region. In addition, these transmissions seem to occur early after the infection of an individual, taking in average 2.39 years (95% CI 1.48-3.30) to succeed. Homosexual/Bisexual individuals transmit the virus as quickly as almost half time of that estimated for the general population sampled here. Public health services can be broadly benefitted from this kind of information whether to focus on specific programs of response to the epidemic whether as guiding of prevention campaigns to specific risk groups.

Effects of dust storm events on weekly clinic visits related to pulmonary tuberculosis disease in Minqin, China

NASA Astrophysics Data System (ADS)

Wang, Yun; Wang, Ruoyu; Ming, Jing; Liu, Guangxiu; Chen, Tuo; Liu, Xinfeng; Liu, Haixia; Zhen, Yunhe; Cheng, Guodong

2016-02-01

Pulmonary tuberculosis (PTB) is a major public health problem in China. Minqin, a Northwest county of China, has a very high number of annual PTB clinic visits and it is also known for its severe dust storms. The epidemic usually begins in February and ends in July, while the dust storms mainly occur throughout spring and early summer, thereby suggesting that there might be a close link between the causative agent of PTB and dust storms. We investigated the general impact of dust storms on PTB over time by analyzing the variation in weekly clinic visits in Minqin during 2005-2012. We used the Mann-Whitney-Pettitt test and a regression model to determine the seasonal periodicity of PTB and dust storms in a time series, as well as assessing the relationships between meteorological variables and weekly PTB clinic visits. After comparing the number of weekly PTB cases in Gansu province with dust storm events, we detected a clear link between the population dynamics of PTB and climate events, i.e., the onset of epidemics and dust storms (defined by an atmospheric index) occurred in almost the same mean week. Thus, particulate matter might be the cause of PTB outbreaks on dust storm days. It is highly likely that the significant decline in annual clinic visits was closely associated with improvements in the local environment, which prevented desertification and decreased the frequency of dust storm events. To the best of our knowledge, this is the first population-based study to provide clear evidence that a PTB epidemic was affected by dust storms in China, which may give insights into the association between this environmental problem and the evolution of epidemic disease.

Retinopathy of prematurity-induced blindness: birth weight-specific survival and the new epidemic.

PubMed

Gibson, D L; Sheps, S B; Uh, S H; Schechter, M T; McCormick, A Q

1990-09-01

A recent population-based study in the Canadian province of British Columbia showed that, since the mid-1960s, there has been a significant increase in the incidence of retinopathy of prematurity-induced blindness in infants weighing 750 to 999 g at birth. To determine the impact of changing birth weight-specific survival on this new epidemic, all infants born in the province in the period 1952 through 1986 and known to the British Columbia Health Surveillance Registry as having retinopathy of prematurity-induced blindness were identified. In addition, the birth registration records for the 1,299 740 infants born in British Columbia in the same period and the death records of the 22,940 British Columbia-born infants who died in the province before the end of their first year of life were linked using a combination of probabilistic and manual record linkage techniques. These linked records and the records from the Health Surveillance Registry were used to calculate birth weight-specific incidence rates of retinopathy of prematurity-induced blindness in liveborn infants and first-year-of-life survivors. The rates, in 5-year intervals, showed that, in both liveborn infants and first-year survivors, the highest birth weight-specific rates occurred during the first epidemic of retinopathy of prematurity, which ended in British Columbia in 1954. Since the mid-to late-1960s, the incidence of retinopathy of prematurity-induced blindness in liveborn infants weighing less than 1000 g increased steadily whereas in infants weighting 1000 to 1499 g, incidence decreased slightly since the original epidemic ended. However, the experience of first-year-of-life survivors is substantially different.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular epidemiology of HIV-1 infection in Europe: An overview.

PubMed

Beloukas, Apostolos; Psarris, Alexandros; Giannelou, Polina; Kostaki, Evangelia; Hatzakis, Angelos; Paraskevis, Dimitrios

2016-12-01

Human Immunodeficiency Virus type 1 (HIV-1) is characterised by vast genetic diversity. Globally circulating HIV-1 viruses are classified into distinct phylogenetic strains (subtypes, sub-subtypes) and several recombinant forms. Here we describe the characteristics and evolution of European HIV-1 epidemic over time through a review of published literature and updated queries of existing HIV-1 sequence databases. HIV-1 in Western and Central Europe was introduced in the early-1980s in the form of subtype B, which is still the predominant clade. However, in Eastern Europe (Former Soviet Union (FSU) countries and Russia) the predominant strain, introduced into Ukraine in the mid-1990s, is subtype A (A FSU ) with transmission mostly occurring in People Who Inject Drugs (PWID). In recent years, the epidemic is evolving towards a complex tapestry with an increase in the prevalence of non-B subtypes and recombinants in Western and Central Europe. Non-B epidemics are mainly associated with immigrants, heterosexuals and females but more recently, non-B clades have also spread amongst groups where non-B strains were previously absent - non-immigrant European populations and amongst men having sex with men (MSM). In some countries, non-B clades have spread amongst the native population, for example subtype G in Portugal and subtype A in Greece, Albania and Cyprus. Romania provides a unique case where sub-subtype F1 has predominated throughout the epidemic. In contrast, HIV-1 epidemic in FSU countries remains more homogeneous with A FSU clade predominating in all countries. The differences between the evolution of the Western epidemic and the Eastern epidemic may be attributable to differences in transmission risk behaviours, lifestyle and the patterns of human mobility. The study of HIV-1 epidemic diversity provides a useful tool by which we can understand the history of the pandemic in addition to allowing us to monitor the spread and growth of the epidemic over time. Copyright © 2016 Elsevier B.V. All rights reserved.

Estimating Influenza Outbreaks Using Both Search Engine Query Data and Social Media Data in South Korea.

PubMed

Woo, Hyekyung; Cho, Youngtae; Shim, Eunyoung; Lee, Jong-Koo; Lee, Chang-Gun; Kim, Seong Hwan

2016-07-04

As suggested as early as in 2006, logs of queries submitted to search engines seeking information could be a source for detection of emerging influenza epidemics if changes in the volume of search queries are monitored (infodemiology). However, selecting queries that are most likely to be associated with influenza epidemics is a particular challenge when it comes to generating better predictions. In this study, we describe a methodological extension for detecting influenza outbreaks using search query data; we provide a new approach for query selection through the exploration of contextual information gleaned from social media data. Additionally, we evaluate whether it is possible to use these queries for monitoring and predicting influenza epidemics in South Korea. Our study was based on freely available weekly influenza incidence data and query data originating from the search engine on the Korean website Daum between April 3, 2011 and April 5, 2014. To select queries related to influenza epidemics, several approaches were applied: (1) exploring influenza-related words in social media data, (2) identifying the chief concerns related to influenza, and (3) using Web query recommendations. Optimal feature selection by least absolute shrinkage and selection operator (Lasso) and support vector machine for regression (SVR) were used to construct a model predicting influenza epidemics. In total, 146 queries related to influenza were generated through our initial query selection approach. A considerable proportion of optimal features for final models were derived from queries with reference to the social media data. The SVR model performed well: the prediction values were highly correlated with the recent observed influenza-like illness (r=.956; P<.001) and virological incidence rate (r=.963; P<.001). These results demonstrate the feasibility of using search queries to enhance influenza surveillance in South Korea. In addition, an approach for query selection using social media data seems ideal for supporting influenza surveillance based on search query data.

Estimating Influenza Outbreaks Using Both Search Engine Query Data and Social Media Data in South Korea

PubMed Central

Woo, Hyekyung; Shim, Eunyoung; Lee, Jong-Koo; Lee, Chang-Gun; Kim, Seong Hwan

2016-01-01

Background As suggested as early as in 2006, logs of queries submitted to search engines seeking information could be a source for detection of emerging influenza epidemics if changes in the volume of search queries are monitored (infodemiology). However, selecting queries that are most likely to be associated with influenza epidemics is a particular challenge when it comes to generating better predictions. Objective In this study, we describe a methodological extension for detecting influenza outbreaks using search query data; we provide a new approach for query selection through the exploration of contextual information gleaned from social media data. Additionally, we evaluate whether it is possible to use these queries for monitoring and predicting influenza epidemics in South Korea. Methods Our study was based on freely available weekly influenza incidence data and query data originating from the search engine on the Korean website Daum between April 3, 2011 and April 5, 2014. To select queries related to influenza epidemics, several approaches were applied: (1) exploring influenza-related words in social media data, (2) identifying the chief concerns related to influenza, and (3) using Web query recommendations. Optimal feature selection by least absolute shrinkage and selection operator (Lasso) and support vector machine for regression (SVR) were used to construct a model predicting influenza epidemics. Results In total, 146 queries related to influenza were generated through our initial query selection approach. A considerable proportion of optimal features for final models were derived from queries with reference to the social media data. The SVR model performed well: the prediction values were highly correlated with the recent observed influenza-like illness (r=.956; P<.001) and virological incidence rate (r=.963; P<.001). Conclusions These results demonstrate the feasibility of using search queries to enhance influenza surveillance in South Korea. In addition, an approach for query selection using social media data seems ideal for supporting influenza surveillance based on search query data. PMID:27377323

Identifying highly connected counties compensates for resource limitations when evaluating national spread of an invasive pathogen.

PubMed

Sutrave, Sweta; Scoglio, Caterina; Isard, Scott A; Hutchinson, J M Shawn; Garrett, Karen A

2012-01-01

Surveying invasive species can be highly resource intensive, yet near-real-time evaluations of invasion progress are important resources for management planning. In the case of the soybean rust invasion of the United States, a linked monitoring, prediction, and communication network saved U.S. soybean growers approximately $200 M/yr. Modeling of future movement of the pathogen (Phakopsora pachyrhizi) was based on data about current disease locations from an extensive network of sentinel plots. We developed a dynamic network model for U.S. soybean rust epidemics, with counties as nodes and link weights a function of host hectarage and wind speed and direction. We used the network model to compare four strategies for selecting an optimal subset of sentinel plots, listed here in order of increasing performance: random selection, zonal selection (based on more heavily weighting regions nearer the south, where the pathogen overwinters), frequency-based selection (based on how frequently the county had been infected in the past), and frequency-based selection weighted by the node strength of the sentinel plot in the network model. When dynamic network properties such as node strength are characterized for invasive species, this information can be used to reduce the resources necessary to survey and predict invasion progress.

On the Use of Human Mobility Proxies for Modeling Epidemics

PubMed Central

Tizzoni, Michele; Bajardi, Paolo; Decuyper, Adeline; Kon Kam King, Guillaume; Schneider, Christian M.; Blondel, Vincent; Smoreda, Zbigniew; González, Marta C.; Colizza, Vittoria

2014-01-01

Human mobility is a key component of large-scale spatial-transmission models of infectious diseases. Correctly modeling and quantifying human mobility is critical for improving epidemic control, but may be hindered by data incompleteness or unavailability. Here we explore the opportunity of using proxies for individual mobility to describe commuting flows and predict the diffusion of an influenza-like-illness epidemic. We consider three European countries and the corresponding commuting networks at different resolution scales, obtained from (i) official census surveys, (ii) proxy mobility data extracted from mobile phone call records, and (iii) the radiation model calibrated with census data. Metapopulation models defined on these countries and integrating the different mobility layers are compared in terms of epidemic observables. We show that commuting networks from mobile phone data capture the empirical commuting patterns well, accounting for more than 87% of the total fluxes. The distributions of commuting fluxes per link from mobile phones and census sources are similar and highly correlated, however a systematic overestimation of commuting traffic in the mobile phone data is observed. This leads to epidemics that spread faster than on census commuting networks, once the mobile phone commuting network is considered in the epidemic model, however preserving to a high degree the order of infection of newly affected locations. Proxies' calibration affects the arrival times' agreement across different models, and the observed topological and traffic discrepancies among mobility sources alter the resulting epidemic invasion patterns. Results also suggest that proxies perform differently in approximating commuting patterns for disease spread at different resolution scales, with the radiation model showing higher accuracy than mobile phone data when the seed is central in the network, the opposite being observed for peripheral locations. Proxies should therefore be chosen in light of the desired accuracy for the epidemic situation under study. PMID:25010676

Social crisis and epidemic disease in the famines of nineteenth-century India.

PubMed

Arnold, D

1993-12-01

The onset of famine in nineteenth-century India resulted in the breakdown of normal social relations and produced a series of often dysfunctional behavioural responses. Survival strategies like the use of 'famine foods' and migration in search of food and work facilitated the spread of such epidemic diseases as cholera, dysentery, malaria, and smallpox. Although many of these diseases are not normally thought of as having a synergistic relationship with malnutrition and hunger, they were linked to it (as the Madras famine of 1876-78 illustrates) through abnormal social and environmental conditions created by drought and an extreme crisis of substance.

[MPOWER--strategy for fighting the global tobacco epidemic].

PubMed

Kaleta, Dorota; Kozieł, Anna; Miśkiewicz, Paulina

2009-01-01

It is estimated that tobacco use may cause death of 5 million people in 2008, which is higher than the number of deaths attributed to tuberculosis (TB), HIV/AIDS and malaria taken together. By 2030, the number of deaths related to the tobacco epidemic could exceed annually even 8 million. Despite many difficulties, a growing number of countries undertake intensive actions aimed at tobacco control. The objective of this paper was to discuss the major objectives of the MPOWER Report issued by the World Health Organization (WHO). The MPOWER package consists a set of six key and most effective strategies for fighting the global tobacco epidemic: 1) Monitoring tobacco consumption and the effectiveness of preventive measures; 2) Protect people from tobacco smoke; 3) Offer help to quit tobacco use; 4) Warn about the dangers of tobacco; 5) Enforce bans on tobacco advertising, promotion and sponsorship; and 6) Raise taxes on tobacco. It is proven that these strategies implemented in the compatible way, effectively decreases tobacco use. In addition, MPOWER comprises epidemiological data, information on implemented tobacco control measures and their efficiency. MPOWER is the only one document of a somewhat strategic nature that is a source of information on the spread of tobacco epidemic, as well as of suggestions concerning specific actions for supporting the fight against this epidemic.

Konzo and continuing cyanide intoxication from cassava in Mozambique.

PubMed

Cliff, J; Muquingue, H; Nhassico, D; Nzwalo, H; Bradbury, J H

2011-03-01

In Mozambique, epidemics of the cassava-associated paralytic disease, konzo, have been reported in association with drought or war: over 1100 cases in 1981, over 600 cases in 1992-1993, and over 100 cases in 2005. Smaller epidemics and sporadic cases have also been reported. Large epidemics have occurred at times of agricultural crisis, during the cassava harvest, when the population has been dependent on a diet of insufficiently processed bitter cassava. Konzo mostly affects women of child-bearing age and children over 2 years of age. When measured, serum or urinary thiocyanate concentrations, indicative of cyanide poisoning, have been high in konzo patients during epidemics and in succeeding years. Monitoring of urinary thiocyanate concentrations in schoolchildren in konzo areas has shown persistently high concentrations at the time of the cassava harvest. Inorganic sulphate concentrations have been low during and soon after epidemics. Programmes to prevent konzo have focused on distributing less toxic varieties of cassava and disseminating new processing methods, such as grating and the flour wetting method. Attention should be given to the wider question of agricultural development and food security in the regions of Africa where dependence on bitter cassava results in chronic cyanide intoxication and persistent and emerging konzo. Copyright © 2010 Elsevier Ltd. All rights reserved.

The breast cancer epidemic: 10 facts

PubMed Central

Schneider, A. Patrick; Zainer, Christine M.; Kubat, Christopher Kevin; Mullen, Nancy K.; Windisch, Amberly K.

2014-01-01

Breast cancer, affecting one in eight American women, is a modern epidemic. The increasing frequency of breast cancer is widely recognized. However, the wealth of compelling epidemiological data on its prevention is generally not available, and as a consequence, is largely unknown to the public. The purpose of this report is to review the epidemiological evidence of preventable causes of breast cancer. TABLE 1 Frequently used abbreviations and terms (listed alphabetically)AbbreviationsTermsABC linkAbortion–breast cancer linkCEE(s)Conjugated equine estrogen(s)CHDCoronary heart diseaseCHRTCombined hormone replacement therapyCIConfidence IntervalCOC(s)Combined oral contraceptive(s)ECEmergency contraceptionECP(s)Emergency contraception pill(s)ERTEstrogen replacement therapyFDAFood and Drug AdministrationFFTPFirst full-term pregnancyHRTHormone replacement therapyIA(s)Induced abortion(s)IARCInternational Agency for Research on CancerMPAMedroxyprogesterone acetateOC(s)Oral contraceptive(s)OROdds ratioOTCOver-the-counterPOC(s)Progestin-only contraceptive(s)RRRelative RiskWHIWomen's Health InitiativeWHOWorld Health Organization PMID:25249706

Ischaemic heart disease mortality and the business cycle in Australia.

PubMed Central

Bunn, A R

1979-01-01

Trends in Australian heart disease mortality were assessed for association with the business cycle. Correlation models of mortality and unemployment series were used to test for association. An indicator series of "national stress" was developed. The three series were analyzed in path models to quantify the links between unemployment, national stress, and heart disease. Ischemic heart disease (IHD) mortality and national stress were found to follow the business cycle. The two periods of accelerating IHD mortality coincided with economic recession. The proposed "wave hypothesis" links the trend in IHD mortality to the high unemployment of severe recession. The mortality trend describes a typical epidemic parabolic path from the Great Depression to 1975, with a smaller parabolic trend at the 1961 recession. These findings appear consistent with the hypothesis that heart disease is, to some degree, a point source epidemic arising with periods of severe economic recession. Forecasts under the hypothesis indicate a turning point in the mortality trend between 1976 and 1978. (Am J Public Health 69:772-781, 1979). PMID:453409

Opioid management of pain: the impact of the prescription opioid abuse epidemic.

PubMed

Rauenzahn, Sherri; Del Fabbro, Egidio

2014-09-01

The greater emphasis on pain control over the last decade has been accompanied by increased opioid prescriptions and an epidemic of opioid abuse. This review examines the financial, regulatory, and clinical practice impact of the epidemic, the factors contributing to its growth, and strategies that may counter this public health crisis. Despite the call for urgent practice change and the introduction of new initiatives such as electronic prescription monitoring and additional education programs for providers and patients, the evidence for improved outcomes are limited. There are also concerns that some patients may suffer from underprescribing as an unintended consequence of more stringent state and federal regulations. There is consensus that some form of universal precautions should be adopted for all patients, including those being treated for cancer-related pain, in order to better identify and manage those at risk of opioid abuse. The opioid prescription abuse epidemic has precipitated calls for increased regulation. Clinicians can improve patient care and diminish opioid abuse by identifying patient risk factors, increasing vigilance and structure for those at risk, and providing interdisciplinary care for any patients coping in a maladaptive manner.

Changing the Future of Obesity: Science, Policy and Action

PubMed Central

Gortmaker, Steven L; Swinburn, Boyd; Levy, David; Carter, Rob; Mabry, Patricia L.; Finegood, Diane; Huang, Terry; Marsh, Tim; Moodie, Marj

2011-01-01

The global obesity epidemic has been on the rise for four decades, yet sustained prevention efforts have barely begun. An emerging science using quantitative models has provided key insights into the dynamics of this epidemic, and made it possible to combine different pieces of evidence and calculate the impact of behaviors, interventions and policies at multiple levels – from person to population. Forecasts indicate large effects of high levels of obesity on future population health and economic outcomes. Energy gap models have quantified the relationships of changes in energy intake and expenditure to weight change, and documented the dominant role of increasing intake on obesity prevalence. The empirical evidence base for effective interventions is limited but growing. Several cost-effective policies are identified that governments should prioritize for implementation. Systems science provides a framework for organizing the complexity of forces driving the obesity epidemic and has important implications for policy-makers. Multiple players (including governments, international organizations, the private sector, and civil society) need to contribute complementary actions in a coordinated approach. Priority actions include policies to improve the food and built environments, cross-cutting actions (such as leadership, health-in-all policies, and monitoring), and much greater funding for prevention programs. Increased investment in population obesity monitoring would improve the accuracy of forecasts and evaluations. Embedding actions within existing systems in both health and non-health sectors (trade, agriculture, transport, urban planning, development) can greatly increase impact and sustainability. We call for a sustained worldwide effort to monitor, prevent and control obesity. PMID:21872752

Redressing the epidemics of opioid overdose and HIV among people who inject drugs in Central Asia: the need for a syndemic approach.

PubMed

Gilbert, Louisa; Primbetova, Sholpan; Nikitin, Danil; Hunt, Timothy; Terlikbayeva, Assel; Momenghalibaf, Azzi; Ruziev, Murodali; El-Bassel, Nabila

2013-11-01

Accumulating evidence suggests that opioid overdose and HIV infection are burgeoning intertwined epidemics among people who inject drugs (PWID) in Central Asia. To date, however, research on overdose and its associations with HIV risks among PWID in Central Asia remains virtually absent. This paper aims to provide a regional overview of the hidden epidemic of overdose and how it is linked to HIV among PWID in Central Asia, using a syndemic framework that is guided by risk environment research. We conducted a comprehensive literature search of peer-reviewed publications and gray literature on opioid overdose and its associations with HIV in five countries of Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan) as well as on policies and programs that address these co-occurring epidemics. Regional data indicate high rates of fatal and non-fatal overdose among PWID. Evidence suggests mortality rates from overdose exceed HIV/AIDS as the leading cause of death among PWID. The syndemic framework suggests multiple macro-level and micro-level environmental risk factors that drive the co-occurring epidemics of HIV and overdose. This framework identifies several interacting biological and behavioral risks that result in additive effects for HIV and overdose. The high rates of overdose and its associations with HIV underscore the need for a syndemic approach that considers overdose on parity with HIV. Such an approach should focus on the biological, behavioral and structural interactions between these epidemics to reduce social suffering, morbidity and mortality among PWID in Central Asia. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Temporal dynamics of connectivity and epidemic properties of growing networks

NASA Astrophysics Data System (ADS)

Fotouhi, Babak; Shirkoohi, Mehrdad Khani

2016-01-01

Traditional mathematical models of epidemic disease had for decades conventionally considered static structure for contacts. Recently, an upsurge of theoretical inquiry has strived towards rendering the models more realistic by incorporating the temporal aspects of networks of contacts, societal and online, that are of interest in the study of epidemics (and other similar diffusion processes). However, temporal dynamics have predominantly focused on link fluctuations and nodal activities, and less attention has been paid to the growth of the underlying network. Many real networks grow: Online networks are evidently in constant growth, and societal networks can grow due to migration flux and reproduction. The effect of network growth on the epidemic properties of networks is hitherto unknown, mainly due to the predominant focus of the network growth literature on the so-called steady state. This paper takes a step towards alleviating this gap. We analytically study the degree dynamics of a given arbitrary network that is subject to growth. We use the theoretical findings to predict the epidemic properties of the network as a function of time. We observe that the introduction of new individuals into the network can enhance or diminish its resilience against endemic outbreaks and investigate how this regime shift depends upon the connectivity of newcomers and on how they establish connections to existing nodes. Throughout, theoretical findings are corroborated with Monte Carlo simulations over synthetic and real networks. The results shed light on the effects of network growth on the future epidemic properties of networks and offers insights for devising a priori immunization strategies.

Redressing the Epidemics of Opioid Overdose and HIV among People who Inject Drugs in Central Asia: The Need for a Syndemic Approach

PubMed Central

Gilbert, Louisa; Primbetova, Sholpan; Nikitin, Danil; Hunt, Timothy; Terlikbayeva, Assel; Momenghalibaf, Azzi; Ruziev, Murodali; El-Bassel, Nabila

2013-01-01

Background Accumulating evidence suggests that opioid overdose and HIV infection are burgeoning intertwined epidemics among people who inject drugs (PWID) in Central Asia. To date, however, research on overdose and its associations with HIV risks among PWID in Central Asia remains virtually absent. This paper aims to provide a regional overview of the hidden epidemic of overdose and how it is linked to HIV among PWID in Central Asia, using a syndemic framework that is guided by risk environment research. Methods We conducted a comprehensive literature search of peer-reviewed publications and grey literature on opioid overdose and its associations with HIV in five countries of Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan) as well as on policies and programs that address these co-occurring epidemics. Results Regional data indicate high rates of fatal and non-fatal overdose among PWID. Evidence suggests mortality rates from overdose exceed HIV/AIDS as the leading cause of death among PWID. The syndemic framework suggests multiple macro-level and micro-level environmental risk factors that drive the co-occurring epidemics of HIV and overdose. This framework identifies several interacting biological and behavioral risks that result in additive effects for HIV and overdose. Conclusion The high rates of overdose and its associations with HIV underscore the need for a syndemic approach that considers overdose on parity with HIV. Such an approach should focus on the biological, behavioral and structural interactions between these epidemics to reduce social suffering, morbidity and mortality among PWID in Central Asia. PMID:23954070

Sharing Earth Observation Data When Health Management

NASA Astrophysics Data System (ADS)

Cox, E. L., Jr.

2015-12-01

While the global community is struck by pandemics and epidemics from time to time the ability to fully utilize earth observations and integrate environmental information has been limited - until recently. Mature science understanding is allowing new levels of situational awareness be possible when and if the relevant data is available and shared in a timely and useable manner. Satellite and other remote sensing tools have been used to observe, monitor, assess and predict weather and water impacts for decades. In the last few years much of this has included a focus on the ability to monitor changes on climate scales that suggest changes in quantity and quality of ecosystem resources or the "one-health" approach where trans-disciplinary links between environment, animal and vegetative health may provide indications of best ways to manage susceptibility to infectious disease or outbreaks. But the scale of impacts and availability of information from earth observing satellites, airborne platforms, health tracking systems and surveillance networks offer new integrated tools. This presentation will describe several recent events, such as Superstorm Sandy in the United States and the Ebola outbreak in Africa, where public health and health infrastructure have been exposed to environmental hazards and lessons learned from disaster response in the ability to share data have been effective in risk reduction.

Diabetes mellitus and tuberculosis: programmatic management issues

PubMed Central

Kumar, A. M. V.; Satyanarayana, S.; Lin, Y.; Zachariah, R.; Lönnroth, K.; Kapur, A.

2015-01-01

SUMMARY In August 2011, the World Health Organization and the International Union Against Tuberculosis and Lung Disease launched the Collaborative Framework for Care and Control of Tuberculosis (TB) and diabetes mellitus (DM) to guide policy makers and implementers in combatting the epidemics of both diseases. Progress has been made, and includes identifying how best to undertake bidirectional screening for both diseases, how to provide optimal treatment and care for patients with dual disease and the most suitable framework for monitoring and evaluation. Key programmatic challenges include the following: whether screening should be directed at all patients or targeted at those with high-risk characteristics; the most suitable technologies for diagnosing TB and diabetes in routine settings; the best time to screen TB patients for DM; how to provide an integrated, coordinated approach to case management; and finally, how to persuade non-communicable disease programmes to adopt a cohort analysis approach, preferably using electronic medical records, for monitoring and evaluation. The link between DM and TB and the implementation of the collaborative framework for care and control have the potential to stimulate and strengthen the scale-up of non-communicable disease care and prevention programmes, which may help in reducing not only the global burden of DM but also the global burden of TB. PMID:26162352

Rescue of endemic states in interconnected networks with adaptive coupling

NASA Astrophysics Data System (ADS)

Vazquez, F.; Serrano, M. Ángeles; Miguel, M. San

2016-07-01

We study the Susceptible-Infected-Susceptible model of epidemic spreading on two layers of networks interconnected by adaptive links, which are rewired at random to avoid contacts between infected and susceptible nodes at the interlayer. We find that the rewiring reduces the effective connectivity for the transmission of the disease between layers, and may even totally decouple the networks. Weak endemic states, in which the epidemics spreads when the two layers are interconnected but not in each layer separately, show a transition from the endemic to the healthy phase when the rewiring overcomes a threshold value that depends on the infection rate, the strength of the coupling and the mean connectivity of the networks. In the strong endemic scenario, in which the epidemics is able to spread on each separate network -and therefore on the interconnected system- the prevalence in each layer decreases when increasing the rewiring, arriving to single network values only in the limit of infinitely fast rewiring. We also find that rewiring amplifies finite-size effects, preventing the disease transmission between finite networks, as there is a non zero probability that the epidemics stays confined in only one network during its lifetime.

Rescue of endemic states in interconnected networks with adaptive coupling

PubMed Central

Vazquez, F.; Serrano, M. Ángeles; Miguel, M. San

2016-01-01

We study the Susceptible-Infected-Susceptible model of epidemic spreading on two layers of networks interconnected by adaptive links, which are rewired at random to avoid contacts between infected and susceptible nodes at the interlayer. We find that the rewiring reduces the effective connectivity for the transmission of the disease between layers, and may even totally decouple the networks. Weak endemic states, in which the epidemics spreads when the two layers are interconnected but not in each layer separately, show a transition from the endemic to the healthy phase when the rewiring overcomes a threshold value that depends on the infection rate, the strength of the coupling and the mean connectivity of the networks. In the strong endemic scenario, in which the epidemics is able to spread on each separate network –and therefore on the interconnected system– the prevalence in each layer decreases when increasing the rewiring, arriving to single network values only in the limit of infinitely fast rewiring. We also find that rewiring amplifies finite-size effects, preventing the disease transmission between finite networks, as there is a non zero probability that the epidemics stays confined in only one network during its lifetime. PMID:27380771

Simulated effect of pig-population density on epidemic size and choice of control strategy for classical swine fever epidemics in The Netherlands.

PubMed

Mangen, M-J J; Nielen, M; Burrell, A M

2002-12-18

We examined the importance of pig-population density in the area of an outbreak of classical swine fever (CSF) for the spread of the infection and the choice of control measures. A spatial, stochastic, dynamic epidemiological simulation model linked to a sector-level market-and-trade model for The Netherlands were used. Outbreaks in sparsely and densely populated areas were compared under four different control strategies and with two alternative trade assumptions. The obligatory control strategy required by current EU legislation was predicted to be enough to eradicate an epidemic starting in an area with sparse pig population. By contrast, additional control measures would be necessary if the outbreak began in an area with high pig density. The economic consequences of using preventive slaughter rather than emergency vaccination as an additional control measure depended strongly on the reactions of trading partners. Reducing the number of animal movements significantly reduced the size and length of epidemics in areas with high pig density. The phenomenon of carrier piglets was included in the model with realistic probabilities of infection by this route, but it made a negligible contribution to the spread of the infection.

Accelerating harm reduction interventions to confront the HIV epidemic in the Western Pacific and Asia: the role of WHO (WPRO)

PubMed Central

Mesquita, Fabio; Jacka, David; Ricard, Dominique; Shaw, Graham; Tieru, Han; Yifei, Hu; Poundstone, Katharine; Salva, Madeline; Fujita, Masami; Singh, Nirmal

2008-01-01

The epidemic of HIV/AIDS linked to injecting drug usage is one of the most explosive in recent years. After a historical epicentre in Europe, South and North America, at present it is clearly the main cause of dissemination of the epidemic in Eastern Europe and some key Asian countries. Recently, 10 African countries reported the spread of HIV through people who inject drugs (PWID), breaking one of the final geographical barriers to the globalization of the epidemic of HIV among and from PWID. Several countries of the Asia and Pacific Region have HIV epidemics that are driven by injecting drug usage. Harm reduction interventions have been implemented in many countries and potential barriers to implementation are being overcome. Harm reduction is no longer a marginal approach in the Region; instead, it is the core tool for responding to the HIV/AIDS epidemic among PWID. The development of a comprehensive response in the Region has been remarkable, including scaling up of needle and syringe programmes (NSPs), methadone maintenance treatment (MMT), and care, support and treatment for PWID. This development is being followed up by strong ongoing changes in policies and legislations. The main issue now is to enhance interventions to a level that can impact the epidemic. The World Health Organization (WHO) is one of the leading UN agencies promoting harm reduction. Since the establishment of the Global Programme on AIDS, WHO has been working towards an effective response to the HIV epidemic among PWID. WHO's work is organized into a number of components: establishing an evidence base; advocacy; development of normative standards, tools and guidelines; providing technical support to countries; ensuring access to essential medicines, diagnostics and commodities; and mobilizing resources. In this paper, we trace the course of development of the HIV/AIDS epidemic among and from PWID in the Western Pacific and Asia Region (WPRO) as well as WHO's role in supporting the response in some of the key countries: Cambodia, China, Lao PDR, Malaysia, the Philippines and Viet Nam. PMID:18680604

Reemergence of enterovirus 71 epidemic in northern Taiwan, 2012.

PubMed

Luo, Shu-Ting; Chiang, Pai-Shan; Chung, Wan-Yu; Chia, Min-Yuan; Tsao, Kuo-Chien; Wang, Ying-Hsiang; Lin, Tzou-Yien; Lee, Min-Shi

2015-01-01

Enterovirus 71 (EV71) belongs to picornavirus family and could be classified phylogenetically into three major genogroups (A, B and C) including 11 genotypes (A, B1-B5 and C1-C5). Since 1997, EV71 has caused large-scale of epidemics with neurological complications in Asian children. In Taiwan, nationwide EV71 epidemics with different predominant genotypes have occurred cyclically since 1998. A nationwide EV71 epidemic occurred again in 2012. We conducted genetic and antigenic characterizations of the 2012 epidemic. Chang Gung Memorial Hospital (CGMH) is a medical center in northern Taiwan. In CGMH, specimens were collected from pediatric inpatients with suspected enterovirus infections for virus isolation. Enterovirus isolates were serotyped and genotyped and sera from EV71 inpatients were collected for measuring neutralizing antibody titers. There were 10, 16 and 99 EV71 inpatients identified in 2010, 2011 and 2012, respectively. There were 82 EV71 isolates genotyped, which identified 17 genotype C4a viruses and 65 genotype B5 viruses. The genotype B5 viruses were not detected until November 2011 and caused epidemics in 2012. Interestingly, the B5-2011 viruses were genetically distinguishable from the B5 viruses causing the 2008 epidemic and are likely introduced from China or Southeastern Asia. Based on antigenic analysis, minor antigenic variations were detected among the B5-2008, B5-2011, C4a-2008 and C4a-2012 viruses but these viruses antigenically differed from genotype A. Genotype B5 and C4a viruses antigenically differ from genotype A viruses which have disappeared globally for 30 years but have been detected in China since 2008. Enterovirus surveillance should monitor genetic and antigenic variations of EV71.

Research Spotlight: Model suggests path to ending the ongoing Haitian cholera epidemic

NASA Astrophysics Data System (ADS)

Schultz, Colin

2011-05-01

Since early November 2010 a deadly cholera epidemic has been spreading across the Caribbean nation of Haiti, killing thousands of people and infecting hundreds of thousands. While infection rates are being actively monitored, health organizations have been left without a clear understanding of exactly how the disease has spread across Haiti. Cholera can spread through exposure to contaminated water, and the disease travels over long distances if an infected individual moves around the country. Using representations of these two predominant dispersion mechanisms, along with information on the size of the susceptible population, the number of infected individuals, and the aquatic concentration of the cholera-causing bacteria for more than 500 communities, Bertuzzo et al. designed a model that was able to accurately reproduce the progression of the Haitian cholera epidemic. (Geophysical Research Letters, doi:10.1029/2011GL046823, 2011)

Distribution and abundance of host-seeking Culex species at three proximate locations with different levels of West Nile virus activity

USGS Publications Warehouse

Rochlin, I.; Ginsberg, H.S.; Campbell, S.R.

2009-01-01

Culex species were monitored at three proximate sites with historically different West Nile virus (WNV) activities. The site with human WNV transmission (epidemic) had the lowest abundance of the putative bridge vectors, Culex pipiens and Cx. salinarius. The site with horse cases but not human cases (epizootic) had the highest percent composition of Cx. salinarius, whereas the site with WNV-positive birds only (enzootic) had the highest Cx. pipiens abundance and percent composition. A total of 29 WNV-positive Culex pools were collected at the enzootic site, 17 at the epidemic site, and 14 at the epizootic site. Published models of human risk using Cx. pipiens and Cx. salinarius as the primary bridge vectors did not explain WNV activity at our sites. Other variables, such as additional vector species, environmental components, and socioeconomic factors, need to be examined to explain the observed patterns of WNV epidemic activity.

Theileria parva epidemics: a case study in eastern Zambia.

PubMed

Billiouw, M; Vercruysse, J; Marcotty, T; Speybroeck, N; Chaka, G; Berkvens, D

2002-07-29

This paper presents the results of the follow-up of three sentinel herds between 1994 and 2000 during an East Coast fever (ECF) epidemic in eastern Zambia. The animals of the sentinel herds were closely monitored clinically and serologically together with detailed Rhipicephalus appendiculatus counts. Peaks of disease incidence occurred in the rainy season (December-February) and the dry months of May-July with nymph-to-adult tick transmission dominating the infection dynamics. A second wave of adult R. appendiculatus at the start of the dry season is essential for the occurrence of a full-blown epidemic while the size of the susceptible cattle population acts as a most important limiting factor. The majority of adult cattle of the sentinel herds became infected less than 2 years after the introduction of the disease. The median age at first contact for calves born towards the end of the study (1999) was about 6 months. The case-fatality ratio (including sub-clinical cases) is estimated at 60%. It is argued that part of the so-called 'natural mortality' is actually due to ECF and that ECF occurrence and mortality are systematically underestimated. The direct financial cost of the epidemic, based on loss of animals and cost of treatment only and calculated over 4 years running, is estimated at about 6 US dollars per year per animal at risk. The value of the traditional seroprevalence survey as a tool for monitoring ECF epidemiology is put in question and the prevalence of maternal antibodies in new-born calves, reflecting the immune status of the dam population, is introduced as an alternative. It is demonstrated that an efficient immunisation campaign should concentrate its efforts in the period of low adult R. appendiculatus abundance (July-October).

Social Network Sensors for Early Detection of Contagious Outbreaks

PubMed Central

Christakis, Nicholas A.; Fowler, James H.

2010-01-01

Current methods for the detection of contagious outbreaks give contemporaneous information about the course of an epidemic at best. It is known that individuals near the center of a social network are likely to be infected sooner during the course of an outbreak, on average, than those at the periphery. Unfortunately, mapping a whole network to identify central individuals who might be monitored for infection is typically very difficult. We propose an alternative strategy that does not require ascertainment of global network structure, namely, simply monitoring the friends of randomly selected individuals. Such individuals are known to be more central. To evaluate whether such a friend group could indeed provide early detection, we studied a flu outbreak at Harvard College in late 2009. We followed 744 students who were either members of a group of randomly chosen individuals or a group of their friends. Based on clinical diagnoses, the progression of the epidemic in the friend group occurred 13.9 days (95% C.I. 9.9–16.6) in advance of the randomly chosen group (i.e., the population as a whole). The friend group also showed a significant lead time (p<0.05) on day 16 of the epidemic, a full 46 days before the peak in daily incidence in the population as a whole. This sensor method could provide significant additional time to react to epidemics in small or large populations under surveillance. The amount of lead time will depend on features of the outbreak and the network at hand. The method could in principle be generalized to other biological, psychological, informational, or behavioral contagions that spread in networks. PMID:20856792

Real-time, portable genome sequencing for Ebola surveillance.

PubMed

Quick, Joshua; Loman, Nicholas J; Duraffour, Sophie; Simpson, Jared T; Severi, Ettore; Cowley, Lauren; Bore, Joseph Akoi; Koundouno, Raymond; Dudas, Gytis; Mikhail, Amy; Ouédraogo, Nobila; Afrough, Babak; Bah, Amadou; Baum, Jonathan Hj; Becker-Ziaja, Beate; Boettcher, Jan-Peter; Cabeza-Cabrerizo, Mar; Camino-Sanchez, Alvaro; Carter, Lisa L; Doerrbecker, Juiliane; Enkirch, Theresa; Dorival, Isabel Graciela García; Hetzelt, Nicole; Hinzmann, Julia; Holm, Tobias; Kafetzopoulou, Liana Eleni; Koropogui, Michel; Kosgey, Abigail; Kuisma, Eeva; Logue, Christopher H; Mazzarelli, Antonio; Meisel, Sarah; Mertens, Marc; Michel, Janine; Ngabo, Didier; Nitzsche, Katja; Pallash, Elisa; Patrono, Livia Victoria; Portmann, Jasmine; Repits, Johanna Gabriella; Rickett, Natasha Yasmin; Sachse, Andrea; Singethan, Katrin; Vitoriano, Inês; Yemanaberhan, Rahel L; Zekeng, Elsa G; Trina, Racine; Bello, Alexander; Sall, Amadou Alpha; Faye, Ousmane; Faye, Oumar; Magassouba, N'Faly; Williams, Cecelia V; Amburgey, Victoria; Winona, Linda; Davis, Emily; Gerlach, Jon; Washington, Franck; Monteil, Vanessa; Jourdain, Marine; Bererd, Marion; Camara, Alimou; Somlare, Hermann; Camara, Abdoulaye; Gerard, Marianne; Bado, Guillaume; Baillet, Bernard; Delaune, Déborah; Nebie, Koumpingnin Yacouba; Diarra, Abdoulaye; Savane, Yacouba; Pallawo, Raymond Bernard; Gutierrez, Giovanna Jaramillo; Milhano, Natacha; Roger, Isabelle; Williams, Christopher J; Yattara, Facinet; Lewandowski, Kuiama; Taylor, Jamie; Rachwal, Philip; Turner, Daniel; Pollakis, Georgios; Hiscox, Julian A; Matthews, David A; O'Shea, Matthew K; Johnston, Andrew McD; Wilson, Duncan; Hutley, Emma; Smit, Erasmus; Di Caro, Antonino; Woelfel, Roman; Stoecker, Kilian; Fleischmann, Erna; Gabriel, Martin; Weller, Simon A; Koivogui, Lamine; Diallo, Boubacar; Keita, Sakoba; Rambaut, Andrew; Formenty, Pierre; Gunther, Stephan; Carroll, Miles W

2016-02-11

The Ebola virus disease epidemic in West Africa is the largest on record, responsible for over 28,599 cases and more than 11,299 deaths. Genome sequencing in viral outbreaks is desirable to characterize the infectious agent and determine its evolutionary rate. Genome sequencing also allows the identification of signatures of host adaptation, identification and monitoring of diagnostic targets, and characterization of responses to vaccines and treatments. The Ebola virus (EBOV) genome substitution rate in the Makona strain has been estimated at between 0.87 × 10(-3) and 1.42 × 10(-3) mutations per site per year. This is equivalent to 16-27 mutations in each genome, meaning that sequences diverge rapidly enough to identify distinct sub-lineages during a prolonged epidemic. Genome sequencing provides a high-resolution view of pathogen evolution and is increasingly sought after for outbreak surveillance. Sequence data may be used to guide control measures, but only if the results are generated quickly enough to inform interventions. Genomic surveillance during the epidemic has been sporadic owing to a lack of local sequencing capacity coupled with practical difficulties transporting samples to remote sequencing facilities. To address this problem, here we devise a genomic surveillance system that utilizes a novel nanopore DNA sequencing instrument. In April 2015 this system was transported in standard airline luggage to Guinea and used for real-time genomic surveillance of the ongoing epidemic. We present sequence data and analysis of 142 EBOV samples collected during the period March to October 2015. We were able to generate results less than 24 h after receiving an Ebola-positive sample, with the sequencing process taking as little as 15-60 min. We show that real-time genomic surveillance is possible in resource-limited settings and can be established rapidly to monitor outbreaks.

Integrating Remote Sensing and Disease Surveillance to Forecast Malaria Epidemics

NASA Astrophysics Data System (ADS)

Wimberly, M. C.; Beyane, B.; DeVos, M.; Liu, Y.; Merkord, C. L.; Mihretie, A.

2015-12-01

Advance information about the timing and locations of malaria epidemics can facilitate the targeting of resources for prevention and emergency response. Early detection methods can detect incipient outbreaks by identifying deviations from expected seasonal patterns, whereas early warning approaches typically forecast future malaria risk based on lagged responses to meteorological factors. A critical limiting factor for implementing either of these approaches is the need for timely and consistent acquisition, processing and analysis of both environmental and epidemiological data. To address this need, we have developed EPIDEMIA - an integrated system for surveillance and forecasting of malaria epidemics. The EPIDEMIA system includes a public health interface for uploading and querying weekly surveillance reports as well as algorithms for automatically validating incoming data and updating the epidemiological surveillance database. The newly released EASTWeb 2.0 software application automatically downloads, processes, and summaries remotely-sensed environmental data from multiple earth science data archives. EASTWeb was implemented as a component of the EPIDEMIA system, which combines the environmental monitoring data and epidemiological surveillance data into a unified database that supports both early detection and early warning models. Dynamic linear models implemented with Kalman filtering were used to carry out forecasting and model updating. Preliminary forecasts have been disseminated to public health partners in the Amhara Region of Ethiopia and will be validated and refined as the EPIDEMIA system ingests new data. In addition to continued model development and testing, future work will involve updating the public health interface to provide a broader suite of outbreak alerts and data visualization tools that are useful to our public health partners. The EPIDEMIA system demonstrates a feasible approach to synthesizing the information from epidemiological surveillance systems and remotely-sensed environmental monitoring systems to improve malaria epidemic detection and forecasting.

A double epidemic model for the SARS propagation

PubMed Central

Ng, Tuen Wai; Turinici, Gabriel; Danchin, Antoine

2003-01-01

Background An epidemic of a Severe Acute Respiratory Syndrome (SARS) caused by a new coronavirus has spread from the Guangdong province to the rest of China and to the world, with a puzzling contagion behavior. It is important both for predicting the future of the present outbreak and for implementing effective prophylactic measures, to identify the causes of this behavior. Results In this report, we show first that the standard Susceptible-Infected-Removed (SIR) model cannot account for the patterns observed in various regions where the disease spread. We develop a model involving two superimposed epidemics to study the recent spread of the SARS in Hong Kong and in the region. We explore the situation where these epidemics may be caused either by a virus and one or several mutants that changed its tropism, or by two unrelated viruses. This has important consequences for the future: the innocuous epidemic might still be there and generate, from time to time, variants that would have properties similar to those of SARS. Conclusion We find that, in order to reconcile the existing data and the spread of the disease, it is convenient to suggest that a first milder outbreak protected against the SARS. Regions that had not seen the first epidemic, or that were affected simultaneously with the SARS suffered much more, with a very high percentage of persons affected. We also find regions where the data appear to be inconsistent, suggesting that they are incomplete or do not reflect an appropriate identification of SARS patients. Finally, we could, within the framework of the model, fix limits to the future development of the epidemic, allowing us to identify landmarks that may be useful to set up a monitoring system to follow the evolution of the epidemic. The model also suggests that there might exist a SARS precursor in a large reservoir, prompting for implementation of precautionary measures when the weather cools down. PMID:12964944

Epidemic of Febrile Disease in Berbera, Somalia

DTIC Science & Technology

1993-10-01

situated on the Gulf all negative by Widal tests. In July 1989, of Aden, adjacent to the Indian Ocean , is a a U.S. Navy team administered a coastal town...A. (1976): Microplate enzyme linked immunosorbent assay antibody immunoassays for the immunodiagnosis response to C. burnetii in experimentally of

Does obesity increase susceptibility to ozone? Respiratory, behavioral, and metabolic assessments in Brown Norway rats

EPA Science Inventory

There may be a link between obesity and susceptibility to the respiratory, cardiovascular, and other health effects of air pollutants. Furthermore, it has been proposed that some air pollutants are obesogenic and may contribute to obesity. In view of the epidemic growth of obesit...

Clinical Features of Human Immunodeficiency Virus–Infected Patients Presenting with Cholera in Port-au-Prince, Haiti

PubMed Central

Sévère, Karine; Anglade, Stravinsky B.; Bertil, Claudin; Duncan, Aynsley; Joseph, Patrice; Deroncenay, Alexandra; Mabou, Marie M.; Ocheretina, Oksana; Reif, Lindsey; Seo, Grace; Pape, Jean W.; Fitzgerald, Daniel W.

2016-01-01

Human immunodeficiency virus (HIV) infection has been postulated to alter the natural history of cholera, including increased susceptibility to infection, severity of illness, and chronic carriage of Vibrio cholerae. Haiti has a generalized HIV epidemic with an adult HIV prevalence of 1.9% and recently suffered a cholera epidemic. We conducted a prospective study at the cholera treatment center (CTC) of GHESKIO in Haiti to characterize the coinfection. Adults admitted at the CTC for acute diarrhea were invited to participate in the study. Vital signs, frequency, and volume of stools and/or vomiting were monitored, and single-dose doxycycline was administered. After counseling, participants were screened for HIV by enzyme-linked immunosorbent assay and for cholera by culture. Of 729 adults admitted to the CTC, 99 (13.6%) had HIV infection, and 457 (63%) had culture-confirmed cholera. HIV prevalence was three times higher in patients without cholera (23%, 63/272) than in those with culture-confirmed cholera (7.9%, 36/457). HIV prevalence in patients with culture-confirmed cholera (7.9%) was four times higher than the adult prevalence in Port-au-Prince (1.9%). Of the 36 HIV-infected patients with cholera, 25 (69%) had moderate/severe dehydration versus 302/421 (72%) in the HIV negative. Of 30 HIV-infected patients with weekly stool cultures performed after discharge, 29 (97%) were negative at week 1. Of 50 HIV-negative patients with weekly stool cultures, 49 (98%) were negative at week 1. In countries with endemic HIV infection, clinicians should consider screening patients presenting with suspected cholera for HIV coinfection. PMID:27549637

A decade of investments in monitoring the HIV epidemic: how far have we come? A descriptive analysis.

PubMed

Alfven, Tobias; McDougal, Lotus; Frescura, Luisa; Aran, Christian; Amler, Paul; Gill, Wayne

2014-10-16

The 2001 Declaration of Commitment (DoC) adopted by the General Assembly Special Session on HIV/AIDS (UNGASS) included a call to monitor national responses to the HIV epidemic. Since the DoC, efforts and investments have been made globally to strengthen countries' HIV monitoring and evaluation (M&E) capacity. This analysis aims to quantify HIV M&E investments, commitments, capacity, and performance during the last decade in order to assess the success and challenges of national and global HIV M&E systems. M&E spending and performance was assessed using data from UNGASS country progress reports. The National Composite Policy Index (NCPI) was used to measure government commitment, government engagement, partner/civil society engagement, and data generation, as well as to generate a composite HIV M&E System Capacity Index (MESCI) score. Analyses were restricted to low and middle income countries (LMICs) who submitted NCPI reports in 2006, 2008, and 2010 (n = 78). Government commitment to HIV M&E increased considerably between 2006 and 2008 but decreased between 2008 and 2010. The percentage of total AIDS spending allocated to HIV M&E increased from 1.1% to 1.4%, between 2007 and 2010, in high-burden LMICs. Partner/civil society engagement and data generation capacity improved between 2006 and 2010 in the high-burden countries. The HIV MESCI increased from 2006 to 2008 in high-burden countries (78% to 94%), as well as in other LMICs (70% to 77%), and remained relatively stable in 2010 (91% in high-burden countries, 79% in other LMICs). Among high-burden countries, M&E system performance increased from 52% in 2006 to 89% in 2010. The last decade has seen increased commitments and spending on HIV M&E, as well as improved M&E capacity and more available data on the HIV epidemic in both high-burden and other LMICs. However, challenges remain in the global M&E of the AIDS epidemic as we approach the 2015 Millennium Development Goal targets.

Monitoring invasive pathogens in plant nurseries for early-detection and to minimise the probability of escape.

PubMed

Alonso Chavez, Vasthi; Parnell, Stephen; VAN DEN Bosch, Frank

2016-10-21

The global increase in the movement of plant products in recent years has triggered an increase in the number of introduced plant pathogens. Plant nurseries importing material from abroad may play an important role in the introduction and spread of diseases such as ash dieback and sudden oak death which are thought to have been introduced through trade. The economic, environmental and social costs associated with the spread of invasive pathogens become considerably larger as the incidence of the pathogen increases. To control the movement of pathogens across the plant trade network it is crucial to develop monitoring programmes at key points of the network such as plant nurseries. By detecting the introduction of invasive pathogens at low incidence, the control and eradication of an epidemic is more likely to be successful. Equally, knowing the likelihood of having sold infected plants once a disease has been detected in a nursery can help designing tracing plans to control the onward spread of the disease. Here, we develop an epidemiological model to detect and track the movement of an invasive plant pathogen into and from a plant nursery. Using statistical methods, we predict the epidemic incidence given that a detection of the pathogen has occurred for the first time, considering that the epidemic has an asymptomatic period between infection and symptom development. Equally, we calculate the probability of having sold at least one infected plant during the period previous to the first disease detection. This analysis can aid stakeholder decisions to determine, when the pathogen is first discovered in a nursery, the need of tracking the disease to other points in the plant trade network in order to control the epidemic. We apply our method to high profile recent introductions including ash dieback and sudden oak death in the UK and citrus canker and Huanglongbing disease in Florida. These results provide new insight for the design of monitoring strategies at key points of the trade network. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gendered Empowerment and HIV Prevention: Policy and Programmatic Pathways to Success in the MENA Region

PubMed Central

Dworkin, Shari L.; Kambou, Sarah Degnan; Sutherland, Carla; Moalla, Khadija; Kapoor, Archana

2011-01-01

Although HIV in the Middle East and North Africa is currently characterized as a low seroprevalence epidemic, there are numerous factors that are present in the region that could prevent—or exacerbate—the epidemic. The time to invest substantially in prevention—and gender-specific prevention in particular—is now. Given that most policy makers do not make gender-specific plans as epidemics progress, our research team—which draws upon expertise from both within and outside the region—worked together to make programmatic and policy suggestions in the Middle East and North Africa region in 5 key areas: (1) gender-specific and gender transformative HIV prevention interventions; (2) access to quality education and improvements in life skills and sex education; (3) economic empowerment; (4) property rights; and (5) antiviolence. In short, this work builds upon many ongoing efforts in the region and elucidates some of the links between gendered empowerment and health outcomes around the world, particularly HIV and AIDS. PMID:19553778

Epidemic spreading in annealed directed networks: susceptible-infected-susceptible model and contact process.

PubMed

Kwon, Sungchul; Kim, Yup

2013-01-01

We investigate epidemic spreading in annealed directed scale-free networks with the in-degree (k) distribution P(in)(k)~k(-γ(in)) and the out-degree (ℓ) distribution, P(out)(ℓ)~ℓ(-γ(out)). The correlation of each node on the networks is controlled by the probability r(0≤r≤1) in two different algorithms, the so-called k and ℓ algorithms. For r=1, the k algorithm gives =, whereas the ℓ algorithm gives =<ℓ(2)>. For r=0, =<ℓ> for both algorithms. As the prototype of epidemic spreading, the susceptible-infected-susceptible model and contact process on the networks are analyzed using the heterogeneous mean-field theory and Monte Carlo simulations. The directedness of links and the correlation of the network are found to play important roles in the spreading, so that critical behaviors of both models are distinct from those on undirected scale-free networks.

Gendered empowerment and HIV prevention: policy and programmatic pathways to success in the MENA region.

PubMed

Dworkin, Shari L; Kambou, Sarah Degnan; Sutherland, Carla; Moalla, Khadija; Kapoor, Archana

2009-07-01

Although HIV in the Middle East and North Africa is currently characterized as a low seroprevalence epidemic, there are numerous factors that are present in the region that could prevent-or exacerbate-the epidemic. The time to invest substantially in prevention-and gender-specific prevention in particular-is now. Given that most policy makers do not make gender-specific plans as epidemics progress, our research team-which draws upon expertise from both within and outside the region-worked together to make programmatic and policy suggestions in the Middle East and North Africa region in 5 key areas: (1) gender-specific and gender transformative HIV prevention interventions; (2) access to quality education and improvements in life skills and sex education; (3) economic empowerment; (4) property rights; and (5) antiviolence. In short, this work builds upon many ongoing efforts in the region and elucidates some of the links between gendered empowerment and health outcomes around the world, particularly HIV and AIDS.

El Niño Helps Spread Bartonellosis Epidemics in Peru

NASA Astrophysics Data System (ADS)

Zhou, Jiayu; Lau, William K.-M.; Masuoka, Fenny M.; Andre, Richard G.; Chamberlin, Judith; Lawyer, Phillip; Laughlin, Larry W.

The consequences of climate variability on human health, especially for poor and medically underserved populations, have received much attention in recent years. Some of the most severe health hazards induced by climate variability are epidemics of vector-borne infectious diseases. Entomologic studies have shown that insect vectors that transmit diseases, such as malaria, yellow fever, dengue, etc., are sensitive to temperature, humidity wind, and rainfall patterns, and therefore, their abundance is potentially influenced by climate variability. Because of its geographical location, the climate of tropical South America is strongly influenced by El Niño. The episodic outbreaks of various diseases in this region have been linked to the El Niño cycles. Yet, according to a report of the World Health Organization [1999], early results from South American epidemiological studies, which were based on the aggregated national disease data irrespective of the regional meteorological impacts, found no consistent correlation between the El Niño effect with the epidemics of malaria and yellow fever.

Environmental and Social Change Drive the Explosive Emergence of Zika Virus in the Americas

PubMed Central

Ali, Sofia; Gugliemini, Olivia; Harber, Serena; Harrison, Alexandra; Houle, Lauren; Ivory, Javarcia; Kersten, Sierra; Khan, Rebia; Kim, Jenny; LeBoa, Chris; Nez-Whitfield, Emery; O’Marr, Jamieson; Rothenberg, Emma; Segnitz, R. Max; Sila, Stephanie; Verwillow, Anna; Vogt, Miranda; Yang, Adrienne

2017-01-01

Since Zika virus (ZIKV) was detected in Brazil in 2015, it has spread explosively across the Americas and has been linked to increased incidence of microcephaly and Guillain-Barré syndrome (GBS). In one year, it has infected over 500,000 people (suspected and confirmed cases) in 40 countries and territories in the Americas. Along with recent epidemics of dengue (DENV) and chikungunya virus (CHIKV), which are also transmitted by Aedes aegypti and Ae. albopictus mosquitoes, the emergence of ZIKV suggests an ongoing intensification of environmental and social factors that have given rise to a new regime of arbovirus transmission. Here, we review hypotheses and preliminary evidence for the environmental and social changes that have fueled the ZIKV epidemic. Potential drivers include climate variation, land use change, poverty, and human movement. Beyond the direct impact of microcephaly and GBS, the ZIKV epidemic will likely have social ramifications for women’s health and economic consequences for tourism and beyond. PMID:28182667

Environmental and Social Change Drive the Explosive Emergence of Zika Virus in the Americas.

PubMed

Ali, Sofia; Gugliemini, Olivia; Harber, Serena; Harrison, Alexandra; Houle, Lauren; Ivory, Javarcia; Kersten, Sierra; Khan, Rebia; Kim, Jenny; LeBoa, Chris; Nez-Whitfield, Emery; O'Marr, Jamieson; Rothenberg, Emma; Segnitz, R Max; Sila, Stephanie; Verwillow, Anna; Vogt, Miranda; Yang, Adrienne; Mordecai, Erin A

2017-02-01

Since Zika virus (ZIKV) was detected in Brazil in 2015, it has spread explosively across the Americas and has been linked to increased incidence of microcephaly and Guillain-Barré syndrome (GBS). In one year, it has infected over 500,000 people (suspected and confirmed cases) in 40 countries and territories in the Americas. Along with recent epidemics of dengue (DENV) and chikungunya virus (CHIKV), which are also transmitted by Aedes aegypti and Ae. albopictus mosquitoes, the emergence of ZIKV suggests an ongoing intensification of environmental and social factors that have given rise to a new regime of arbovirus transmission. Here, we review hypotheses and preliminary evidence for the environmental and social changes that have fueled the ZIKV epidemic. Potential drivers include climate variation, land use change, poverty, and human movement. Beyond the direct impact of microcephaly and GBS, the ZIKV epidemic will likely have social ramifications for women's health and economic consequences for tourism and beyond.

Suppressing epidemics on networks by exploiting observer nodes.

PubMed

Takaguchi, Taro; Hasegawa, Takehisa; Yoshida, Yuichi

2014-07-01

To control infection spreading on networks, we investigate the effect of observer nodes that recognize infection in a neighboring node and make the rest of the neighbor nodes immune. We numerically show that random placement of observer nodes works better on networks with clustering than on locally treelike networks, implying that our model is promising for realistic social networks. The efficiency of several heuristic schemes for observer placement is also examined for synthetic and empirical networks. In parallel with numerical simulations of epidemic dynamics, we also show that the effect of observer placement can be assessed by the size of the largest connected component of networks remaining after removing observer nodes and links between their neighboring nodes.

Suppressing epidemics on networks by exploiting observer nodes

NASA Astrophysics Data System (ADS)

Takaguchi, Taro; Hasegawa, Takehisa; Yoshida, Yuichi

2014-07-01

To control infection spreading on networks, we investigate the effect of observer nodes that recognize infection in a neighboring node and make the rest of the neighbor nodes immune. We numerically show that random placement of observer nodes works better on networks with clustering than on locally treelike networks, implying that our model is promising for realistic social networks. The efficiency of several heuristic schemes for observer placement is also examined for synthetic and empirical networks. In parallel with numerical simulations of epidemic dynamics, we also show that the effect of observer placement can be assessed by the size of the largest connected component of networks remaining after removing observer nodes and links between their neighboring nodes.

The Emerging HIV Epidemic on the Mexico-US Border: An International Case Study Characterizing the Role of Epidemiology in Surveillance and Response

PubMed Central

Strathdee, Steffanie A.; Magis-Rodriguez, Carlos; Mays, Vickie M.; Jimenez, Richard; Patterson, Thomas L.

2012-01-01

Purpose HIV/AIDS surveillance data are critical for monitoring epidemic trends, but can mask dynamic sub-epidemics, especially in vulnerable populations that under-utilize HIV testing. In this case study, we describe community-based epidemiologic data among injection drug users (IDU) and female sex workers (FSWs) in two northern Mexico-US Border States that identified an emerging HIV epidemic and generated a policy response. Methods We draw from quantitative and qualitative cross-sectional and prospective epidemiologic studies and behavioral intervention studies among IDUs and FSWs in Tijuana, Baja California and Ciudad Juarez, Chihuahua. Results Recognition that the HIV epidemic on Mexico’s northern border was already well established in subgroups where it had been presumed to be insignificant was met with calls for action and enhanced prevention efforts from researchers, NGOs and policy makers. Conclusions Successful policies and program outcomes included expansion of needle exchange programs, a nation-wide mobile HIV prevention program targeting marginalized populations, a successful funding bid from the Global Fund for HIV, TB and Malaria to scale up targeted HIV prevention programs and the establishment of binational training programs on prevention of HIV and substance use. We discuss how epidemiologic data informed HIV prevention policies and suggest how other countries may learn from Mexico’s experience. PMID:22626001

School closure as an influenza mitigation strategy: how variations in legal authority and plan criteria can alter the impact.

PubMed

Potter, Margaret A; Brown, Shawn T; Cooley, Phillip C; Sweeney, Patricia M; Hershey, Tina B; Gleason, Sherrianne M; Lee, Bruce Y; Keane, Christopher R; Grefenstette, John; Burke, Donald S

2012-11-14

States' pandemic influenza plans and school closure statutes are intended to guide state and local officials, but most faced a great deal of uncertainty during the 2009 influenza H1N1 epidemic. Questions remained about whether, when, and for how long to close schools and about which agencies and officials had legal authority over school closures. This study began with analysis of states' school-closure statutes and pandemic influenza plans to identify the variations among them. An agent-based model of one state was used to represent as constants a population's demographics, commuting patterns, work and school attendance, and community mixing patterns while repeated simulations explored the effects of variations in school closure authority, duration, closure thresholds, and reopening criteria. The results show no basis on which to justify statewide rather than school-specific or community-specific authority for school closures. Nor do these simulations offer evidence to require school closures promptly at the earliest stage of an epidemic. More important are criteria based on monitoring of local case incidence and on authority to sustain closure periods sufficiently to achieve epidemic mitigation. This agent-based simulation suggests several ways to improve statutes and influenza plans. First, school closure should remain available to state and local authorities as an influenza mitigation strategy. Second, influenza plans need not necessarily specify the threshold for school closures but should clearly define provisions for early and ongoing local monitoring. Finally, school closure authority may be exercised at the statewide or local level, so long as decisions are informed by monitoring incidence in local communities and schools.

The Stochastic Multi-strain Dengue Model: Analysis of the Dynamics

NASA Astrophysics Data System (ADS)

Aguiar, Maíra; Stollenwerk, Nico; Kooi, Bob W.

2011-09-01

Dengue dynamics is well known to be particularly complex with large fluctuations of disease incidences. An epidemic multi-strain model motivated by dengue fever epidemiology shows deterministic chaos in wide parameter regions. The addition of seasonal forcing, mimicking the vectorial dynamics, and a low import of infected individuals, which is realistic in the dynamics of infectious diseases epidemics show complex dynamics and qualitatively a good agreement between empirical DHF monitoring data and the obtained model simulation. The addition of noise can explain the fluctuations observed in the empirical data and for large enough population size, the stochastic system can be well described by the deterministic skeleton.

Individual rights over public good? The future of anthropometric monitoring of school children in the fight against obesity.

PubMed

Stubbs, Joanne M; Achat, Helen M

2009-02-02

Available evidence indicates that rates of childhood overweight and obesity have been increasing over the past two decades, but inconsistencies between study methods moderate the strength of this evidence. Concomitant health problems and associated costs make it imperative that primary prevention initiatives are introduced to combat the obesity epidemic. Fundamental to informed action is anthropometric monitoring, which if properly implemented will identify changes over time in specific populations to inform policies, practices and services aimed at prevention and treatment. Sample representativeness is essential for valid trend and prevalence data, but efforts to obtain population-based anthropometric data from school children with the required written parental consent have been thwarted by low participation rates. Notable improvements in participation rates when utilising opt-out consent, in which participation is assumed unless otherwise indicated, are evident from local as well as international studies. Opt-out consent can facilitate anthropometric monitoring, delivering a more informed, best-value-for-money response to the obesity epidemic. Health and education ethics committees need to acknowledge the benefits of opt-out consent for "low-risk" anthropometric measurement, which ultimately upholds the individual's rights.

Impact of the Ebola epidemic on general and HIV care in Macenta, Forest Guinea, 2014.

PubMed

Leuenberger, David; Hebelamou, Jean; Strahm, Stefan; De Rekeneire, Nathalie; Balestre, Eric; Wandeler, Gilles; Dabis, François

2015-09-10

The current Ebola epidemic massively affected the Macenta district in Forest Guinea. We aimed at investigating its impact on general and HIV care at the only HIV care facility in the district. Prospective observational single-facility study. Routinely collected data on use of general hospital services and HIV care were linked to Ebola surveillance data published by the Guinea Ministry of Health. In addition, we compared retention among HIV-infected patients enrolled into care in the first semesters of 2013 and 2014. Throughout 2014, service offer was continuous and unaltered at the facility. During the main epidemic period (August-December 2014), compared with the same period of 2013, there were important reductions in attendance at the primary care outpatient clinic (-40%), in HIV tests done (-46%), in new diagnoses of tuberculosis (-53%) and in patients enrolled into HIV care (-47%). There was a smaller reduction in attendance at the HIV follow-up clinic (-11%). Kaplan-Meier estimates of retention were similar among the patients enrolled into care in 2014 and 2013. In a multivariable Cox regression analysis, the year of enrolment was not associated with attrition (hazard ratio 1.02; 95% confidence interval: 0.72-1.43). The Ebola epidemic resulted in an important decrease in utilization of the facility despite unaltered service offer. Effects on care of HIV-positive patients enrolled prior to the epidemic were limited. HIV care in such circumstances is challenging, but not impossible.

[Epidemic meningitis in 2013 in Republic of Guinea: Nesseria meningitidis W135 emergence].

PubMed

Traoré, F A; Sako, F B; Sylla, D; Kader, D S; Bangoura, M; Traoré, M; Keita, A; Sidibé, A; Keita, S; Barry, M; Cisse, M; Touré, A

2016-12-01

A prospective study conducted from 1 January to 31 December 2013 described a meningitis epidemic in Republic of Guinea. The identification of the germs was based on Gram stain, latex agglutination and culture. During the study period, 480 suspected cases of meningitis were reported by 21 health districts. The average age was 18±8 years and 62.5% were men. The vaccination status was unknown in all patients. The largest attack rates were found in Siguiri (3.2 per 10,000), Kankan (2.6 per 10,000) and Dabola (3.9 per 10,000). The locality of Kintinian in Siguiri was the only one to cross the epidemic threshold. The identified microorganisms were Haemophilus influenzae (1 time), Pneumococcus (2 times), Neisseria meningitidis A (4 times) and W135 (10 times) with a total of 17 positive samples. All of these germs were sensitive to chloramphenicol, ceftriaxone and ciprofloxacin. The average hospital stay was 6.5±2 days. The lethality was 13.8%. This meningitis epidemic was characterized by the emergence of Neisseria meningitidis W135. The monitoring of this serogroup should be increased and future vaccination strategies must include it presence.

Pilot study to harmonize the reported influenza intensity levels within the Spanish Influenza Sentinel Surveillance System (SISSS) using the Moving Epidemic Method (MEM).

PubMed

Bangert, M; Gil, H; Oliva, J; Delgado, C; Vega, T; DE Mateo, S; Larrauri, A

2017-03-01

The intensity of annual Spanish influenza activity is currently estimated from historical data of the Spanish Influenza Sentinel Surveillance System (SISSS) using qualitative indicators from the European Influenza Surveillance Network. However, these indicators are subjective, based on qualitative comparison with historical data of influenza-like illness rates. This pilot study assesses the implementation of Moving Epidemic Method (MEM) intensity levels during the 2014-2015 influenza season within the 17 sentinel networks covered by SISSS, comparing them to historically reported indicators. Intensity levels reported and those obtained with MEM at the epidemic peak of the influenza wave, and at national and regional levels did not show statistical difference (P = 0·74, Wilcoxon signed-rank test), suggesting that the implementation of MEM would have limited disrupting effects on the dynamic of notification within the surveillance system. MEM allows objective influenza surveillance monitoring and standardization of criteria for comparing the intensity of influenza epidemics in regions in Spain. Following this pilot study, MEM has been adopted to harmonize the reporting of intensity levels of influenza activity in Spain, starting in the 2015-2016 season.

Detection and measurement of plant disease symptoms using visible-wavelength photography and image analysis

USDA-ARS?s Scientific Manuscript database

Disease assessment is required for many purposes including predicting yield loss, monitoring and forecasting epidemics, judging host resistance, and for studying fundamental biological host-pathogen processes. Inaccurate and/or imprecise assessments can result in incorrect conclusions or actions. Im...

Automated image analysis of the severity of foliar citrus canker symptoms

USDA-ARS?s Scientific Manuscript database

Citrus canker (caused by Xanthomonas citri subsp. citri) is a destructive disease, reducing yield, and rendering fruit unfit for fresh sale. Accurate assessment of citrus canker severity and other diseases is needed for several purposes, including monitoring epidemics and evaluation of germplasm. ...

Exploratory behavior is linked to stress physiology and social network centrality in free-living house finches (Haemorhous mexicanus).

PubMed

Moyers, Sahnzi C; Adelman, James S; Farine, Damien R; Moore, Ignacio T; Hawley, Dana M

2018-06-01

Animal personality has been linked to individual variation in both stress physiology and social behaviors, but few studies have simultaneously examined covariation between personality traits, stress hormone levels, and behaviors in free-living animals. We investigated relationships between exploratory behavior (one aspect of animal personality), stress physiology, and social and foraging behaviors in wild house finches (Haemorhous mexicanus). We conducted novel environment assays after collecting samples of baseline and stress-induced plasma corticosterone concentrations from a subset of house finches. We then fitted individuals with Passive Integrated Transponder tags and monitored feeder use and social interactions at radio-frequency identification equipped bird feeders. First, we found that individuals with higher baseline corticosterone concentrations exhibit more exploratory behaviors in a novel environment. Second, more exploratory individuals interacted with more unique conspecifics in the wild, though this result was stronger for female than for male house finches. Third, individuals that were quick to begin exploring interacted more frequently with conspecifics than slow-exploring individuals. Finally, exploratory behaviors were unrelated to foraging behaviors, including the amount of time spent on bird feeders, a behavior previously shown to be predictive of acquiring a bacterial disease that causes annual epidemics in house finches. Overall, our results indicate that individual differences in exploratory behavior are linked to variation in both stress physiology and social network traits in free-living house finches. Such covariation has important implications for house finch ecology, as both traits can contribute to fitness in the wild. Copyright © 2018 Elsevier Inc. All rights reserved.

Estimating the impact of reducing violence against female sex workers on HIV epidemics in Kenya and Ukraine: a policy modeling exercise.

PubMed

Decker, Michele R; Wirtz, Andrea L; Pretorius, Carel; Sherman, Susan G; Sweat, Michael D; Baral, Stefan D; Beyrer, Chris; Kerrigan, Deanna L

2013-02-01

Female sex workers (FSWs) worldwide suffer disproportionate burdens of HIV and gender-based violence. Despite evidence linking these threats, little is known about the potential HIV epidemic impact of reducing abuse. The Goals model approximated the impact of reducing violence against FSWs on HIV epidemics in Ukraine and Kenya, measured by reductions in new infections among FSWs and adults. Cumulative infections averted over a 5-year period, in which violence declined was calculated, relative to a status quo with no reduction. Projections held HIV interventions constant at baseline levels; subsequently, scenarios adjusted for planned expansion of antiretroviral therapy (ART) coverage. An approximate 25% reduction in incident HIV infections among FSWs was observed when physical or sexual violence was reduced; cumulative infections averted were 21,200 and 4700 in Kenya and Ukraine, respectively. Similar percent reductions were observed assuming ART coverage expansion, with approximately 18,200 and 4400 infections averted among FSWs in Kenya and Ukraine. New infections were also averted in the general population. Reducing violence against FSWs appears to impart significant reductions in new infections among FSWs and in the general adult population in both generalized and concentrated epidemics. Limitations provide direction to improve the precision of future estimates. © 2013 John Wiley & Sons A/S.

The Past, Present, and Future of Public Health Surveillance

PubMed Central

Choi, Bernard C. K.

2012-01-01

This paper provides a review of the past, present, and future of public health surveillance—the ongoing systematic collection, analysis, interpretation, and dissemination of health data for the planning, implementation, and evaluation of public health action. Public health surveillance dates back to the first recorded epidemic in 3180 B.C. in Egypt. Hippocrates (460 B.C.–370 B.C.) coined the terms endemic and epidemic, John Graunt (1620–1674) introduced systematic data analysis, Samuel Pepys (1633–1703) started epidemic field investigation, William Farr (1807–1883) founded the modern concept of surveillance, John Snow (1813–1858) linked data to intervention, and Alexander Langmuir (1910–1993) gave the first comprehensive definition of surveillance. Current theories, principles, and practice of public health surveillance are summarized. A number of surveillance dichotomies, such as epidemiologic surveillance versus public health surveillance, are described. Some future scenarios are presented, while current activities that can affect the future are summarized: exploring new frontiers; enhancing computer technology; improving epidemic investigations; improving data collection, analysis, dissemination, and use; building on lessons from the past; building capacity; enhancing global surveillance. It is concluded that learning from the past, reflecting on the present, and planning for the future can further enhance public health surveillance. PMID:24278752

An estimate of the magnitude and trend of HIV/AIDS epidemic using data from the routine VCT services as an alternative data source to ANC sentinel surveillance in Addis Ababa, Ethiopia.

PubMed

Getachew, Yehenew; Gotu, Butte; Enquselassie, Fikre

2010-10-01

Since early 1980s when AIDS was first recognized, there has been uncertainty about the future trend and the ultimate dimensions of the pandemic. This uncertainty persists because of difficulties in measuring HIV incidence and prevalence with a substantial degree of precision in a given population. One of the many factors for the lack of precision is the problem of obtaining representative data sources that can be extrapolated to the general population. National and regional HIV estimates for Ethiopia are derived from ANC based HIV surveillance data. Alternative data sources have not been exhaustively explored as potential tools to monitor the trend of HIV/ AIDS epidemic in the country. To estimate the magnitude and trend of HIV/AIDS epidemic using data from the routine VCT services as an alternative data source to ANC sentinel surveillance data. The study used secondary data sources from all government, private and NGO VCT centers, of the period of 2003-2005 in Addis Ababa. For the purpose of making comparative analysis of the VCT based estimations and projections, records of all five sentinel sites in Addis Ababa for the period 1983-2003 were reviewed. Both ANC and VCT data sources showed similar and regular trends from the beginning of the HIV epidemic till the year 1995 where the ANC showed a relatively higher prevalence rates than VCT data, with a maximum difference in HIV prevalence of 1.06% in 1993. However, a higher HIV prevalence was noted for the VCT than the ANC data source for the period of 1996-2002, with a maximum difference of 1.4% in 1998, the year when both the ANC and VCT modeled HIV prevalence reached the highest peak in Addis Ababa. On the contrary, the ANC based prevalence was higher than the VCT data for the period 2004-2010, with a maximum difference of 2.2%. This study suggests that VCT based HIV prevalence data closely approximates the ANC based data. Therefore VCT data source can be valuable to complement the ANC data in monitoring the HIV epidemic and trend.

Development of Enzyme-Linked Immunosorbent Assays Using Expressed Proteins of Rift Valley Fever Virus

USDA-ARS?s Scientific Manuscript database

Rift Valley fever virus (RVFV) is a member of the genus Phlebovirus, family Bunyaviridae that can cause severe disease in both humans and animals. The disease is enzootic in sub-Saharan Africa and RVFV epidemics/epizootics occur periodically, primarily in eastern and southern Africa. Since the virus...

A New Discourse on the Kitchen: Feminism and Environmental Education

ERIC Educational Resources Information Center

Stovall, Holly A.; Baker-Sperry, Lori; Dallinger, Judith M.

2015-01-01

Popularised feminist discourse has devalued daily cooking and implicitly defined it as work that reinforces women's second-class status. In an era of climate change linked to industrialised foods and disease epidemics caused by the modern Western diet, kitchen work has acquired political importance. Daily cooking must be understood as public, as…

Parental Efficacy and Role Responsibility for Assisting in Child's Healthful Behaviors

ERIC Educational Resources Information Center

Ice, Christa L.; Neal, William A.; Cottrell, Lesley

2014-01-01

The epidemic of childhood obesity, and its subsequent impact on negative health outcomes, continues to plague the United States. Better health outcomes have been linked to increased child achievement in school. Due to the strong influence parents have on children's healthful behaviors particularly in younger years, it's imperative to examine the…

Vitamin D status in young women and its relationship to body fat, final height and peak bone mass

USDA-ARS?s Scientific Manuscript database

Vitamin D insufficiency has now reached epidemic proportion and has been linked to low bone mineral density (BMD), increased risk of fracture and obesity in adults. However, this relationship has not been well characterized in adolescents and young adults. We examined the relationship between seru...

Vitamin D Status and Its Relationship to Body Fat, Final Height, and Peak Bone Mass in Young Women

USDA-ARS?s Scientific Manuscript database

Vitamin D insufficiency has now reached epidemic proportion and has been linked to low bone mineral density (BMD), increased risk of fracture and obesity in adults. However, this relationship has not been well characterized in adolescents and young adults. We examined the relationship between seru...

Optimizing interconnections to maximize the spectral radius of interdependent networks

NASA Astrophysics Data System (ADS)

Chen, Huashan; Zhao, Xiuyan; Liu, Feng; Xu, Shouhuai; Lu, Wenlian

2017-03-01

The spectral radius (i.e., the largest eigenvalue) of the adjacency matrices of complex networks is an important quantity that governs the behavior of many dynamic processes on the networks, such as synchronization and epidemics. Studies in the literature focused on bounding this quantity. In this paper, we investigate how to maximize the spectral radius of interdependent networks by optimally linking k internetwork connections (or interconnections for short). We derive formulas for the estimation of the spectral radius of interdependent networks and employ these results to develop a suite of algorithms that are applicable to different parameter regimes. In particular, a simple algorithm is to link the k nodes with the largest k eigenvector centralities in one network to the node in the other network with a certain property related to both networks. We demonstrate the applicability of our algorithms via extensive simulations. We discuss the physical implications of the results, including how the optimal interconnections can more effectively decrease the threshold of epidemic spreading in the susceptible-infected-susceptible model and the threshold of synchronization of coupled Kuramoto oscillators.

Estimation of plant disease severity visually, by digital photography and image analysis, and by hyperspectral imaging

USDA-ARS?s Scientific Manuscript database

Reliable, precise and accurate estimates of disease severity are important for predicting yield loss, monitoring and forecasting epidemics, for assessing crop germplasm for disease resistance, and for understanding fundamental biological processes including co-evolution. In some situations poor qual...

Design and modelling of a link monitoring mechanism for the Common Data Link (CDL)

NASA Astrophysics Data System (ADS)

Eichelberger, John W., III

1994-09-01

The Common Data Link (CDL) is a full duplex, point-to-point microwave communications system used in imagery and signals intelligence collection systems. It provides a link between two remote Local Area Networks (LAN's) aboard collection and surface platforms. In a hostile environment, there is an overwhelming need to dynamically monitor the link and thus, limit the impact of jamming. This work describes steps taken to design, model, and evaluate a link monitoring system suitable for the CDL. The monitoring system is based on features and monitoring constructs of the Link Control Protocol (LCP) in the Point-to-Point Protocol (PPP) suite. The CDL model is based on a system of two remote Fiber Distributed Data Interface (FDDI) LAN's. In particular, the policies and mechanisms associated with monitoring are described in detail. An implementation of the required mechanisms using the OPNET network engineering tool is described. Performance data related to monitoring parameters is reported. Finally, integration of the FDDI-CDL model with the OPNET Internet model is described.

Preparing for an Epidemic of Limited Health Literacy: Weathering the Perfect Storm

PubMed Central

Parker, Ruth M.; Kirsch, Irwin

2008-01-01

Empirical data collected over the past two decades have demonstrated strong links between low literacy skills and poor health outcomes, including mortality. Recently, the Educational Testing Service released a relevant report predicting that our nation is at great risk as a result of declining adult literacy, shifting demographics, and a changing economy. It is essential to understand how these educational and socioeconomic changes will impact health care and prepare for a likely epidemic of limited health literacy. A formative public health response should include seeking out new strategies for health systems to advance our public’s health literacy, while working with the educational system to better equip younger generations with the knowledge and skills necessary to navigate health care. PMID:18452047

Epidemic microclusters of blood-culture proven sepsis in very-low-birth weight infants: experience of the German Neonatal Network.

PubMed

Härtel, Christoph; Faust, Kirstin; Avenarius, Stefan; Bohnhorst, Bettina; Emeis, Michael; Gebauer, Corinna; Groneck, Peter; Heitmann, Friedhelm; Hoehn, Thomas; Hubert, Mechthild; Kribs, Angela; Küster, Helmut; Laux, Reinhard; Mögel, Michael; Müller, Dirk; Olbertz, Dirk; Roll, Claudia; Siegel, Jens; Stein, Anja; Vochem, Matthias; Weller, Ursula; von der Wense, Axel; Wieg, Christian; Wintgens, Jürgen; Hemmelmann, Claudia; Simon, Arne; Herting, Egbert; Göpel, Wolfgang

2012-01-01

We evaluated blood culture-proven sepsis episodes occurring in microclusters in very-low-birth-weight infants born in the German Neonatal Network (GNN) during 2009-2010. Thirty-seven centers participated in GNN; 23 centers enrolled ≥50 VLBW infants in the study period. Data quality was approved by on-site monitoring. Microclusters of sepsis were defined as occurrence of at least two blood-culture proven sepsis events in different patients of one center within 3 months with the same bacterial species. For microcluster analysis, we selected sepsis episodes with typically cross-transmitted bacteria of high clinical significance including gram-negative rods and Enterococcus spp. In our cohort, 12/2110 (0.6%) infants were documented with an early-onset sepsis and 235 late-onset sepsis episodes (≥72 h of age) occurred in 203/2110 (9.6%) VLBW infants. In 182/235 (77.4%) late-onset sepsis episodes gram-positive bacteria were documented, while coagulase negative staphylococci were found to be the most predominant pathogens (48.5%, 95%CI: 42.01-55.01). Candida spp. and gram-negative bacilli caused 10/235 (4.3%, 95%CI: 1.68% -6.83%) and 43/235 (18.5%) late-onset sepsis episodes, respectively. Eleven microclusters of blood-culture proven sepsis were detected in 7 hospitals involving a total 26 infants. 16/26 cluster patients suffered from Klebsiella spp. sepsis. The median time interval between the first patient's Klebsiella spp. sepsis and cluster cases was 14.1 days (interquartile range: 1-27 days). First patients in the cluster, their linked cases and sporadic sepsis events did not show significant differences in short term outcome parameters. Microclusters of infection are an important phenomenon for late-onset sepsis. Most gram-negative cluster infections occur within 30 days after the first patient was diagnosed and Klebsiella spp. play a major role. It is essential to monitor epidemic microclusters of sepsis in surveillance networks to adapt clinical practice, inform policy and further improve quality of care.

Mandatory Provider Review And Pain Clinic Laws Reduce The Amounts Of Opioids Prescribed And Overdose Death Rates.

PubMed

Dowell, Deborah; Zhang, Kun; Noonan, Rita K; Hockenberry, Jason M

2016-10-01

To address the opioid overdose epidemic in the United States, states have implemented policies to reduce inappropriate opioid prescribing. These policies could affect the coincident heroin overdose epidemic by either driving the substitution of heroin for opioids or reducing simultaneous use of both substances. We used IMS Health's National Prescription Audit and government mortality data to examine the effect of these policies on opioid prescribing and on prescription opioid and heroin overdose death rates in the United States during 2006-13. The analysis revealed that combined implementation of mandated provider review of state-run prescription drug monitoring program data and pain clinic laws reduced opioid amounts prescribed by 8 percent and prescription opioid overdose death rates by 12 percent. We also observed relatively large but statistically insignificant reductions in heroin overdose death rates after implementation of these policies. This combination of policies was effective, but broader approaches to address these coincident epidemics are needed. Project HOPE—The People-to-People Health Foundation, Inc.

The Complex Relationship between Weather and Dengue Virus Transmission in Thailand

PubMed Central

Campbell, Karen M.; Lin, C. D.; Iamsirithaworn, Sopon; Scott, Thomas W.

2013-01-01

Using a novel analytical approach, weather dynamics and seasonal dengue virus transmission cycles were profiled for each Thailand province, 1983–2001, using monthly assessments of cases, temperature, humidity, and rainfall. We observed systematic differences in the structure of seasonal transmission cycles of different magnitude, the role of weather in regulating seasonal cycles, necessary versus optimal transmission “weather-space,” basis of large epidemics, and predictive indicators that estimate risk. Larger epidemics begin earlier, develop faster, and are predicted at Onset change-point when case counts are low. Temperature defines a viable range for transmission; humidity amplifies the potential within that range. This duality is central to transmission. Eighty percent of 1.2 million severe dengue cases occurred when mean temperature was 27–29.5°C and mean humidity was > 75%. Interventions are most effective when applied early. Most cases occur near Peak, yet small reductions at Onset can substantially reduce epidemic magnitude. Monitoring the Quiet-Phase is fundamental in effectively targeting interventions pre-emptively. PMID:23958906

The complex relationship between weather and dengue virus transmission in Thailand.

PubMed

Campbell, Karen M; Lin, C D; Iamsirithaworn, Sopon; Scott, Thomas W

2013-12-01

Using a novel analytical approach, weather dynamics and seasonal dengue virus transmission cycles were profiled for each Thailand province, 1983-2001, using monthly assessments of cases, temperature, humidity, and rainfall. We observed systematic differences in the structure of seasonal transmission cycles of different magnitude, the role of weather in regulating seasonal cycles, necessary versus optimal transmission "weather-space," basis of large epidemics, and predictive indicators that estimate risk. Larger epidemics begin earlier, develop faster, and are predicted at Onset change-point when case counts are low. Temperature defines a viable range for transmission; humidity amplifies the potential within that range. This duality is central to transmission. Eighty percent of 1.2 million severe dengue cases occurred when mean temperature was 27-29.5°C and mean humidity was > 75%. Interventions are most effective when applied early. Most cases occur near Peak, yet small reductions at Onset can substantially reduce epidemic magnitude. Monitoring the Quiet-Phase is fundamental in effectively targeting interventions pre-emptively.

Fear and Stigma: The Epidemic within the SARS Outbreak

PubMed Central

Sy, Francisco; Holton, Kelly; Govert, Barbara; Liang, Arthur; Garza, Brenda; Gould, Deborah; Hickson, Meredith; McDonald, Marian; Meijer, Cecilia; Smith, Julia; Veto, Liza; Williams, Walter; Zauderer, Laura

2004-01-01

Because of their evolving nature and inherent scientific uncertainties, outbreaks of emerging infectious diseases can be associated with considerable fear in the general public or in specific communities, especially when illness and deaths are substantial. Mitigating fear and discrimination directed toward persons infected with, and affected by, infectious disease can be important in controlling transmission. Persons who are feared and stigmatized may delay seeking care and remain in the community undetected. This article outlines efforts to rapidly assess, monitor, and address fears associated with the 2003 severe acute respiratory syndrome (SARS) epidemic in the United States. Although fear, stigmatization, and discrimination were not widespread in the general public, Asian-American communities were particularly affected. PMID:15030713

76 FR 17869 - Agency Forms Undergoing Paperwork Reduction Act Review

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-31

... complexity to respond to changes in the epidemic, including the diffusion and implementation of Effective... interventions by monitoring changes in clients' self-reported HIV transmission risk behaviors after... project. Each agency will recruit 400 men who are 18 years of age and older, report having had anal sex...

Global Climate Teleconnections to Forecast Increased Risk of Vector-Borne Animal and Human Disease Transmission

USDA-ARS?s Scientific Manuscript database

We willexamine how climate teleconnect ions and variability impact vector biology and vector borne disease ecology, and demonstrate that global climate monitoring can be used to anticipate and forecast epidemics and epizootics. In this context we willexamine significant worldwide weather anomalies t...

The forests of Maine: 2003

Treesearch

William H. McWilliams; Brett J. Butler; Laurence E. Caldwell; Douglas M. Griffith; Michael L. Hoppus; Kenneth M. Laustsen; Andrew J. Lister; Tonya W. Lister; Jacob W. Metzler; Randall S. Morin; Steven A. Sader; Lucretia B. Stewart; James R. Steinman; James, A. Westfall; David A. Williams; Andrew Whitman; Christopher W. Woodall; Christopher W. Woodall

2005-01-01

In 1999, the Maine Forest Service and USDA Forest Service's Forest Inventory and Analysis program implemented a new system for inventorying and monitoring Maine's forests. The effects of the spruce budworm epidemic continue to affect the composition, structure, and distribution of Maine's forested ecosystems. The area of forest land in Maine has remained...

Ethics, health policy, and Zika: From emergency to global epidemic?

PubMed

Jamrozik, Euzebiusz; Selgelid, Michael J

2018-05-01

Zika virus was recognised in 2016 as an important vector-borne cause of congenital malformations and Guillain-Barré syndrome, during a major epidemic in Latin America, centred in Northeastern Brazil. The WHO and Pan American Health Organisation (PAHO), with partner agencies, initiated a coordinated global response including public health intervention and urgent scientific research, as well as ethical analysis as a vital element of policy design. In this paper, we summarise the major ethical issues raised during the Zika epidemic, highlighting the PAHO ethics guidance and the role of ethics in emergency responses, before turning to ethical issues that are yet to be resolved. Zika raises traditional bioethical issues related to reproduction, prenatal diagnosis of serious malformations and unjust disparities in health outcomes. But the epidemic has also highlighted important issues of growing interest in public health ethics, such as the international spread of infectious disease; the central importance of reproductive healthcare in preventing maternal and neonatal morbidity and mortality; diagnostic and reporting biases; vector control and the links between vectors, climate change, and disparities in the global burden of disease. Finally, there are controversies regarding Zika vaccine research and eventual deployment. Zika virus was a neglected disease for over 50 years before the outbreak in Brazil. As it continues to spread, public health agencies should promote gender equity and disease control efforts in Latin America, while preparing for the possibility of a global epidemic. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Haemagglutinin mutations and glycosylation changes shaped the 2012/13 influenza A(H3N2) epidemic, Houston, Texas

PubMed Central

Stucker, K M; Schobel, S A; Olsen, R J; Hodges, H L; Lin, X; Halpin, R A; Fedorova, N; Stockwell, T B; Tovchigrechko, A; Das, S R; Wentworth, D E; Musser, J M

2017-01-01

While the early start and higher intensity of the 2012/13 influenza A virus (IAV) epidemic was not unprecedented, it was the first IAV epidemic season since the 2009 H1N1 influenza pandemic where the H3N2 subtype predominated. We directly sequenced the genomes of 154 H3N2 clinical specimens collected throughout the epidemic to better understand the evolution of H3N2 strains and to inform the H3N2 vaccine selection process. Phylogenetic analyses indicated that multiple co-circulating clades and continual antigenic drift in the haemagglutinin (HA) of clades 5, 3A, and 3C, with the evolution of a new 3C subgroup (3C-2012/13), were the driving causes of the epidemic. Drift variants contained HA substitutions and alterations in the potential N-linked glycosylation sites of HA. Antigenic analysis demonstrated that viruses in the emerging subclade 3C.3 and subgroup 3C-2012/13 were not well inhibited by antisera generated against the 3C.1 vaccine strains used for the 2012/13 (A/Victoria/361/2011) or 2013/14 (A/Texas/50/2012) seasons. Our data support updating the H3N2 vaccine strain to a clade 3C.2 or 3C.3-like strain or a subclade that has drifted further. They also underscore the challenges in vaccine strain selection, particularly regarding HA and neuraminidase substitutions derived during laboratory passage that may alter antigenic testing accuracy. PMID:25990233

HSV-1/HSV-2 Infection-Related Cancers in Bantu Populations Driving HIV-1 Prevalence in Africa: Tracking the Origin of AIDS at the Onset of the 20th Century.

PubMed

Le Goaster, Jacqueline; Bouree, Patrice; El Sissy, Franck N; Phuong Bui, Florence; Pokossy Epee, Johanna; Rollin, Paul; Tangy, Frédéric; Haenni, Anne-Lise

2016-01-01

At the onset of the 20th century, ancient clinical observations of cancer epidemics in Bantu populations of Sub-Saharan Africa were discovered. They were reported from 1914 to 1960, but remained unexplained. In 1983, in San Francisco, Calif., USA, cancer epidemics were related to infections by the human immunodeficiency virus type 1 (HIV-1) known as AIDS disease. Yet since 1996, it is known that HIV-1 strains are not the only ones involved. In Sub-Saharan Africa, recurrent orobuccal herpes simplex virus type 1 (HSV-1) and genital recurrent herpes simplex virus type 2 (HSV-2) appeared many times prior to infection by HIV-1. Data on these ancient medical observations regarding African cancer epidemics can today be referred to as the relationship between the unfortunate immune deficiency of herpes in Bantu populations and HIV-1 viral strains. For centuries, the Bantu populations dispersed in forests were living in close proximity to chimpanzees infected by simian immunodeficiency virus (SIV) and were exposed to SIV contamination which became HIV-1 in human beings. Presently, these unexplained Bantu cancer epidemics can be linked to the viral partnership of HSV-1/HSV-2 to HIV-1 strains. The key issue is now to prevent HSV-1/HSV-2 diseases related to HIV-1. An anti-herpes treatment administered early during childhood to Bantu populations will offer a mean of preventing herpes diseases related to HIV-1 infection and hence avoid cancer epidemics.

HSV-1/HSV-2 Infection-Related Cancers in Bantu Populations Driving HIV-1 Prevalence in Africa: Tracking the Origin of AIDS at the Onset of the 20th Century

PubMed Central

Le Goaster, Jacqueline; Bouree, Patrice; El Sissy, Franck N.; Phuong Bui, Florence; Pokossy Epee, Johanna; Rollin, Paul; Tangy, Frédéric; Haenni, Anne-Lise

2016-01-01

Introduction At the onset of the 20th century, ancient clinical observations of cancer epidemics in Bantu populations of Sub-Saharan Africa were discovered. They were reported from 1914 to 1960, but remained unexplained. In 1983, in San Francisco, Calif., USA, cancer epidemics were related to infections by the human immunodeficiency virus type 1 (HIV-1) known as AIDS disease. Yet since 1996, it is known that HIV-1 strains are not the only ones involved. In Sub-Saharan Africa, recurrent orobuccal herpes simplex virus type 1 (HSV-1) and genital recurrent herpes simplex virus type 2 (HSV-2) appeared many times prior to infection by HIV-1. Case Reports Data on these ancient medical observations regarding African cancer epidemics can today be referred to as the relationship between the unfortunate immune deficiency of herpes in Bantu populations and HIV-1 viral strains. For centuries, the Bantu populations dispersed in forests were living in close proximity to chimpanzees infected by simian immunodeficiency virus (SIV) and were exposed to SIV contamination which became HIV-1 in human beings. Presently, these unexplained Bantu cancer epidemics can be linked to the viral partnership of HSV-1/HSV-2 to HIV-1 strains. Conclusion The key issue is now to prevent HSV-1/HSV-2 diseases related to HIV-1. An anti-herpes treatment administered early during childhood to Bantu populations will offer a mean of preventing herpes diseases related to HIV-1 infection and hence avoid cancer epidemics. PMID:28413399

Late or Lack of Vaccination Linked to Importation of Yellow Fever from Angola to China.

PubMed

Song, Rui; Guan, Shengcan; Lee, Shui Shan; Chen, Zhihai; Chen, Chen; Han, Lifen; Xu, Yanli; Li, Ang; Zeng, Hui; Ye, Hanhui; Zhang, Fujie

2018-07-17

During March and April 2016, 11 yellow fever cases were identified in China. We report epidemic and viral information for 10 of these patients, 6 of whom had been vaccinated before travel. Phylogenetic analyses suggest these viruses nested within the diversity of strains endemic to Angola, where an outbreak began in 2015.

White pines, Ribes, and blister rust: a review and synthesis

Treesearch

Brian W. Geils; Kim E. Hummer; Richard S. Hunt

2010-01-01

For over a century, white pine blister rust (Cronartium ribicola) has linked white pines (Strobus) with currants and gooseberries (Ribes) in a complex and serious disease epidemic in Asia, Europe, and North America. Because of ongoing changes in climate, societal demands for forests and their amenities, and scientific advances in genetics and proteomics, our current...

Clinical Features of Human Immunodeficiency Virus-Infected Patients Presenting with Cholera in Port-au-Prince, Haiti.

PubMed

Sévère, Karine; Anglade, Stravinsky B; Bertil, Claudin; Duncan, Aynsley; Joseph, Patrice; Deroncenay, Alexandra; Mabou, Marie M; Ocheretina, Oksana; Reif, Lindsey; Seo, Grace; Pape, Jean W; Fitzgerald, Daniel W

2016-11-02

Human immunodeficiency virus (HIV) infection has been postulated to alter the natural history of cholera, including increased susceptibility to infection, severity of illness, and chronic carriage of Vibrio cholerae Haiti has a generalized HIV epidemic with an adult HIV prevalence of 1.9% and recently suffered a cholera epidemic. We conducted a prospective study at the cholera treatment center (CTC) of GHESKIO in Haiti to characterize the coinfection. Adults admitted at the CTC for acute diarrhea were invited to participate in the study. Vital signs, frequency, and volume of stools and/or vomiting were monitored, and single-dose doxycycline was administered. After counseling, participants were screened for HIV by enzyme-linked immunosorbent assay and for cholera by culture. Of 729 adults admitted to the CTC, 99 (13.6%) had HIV infection, and 457 (63%) had culture-confirmed cholera. HIV prevalence was three times higher in patients without cholera (23%, 63/272) than in those with culture-confirmed cholera (7.9%, 36/457). HIV prevalence in patients with culture-confirmed cholera (7.9%) was four times higher than the adult prevalence in Port-au-Prince (1.9%). Of the 36 HIV-infected patients with cholera, 25 (69%) had moderate/severe dehydration versus 302/421 (72%) in the HIV negative. Of 30 HIV-infected patients with weekly stool cultures performed after discharge, 29 (97%) were negative at week 1. Of 50 HIV-negative patients with weekly stool cultures, 49 (98%) were negative at week 1. In countries with endemic HIV infection, clinicians should consider screening patients presenting with suspected cholera for HIV coinfection. © The American Society of Tropical Medicine and Hygiene.

Elimination of Porcine Epidemic Diarrhea Virus in an Animal Feed Manufacturing Facility.

PubMed

Huss, Anne R; Schumacher, Loni L; Cochrane, Roger A; Poulsen, Elizabeth; Bai, Jianfa; Woodworth, Jason C; Dritz, Steve S; Stark, Charles R; Jones, Cassandra K

2017-01-01

Porcine Epidemic Diarrhea Virus (PEDV) was the first virus of wide scale concern to be linked to possible transmission by livestock feed or ingredients. Measures to exclude pathogens, prevent cross-contamination, and actively reduce the pathogenic load of feed and ingredients are being developed. However, research thus far has focused on the role of chemicals or thermal treatment to reduce the RNA in the actual feedstuffs, and has not addressed potential residual contamination within the manufacturing facility that may lead to continuous contamination of finished feeds. The purpose of this experiment was to evaluate the use of a standardized protocol to sanitize an animal feed manufacturing facility contaminated with PEDV. Environmental swabs were collected throughout the facility during the manufacturing of a swine diet inoculated with PEDV. To monitor facility contamination of the virus, swabs were collected at: 1) baseline prior to inoculation, 2) after production of the inoculated feed, 3) after application of a quaternary ammonium-glutaraldehyde blend cleaner, 4) after application of a sodium hypochlorite sanitizing solution, and 5) after facility heat-up to 60°C for 48 hours. Decontamination step, surface, type, zone and their interactions were all found to impact the quantity of detectable PEDV RNA (P < 0.05). As expected, all samples collected from equipment surfaces contained PEDV RNA after production of the contaminated feed. Additionally, the majority of samples collected from non-direct feed contact surfaces were also positive for PEDV RNA after the production of the contaminated feed, emphasizing the potential role dust plays in cross-contamination of pathogen throughout a manufacturing facility. Application of the cleaner, sanitizer, and heat were effective at reducing PEDV genomic material (P < 0.05), but did not completely eliminate it.

[THE EPIZOOTIC AND EPIDEMIC ACTIVITY OF NATURAL TULAREMIA FOCI OF DIFFERENT LANDSCAPE EPIDEMIOLOGICAL TYPES IN 2009-2014].

PubMed

Meshcheryakova, I S; Mikhailova, T V; Demidova, T N; Kormilitsyna, M I

2016-01-01

to assess the present state of the natural tularemia foci of different landscape epidemiological types, by using individual focal areas as an example. Epizootological monitoring and epidemiological analysis were conducted in the areas of natural tularemia foci of tundra (Wrangel Island), meadow-field (Central Federal District of the Russian Federation), flood-swamp (Arkhangelsk Region, Khanty-Mansi Autonomous District), and steppe (Mongolii) types. Small mammals (organs, blood), tularemia patients' sera, and environniental objects were examined. Molecular genetic and immune serological diagnostic assays were used. The incidence of tularemia in the past decade was analyzed using the maps for the epidemiological examinations of tularemia cases and medical reports. The natural foci of tularemia were established to continue to actively operate. There were 2913 cases of tularemia in the Russian Federation in 2001 to 2014. The flood-swamp natural foci, in which there were summer transmissive tularemia outbreaks, the largest of high occurred in Khanti-Mansiysk in 2013 when a total of 1005 people fell ill, are a special epidemic hazard. Analysis of the tularemia outbreaks suggests that there is a need for continuous epizootological monitoring of the areas of natural tularemia foci for the timely prediction and prevention of epidemic complications. It is noted that there is an unfounded reduction in the scope of preventive measures, and immunoprevention in particular, and a weaker control of the antitularemia immune status in the population residing in the area of active natural foci of tularemia.

Children and encephalitis lethargica: a historical review.

PubMed

Vilensky, Joel A; Foley, Paul; Gilman, Sid

2007-08-01

Between 1917 and the late 1920s, encephalitis lethargica was an epidemic and often lethal neurologic disease. In adults, it typically elicited severe somatic effects, and in particular, various forms of cranial nerve and motor dysfunction. In children, the psychiatric effects were often as severe as the physical consequences. Approximately one third of affected children underwent a rapid transformation from normal behavior to delinquency, often leading to institutionalization. Many neurologic and psychological theories were advanced to explain these severe behavioral changes, and the therapeutic approaches employed ranged from training in dedicated schools to frontal leucotomy. Whereas epidemiologic associations provide both positive and negative support for an etiologic relationship between encephalitis lethargica and the approximately contemporaneous "Spanish" influenza epidemic, previously unutilized data from children provide some of the strongest links between influenza and encephalitis lethargica. Encephalitis lethargica triggered behavioral changes in children that are not duplicated by any other neurologic condition, with the possible exception of traumatic brain injury. These unique behavioral abnormalities may provide the earliest clear indication of new encephalitis lethargica cases, whether alone or in concert with an influenza epidemic.

A Decade of Monitoring HIV Epidemics in Nigeria: Positioning for Post-2015 Agenda.

PubMed

Akinwande, Oluyemisi; Bashorun, Adebobola; Azeez, Aderemi; Agbo, Francis; Dakum, Patrick; Abimiku, Alashle; Bilali, Camara; Idoko, John; Ogungbemi, Kayode

2017-07-01

Nigeria accounts for 9% of the global HIV burden and is a signatory to Millennium Development Goals as well as the post-2015 Sustainable Development Goals. This paper reviews maturation of her HIV M&E system and preparedness for monitoring of the post-2015 agenda. Using the UNAIDS criteria for assessing a functional M&E system, a mixed-methods approach of desk review and expert consultations, was employed. Following adoption of a multi-sectoral M&E system, Nigeria experienced improved HIV coordination at the National and State levels, capacity building for epidemic appraisals, spectrum estimation and routine data quality assessments. National data and systems audit processes were instituted which informed harmonization of tools and indicators. The M&E achievements of the HIV response enhanced performance of the National Health Management Information System (NHMIS) using DHIS2 platform following its re-introduction by the Federal Ministry of Health, and also enabled decentralization of data management to the periphery. A decade of implementing National HIV M&E framework in Nigeria and the recent adoption of the DHIS2 provides a strong base for monitoring the Post 2015 agenda. There is however a need to strengthen inter-sectoral data linkages and reduce the rising burden of data collection at the global level.

Real-time, portable genome sequencing for Ebola surveillance

PubMed Central

Bore, Joseph Akoi; Koundouno, Raymond; Dudas, Gytis; Mikhail, Amy; Ouédraogo, Nobila; Afrough, Babak; Bah, Amadou; Baum, Jonathan HJ; Becker-Ziaja, Beate; Boettcher, Jan-Peter; Cabeza-Cabrerizo, Mar; Camino-Sanchez, Alvaro; Carter, Lisa L.; Doerrbecker, Juiliane; Enkirch, Theresa; Dorival, Isabel Graciela García; Hetzelt, Nicole; Hinzmann, Julia; Holm, Tobias; Kafetzopoulou, Liana Eleni; Koropogui, Michel; Kosgey, Abigail; Kuisma, Eeva; Logue, Christopher H; Mazzarelli, Antonio; Meisel, Sarah; Mertens, Marc; Michel, Janine; Ngabo, Didier; Nitzsche, Katja; Pallash, Elisa; Patrono, Livia Victoria; Portmann, Jasmine; Repits, Johanna Gabriella; Rickett, Natasha Yasmin; Sachse, Andrea; Singethan, Katrin; Vitoriano, Inês; Yemanaberhan, Rahel L; Zekeng, Elsa G; Trina, Racine; Bello, Alexander; Sall, Amadou Alpha; Faye, Ousmane; Faye, Oumar; Magassouba, N’Faly; Williams, Cecelia V.; Amburgey, Victoria; Winona, Linda; Davis, Emily; Gerlach, Jon; Washington, Franck; Monteil, Vanessa; Jourdain, Marine; Bererd, Marion; Camara, Alimou; Somlare, Hermann; Camara, Abdoulaye; Gerard, Marianne; Bado, Guillaume; Baillet, Bernard; Delaune, Déborah; Nebie, Koumpingnin Yacouba; Diarra, Abdoulaye; Savane, Yacouba; Pallawo, Raymond Bernard; Gutierrez, Giovanna Jaramillo; Milhano, Natacha; Roger, Isabelle; Williams, Christopher J; Yattara, Facinet; Lewandowski, Kuiama; Taylor, Jamie; Rachwal, Philip; Turner, Daniel; Pollakis, Georgios; Hiscox, Julian A.; Matthews, David A.; O’Shea, Matthew K.; Johnston, Andrew McD; Wilson, Duncan; Hutley, Emma; Smit, Erasmus; Di Caro, Antonino; Woelfel, Roman; Stoecker, Kilian; Fleischmann, Erna; Gabriel, Martin; Weller, Simon A.; Koivogui, Lamine; Diallo, Boubacar; Keita, Sakoba; Rambaut, Andrew; Formenty, Pierre; Gunther, Stephan; Carroll, Miles W.

2016-01-01

The Ebola virus disease (EVD) epidemic in West Africa is the largest on record, responsible for >28,599 cases and >11,299 deaths 1. Genome sequencing in viral outbreaks is desirable in order to characterize the infectious agent to determine its evolutionary rate, signatures of host adaptation, identification and monitoring of diagnostic targets and responses to vaccines and treatments. The Ebola virus genome (EBOV) substitution rate in the Makona strain has been estimated at between 0.87 × 10−3 to 1.42 × 10−3 mutations per site per year. This is equivalent to 16 to 27 mutations in each genome, meaning that sequences diverge rapidly enough to identify distinct sub-lineages during a prolonged epidemic 2-7. Genome sequencing provides a high-resolution view of pathogen evolution and is increasingly sought-after for outbreak surveillance. Sequence data may be used to guide control measures, but only if the results are generated quickly enough to inform interventions 8. Genomic surveillance during the epidemic has been sporadic due to a lack of local sequencing capacity coupled with practical difficulties transporting samples to remote sequencing facilities 9. In order to address this problem, we devised a genomic surveillance system that utilizes a novel nanopore DNA sequencing instrument. In April 2015 this system was transported in standard airline luggage to Guinea and used for real-time genomic surveillance of the ongoing epidemic. Here we present sequence data and analysis of 142 Ebola virus (EBOV) samples collected during the period March to October 2015. We were able to generate results in less than 24 hours after receiving an Ebola positive sample, with the sequencing process taking as little as 15-60 minutes. We show that real-time genomic surveillance is possible in resource-limited settings and can be established rapidly to monitor outbreaks. PMID:26840485

The wisdom of crowds in action: Forecasting epidemic diseases with a web-based prediction market system.

PubMed

Li, Eldon Y; Tung, Chen-Yuan; Chang, Shu-Hsun

2016-08-01

The quest for an effective system capable of monitoring and predicting the trends of epidemic diseases is a critical issue for communities worldwide. With the prevalence of Internet access, more and more researchers today are using data from both search engines and social media to improve the prediction accuracy. In particular, a prediction market system (PMS) exploits the wisdom of crowds on the Internet to effectively accomplish relatively high accuracy. This study presents the architecture of a PMS and demonstrates the matching mechanism of logarithmic market scoring rules. The system was implemented to predict infectious diseases in Taiwan with the wisdom of crowds in order to improve the accuracy of epidemic forecasting. The PMS architecture contains three design components: database clusters, market engine, and Web applications. The system accumulated knowledge from 126 health professionals for 31 weeks to predict five disease indicators: the confirmed cases of dengue fever, the confirmed cases of severe and complicated influenza, the rate of enterovirus infections, the rate of influenza-like illnesses, and the confirmed cases of severe and complicated enterovirus infection. Based on the winning ratio, the PMS predicts the trends of three out of five disease indicators more accurately than does the existing system that uses the five-year average values of historical data for the same weeks. In addition, the PMS with the matching mechanism of logarithmic market scoring rules is easy to understand for health professionals and applicable to predict all the five disease indicators. The PMS architecture of this study affords organizations and individuals to implement it for various purposes in our society. The system can continuously update the data and improve prediction accuracy in monitoring and forecasting the trends of epidemic diseases. Future researchers could replicate and apply the PMS demonstrated in this study to more infectious diseases and wider geographical areas, especially the under-developed countries across Asia and Africa. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

SIR epidemics with long-range infection in one dimension

NASA Astrophysics Data System (ADS)

Grassberger, Peter

2013-04-01

We study epidemic processes with immunization on very large 1-dimensional lattices, where at least some of the infections are non-local, with rates decaying as power laws p(x) ˜ x-σ-1 for large distances x. When starting with a single infected site, the cluster of infected sites stays always bounded if σ > 1 (and dies with probability 1, if its size is allowed to fluctuate down to zero), but the process can lead to an infinite epidemic for σ < 1. For σ < 0 the behavior is essentially of mean-field type, but for 0 < σ ≤ 1 the behavior is non-trivial, both for the critical and for supercritical cases. For critical epidemics we confirm a previous prediction that the critical exponents controlling the correlation time and the correlation length are simply related to each other, and we verify detailed field theoretic predictions for σ↘1/3. For σ = 1 we find generic power laws with continuously varying exponents even in the supercritical case, and confirm in detail the predicted Kosterlitz-Thouless nature of the transition. Finally, the mass N(t) of supercritical clusters grows for 0 < σ < 1 like a stretched exponential. This implies that networks embedded in 1-d space with power-behaved link distributions have infinite intrinsic dimension (based on the graph distance), but are not small world.

[Seasonal and periodic rhythms of infectious diseases (author's transl)].

PubMed

Knorr, M; Schadewaldt, H

1979-03-01

The causes of epidemics are plainly not the pathogens alone as was initially assumed by Koch's school, predisposition and constitution of the population proved to be equally important. Ever since ancient times problems linked with the "constitutio epidemica" have been topical; the "physis", the "natura hominis" and the invironment of man play an increasingly important role in the symptomatology of disease, as can be gathered from such early documents as the "Corpus hippocraticum". Fracastoro distinguished between contagious and non-contagious epidemics. The casual organisms were considered to be miasmas -- noxious emanations -- or "contagia" i.e. likewise toxic substances. Questions concerning the origin of these miasmas turned attention to the environment (air, soil, water) and even led to astrological medicine. Not until the Renaissance were attempts made to differentiate the usual global words for epidemic, such as "loimos", "lues" and "pestis" with the result that a symptom was used more and more to designate a disease. For example, the symptom fever led to the designation "three-day fever" or "four-day fever", "typhus fever". This terminology made a differential diagnosis difficult to establish, thwarted selection measures to check epidemics and the medical world was thus helpless in explaining the causal agents and the phenomena of epidemics. This is illustrated by some epidemiological examples (ergotism, scurvy, yellow fever, English sweat, diphtheria and malaria). In this connection the "morbus novus", the transformation of the pathogen and the change of the pathogen is discussed. Many questions still left unanswered regarding the seasonal incidence, the fluctuation and disappearance of epidemics over decades or even centuries lead more frequently to sociomedical considerations with respect to the victims of epidemics, their predisposition, constitution and environment exposure term "hospital gangrene" with the modern term "hospitalism", we are not dealing with a transformation but a change of the pathogen. The impressive effects produced by antibiotics resulted in carelessness and along with the unprecedented advances in medicine and engineering we forgot to bear in mind that almost all great steps forward have an adverse side. Hygiene and practical medicine have only made a modest beginning in establishing the contact which should indeed be a matter of course in the hospital.

[Brazilian biomedical and epidemiological research vis-à-vis the UNGASS targets].

PubMed

Bastos, Francisco Inácio; Hacker, Mariana A

2006-04-01

The focus of the present study is the Brazilian response within science, technology and innovation to the targets formulated in the UNGASS document. An analysis was made of items 70-73 of the UNGASS Draft Declaration of Commitment on HIV/AIDS (2001), which defined science, technology and innovation targets relating to HIV/AIDS. The main topics listed in these items were put into operation in the form of keywords, in order to guide systematic searches within the standard biomedicine databases, also including the subdivisions of the Web of Science relating to natural and social sciences. The success of Brazilian research within the field of characterization and isolation of HIV-1 is undeniable. Phase II/III vaccine studies have been developed in Rio de Janeiro, Belo Horizonte and São Paulo. Empirical studies on the monitoring of primary resistance have been developed in specific populations, through the Brazilian HIV Resistance Monitoring Network. Within the field of monitoring secondary resistance, initiatives such as the National Genotyping Network have been highlighted. Two national systems--the Mortality Information System and the Notifiable Diseases Information System (Aids)--and some studies with wider coverage have given rise to work on trends within the epidemic. The production of high-quality generic medications and their free distribution to patients have been highlighted. Brazil has implemented a consistent and diversified response within the field of HIV/AIDS, with studies relating to the development of vaccines, new medications and monitoring of the epidemic.

Taxing Soda: Strategies for Dealing with the Obesity and Diabetes Epidemic.

PubMed

Maa, John

2016-01-01

Over the past several decades, the United States has been experiencing a twin epidemic of obesity and type 2 diabetes. Recently, advocacy efforts to tax sugary drinks, place warning labels on soda, improve nutritional labeling, and reduce sugar overconsumption have swept across the nation to address public health concerns from sugary drinks that strain our nation's health-care resources. In this article, the historical and scientific framework of this public health policy and valuable lessons learned from implementation efforts thus far will be examined to shape the next steps forward for the movement. Additional goals of this article are to share a surgeon's perspective about trends in bariatric surgery and the link between obesity and type 2 diabetes as a result of peripheral insulin resistance.

Association of Kawasaki disease with tropospheric wind patterns.

PubMed

Rodó, Xavier; Ballester, Joan; Cayan, Dan; Melish, Marian E; Nakamura, Yoshikazu; Uehara, Ritei; Burns, Jane C

2011-01-01

The causal agent of Kawasaki disease (KD) remains unknown after more than 40 years of intensive research. The number of cases continues to rise in many parts of the world and KD is the most common cause of acquired heart disease in childhood in developed countries. Analyses of the three major KD epidemics in Japan, major non-epidemic interannual fluctuations of KD cases in Japan and San Diego, and the seasonal variation of KD in Japan, Hawaii, and San Diego, reveals a consistent pattern wherein KD cases are often linked to large-scale wind currents originating in central Asia and traversing the north Pacific. Results suggest that the environmental trigger for KD could be wind-borne. Efforts to isolate the causative agent of KD should focus on the microbiology of aerosols.

Association of Kawasaki disease with tropospheric wind patterns

PubMed Central

Rodó, Xavier; Ballester, Joan; Cayan, Dan; Melish, Marian E.; Nakamura, Yoshikazu; Uehara, Ritei; Burns, Jane C.

2011-01-01

The causal agent of Kawasaki disease (KD) remains unknown after more than 40 years of intensive research. The number of cases continues to rise in many parts of the world and KD is the most common cause of acquired heart disease in childhood in developed countries. Analyses of the three major KD epidemics in Japan, major non-epidemic interannual fluctuations of KD cases in Japan and San Diego, and the seasonal variation of KD in Japan, Hawaii, and San Diego, reveals a consistent pattern wherein KD cases are often linked to large-scale wind currents originating in central Asia and traversing the north Pacific. Results suggest that the environmental trigger for KD could be wind-borne. Efforts to isolate the causative agent of KD should focus on the microbiology of aerosols. PMID:22355668

Optimal Network-based Intervention in the Presence of Undetectable Viruses.

PubMed

Youssef, Mina; Scoglio, Caterina

2014-08-01

This letter presents an optimal control framework to reduce the spread of viruses in networks. The network is modeled as an undirected graph of nodes and weighted links. We consider the spread of viruses in a network as a system, and the total number of infected nodes as the state of the system, while the control function is the weight reduction leading to slow/reduce spread of viruses. Our epidemic model overcomes three assumptions that were extensively used in the literature and produced inaccurate results. We apply the optimal control formulation to crucial network structures. Numerical results show the dynamical weight reduction and reveal the role of the network structure and the epidemic model in reducing the infection size in the presence of indiscernible infected nodes.

Optimal Network-based Intervention in the Presence of Undetectable Viruses

PubMed Central

Youssef, Mina; Scoglio, Caterina

2014-01-01

This letter presents an optimal control framework to reduce the spread of viruses in networks. The network is modeled as an undirected graph of nodes and weighted links. We consider the spread of viruses in a network as a system, and the total number of infected nodes as the state of the system, while the control function is the weight reduction leading to slow/reduce spread of viruses. Our epidemic model overcomes three assumptions that were extensively used in the literature and produced inaccurate results. We apply the optimal control formulation to crucial network structures. Numerical results show the dynamical weight reduction and reveal the role of the network structure and the epidemic model in reducing the infection size in the presence of indiscernible infected nodes. PMID:25422579

Visual rating and the use of image analysis for assessing different symptoms of citrus canker on grapefruit leaves

USDA-ARS?s Scientific Manuscript database

Citrus canker is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac) and infects several citrus species in wet tropical and subtropical citrus growing regions. Accurate, precise and reproducible disease assessment is needed for monitoring epidemics and disease response in breeding...

Pedometers and Brief E-Counseling: Increasing Physical Activity for Overweight Adults

ERIC Educational Resources Information Center

VanWormer, Jeffrey J.

2004-01-01

Physical inactivity has emerged as a public health epidemic and is associated with the rising obesity rate. A multiple-treatments reversal design was utilized to test whether pedometer-aided self-monitoring and brief e-counseling could help 3 overweight adults increase their physical activity. Dependent measures were taken for pedometer steps and…

77 FR 69484 - Agency Forms Undergoing Paperwork Reduction Act Review

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-19

... data, may be used to monitor the effects of change in the health care system, plan health services... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention [30Day-13-0008... provide for the prevention and control of epidemics, and protect the population from public health crises...

Improving the Representativeness of Behavioral and Clinical Surveillance for Persons with HIV in the United States: The Rationale for Developing a Population-Based Approach

PubMed Central

McNaghten, A. D.; Wolfe, Mitchell I.; Onorato, Ida; Nakashima, Allyn K.; Valdiserri, Ronald O.; Mokotoff, Eve; Romaguera, Raul A.; Kroliczak, Alice; Janssen, Robert S.; Sullivan, Patrick S.

2007-01-01

The need for a new surveillance approach to understand the clinical outcomes and behaviors of people in care for HIV evolved from the new challenges for monitoring clinical outcomes in the HAART era, the impact of the epidemic on an increasing number of areas in the US, and the need for representative data to describe the epidemic and related resource utilization and needs. The Institute of Medicine recommended that the Centers for Disease Control and Prevention and the Heath Resources and Services Administration coordinate efforts to survey a random sample of HIV-infected persons in care, in order to more accurately measure the need for prevention and care services. The Medical Monitoring Project (MMP) was created to meet these needs. This manuscript describes the evolution and design of MMP, a new nationally representative clinical outcomes and behavioral surveillance system, and describes how MMP data will be used locally and nationally to identify care and treatment utilization needs, and to plan for prevention interventions and services. PMID:17579722

Nanorobot Hardware Architecture for Medical Defense.

PubMed

Cavalcanti, Adriano; Shirinzadeh, Bijan; Zhang, Mingjun; Kretly, Luiz C

2008-05-06

This work presents a new approach with details on the integrated platform and hardware architecture for nanorobots application in epidemic control, which should enable real time in vivo prognosis of biohazard infection. The recent developments in the field of nanoelectronics, with transducers progressively shrinking down to smaller sizes through nanotechnology and carbon nanotubes, are expected to result in innovative biomedical instrumentation possibilities, with new therapies and efficient diagnosis methodologies. The use of integrated systems, smart biosensors, and programmable nanodevices are advancing nanoelectronics, enabling the progressive research and development of molecular machines. It should provide high precision pervasive biomedical monitoring with real time data transmission. The use of nanobioelectronics as embedded systems is the natural pathway towards manufacturing methodology to achieve nanorobot applications out of laboratories sooner as possible. To demonstrate the practical application of medical nanorobotics, a 3D simulation based on clinical data addresses how to integrate communication with nanorobots using RFID, mobile phones, and satellites, applied to long distance ubiquitous surveillance and health monitoring for troops in conflict zones. Therefore, the current model can also be used to prevent and save a population against the case of some targeted epidemic disease.

Comparing Multi-Informant Assessment Measures of Parental Monitoring and Their Links with Adolescent Delinquent Behavior

PubMed Central

Augenstein, Tara M.; Thomas, Sarah A.; Ehrlich, Katherine B.; Daruwala, Samantha; Reyes, Shelby M.; Chrabaszcz, Jeffrey S.; De Los Reyes, Andres

2016-01-01

SYNOPSIS Objective Parents’ poor monitoring of adolescents’ whereabouts and activities is commonly linked to adolescents’ increased engagement in delinquent behaviors. Yet, different domains of parental monitoring (parental monitoring behaviors vs. parental knowledge) and reports from multiple informants (parent vs. adolescent) may vary in their links to delinquent behavior. Design Seventy-four parental caregivers and 74 adolescents completed survey measures of parental monitoring and knowledge, and adolescents completed self-report surveys of delinquent behavior. Results We observed low-to-moderate magnitudes of correspondence between parent- and adolescent-reports of parental monitoring behaviors and parental knowledge. Adolescent self-reported delinquent behavior related to parent and adolescent reports of parental monitoring behaviors and parental knowledge, with adolescents who self-reported engagement in delinquent behaviors evidencing lower levels of parental knowledge and higher levels of poor monitoring compared to adolescents who did not self-report engagement in delinquent behaviors. Adolescent self-reported engagement in delinquent behaviors evidenced stronger links to parental monitoring when based on adolescent reports of monitoring (relative to parent reports), whereas stronger links held between adolescent self-reported delinquent behavior and parental knowledge when based on parent reports of knowledge (relative to adolescent reports). Conclusions Links between monitoring and adolescents’ delinquent behavior vary by the kind of monitoring measure completed as well as the informant completing the measure. These findings inform measurement selection in research and clinical assessments of parental monitoring and adolescent delinquent behavior. PMID:27482171

Pesticides and human diabetes: a link worth exploring?

PubMed

Swaminathan, K

2013-11-01

It is no exaggeration to claim that the 'diabetes epidemic' has become a 'runaway train' causing huge health and economic consequences, especially in the developing nations. Traditionally, the risk factors for diabetes have largely focused on genetics and lifestyle. Great emphasis is placed on lifestyle measures and finding novel pharmacological treatment options to combat diabetes, but there is increasing evidence linking environmental pollutants, especially pesticides, to the development of insulin resistance and Type 2 diabetes. Pesticide use has increased dramatically worldwide and the effects of pesticides on glucose metabolism are too significant for a possible diabetogenic link to be dismissed. The aim of this review article was to assess the links between pesticides and human diabetes with the goal of stimulating further research in this area. © 2013 The Author. Diabetic Medicine © 2013 Diabetes UK.

Zika Virus Infection and Microcephaly: Evidence for a Causal Link.

PubMed

Wang, Jin-Na; Ling, Feng

2016-10-20

Zika virus (ZIKV) is a flavivirus related to the Dengue, yellow fever and West Nile viruses. Since the explosive outbreaks of ZIKV in Latin America in 2015, a sudden increase in the number of microcephaly cases has been observed in infants of women who were pregnant when they contracted the virus. The severity of this condition raises grave concerns, and extensive studies on the possible link between ZIKV infection and microcephaly have been conducted. There is substantial evidence suggesting that there is a causal link between ZIKV and microcephaly, however, future studies are warranted to solidify this association. To summarize the most recent evidence on this issue and provide perspectives for future studies, we reviewed the literature to identify existing evidence of the causal link between ZIKV infection and microcephaly within research related to the epidemics, laboratory diagnosis, and possible mechanisms.

Effects of Sudden Oak Death on the crown fire ignition potential of tanoak (Lithocarpus densiflorus)

Treesearch

Howard Kuljian; J. Morgan Varner

2010-01-01

In the face of the sudden oak death (SOD) epidemic, decreasing foliar moisture content (FMC) of tanoak (Lithocarpus densiflorus) has land managers, fire managers, and property owners concerned with the increased possibility of crown fire in affected areas. A need exists to link local SOD-affected foliar moisture content (FMC) values and current FMC...

Identification of an atypical strain of Toxoplasma gondii as the cause of a waterborne outbreak of toxoplasmosis in Santa IsabeldoIvai, Brazil

USDA-ARS?s Scientific Manuscript database

We have identified an atypical strain of Toxoplasmagondii as the causative agent of the 2001 outbreak of toxoplasmosis in Santa Isabel do Ivai, Brazil, which resulted in approximately 426 human infections. The epidemic clone was isolated from multiple water filters collected from a cistern linked ep...

Maternal Obesity and Developmental Programming of Metabolic Disorders in Offspring: Evidence from Animal Models

PubMed Central

Li, M.; Sloboda, D. M.; Vickers, M. H.

2011-01-01

The incidence of obesity and overweight has reached epidemic proportions in the developed world as well as in those countries transitioning to first world economies, and this represents a major global health problem. Concern is rising over the rapid increases in childhood obesity and metabolic disease that will translate into later adult obesity. Although an obesogenic nutritional environment and increasingly sedentary lifestyle contribute to our risk of developing obesity, a growing body of evidence links early life nutritional adversity to the development of long-term metabolic disorders. In particular, the increasing prevalence of maternal obesity and excess maternal weight gain has been associated with a heightened risk of obesity development in offspring in addition to an increased risk of pregnancy-related complications. The mechanisms that link maternal obesity to obesity in offspring and the level of gene-environment interactions are not well understood, but the early life environment may represent a critical window for which intervention strategies could be developed to curb the current obesity epidemic. This paper will discuss the various animal models of maternal overnutrition and their importance in our understanding of the mechanisms underlying altered obesity risk in offspring. PMID:21969822

Management of Pregnant Women with Type 2 Diabetes Mellitus and the Consequences of Fetal Programming in Their Offspring.

PubMed

Berry, Diane C; Boggess, Kim; Johnson, Quinetta B

2016-05-01

The obesity epidemic has fueled an epidemic of prediabetes and type 2 diabetes mellitus in women of childbearing age. This paper examines the state of the science on preconception and pregnancy management of women with type 2 diabetes to optimize outcomes for the women and their infants. In addition, the consequence of fetal programming as a result of suboptimal maternal glycemic control is discussed. The paper focuses on type 2 diabetes, not type 1 diabetes or gestational diabetes. Management of women with type 2 diabetes includes preconception counseling, preconception weight management and weight loss, proper weight gain during pregnancy, self-monitoring of blood glucose levels, medication, medical nutrition therapy, and exercise.

Two viral strains and a possible novel recombinant are responsible for the explosive injecting drug use-associated HIV type 1 epidemic in Estonia.

PubMed

Zetterberg, Veera; Ustina, Valentina; Liitsola, Kirsi; Zilmer, Kai; Kalikova, Nelli; Sevastianova, Ksenia; Brummer-Korvenkontio, Henrikki; Leinikki, Pauli; Salminen, Mika O

2004-11-01

HIV-1 infection has been rare in Estonia. In 2000, an explosive epidemic among injecting drug users was detected in the Eastern border region, resulting in 3603 newly reported cases by the end of 2003. The molecular epidemiology of the outbreak was studied to establish whether the Estonian epidemic is linked to the epidemics in Eastern Europe. Over 200 newly infected individuals were prospectively sampled from June 2000 to March 2002 in a geographically representative way, with known dates of diagnosis and information of probable route of transmission. Viral regions coding for two viral gene regions were directly sequenced from plasma viral RNA and phylogenetically analyzed. In addition, a larger region coding for the entire env gene was sequenced from one sample and studied for indications of possible recombinant structure. The Estonian HIV outbreak was found to be caused by simultaneous introduction of two strains: a minor subtype A strain very similar to the Eastern European subtype A strain (approximately 8% of cases), and a second major strain (77%) found to be most closely related to the CRF06-cpx strain, previously described only from African countries. The variability in the two clusters was very low, suggesting point source introductions. Ten percent of cases seemed to be newly generated recombinants of the A and CRF06-cpx strains. Analysis of viral diversification over time revealed a rate of change within the V3 region of 0.83%/year for the CRF06-cpx strain, consistent with findings from other subtypes. Due to the relatively frequently found novel recombinant forms, the Estonian HIV-1 epidemic may allow studies of coinfection and intersubtype recombination in detail.

Population Explosions of Tiger Moth Lead to Lepidopterism Mimicking Infectious Fever Outbreaks

PubMed Central

Wills, Pallara Janardhanan; Anjana, Mohan; Nitin, Mohan; Varun, Raghuveeran; Sachidanandan, Parayil; Jacob, Tharaniyil Mani; Lilly, Madhavan; Thampan, Raghava Varman; Karthikeya Varma, Koyikkal

2016-01-01

Lepidopterism is a disease caused by the urticating scales and toxic fluids of adult moths, butterflies or its caterpillars. The resulting cutaneous eruptions and systemic problems progress to clinical complications sometimes leading to death. High incidence of fever epidemics were associated with massive outbreaks of tiger moth Asota caricae adult populations during monsoon in Kerala, India. A significant number of monsoon related fever characteristic to lepidopterism was erroneously treated as infectious fevers due to lookalike symptoms. To diagnose tiger moth lepidopterism, we conducted immunoblots for tiger moth specific IgE in fever patients’ sera. We selected a cohort of patients (n = 155) with hallmark symptoms of infectious fevers but were tested negative to infectious fevers. In these cases, the total IgE was elevated and was detected positive (78.6%) for tiger moth specific IgE allergens. Chemical characterization of caterpillar and adult moth fluids was performed by HPLC and GC-MS analysis and structural identification of moth scales was performed by SEM analysis. The body fluids and chitinous scales were found to be highly toxic and inflammatory in nature. To replicate the disease in experimental model, wistar rats were exposed to live tiger moths in a dose dependant manner and observed similar clinico-pathological complications reported during the fever epidemics. Further, to link larval abundance and fever epidemics we conducted cointegration test for the period 2009 to 2012 and physical presence of the tiger moths were found to be cointegrated with fever epidemics. In conclusion, our experiments demonstrate that inhalation of aerosols containing tiger moth fluids, scales and hairs cause systemic reactions that can be fatal to human. All these evidences points to the possible involvement of tiger moth disease as a major cause to the massive and fatal fever epidemics observed in Kerala. PMID:27073878

Widespread epidemic cholera caused by a restricted subset of Vibrio cholerae clones.

PubMed

Moore, S; Thomson, N; Mutreja, A; Piarroux, R

2014-05-01

Since 1817, seven cholera pandemics have plagued humankind. As the causative agent, Vibrio cholerae, is autochthonous in the aquatic ecosystem and some studies have revealed links between outbreaks and fluctuations in climatic and aquatic conditions, it has been widely assumed that cholera epidemics are triggered by environmental factors that promote the growth of local bacterial reservoirs. However, mounting epidemiological findings and genome sequence analysis of clinical isolates have indicated that epidemics are largely unassociated with most of the V. cholerae strains in aquatic ecosystems. Instead, only a specific subset of V. cholerae El Tor 'types' appears to be responsible for current epidemics. A recent report examining the evolution of a variety of V. cholerae strains indicates that the current pandemic is monophyletic and originated from a single ancestral clone that has spread globally in successive waves. In this review, we examine the clonal nature of the disease, with the example of the recent history of cholera in the Americas. Epidemiological data and genome sequence-based analysis of V. cholerae isolates demonstrate that the cholera epidemics of the 1990s in South America were triggered by the importation of a pathogenic V. cholerae strain that gradually spread throughout the region until local outbreaks ceased in 2001. Latin America remained almost unaffected by the disease until a new toxigenic V. cholerae clone was imported into Haiti in 2010. Overall, cholera appears to be largely caused by a subset of specific V. cholerae clones rather than by the vast diversity of V. cholerae strains in the environment. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

Estimating the reproductive numbers for the 2008–2009 cholera outbreaks in Zimbabwe

PubMed Central

Mukandavire, Zindoga; Liao, Shu; Wang, Jin; Gaff, Holly; Smith, David L.; Morris, J. Glenn

2011-01-01

Cholera remains an important global cause of morbidity and mortality, capable of causing periodic epidemic disease. Beginning in August 2008, a major cholera epidemic occurred in Zimbabwe, with 98,585 reported cases and 4,287 deaths. The dynamics of such outbreaks, particularly in nonestuarine regions, are not well understood. We explored the utility of mathematical models in understanding transmission dynamics of cholera and in assessing the magnitude of interventions necessary to control epidemic disease. Weekly data on reported cholera cases were obtained from the Zimbabwe Ministry of Health and Child Welfare (MoHCW) for the period from November 13, 2008 to July 31, 2009. A mathematical model was formulated and fitted to cumulative cholera cases to estimate the basic reproductive numbers R0 and the partial reproductive numbers from all 10 provinces for the 2008–2009 Zimbabwe cholera epidemic. Estimated basic reproductive numbers were highly heterogeneous, ranging from a low value of just above unity to 2.72. Partial reproductive numbers were also highly heterogeneous, suggesting that the transmission routes varied by province; human-to-human transmission accounted for 41–95% of all transmission. Our models suggest that the underlying patterns of cholera transmission varied widely from province to province, with a corresponding variation in the amenability of outbreaks in different provinces to control measures such as immunization. These data underscore the heterogeneity of cholera transmission dynamics, potentially linked to differences in environment, socio-economic conditions, and cultural practices. The lack of traditional estuarine reservoirs combined with these estimates of R0 suggest that mass vaccination against cholera deployed strategically in Zimbabwe and surrounding regions could prevent future cholera epidemics and eventually eliminate cholera from the region. PMID:21518855

[Epidemic outbreak of 81 cases of brucellosis following the consumption of fresh cheese without pasteurization].

PubMed

Castell Monsalve, J; Rullán, J V; Peiró Callizo, E F; Nieto-Sandoval Alcolea, A

1996-01-01

In spite of the great effort that has been made in recent years in Castilla-La Mancha to control brucelosis, a lack of awareness on the part of producers and consumers leads to major epidemic outbreak, such as the one described below. A description of the outbreak is described and a study is conducted of cases and controls to determine the factors which are responsible for the epidemic. Unadjusted and adjusted Odds Ratios (O.R.) are obtained together with their confidence intervals, for the main epidemiological factors studied. A total of 81 cases of brucelosis were recorded in a period of 25 weeks. All the cases occurred in the same borough or were in some way linked to it. In the case and controls study no differences were found with regard to age, sex, contact with livestock or the consumption of pasteurised milk or cheese. A strong link was established between the illness and the consumption of home-made cottage cheese prepared by a small-scale producer in the borough, (O.R. = 311.9; C.I. = 95% = 41.48-12735)., whose livestock turned out to be infected with Brucella Mellitensis. This outbreak showed that in Spain, there is a risk of contracting brucelosis by consuming non-pasteurised dairy products, particularly cheese, when these are not subjected to the normal sanitary and health controls. The benefits of epidemiological research in the search for cases and determining the factors responsible for the outbreak are also demonstrated. An intensification of controls, the cleansing of the herds and flocks and health education in general, are suitable instruments for controlling this zoonosis in Spain.

The iatrogenic epidemic of prescription drug abuse: county-level determinants of opioid availability and abuse.

PubMed

Wright, Eric R; Kooreman, Harold E; Greene, Marion S; Chambers, R Andrew; Banerjee, Aniruddha; Wilson, Jeffrey

2014-05-01

Opioid use and abuse in the United States continues to expand at an alarming rate. In this study, we examine the county-level determinants of the availability and abuse of prescription opioids to better understand the socio-ecological context, and in particular the role of the healthcare delivery system, on the prescription drug abuse epidemic. We use community-level information, data from Indiana's prescription drug monitoring program in 2011, and geospatial regression methods to identify county-level correlates of the availability and abuse of prescription opioids among Indiana's 92 counties. The findings suggest that access to healthcare generally, and to dentists and pharmacists in particular, increases the availability of prescription opioids in communities, which, in turn, is associated with higher rates of opioid abuse. The results suggest that the structure of the local healthcare system is a major determinant of community-level access to opioids adding to a growing body of evidence that the problem of prescription opioid abuse is, at least in part, an "iatrogenic epidemic." Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Gender-specific mediational links between parenting styles, parental monitoring, impulsiveness, drinking control, and alcohol-related problems.

PubMed

Patock-Peckham, Julie A; King, Kevin M; Morgan-Lopez, Antonio A; Ulloa, Emilio C; Moses, Jennifer M Filson

2011-03-01

Recently, it has been suggested that traits may dynamically change as conditions change. One possible mechanism that may influence impulsiveness is parental monitoring. Parental monitoring reflects a knowledge regarding one's offspring's whereabouts and social connections. The aim of this investigation was to examine potential gender-specific parental influences to impulsiveness (general behavioral control), control over one's own drinking (specific behavioral control), and alcohol-related problems among individuals in a period of emerging adulthood. Direct and mediational links between parenting styles (permissive, authoritarian, and authoritative), parental monitoring, impulsiveness, drinking control, and alcohol-related problems were investigated. A multiple-group, SEM model with (316 women, 265 men) university students was examined. In general, the overall pattern among male and female respondents was distinct. For daughters, perceptions of a permissive father were indirectly linked to more alcohol-related problems through lower levels of monitoring by fathers and more impulsive symptoms. Perceptions of an authoritative father were also indirectly linked to fewer impulsive symptoms through higher levels of monitoring by fathers among daughters. For men, perceptions of a permissive mother were indirectly linked to more alcohol-related problems through lower levels of monitoring by mothers and more impulsive symptoms. For sons, perceptions of mother authoritativeness were indirectly linked to fewer alcohol-related problems through more monitoring by mothers and fewer impulsive symptoms. Monitoring by an opposite-gender parent mediated the link between parenting styles (i.e., permissive, authoritative) on impulsiveness.

Impacts of hot and cold temperature extremes on hospital admissions for cardiovascular diseases

NASA Astrophysics Data System (ADS)

Davídkovová, H.; Kyselý, J.; Kříž, B.

2010-09-01

Elevated mortality associated with high ambient temperatures in summer represents one of the main impacts of weather extremes on human society. Increases in mortality during heat waves were examined in many European countries; much less is known about the effects of heat waves on morbidity, measured for example by the number of hospital admissions. Relatively less understood is also cold-related mortality and morbidity in winter, when the relationships between weather and human health are more complex, less direct, and confounded by other factors such as epidemics of influenza/acute respiratory infections. The present study examines links between hot and cold temperature extremes and daily hospital admissions for cardiovascular diseases in the population of the Czech Republic over 1994-2007. We make use of a recently completed database of all admissions for cardiovascular diseases to hospitals in the area of the Czech Republic since 1994, with a detailed classification of diseases and detailed information concerning each patient (in total 1,467,675 hospital admissions over 1994-2007). The main goals of the study are (i) to identify excess/deficit morbidity during and after periods of heat waves in summer and cold spells in winter, (ii) to compare the links for individual diseases (e.g. acute myocardial infarction, I21; angina pectoris, I20; cerebral infarction, I63; brain ischemia, I64) and to identify those diagnoses that are most closely linked to weather, (iii) to identify population groups most vulnerable to temperature extremes, and (iv) to compare the links to temperature extremes for morbidity and mortality. Periods when morbidity data were affected by epidemics of influenza and acute respiratory infections in winter were excluded from the analysis.

Developmental origins of type 2 diabetes: a perspective from China.

PubMed

Ma, R C W; Tsoi, K Y; Tam, W H; Wong, C K C

2017-07-01

There has been a marked increase in the prevalence of diabetes in Asia, including China, over the last few decades. While the increased prevalence of diabetes has often been attributed to the nutritional transition associated with recent economic development, emerging data suggest that early-life exposures also play a major role in shaping developmental trajectories, and contributes to alter an individual's susceptibility to diabetes and other non-communicable diseases (NCDs). Early-life exposures such as in utero exposure to undernutrition has been consistently linked with later risk of diabetes and obesity. Furthermore, in utero exposure to maternal hyperglycemia, maternal obesity and excess gestational weight gain are all linked with increased childhood obesity and later risk of diabetes. Emerging data have also highlighted the potential link between early-feeding practices, the role of one-carbon metabolism in metabolic programming and endocrine disrupting chemicals (EDCs) with later risk of diabetes. These different developmental exposures may all be highly relevant to the current epidemic of diabetes in China. For example, the prevalence of gestational diabetes has increased markedly over the last two decades, and may contribute to the diabetes epidemic by driving macrosomia, childhood obesity and later risk of diabetes. In order to address the current burden of diabetes, a lifecourse perspective, incorporating multisectoral efforts from public health policy down to the individuals, will be needed. Several major initiatives have been launched in China as part of its national plans for NCD prevention and treatment, and the experience from these efforts would be invaluable.

Long-term and short-term action-effect links and their impact on effect monitoring.

PubMed

Wirth, Robert; Steinhauser, Robert; Janczyk, Markus; Steinhauser, Marco; Kunde, Wilfried

2018-04-23

People aim to produce effects in the environment, and according to ideomotor theory, actions are selected and executed via anticipations of their effects. Further, to ensure that an action has been successful and an effect has been realized, we must be able to monitor the consequences of our actions. However, action-effect links might vary between situations, some might apply for a majority of situations, while others might only apply to special occasions. With a combination of behavioral and electrophysiological markers, we show that monitoring of self-produced action effects interferes with other tasks, and that the length of effect monitoring is determined by both, long-term action-effect links that hold for most situations, and short-term action-effect links that emerge from a current setting. Effect monitoring is fast and frugal when these action-effect links allow for valid anticipation of action effects, but otherwise effect monitoring takes longer and delays a subsequent task. Specific influences of long-term and short-term links on the P1/N1 and P3a further allow to dissect the temporal dynamics of when these links interact for the purpose of effect monitoring. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Dynamic Forecasting of Zika Epidemics Using Google Trends

PubMed Central

Jin, Yuan; Huang, Yong; Lin, Baihan; An, Xiaoping; Feng, Dan; Tong, Yigang

2017-01-01

We developed a dynamic forecasting model for Zika virus (ZIKV), based on real-time online search data from Google Trends (GTs). It was designed to provide Zika virus disease (ZVD) surveillance and detection for Health Departments, and predictive numbers of infection cases, which would allow them sufficient time to implement interventions. In this study, we found a strong correlation between Zika-related GTs and the cumulative numbers of reported cases (confirmed, suspected and total cases; p<0.001). Then, we used the correlation data from Zika-related online search in GTs and ZIKV epidemics between 12 February and 20 October 2016 to construct an autoregressive integrated moving average (ARIMA) model (0, 1, 3) for the dynamic estimation of ZIKV outbreaks. The forecasting results indicated that the predicted data by ARIMA model, which used the online search data as the external regressor to enhance the forecasting model and assist the historical epidemic data in improving the quality of the predictions, are quite similar to the actual data during ZIKV epidemic early November 2016. Integer-valued autoregression provides a useful base predictive model for ZVD cases. This is enhanced by the incorporation of GTs data, confirming the prognostic utility of search query based surveillance. This accessible and flexible dynamic forecast model could be used in the monitoring of ZVD to provide advanced warning of future ZIKV outbreaks. PMID:28060809

Dynamic Forecasting of Zika Epidemics Using Google Trends.

PubMed

Teng, Yue; Bi, Dehua; Xie, Guigang; Jin, Yuan; Huang, Yong; Lin, Baihan; An, Xiaoping; Feng, Dan; Tong, Yigang

2017-01-01

We developed a dynamic forecasting model for Zika virus (ZIKV), based on real-time online search data from Google Trends (GTs). It was designed to provide Zika virus disease (ZVD) surveillance and detection for Health Departments, and predictive numbers of infection cases, which would allow them sufficient time to implement interventions. In this study, we found a strong correlation between Zika-related GTs and the cumulative numbers of reported cases (confirmed, suspected and total cases; p<0.001). Then, we used the correlation data from Zika-related online search in GTs and ZIKV epidemics between 12 February and 20 October 2016 to construct an autoregressive integrated moving average (ARIMA) model (0, 1, 3) for the dynamic estimation of ZIKV outbreaks. The forecasting results indicated that the predicted data by ARIMA model, which used the online search data as the external regressor to enhance the forecasting model and assist the historical epidemic data in improving the quality of the predictions, are quite similar to the actual data during ZIKV epidemic early November 2016. Integer-valued autoregression provides a useful base predictive model for ZVD cases. This is enhanced by the incorporation of GTs data, confirming the prognostic utility of search query based surveillance. This accessible and flexible dynamic forecast model could be used in the monitoring of ZVD to provide advanced warning of future ZIKV outbreaks.

Pepino mosaic virus genotype shift in North America and development of a loop-mediated isothermal amplification for rapid genotype identification

PubMed Central

2013-01-01

Background Pepino mosaic, once an emerging disease a decade ago, has become endemic on greenhouse tomatoes worldwide in recent years. Three distinct genotypes of Pepino mosaic virus (PepMV), including EU, US1 and CH2 have been recognized. Our earlier study conducted in 2006–2007 demonstrated a predominant EU genotype in Canada and United States. The objective of the present study was to monitor the dynamic of PepMV genetic composition and its current status in North America. Results Through yearly monitoring efforts in 2009–2012, we detected a dramatic shift in the prevalent genotype of PepMV from the genotype EU to CH2 in North America since early 2010, with another shift from CH2 to US1 occurring in Mexico only two years later. Through genetic diversity analysis using the coat protein gene, such genotype shifting of PepMV in North America was linked to the positive identification of similar sequence variants in two different commercial tomato seed sources used for scion and rootstock, respectively. To allow for a quick identification, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) system was developed and demonstrated to achieve a rapid identification for each of the three genotypes of PepMV, EU, US1 and CH2. Conclusion Through systemic yearly monitoring and genetic diversity analysis, we identified a linkage between the field epidemic isolates and those from commercial tomato seed lots as the likely sources of initial PepMV inoculum that resulted in genetic shifting as observed on greenhouse tomatoes in North America. Application of the genotype-specific RT-LAMP system would allow growers to efficiently determine the genetic diversity on their crops. PMID:23587202

Characteristics of the perception of different severity measures of citrus canker and the relations between the various symptom types

USDA-ARS?s Scientific Manuscript database

Citrus canker is a disease of citrus and is caused by the bacterial pathogen Xanthomonas axonopodis pv citri (Xac). Ways of managing the disease are being sought, and accurate, precise, reproducible disease assessment is needed for monitoring epidemics. The objective of this study was to investigate...

Analysis of populations of the sudden oak death pathogen in Oregon forests

Treesearch

Zhian N. Kamvar; Everett M. Hansen; Alan M. Kanaskie; Meredith M. Larsen; Niklaus J. Grünwald

2017-01-01

Sudden oak death, caused by the oomycete Phytophthora ramorum, was first discovered in California toward the end of the 20th century and subsequently emerged on tanoak forests in Oregon before its first detection in 2001 by aerial surveys. The Oregon Department of Forestry has since monitored the epidemic and sampled symptomatic tanoak trees from...

[Mathematical models and epidemiological analysis].

PubMed

Gerasimov, A N

2010-01-01

The limited use of mathematical simulation in epidemiology is due not only to the difficulty of monitoring the epidemic process and identifying its parameters but also to the application of oversimplified models. It is shown that realistic reproduction of actual morbidity dynamics requires taking into account heterogeneity and finiteness of the population and seasonal character of pathogen transmission mechanism.

Monitoring occurrence and distribution of Phytophthora species in forest streams in North Carolina using bait and filtration methods

Treesearch

Jaesoon Hwang; S.W. Oak; S.N. Jeffers

2009-01-01

The recent epidemics of sudden oak death, caused by Phytophthora ramorum, in the coastal forests of California and southwest Oregon have drawn attention to other species of Phytophthora present in natural ecosystems that may threaten forest tree health. Since Phytophthora species are well adapted to aquatic...

Urethral lymphogranuloma venereum infections in men with anorectal lymphogranuloma venereum and their partners: the missing link in the current epidemic?

PubMed

de Vrieze, Nynke Hesselina Neeltje; van Rooijen, Martijn; Speksnijder, Arjen Gerard Cornelis Lambertus; de Vries, Henry John C

2013-08-01

Urethral lymphogranuloma venereum (LGV) is not screened routinely. We found that in 341 men having sex with men with anorectal LGV, 7 (2.1%) had concurrent urethral LGV. Among 59 partners, 4 (6.8%) had urethral LGV infections. Urethral LGV is common, probably key in transmission, and missed in current routine LGV screening algorithms.

An Active Living Perspective on Recreation Research: Examples of Urban Trail Use and Suggestions for Further Involvement

Treesearch

Paul H. Gobster

2004-01-01

By now the statistics are all too familiar: rates of obesity and incidents of related diseases such as diabetes, heart disease, and depression have reached epidemic proportions among US adults and children. These conditions have been linked along with other factors such as nutrition to our increasingly sedentary lifestyles brought on by changes in technology in our...

[Emerging and reemerging diseases: a health problem in the Americas].

PubMed

Ridel, Guillermo Mesa; Luis, Iraida Rodríguez; Teja, Julio

2004-04-01

In the Region of the Americas the emerging and reemerging infectious diseases that had the greatest impact on health, in terms of their incidence and the number of deaths that they caused during the five-year period of 1999-2003, were: malaria, yellow fever, dengue hemorrhagic fever, AIDS, anthrax, and SARS, as well as infection by hantavirus and by West Nile virus. The appearance of epidemics of emerging and reemerging diseases is related to biological, social, and economic factors. Growth in international trade, the movement of large numbers of people across national borders, the variability and genetic adaptability of the causative microorganisms, and inefficiencies in public health systems help to spread infections and epidemics. To avoid or reduce the serious effects of these epidemics, countries should give priority in their national agendas to surveillance of emerging and reemerging diseases and should implement a set of measures to combat the diseases. The most important of these measures is to develop a strategy that is based on early warning and rapid response mechanisms, with personnel and laboratories as well as communications networks that link laboratories with health service providers. This strategy should be backed by priority funding and adequate policies.

Epidemic outbreaks in growing scale-free networks with local structure

NASA Astrophysics Data System (ADS)

Ni, Shunjiang; Weng, Wenguo; Shen, Shifei; Fan, Weicheng

2008-09-01

The class of generative models has already attracted considerable interest from researchers in recent years and much expanded the original ideas described in BA model. Most of these models assume that only one node per time step joins the network. In this paper, we grow the network by adding n interconnected nodes as a local structure into the network at each time step with each new node emanating m new edges linking the node to the preexisting network by preferential attachment. This successfully generates key features observed in social networks. These include power-law degree distribution pk∼k, where μ=(n-1)/m is a tuning parameter defined as the modularity strength of the network, nontrivial clustering, assortative mixing, and modular structure. Moreover, all these features are dependent in a similar way on the parameter μ. We then study the susceptible-infected epidemics on this network with identical infectivity, and find that the initial epidemic behavior is governed by both of the infection scheme and the network structure, especially the modularity strength. The modularity of the network makes the spreading velocity much lower than that of the BA model. On the other hand, increasing the modularity strength will accelerate the propagation velocity.

Thermoregulatory behaviour affects prevalence of chytrid fungal infection in a wild population of Panamanian golden frogs

PubMed Central

Richards-Zawacki, Corinne L.

2010-01-01

Predicting how climate change will affect disease dynamics requires an understanding of how the environment affects host–pathogen interactions. For amphibians, global declines and extinctions have been linked to a pathogenic chytrid fungus, Batrachochytrium dendrobatidis. Using a combination of body temperature measurements and disease assays conducted before and after the arrival of B. dendrobatidis, this study tested the hypothesis that body temperature affects the prevalence of infection in a wild population of Panamanian golden frogs (Atelopus zeteki). The timing of first detection of the fungus was consistent with that of a wave of epidemic infections spreading south and eastward through Central America. During the epidemic, many golden frogs modified their thermoregulatory behaviour, raising body temperatures above their normal set point. Odds of infection decreased with increasing body temperature, demonstrating that even slight environmental or behavioural changes have the potential to affect an individual's vulnerability to infection. The thermal dependency of the relationship between B. dendrobatidis and its amphibian hosts demonstrates how the progression of an epidemic can be influenced by complex interactions between host and pathogen phenotypes and the environments in which they are found. PMID:19864287

Climate and cholera in KwaZulu-Natal, South Africa: the role of environmental factors and implications for epidemic preparedness.

PubMed

Mendelsohn, Joshua; Dawson, Terry

2008-03-01

A cholera epidemic that took place in KwaZulu-Natal, South Africa (2000-2001) was employed to investigate the impact of climatic and environmental drivers on cholera dynamics. Precipitation (PRE), sea surface temperature (SST) and chlorophyll-a (CHL-a) data acquired from publicly available satellite and ground measurements were analysed together with disease incidence in an effort to assess the environmental contribution to the outbreak. SST (r(2)=0.749, lag=0 months) and PRE (r(2)=0.744, lag=2 months) showed strong associations with incidence. CHL-a showed a moderately strong (r(2)=0.656, lag=6 months) association with incidence while sea surface height (SSH) demonstrated a weak relationship with incidence (r(2)=0.326, lag=5 months). Our analysis tentatively supports a coastal transmission hypothesis, heavily influenced by localized PRE extremes. The role of SSH is likely attenuated by local coastal topography. Future work should clarify the mechanism linking coastal cholera reservoirs and the regional climate system to outbreaks in this region. Finally, we discuss benefits of further research in this area using extended remotely sensed and epidemiological datasets towards the development of early-warning systems and enhanced epidemic preparedness.

Homeostatic theory of obesity

PubMed Central

2015-01-01

Health is regulated by homeostasis, a property of all living things. Homeostasis maintains equilibrium at set-points using feedback loops for optimum functioning of the organism. Imbalances in homeostasis causing overweight and obesity are evident in more than 1 billion people. In a new theory, homeostatic obesity imbalance is attributed to a hypothesized ‘Circle of Discontent’, a system of feedback loops linking weight gain, body dissatisfaction, negative affect and over-consumption. The Circle of Discontent theory is consistent with an extensive evidence base. A four-armed strategy to halt the obesity epidemic consists of (1) putting a stop to victim-blaming, stigma and discrimination; (2) devalorizing the thin-ideal; (3) reducing consumption of energy-dense, low-nutrient foods and drinks; and (4) improving access to plant-based diets. If fully implemented, interventions designed to restore homeostasis have the potential to halt the obesity epidemic. PMID:28070357

A possible outbreak of swine influenza, 1892.

PubMed

Morens, David M; Taubenberger, Jeffery K

2014-02-01

Influenza A viruses are globally enzootic in swine populations. Swine influenza has been recognised only since 1918, but an anecdotal report suggests that a swine-influenza epizootic might have occurred in England in 1892, at the same time as an explosive epidemic (or pandemic recurrence) of human influenza. This outbreak suggests that the ecobiological association between human and swine influenza could extend to before 1918. By contrast with the recent documentation of swine influenza, influenza in horses has been well documented for hundreds of years, and was often linked temporally and geographically to epidemics of human influenza. Both decreased contact between people and horses, and the concomitant increase in swine production over the past century, might have altered the character and dynamics of influenza host-switch events between people and domestic mammals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Earth System Science at NASA: Teleconnections Between Sea Surface Temperature and Epidemics in Africa

NASA Technical Reports Server (NTRS)

Meeson, Blanche W.

2000-01-01

The research carried out in the Earth Sciences in NASA and at NASA's Goddard Space Flight Center will be the focus of the presentations. In addition, one research project that links sea surface temperature to epidemics in Africa will be highlighted. At GSFC research interests span the full breath of disciplines in Earth Science. Branches and research groups focus on areas as diverse as planetary geomagnetics and atmospheric chemistry. These organizations focus on atmospheric sciences (atmospheric chemistry, climate and radiation, regional processes, atmospheric modeling), hydrological sciences (snow, ice, oceans, and seasonal-to-interannual prediction), terrestrial physics (geology, terrestrial biology, land-atmosphere interactions, geophysics), climate modeling (global warming, greenhouse gases, climate change), on sensor development especially using lidar and microwave technologies, and on information technologies, that enable support of scientific and technical research.

Rape and HIV post-exposure prophylaxis: addressing the dual epidemics in South Africa.

PubMed

Kim, Julia C; Martin, Lorna J; Denny, Lynette

2003-11-01

In South Africa, a country notable for both a rapidly escalating AIDS epidemic and high levels of sexual violence, the issue of HIV post-exposure prophylaxis (PEP) following rape has recently come to the fore, and a policy supporting provision of PEP has been approved by the national government. This paper compares the conditions for providing PEP in Europe and North America with the conditions faced by two initiatives in South Africa, one serving a primarily rural base, and one urban. It is based on a review of the literature on sexual violence in South Africa and use of PEP following occupational and non-occupational exposure. It incorporates perspectives from in-depth interviews in 2000 with 18 key informants, including survivors of sexual violence, gender and HIV activists, domestic violence NGOs, rape crisis centres, physicians, lawyers, researchers and HIV/AIDS advisors in the Department of Health. The paper argues that given the scientific evidence for PEP, and the nature of the dual epidemics of HIV and sexual violence in South Africa, the public health and social justice rationale for implementing PEP equals and indeed exceeds that put forward in industrialised countries. However, delays in accessing PEP caused by the public justice system and lack of training for service providers constitute significant obstacles to effective implementation. In this respect, provision of PEP presents an opportunity to reform and strengthen existing services for post-rape care and to link attention to the epidemic of sexual violence to HIV/AIDS prevention.

Ross River Virus Transmission, Infection, and Disease: a Cross-Disciplinary Review

PubMed Central

Harley, David; Sleigh, Adrian; Ritchie, Scott

2001-01-01

Ross River virus (RRV) is a fascinating, important arbovirus that is endemic and enzootic in Australia and Papua New Guinea and was epidemic in the South Pacific in 1979 and 1980. Infection with RRV may cause disease in humans, typically presenting as peripheral polyarthralgia or arthritis, sometimes with fever and rash. RRV disease notifications in Australia average 5,000 per year. The first well-described outbreak occurred in 1928. During World War II there were more outbreaks, and the name epidemic polyarthritis was applied. During a 1956 outbreak, epidemic polyarthritis was linked serologically to a group A arbovirus (Alphavirus). The virus was subsequently isolated from Aedes vigilax mosquitoes in 1963 and then from epidemic polyarthritis patients. We review the literature on the evolutionary biology of RRV, immune response to infection, pathogenesis, serologic diagnosis, disease manifestations, the extraordinary variety of vertebrate hosts, mosquito vectors, and transmission cycles, antibody prevalence, epidemiology of asymptomatic and symptomatic human infection, infection risks, and public health impact. RRV arthritis is due to joint infection, and treatment is currently based on empirical anti-inflammatory regimens. Further research on pathogenesis may improve understanding of the natural history of this disease and lead to new treatment strategies. The burden of morbidity is considerable, and the virus could spread to other countries. To justify and design preventive programs, we need accurate data on economic costs and better understanding of transmission and behavioral and environmental risks. PMID:11585790

Effect of chemotherapy on malaria transmission among Yanomami Amerindians: simulated consequences of placebo treatment.

PubMed

Freeman, J; Laserson, K F; Petralanda, I; Spielman, A

1999-05-01

To determine whether chemotherapy effectively reduces Plasmodium falciparum malaria transmission in isolated human populations, we followed two abrupt sequential outbreaks of malaria infection among Yanomami Amerindians and modeled the effect of chemotherapy and the consequences if no drug was available. A Macdonald-type mathematical model demonstrated that both outbreaks comprised a single epidemic event linked by an invisible outbreak in vector mosquitoes. The basic reproductive number, R0, from fitted values based on the treated epidemic was 2 during the initial phase of the epidemic, and waned as vector density decreased with the onset of the dry season. In the observed epidemic, 60 (45%) of 132 village residents were affected, and the treated outbreak ended after two months. Although the initial chemotherapy regimen was only marginally effective, the duration of human infectivity was reduced from an expected nine months to two weeks. In the absence of this intervention, the initial R0 value would have been 40, more than 60% of the population would have been infected, and more than 30% would have remained parasitemic until the next rainy season (about six months later). Another outbreak would then have ensued, and malaria probably would have remained endemic in this village. Our simulated placebo treatment permits us to conclude that even partially effective chemotherapeutic interventions, such as those in our study, interrupt serial transmission of P. falciparum among isolated human populations that are exposed to infection seasonally.

The Asian house shrew Suncus murinus as a reservoir and source of human outbreaks of plague in Madagascar.

PubMed

Rahelinirina, Soanandrasana; Rajerison, Minoarisoa; Telfer, Sandra; Savin, Cyril; Carniel, Elisabeth; Duplantier, Jean-Marc

2017-11-01

Identifying key reservoirs for zoonoses is crucial for understanding variation in incidence. Plague re-emerged in Mahajanga, Madagascar in the 1990s but there has been no confirmed case since 1999. Here we combine ecological and genetic data, from during and after the epidemics, with experimental infections to examine the role of the shrew Suncus murinus in the plague epidemiological cycle. The predominance of S. murinus captures during the epidemics, their carriage of the flea vector and their infection with Yersinia pestis suggest they played an important role in the maintenance and transmission of plague. S. murinus exhibit a high but variable resistance to experimental Y. pestis infections, providing evidence of its ability to act as a maintenance host. Genetic analyses of the strains isolated from various hosts were consistent with two partially-linked transmission cycles, with plague persisting within the S. murinus population, occasionally spilling over into the rat and human populations. The recent isolation from a rat in Mahajanga of a Y. pestis strain genetically close to shrew strains obtained during the epidemics reinforces this hypothesis and suggests circulation of plague continues. The observed decline in S. murinus and Xenopsylla cheopis since the epidemics appears to have decreased the frequency of spillover events to the more susceptible rats, which act as a source of infection for humans. Although this may explain the lack of confirmed human cases in recent years, the current circulation of plague within the city highlights the continuing health threat.

Laboratory and Molecular Characterization of Dengue Viruses in a 2014 Outbreak in Guangfo Region, Southern China.

PubMed

Luo, Zhao-Fan; Hu, Bo; Zhang, Feng-Yi; Lin, Xiang-Hua; Xie, Xiao-Ying; Pan, Kun-Yi; Li, Hong-Yu; Ren, Rui-Wen; Zhao, Wen-Zhong

2017-09-25

Non-specific symptoms and low viremia levels make early diagnosis of dengue virus (DENV) infection challenging. This study aimed to i) identify laboratory markers that can be used to predict a DENV-positive diagnosis and ii) perform a molecular characterization of DENVs from the 2014 Guangdong epidemic. This retrospective study analyzed 1,044 patients from the Guangdong epidemic who were clinically suspected cases of dengue. Viral RNA was detected by real-time RT-PCR, and viral-specific NS1 antigen was detected using enzyme-linked immuno sorbent assay. A molecular phylogenetic analysis was performed for the with the DENV C-prM gene junction. Patients with dengue infection had leukopenia (2.8 × 10 9 /L), thrombocytopenia (109.0 × 10 9 /L), elevated aspartate aminotransferase (56.0 IU/L) and alanine aminotransferase (43.5 IU/L), and prolonged activated partial thromboplastin time (APTT, 33.5 s) (all P ＜ 0.001) compared to patients without dengue. The positive predictive value of leukopenia and thrombocytopenia for DENV infection were 96.9% and 93.0%, respectively. Leukopenia, thrombocytopenia, elevated aminotransferases, and prolonged APTT were useful predictive markers for an early diagnosis of DENV infection. Phylogenetic analysis indicated that the DENVs from the 2014 epidemic were closely related to a 2010 New Delhi strain and a 2013 Guangzhou strain. The 2014 epidemic consisted of co-circulating DENV-1 genotypes I and V from multiple origins. Efficient dengue surveillance can facilitate rapid response to future outbreaks.

Negative reactions to monitoring: Do they undermine the ability of monitoring to protect adolescents?

PubMed

Laird, Robert D; Zeringue, Megan M; Lambert, Emily S

2018-02-01

This study focused on adolescents' negative reactions to parental monitoring to determine whether parents should avoid excessive monitoring because adolescents find monitoring behaviors to be over-controlling and privacy invasive. Adolescents (n = 242, M age = 15.4 years; 51% female) reported monitoring, negative reactions, warmth, antisocial behavior, depressive symptoms, and disclosure. Adolescents additionally reported antisocial behavior, depressive symptoms, and disclosure one to two years later. In cross-sectional analyses, less monitoring but more negative reactions were linked with less disclosure, suggesting that negative reactions can undermine parents' ability to obtain information. Although monitoring behaviors were not related to depressive symptoms, more negative reactions were linked with more depressive symptoms, suggesting that negative reactions also may increase depressive symptoms as a side effect of monitoring behavior. Negative reactions were not linked to antisocial behavior. There were no longitudinal links between negative reactions and changes in disclosure, antisocial behavior, or depressive symptoms. Copyright © 2017. Published by Elsevier Ltd.

Epidemics in networks: a master equation approach

NASA Astrophysics Data System (ADS)

Cotacallapa, M.; Hase, M. O.

2016-02-01

A problem closely related to epidemiology, where a subgraph of ‘infected’ links is defined inside a larger network, is investigated. This subgraph is generated from the underlying network by a random variable, which decides whether a link is able to propagate a disease/information. The relaxation timescale of this random variable is examined in both annealed and quenched limits, and the effectiveness of propagation of disease/information is analyzed. The dynamics of the model is governed by a master equation and two types of underlying network are considered: one is scale-free and the other has exponential degree distribution. We have shown that the relaxation timescale of the contagion variable has a major influence on the topology of the subgraph of infected links, which determines the efficiency of spreading of disease/information over the network.

Reviewing and addressing the link between mass media and the increase in obesity among European children: The European Academy of Paediatrics (EAP) and The European Childhood Obesity Group (ECOG) consensus statement.

PubMed

Mazur, Artur; Caroli, Margherita; Radziewicz-Winnicki, Igor; Nowicka, Paulina; Weghuber, Daniel; Neubauer, David; Dembiński, Łukasz; Crawley, Francis P; White, Martin; Hadjipanayis, Adamos

2018-04-01

This study reviewed the link between social media and the growing epidemic of childhood obesity in Europe. A task force from the European Academy of Paediatrics and the European Childhood Obesity Group searched published literature and developed a consensus statement. It found that there was evidence of a strong link between obesity levels across European countries and childhood media exposure and that parents and society needed a better understanding of the influence of social media on dietary habits. Health policies in Europe must take account of the range of social media influences that promote the development of childhood obesity. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Description of a large measles epidemic in Democratic Republic of Congo, 2010-2013.

PubMed

Mancini, Silvia; Coldiron, Matthew E; Ronsse, Axelle; Ilunga, Benoît Kebela; Porten, Klaudia; Grais, Rebecca F

2014-01-01

Although measles mortality has declined dramatically in Sub-Saharan Africa, measles remains a major public health problem in countries like the Democratic Republic of Congo (DRC). Here, we describe the large measles epidemic that occurred in the Democratic Republic of Congo between 2010 and 2013 using data from the national surveillance system as well as vaccine coverage surveys to provide a snapshot of the epidemiology of measles in DRC. Standardized national surveillance data were used to describe measles cases from 2010 to 2013. Attack rates and case fatality ratios were calculated and the temporal and spatial evolution of the epidemic described. Data on laboratory confirmation and vaccination coverage surveys as a part of routine program monitoring are also presented. Between week 1 of 2010 and week 45 of 2013, a total of 294,455 cases and 5,045 deaths were reported. The cumulative attack rate (AR) was 0.4%. The Case Fatality Ratio (CFR) was 1.7% among cases reported in health structures through national surveillance. A total of 186,178 cases (63%) were under 5 years old, representing an estimated AR of 1.4% in this age group. Following the first mass vaccination campaigns, weekly reported cases decreased by 21.5%. Results of post-vaccination campaign coverage surveys indicated sub-optimal (under 95%) vaccination coverage among children surveyed. The data reported here highlight the need to seek additional means to reinforce routine immunization as well as ensure the timely implementation of Supplementary Immunization Activities to prevent large and repeated measles epidemics in DRC. Although reactive campaigns were conducted in response to the epidemic, strategies to ensure that children are vaccinated in the routine system remains the foundation of measles control.

Rabies and canine distemper virus epidemics in the red fox population of northern Italy (2006-2010).

PubMed

Nouvellet, Pierre; Donnelly, Christl A; De Nardi, Marco; Rhodes, Chris J; De Benedictis, Paola; Citterio, Carlo; Obber, Federica; Lorenzetto, Monica; Pozza, Manuela Dalla; Cauchemez, Simon; Cattoli, Giovanni

2013-01-01

Since 2006 the red fox (Vulpes vulpes) population in north-eastern Italy has experienced an epidemic of canine distemper virus (CDV). Additionally, in 2008, after a thirteen-year absence from Italy, fox rabies was re-introduced in the Udine province at the national border with Slovenia. Disease intervention strategies are being developed and implemented to control rabies in this area and minimise risk to human health. Here we present empirical data and the epidemiological picture relating to these epidemics in the period 2006-2010. Of important significance for epidemiological studies of wild animals, basic mathematical models are developed to exploit information collected from the surveillance program on dead and/or living animals in order to assess the incidence of infection. These models are also used to estimate the rate of transmission of both diseases and the rate of vaccination, while correcting for a bias in early collection of CDV samples. We found that the rate of rabies transmission was roughly twice that of CDV, with an estimated effective contact between infected and susceptible fox leading to a new infection occurring once every 3 days for rabies, and once a week for CDV. We also inferred that during the early stage of the CDV epidemic, a bias in the monitoring protocol resulted in a positive sample being almost 10 times more likely to be collected than a negative sample. We estimated the rate of intake of oral vaccine at 0.006 per day, allowing us to estimate that roughly 68% of the foxes would be immunised. This was confirmed by field observations. Finally we discuss the implications for the eco-epidemiological dynamics of both epidemics in relation to control measures.

Rabies and Canine Distemper Virus Epidemics in the Red Fox Population of Northern Italy (2006–2010)

PubMed Central

De Benedictis, Paola; Citterio, Carlo; Obber, Federica; Lorenzetto, Monica; Pozza, Manuela Dalla; Cauchemez, Simon; Cattoli, Giovanni

2013-01-01

Since 2006 the red fox (Vulpes vulpes) population in north-eastern Italy has experienced an epidemic of canine distemper virus (CDV). Additionally, in 2008, after a thirteen-year absence from Italy, fox rabies was re-introduced in the Udine province at the national border with Slovenia. Disease intervention strategies are being developed and implemented to control rabies in this area and minimise risk to human health. Here we present empirical data and the epidemiological picture relating to these epidemics in the period 2006–2010. Of important significance for epidemiological studies of wild animals, basic mathematical models are developed to exploit information collected from the surveillance program on dead and/or living animals in order to assess the incidence of infection. These models are also used to estimate the rate of transmission of both diseases and the rate of vaccination, while correcting for a bias in early collection of CDV samples. We found that the rate of rabies transmission was roughly twice that of CDV, with an estimated effective contact between infected and susceptible fox leading to a new infection occurring once every 3 days for rabies, and once a week for CDV. We also inferred that during the early stage of the CDV epidemic, a bias in the monitoring protocol resulted in a positive sample being almost 10 times more likely to be collected than a negative sample. We estimated the rate of intake of oral vaccine at 0.006 per day, allowing us to estimate that roughly 68% of the foxes would be immunised. This was confirmed by field observations. Finally we discuss the implications for the eco-epidemiological dynamics of both epidemics in relation to control measures. PMID:23630599

Relationship between Distinct African Cholera Epidemics Revealed via MLVA Haplotyping of 337 Vibrio cholerae Isolates.

PubMed

Moore, Sandra; Miwanda, Berthe; Sadji, Adodo Yao; Thefenne, Hélène; Jeddi, Fakhri; Rebaudet, Stanislas; de Boeck, Hilde; Bidjada, Bawimodom; Depina, Jean-Jacques; Bompangue, Didier; Abedi, Aaron Aruna; Koivogui, Lamine; Keita, Sakoba; Garnotel, Eric; Plisnier, Pierre-Denis; Ruimy, Raymond; Thomson, Nicholas; Muyembe, Jean-Jacques; Piarroux, Renaud

2015-01-01

Since cholera appeared in Africa during the 1970s, cases have been reported on the continent every year. In Sub-Saharan Africa, cholera outbreaks primarily cluster at certain hotspots including the African Great Lakes Region and West Africa. In this study, we applied MLVA (Multi-Locus Variable Number Tandem Repeat Analysis) typing of 337 Vibrio cholerae isolates from recent cholera epidemics in the Democratic Republic of the Congo (DRC), Zambia, Guinea and Togo. We aimed to assess the relationship between outbreaks. Applying this method, we identified 89 unique MLVA haplotypes across our isolate collection. MLVA typing revealed the short-term divergence and microevolution of these Vibrio cholerae populations to provide insight into the dynamics of cholera outbreaks in each country. Our analyses also revealed strong geographical clustering. Isolates from the African Great Lakes Region (DRC and Zambia) formed a closely related group, while West African isolates (Togo and Guinea) constituted a separate cluster. At a country-level scale our analyses revealed several distinct MLVA groups, most notably DRC 2011/2012, DRC 2009, Zambia 2012 and Guinea 2012. We also found that certain MLVA types collected in the DRC persisted in the country for several years, occasionally giving rise to expansive epidemics. Finally, we found that the six environmental isolates in our panel were unrelated to the epidemic isolates. To effectively combat the disease, it is critical to understand the mechanisms of cholera emergence and diffusion in a region-specific manner. Overall, these findings demonstrate the relationship between distinct epidemics in West Africa and the African Great Lakes Region. This study also highlights the importance of monitoring and analyzing Vibrio cholerae isolates.

[Monitoring respiratory syncytial virus through the Spanish influenza surveillance system, 2006-2014].

PubMed

Jiménez-Jorge, Silvia; Delgado-Sanz, Concepción; de Mateo, Salvador; Pozo, Francisco; Casas, Inmaculada; Larrauri, Amparo

2016-02-01

The aim of the study is to analyze the information on respiratory syncytial virus (RSV) obtained through the Spanish Influenza Surveillance System (SISS) and to study its usefulness as supplementary information for the characterization of influenza epidemics. The temporal patterns of both RSV and influenza viruses were analyzed by patterns comparing the weekly viral detection rates from 2006 to 2014. In general, the RSV circulation was characterized by showing a peak between 52-1 weeks, and circulated from 2 to 8 weeks before/prior to influenza viruses. RSV information obtained from the SISS is useful for the characterization of influenza epidemics in Spain. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Kenya AIDS Indicator Surveys 2007 and 2012: implications for public health policies for HIV prevention and treatment.

PubMed

Maina, William K; Kim, Andrea A; Rutherford, George W; Harper, Malayah; K'Oyugi, Boniface O; Sharif, Shahnaaz; Kichamu, George; Muraguri, Nicholas M; Akhwale, Willis; De Cock, Kevin M

2014-05-01

AIDS Indicator Surveys are standardized surveillance tools used by countries with generalized HIV epidemics to provide, in a timely fashion, indicators for effective monitoring of HIV. Such data should guide responses to the HIV epidemic, meet program reporting requirements, and ensure comparability of findings across countries and over time. Kenya has conducted 2 AIDS Indicator Surveys, in 2007 (KAIS 2007) and 2012-2013 (KAIS 2012). These nationally representative surveys have provided essential epidemiologic, sociodemographic, behavioral, and biologic data on HIV and related indicators to evaluate the national HIV response and inform policies for prevention and treatment of the disease. We present a summary of findings from KAIS 2007 and KAIS 2012 and the impact that these data have had on changing HIV policies and practice.

Review of evidence that epidemics of type 1 diabetes and type 2 diabetes/metabolic syndrome are polar opposite responses to iatrogenic inflammation.

PubMed

Classen, John B

2012-11-01

There is an epidemic in children of metabolic syndrome, obesity, type 2 diabetes and other individual diseases that form the components of metabolic syndrome. Poor diet and low exercise can not explain many facets of the epidemic including the onset in children 6 month of age, the protective effect of obesity on the incidence of type 1 diabetes and the epidemic of type 2 diabetes/metabolic syndrome in grass fed horses. Poor diet and exercise also do not explain the epidemic of type 1 diabetes in children that resembles the epidemic of type 2 diabetes/metabolic syndrome. Several papers have been published to indicate that the epidemics of type 1 and type 2 diabetes/metabolic syndrome in children are linked and are polar opposite responses to iatrogenic inflammation. Several lines of research support this. Data from different races indicates that there is an inverse relationship between developing type 1 diabetes and type 2 diabetes. Races with high risk of developing type 2 diabetes have a decreased risk of developing type 1 diabetes. Data from Italy confirmed an inverse association between obesity and type 1 diabetes. Further studies indicate the inverse relationship between type 1 diabetes and type 2 diabetes/obesity is due to cortisol production. Data indicates those with low cortisol responses have a predilection for type 1 diabetes and other autoimmune disorders following inflammation, while those with high cortisol/ immune suppressive responses develop type 2 diabetes/metabolic syndrome/obesity which resembles a Cushingoid state but are spared in the autoimmune disorders. Japanese children produce much more cortisol following immunization than Caucasian children. The later explains why discontinuation of BCG vaccination was associated with a decrease in type 1 diabetes in European children and a decrease in type 2 diabetes in Japanese children. Both the epidemics of type 1 diabetes and metabolic syndrome correlate with an increase in immunization. Finally, there is a strong mechanism data that macrophage produced interleukin 1, tumor necrosis factor and interleukin 6, which are released following inflammation, causing destruction of insulin secreting islet cells and increase cortisol release, and thus have the ability to cause both type 1 and type 2 diabetes/metabolic syndrome (which resembles a Cushingoid state). The propensity to develop type 1 diabetes or type 2 diabetes/metabolic syndrome depends on the propensity to release of cortisol which correlates with race.

[Effects of the periodical spread of rinderpest on famine, epidemic, and tiger disasters in the late 17th Century].

PubMed

Kim, Dong Jin; Yoo, Han Sang; Lee, Hang

2014-04-01

This study clarifies the causes of the repetitive occurrences of such phenomena as rinderpest, epidemic, famine, and tiger disasters recorded in the Joseon Dynasty Chronicle and the Seungjeongwon Journals in the period of great catastrophe, the late 17th century in which the great Gyeongsin famine (1670~1671) and the great Eulbyeong famine (1695~1696) occurred, from the perspective that they were biological exchanges caused by the new arrival of rinderpest in the early 17th century. It is an objection to the achievements by existing studies which suggest that the great catastrophes occurring in the late 17th century are evidence of phenomena in a little ice age. First of all, rinderpest has had influence on East Asia as it had been spread from certain areas in Machuria in May 1636 through Joseon, where it raged throughout the nation, and then to the west part of Japan. The new arrival of rinderpest was indigenized in Joseon, where it was localized and spread periodically while it was adjusted to changes in the population of cattle with immunity in accordance with their life spans and reproduction rates. As the new rinderpest, which showed high pathogenicity in the early 17th century, was indigenized with its high mortality and continued until the late 17th century, it broke out periodically in general. Contrastively, epidemics like smallpox and measles that were indigenized as routine ones had occurred constantly from far past times. As a result, the rinderpest, which tried a new indigenization, and the human epidemics, which had been already indigenized long ago, were unexpectedly overlapped in their breakout, and hence great changes were noticed in the aspects of the human casualty due to epidemics. The outbreak of rinderpest resulted in famine due to lack of farming cattle, and the famine caused epidemics among people. The casualty of the human population due to the epidemics in turn led to negligence of farming cattle, which constituted factors that triggered rage and epidemics of rinderpest. The more the number of sources of infection and hosts with low immunity increased, the more lost human resources and farming cattle were lost, which led to a great famine. The periodic outbreak of the rinderpester along with the routine prevalence of various epidemics in the 17thcentury also had influenced on domestic and wild animals. Due to these phenomenon, full-fledged famines occurred that were incomparable with earlier ones. The number of domestic animals that were neglected by people who, faced with famines, were not able to take care of them was increased, and this might have brought about the rage of epidemics like rinderpest in domestic animals like cattle. The great Gyeongsin and Eulbyeong famines due to reoccurrence of the rinderpest in the late 17th century linked rinderpester, epidemics and great famines so that they interacted with each other. Furthermore, the recurring cycle of epidemics-famines-rinderpest-great famines constituted a great cycle with synergy, which resulted in eco-economic-historical great catastrophes accompanied by large scale casualties. Therefore, the Gyeongsin and Eulbyeong famines occurring in the late 17th century can be treated as events caused by the repetition of various periodic disastrous factors generated in 1670~1671 and in 1695~1696 respectively, and particularly as phenomena caused by biological exchanges based on rinderpester., rather than as little ice age phenomena due to relatively long term temperature lowering.

Controlled Substance Lock-In Programs: Examining An Unintended Consequence Of A Prescription Drug Abuse Policy.

PubMed

Roberts, Andrew W; Farley, Joel F; Holmes, G Mark; Oramasionwu, Christine U; Ringwalt, Chris; Sleath, Betsy; Skinner, Asheley C

2016-10-01

Controlled substance lock-in programs are garnering increased attention from payers and policy makers seeking to combat the epidemic of opioid misuse. These programs require high-risk patients to visit a single prescriber and pharmacy for coverage of controlled substance medication services. Despite high prevalence of the programs in Medicaid, we know little about their effects on patients' behavior and outcomes aside from reducing controlled substance-related claims. Our study was the first rigorous investigation of lock-in programs' effects on out-of-pocket controlled substance prescription fills, which circumvent the programs' restrictions and mitigate their potential public health benefits. We linked claims data and prescription drug monitoring program data for the period 2009-12 for 1,647 enrollees in North Carolina Medicaid's lock-in program and found that enrollment was associated with a roughly fourfold increase in the likelihood and frequency of out-of-pocket controlled substance prescription fills. This finding illuminates weaknesses of lock-in programs and highlights the need for further scrutiny of the appropriate role, optimal design, and potential unintended consequences of the programs as tools to prevent opioid abuse. Project HOPE—The People-to-People Health Foundation, Inc.

Monitoring and Evaluating the National Program to Prevent Mother-to-Child HIV Transmission in Thailand

ERIC Educational Resources Information Center

Kanshana, Siripon; Naiwatanakul, Thananda; Simonds, R. J.; Amornwichet, Pornsinee; Teeraratkul, Achara; Culnane, Mary; Chantharojwong, Nartlada; Limpakarnjanarat, Khanchit

2004-01-01

Thailand has had an epidemic of heterosexually transmitted human immunodeficiency virus (HIV) infection since the mid-1980s that has affected both high-risk populations (such as commercial sex workers) and low-risk populations (such as wives of men who have sex with commercial sex workers). As a result, the prevalence of HIV infection among…

Heroin: Challenge for the 21st Century.

ERIC Educational Resources Information Center

Gordon, Susan M.

The rise in heroin use in the 1990s is attributed to an increase in snorting and smoking heroin as opposed to earlier epidemics that relied on intravenous use. An increase in purity has also added to the addiction problem. The trend towards use by young people was confirmed by the 2000 Monitoring the Future Study, which reported that 10.6% of high…

Clinical profile and outcome of Dengue fever cases.

PubMed

Ratageri, Vinod H; Shepur, T A; Wari, P K; Chavan, S C; Mujahid, I B; Yergolkar, P N

2005-08-01

Dengue fever is on rise globally. In India, Dengue epidemics are expanding geographically, even into the rural areas. Dengue can present with varied manifestations. The mortality rate has been brought down with high index of suspicion, strict monitoring and proper fluid resuscitation. Herewith, we are presenting clinical features and outcome of Dengue cases seen in and around Hubli (North Karnataka).

Nanorobot Hardware Architecture for Medical Defense

PubMed Central

Cavalcanti, Adriano; Shirinzadeh, Bijan; Zhang, Mingjun; Kretly, Luiz C.

2008-01-01

This work presents a new approach with details on the integrated platform and hardware architecture for nanorobots application in epidemic control, which should enable real time in vivo prognosis of biohazard infection. The recent developments in the field of nanoelectronics, with transducers progressively shrinking down to smaller sizes through nanotechnology and carbon nanotubes, are expected to result in innovative biomedical instrumentation possibilities, with new therapies and efficient diagnosis methodologies. The use of integrated systems, smart biosensors, and programmable nanodevices are advancing nanoelectronics, enabling the progressive research and development of molecular machines. It should provide high precision pervasive biomedical monitoring with real time data transmission. The use of nanobioelectronics as embedded systems is the natural pathway towards manufacturing methodology to achieve nanorobot applications out of laboratories sooner as possible. To demonstrate the practical application of medical nanorobotics, a 3D simulation based on clinical data addresses how to integrate communication with nanorobots using RFID, mobile phones, and satellites, applied to long distance ubiquitous surveillance and health monitoring for troops in conflict zones. Therefore, the current model can also be used to prevent and save a population against the case of some targeted epidemic disease. PMID:27879858

Avian botulism: a case study in translocated endangered Laysan ducks (Anas laysanensis) on Midway Atoll

USGS Publications Warehouse

Work, Thierry M.; Klavitter, John L.; Reynolds, Michelle H.; Blehert, David S.

2010-01-01

Laysan Ducks are endemic to the Hawaiian archipelago and are one of the world’s most endangered waterfowl. For 150 yr, Laysan Ducks were restricted to an estimated 4 km2 of land on Laysan Island in the northwestern Hawaiian Islands. In 2004 and 2005, 42 Laysan Ducks were translocated to Midway Atoll, and the population increased to approximately 200 by 2007. In August 2008, mortality due to botulism type C was identified, and 181 adult, fledgling, and duckling carcasses were collected from August to October. Diseased birds were found on two islands within Midway Atoll at multiple wetlands; however, one wetland contributed most carcasses. The epidemic was discovered approximately 14–21 days after the mortality started and lasted for 50 additional days. The details of this epidemic highlight the disease risk to birds restricted to small island populations and the challenges associated with managing newly translocated endangered species. Frequent population monitoring for early disease detection and comprehensive wetland monitoring and management will be needed to manage avian botulism in endangered Laysan Ducks. Vaccination may also be beneficial to reduce mortality in this small, geographically closed population.

Quantitative PCR monitoring of the effect of azoxystrobin treatments on Mycosphaerella graminicola epidemics in the field.

PubMed

Rohel, Eric A; Laurent, Paul; Fraaije, Bart A; Cavelier, Nadine; Hollomon, Derek W

2002-03-01

Quantitative PCR and visual monitoring of Mycosphaerella graminicola epidemics were performed to investigate the effect of curative and preventative applications of azoxystrobin in wheat field crops. A non-systemic protectant and a systemic curative fungicide, chlorothalonil and epoxiconazole, respectively, were used as references. PCR diagnosis detected leaf infection by M graminicola 3 weeks before symptom appearance, thereby allowing a clear distinction between curative and preventative treatments. When applied 1 week after the beginning of infection, azoxystrobin curative activity was intermediate between chlorothalonil (low effect) and epoxiconazole. When applied preventatively, none of the fungicides completely prevented leaf infection. There was some indication that azoxystrobin preventative treatments may delay fungal DNA increase more than epoxiconazole at the beginning of leaf infection. Both curative and preventative treatments increased the time lapse between the earliest PCR detection and the measurement of a 10% necrotic leaf area. Azoxystrobin only slightly decreased the speed of necrotic area increase compared with epoxiconazole. Hence, azoxystrobin activity toward M graminicola mainly resides in lengthening the time lapse between the earliest PCR detection and the measurement of a 10% necrotic leaf area. Information generated in this way is useful for optimal positioning of azoxystrobin treatments on M graminicola.

Enterovirus 71: a whole virion inactivated enterovirus 71 vaccine.

PubMed

Zhou, Yang; Li, Jing-Xin; Jin, Peng-Fei; Wang, Yu-Xiao; Zhu, Feng-Cai

2016-07-01

Enterovirus A71 (EV71) is the predominant causative agent of hand, foot, and mouth disease (HFMD), which is often associated with severe cases and even deaths. EV71-associated epidemics have emerged as a serious threat to public health, particularly in the Asia-Pacific region. We searched PubMed using the terms 'enterovirus 71', 'hand, foot, and mouth disease', and 'vaccine', with no date or language restrictions for all publications before April 27, 2016. Among various vaccine candidates, the alum-adjuvant inactivated EV71 vaccines are most promising. Three alum-adjuvant inactivated EV71 vaccines developed by mainland China showed high efficacy, good immunogenicity persistence and acceptable safety profiles in clinical trials. Recently, two of these EV71 vaccines have been approved for marketing in China and the other one is undergoing the review process of licensure. In this manuscript, we summarized previous study results as well as discussed the regulatory affairs and post-market surveillances issues. Expert commentary: The marketing of EV71 vaccines is a milestone in the controlling of HFMD. International clinical trials are needed to further assess the efficacy and cross-immunogenicity. Establishing a sensitive pathogen monitoring system would be essential to monitor the variation of genotypes and control HFMD epidemics.

Efficient network disintegration under incomplete information: the comic effect of link prediction

NASA Astrophysics Data System (ADS)

Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

2016-03-01

The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the “comic effect” of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized.

Efficient network disintegration under incomplete information: the comic effect of link prediction.

PubMed

Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

2016-03-10

The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the "comic effect" of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized.

Efficient network disintegration under incomplete information: the comic effect of link prediction

PubMed Central

Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

2016-01-01

The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the “comic effect” of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized. PMID:26960247

Variation in reactive oxygen species concentration among lettuce types and modulation of their production via PPO during E. coli O157:H7 colonization of injured lettuce leaves(Abstract)

USDA-ARS?s Scientific Manuscript database

Minimally processed leafy vegetables are the biggest culprits in produce-linked outbreaks of foodborne illness and E. coli O157:H7 (EcO157) is the predominant causal agent of these epidemics. Harvesting and processing cause plant lesions thus creating new niches for opportunistic colonization of lea...

School Counselors Perspectives of the Barriers and Facilitators Associated with Their Involvement in the Childhood Obesity Epidemic: A National K-12 Survey

ERIC Educational Resources Information Center

Larrier, Yvonne; Kijai, Jimmy; Bakerson, Michelle A.; Walker, Lynne; Linton, Jeremy; Woolford-Hunt, Carole; Sallinen, Bethany J.; Woolford, Susan J.

2012-01-01

Background: Childhood obesity has become a public health priority in the U.S. and is linked to a number of significant comorbidities including asthma, sleep apnea and depression. In addition, there is an increase in social isolation and peer victimization. Purpose: the purpose of this study was to explore Professional School Counselors (PSC)…

Inferring infection hazard in wildlife populations by linking data across individual and population scales.

PubMed

Pepin, Kim M; Kay, Shannon L; Golas, Ben D; Shriner, Susan S; Gilbert, Amy T; Miller, Ryan S; Graham, Andrea L; Riley, Steven; Cross, Paul C; Samuel, Michael D; Hooten, Mevin B; Hoeting, Jennifer A; Lloyd-Smith, James O; Webb, Colleen T; Buhnerkempe, Michael G

2017-03-01

Our ability to infer unobservable disease-dynamic processes such as force of infection (infection hazard for susceptible hosts) has transformed our understanding of disease transmission mechanisms and capacity to predict disease dynamics. Conventional methods for inferring FOI estimate a time-averaged value and are based on population-level processes. Because many pathogens exhibit epidemic cycling and FOI is the result of processes acting across the scales of individuals and populations, a flexible framework that extends to epidemic dynamics and links within-host processes to FOI is needed. Specifically, within-host antibody kinetics in wildlife hosts can be short-lived and produce patterns that are repeatable across individuals, suggesting individual-level antibody concentrations could be used to infer time since infection and hence FOI. Using simulations and case studies (influenza A in lesser snow geese and Yersinia pestis in coyotes), we argue that with careful experimental and surveillance design, the population-level FOI signal can be recovered from individual-level antibody kinetics, despite substantial individual-level variation. In addition to improving inference, the cross-scale quantitative antibody approach we describe can reveal insights into drivers of individual-based variation in disease response, and the role of poorly understood processes such as secondary infections, in population-level dynamics of disease. © 2017 John Wiley & Sons Ltd/CNRS.

Principal climatic and edaphic determinants of Culicoides biting midge abundance during the 2007-2008 bluetongue epidemic in the Netherlands, based on OVI light trap data.

PubMed

Scolamacchia, F; VAN DEN Broek, J; Meiswinkel, R; Heesterbeek, J A P; Elbers, A R W

2014-06-01

Palaearctic Culicoides midges (Diptera: Ceratopogonidae) represent a vital link in the northward advance of certain arboviral pathogens of livestock such as that caused by bluetongue virus. The effects of relevant ecological factors on weekly Culicoides vector abundances during the bluetongue virus serotype 8 epidemics in the Netherlands in 2007 and 2008 were quantified within a hurdle modelling framework. The relative role of meteorological parameters showed a broadly consistent association across species, with larger catches linked to temperature-related variables and lower wind speed. Moreover, vector abundance was found to be influenced by edaphic factors, likely related to species-specific breeding habitat preferences that differed markedly amongst some species. This is the first study on Culicoides vector species in the Netherlands identified during an entomological surveillance programme, in which an attempt is made to pinpoint the factors that influence midge abundance levels. In addition to providing key inputs into risk-mitigating tools for midge-borne pathogens and disease transmission models, the adoption of methods that explicitly address certain features of abundance datasets (frequent zero-count observations and over-dispersion) helped enhance the robustness of the ecological analysis. © 2013 The Royal Entomological Society.

El Niño and human health.

PubMed Central

Kovats, R. S.

2000-01-01

The El Niño-Southern Oscillation (ENSO) is the best known example of quasi-periodic natural climate variability on the interannual time scale. It comprises changes in sea temperature in the Pacific Ocean (El Niño) and changes in atmospheric pressure across the Pacific Basin (the Southern Oscillation), together with resultant effects on world weather. El Niño events occur at intervals of 2-7 years. In certain countries around the Pacific and beyond, El Niño is associated with extreme weather conditions that can cause floods and drought. Globally it is linked to an increased impact of natural disasters. There is evidence that ENSO is associated with a heightened risk of certain vector-borne diseases in specific geographical areas where weather patterns are linked with the ENSO cycle and disease control is limited. This is particularly true for malaria, but associations are also suggested in respect of epidemics of other mosquito-borne and rodent-borne diseases that can be triggered by extreme weather conditions. Seasonal climate forecasts, predicting the likelihood of weather patterns several months in advance, can be used to provide early indicators of epidemic risk, particularly for malaria. Interdisciplinary research and cooperation are required in order to reduce vulnerability to climate variability and weather extremes. PMID:11019461

Inferring infection hazard in wildlife populations by linking data across individual and population scales

USGS Publications Warehouse

Pepin, Kim M.; Kay, Shannon L.; Golas, Ben D.; Shriner, Susan A.; Gilbert, Amy T.; Miller, Ryan S.; Graham, Andrea L.; Riley, Steven; Cross, Paul C.; Samuel, Michael D.; Hooten, Mevin B.; Hoeting, Jennifer A.; Lloyd-Smith, James O.; Webb, Colleen T.; Buhnerkempe, Michael G.

2017-01-01

Our ability to infer unobservable disease-dynamic processes such as force of infection (infection hazard for susceptible hosts) has transformed our understanding of disease transmission mechanisms and capacity to predict disease dynamics. Conventional methods for inferring FOI estimate a time-averaged value and are based on population-level processes. Because many pathogens exhibit epidemic cycling and FOI is the result of processes acting across the scales of individuals and populations, a flexible framework that extends to epidemic dynamics and links within-host processes to FOI is needed. Specifically, within-host antibody kinetics in wildlife hosts can be short-lived and produce patterns that are repeatable across individuals, suggesting individual-level antibody concentrations could be used to infer time since infection and hence FOI. Using simulations and case studies (influenza A in lesser snow geese and Yersinia pestis in coyotes), we argue that with careful experimental and surveillance design, the population-level FOI signal can be recovered from individual-level antibody kinetics, despite substantial individual-level variation. In addition to improving inference, the cross-scale quantitative antibody approach we describe can reveal insights into drivers of individual-based variation in disease response, and the role of poorly understood processes such as secondary infections, in population-level dynamics of disease.

Epidemiology of Dengue Virus in Iquitos, Peru 1999 to 2005: Interepidemic and Epidemic Patterns of Transmission

PubMed Central

Morrison, Amy C.; Minnick, Sharon L.; Rocha, Claudio; Forshey, Brett M.; Stoddard, Steven T.; Getis, Arthur; Focks, Dana A.; Russell, Kevin L.; Olson, James G.; Blair, Patrick J.; Watts, Douglas M.; Sihuincha, Moises; Scott, Thomas W.; Kochel, Tadeusz J.

2010-01-01

Background Comprehensive, longitudinal field studies that monitor both disease and vector populations for dengue viruses are urgently needed as a pre-requisite for developing locally adaptable prevention programs or to appropriately test and license new vaccines. Methodology and Principal Findings We report the results from such a study spanning 5 years in the Amazonian city of Iquitos, Peru where DENV infection was monitored serologically among ∼2,400 members of a neighborhood-based cohort and through school-based absenteeism surveillance for active febrile illness among a subset of this cohort. At baseline, 80% of the study population had DENV antibodies, seroprevalence increased with age, and significant geographic variation was observed, with neighborhood-specific age-adjusted rates ranging from 67.1 to 89.9%. During the first 15 months, when DENV-1 and DENV-2 were co-circulating, population-based incidence rates ranged from 2–3 infections/100 person-years (p-years). The introduction of DENV-3 during the last half of 2001 was characterized by 3 distinct periods: amplification over at least 5–6 months, replacement of previously circulating serotypes, and epidemic transmission when incidence peaked at 89 infections/100 p-years. Conclusions/Significance Neighborhood-specific baseline seroprevalence rates were not predictive of geographic incidence patterns prior to the DENV-3 introduction, but were closely mirrored during the invasion of this serotype. Transmission varied geographically, with peak incidence occurring at different times among the 8 geographic zones in ∼16 km2 of the city. The lag from novel serotype introduction to epidemic transmission and knowledge of spatially explicit areas of elevated risk should be considered for more effective application of limited resources for dengue prevention. PMID:20454609

Signature-forecasting and early outbreak detection system

PubMed Central

Naumova, Elena N.; MacNeill, Ian B.

2008-01-01

SUMMARY Daily disease monitoring via a public health surveillance system provides valuable information on population risks. Efficient statistical tools for early detection of rapid changes in the disease incidence are a must for modern surveillance. The need for statistical tools for early detection of outbreaks that are not based on historical information is apparent. A system is discussed for monitoring cases of infections with a view to early detection of outbreaks and to forecasting the extent of detected outbreaks. We propose a set of adaptive algorithms for early outbreak detection that does not rely on extensive historical recording. We also include knowledge of infection disease epidemiology into forecasts. To demonstrate this system we use data from the largest water-borne outbreak of cryptosporidiosis, which occurred in Milwaukee in 1993. Historical data are smoothed using a loess-type smoother. Upon receipt of a new datum, the smoothing is updated and estimates are made of the first two derivatives of the smooth curve, and these are used for near-term forecasting. Recent data and the near-term forecasts are used to compute a color-coded warning index, which quantify the level of concern. The algorithms for computing the warning index have been designed to balance Type I errors (false prediction of an epidemic) and Type II errors (failure to correctly predict an epidemic). If the warning index signals a sufficiently high probability of an epidemic, then a forecast of the possible size of the outbreak is made. This longer term forecast is made by fitting a ‘signature’ curve to the available data. The effectiveness of the forecast depends upon the extent to which the signature curve captures the shape of outbreaks of the infection under consideration. PMID:18716671

Gay bathhouse HIV prevention: the use of staff monitoring of patron sexual behavior.

PubMed

Woods, William J; Sheon, Nicolas; Morris, Joseph A; Binson, Diane

2013-06-01

Many HIV prevention interventions have been launched in gay bathhouses and sex clubs since the onset of the AIDS epidemic, such as condom distribution and HIV testing. Perhaps none of these are as intrusive to the venue's environment as what is called "monitoring," which involves staff, during every shift, repeatedly walking throughout the public areas of a bathhouse to check on patrons' sexual behavior. Yet, monitoring has received little evaluation. Between 2002 and 2004, we conducted qualitative interviews with venue managers, staff and patrons in New York City, Los Angeles, and the San Francisco Bay Area. An analysis found that monitoring was influenced by the kinds of space available for sex, suggesting three approaches to monitoring: 1) monitoring all sex in clubs that only had public areas where men had sex ; 2) monitoring some sex in clubs with private rooms for sex; and 3) no monitoring of sex, regardless of the kinds of space for sex. This paper explores each approach as described by club managers, staff, and patrons to understand the potential effectiveness of monitoring as an HIV prevention intervention.

Gay bathhouse HIV prevention: the use of staff monitoring of patron sexual behavior

PubMed Central

Woods, William J.; Sheon, Nicolas; Morris, Joseph A.; Binson, Diane

2013-01-01

Many HIV prevention interventions have been launched in gay bathhouses and sex clubs since the onset of the AIDS epidemic, such as condom distribution and HIV testing. Perhaps none of these are as intrusive to the venue's environment as what is called "monitoring," which involves staff, during every shift, repeatedly walking throughout the public areas of a bathhouse to check on patrons' sexual behavior. Yet, monitoring has received little evaluation. Between 2002 and 2004, we conducted qualitative interviews with venue managers, staff and patrons in New York City, Los Angeles, and the San Francisco Bay Area. An analysis found that monitoring was influenced by the kinds of space available for sex, suggesting three approaches to monitoring: 1) monitoring all sex in clubs that only had public areas where men had sex ; 2) monitoring some sex in clubs with private rooms for sex; and 3) no monitoring of sex, regardless of the kinds of space for sex. This paper explores each approach as described by club managers, staff, and patrons to understand the potential effectiveness of monitoring as an HIV prevention intervention. PMID:24044008

Zika virus: Endemic and epidemic ranges of Aedes mosquito transmission.

PubMed

Attaway, David F; Waters, Nigel M; Geraghty, Estella M; Jacobsen, Kathryn H

As evidence linking Zika virus with serious health complications strengthens, public health officials and clinicians worldwide need to know which locations are likely to be at risk for autochthonous Zika infections. We created risk maps for epidemic and endemic Aedes-borne Zika virus infections globally using a predictive analysis method that draws on temperature, precipitation, elevation, land cover, and population density variables to identify locations suitable for mosquito activity seasonally or year-round. Aedes mosquitoes capable of transmitting Zika and other viruses are likely to live year-round across many tropical areas in the Americas, Africa, and Asia. Our map provides an enhanced global projection of where vector control initiatives may be most valuable for reducing the risk of Zika virus and other Aedes-borne infections. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

The Indirect Impact of Antiretroviral Therapy: Mortality Risk, Mental Health, and HIV-Negative Labor Supply

PubMed Central

Baranov, Victoria; Bennett, Daniel; Kohler, Hans-Peter

2015-01-01

To reduce the burden of the HIV/AIDS epidemic, international donors recently began providing free antiretroviral therapy (ART) in parts of Sub-Saharan Africa. ART dramatically prolongs life and reduces infectiousness for people with HIV. This paper shows that ART availability increases work time for HIV-negative people without caretaker obligations, who do not directly benefit from the medicine. A difference-in-difference design compares people living near and far from ART, before and after treatment becomes available. Next we explore the possible reasons for this pattern. Although we cannot pinpoint the mechanism, we find that ART availability substantially reduces subjective mortality risk and improves mental health. These results show an undocumented economic consequence of the HIV/AIDS epidemic and an important externality of medical innovation. They also provide the first evidence of a link between the disease environment and mental health. PMID:26516983

Proximity Networks and Epidemics

NASA Astrophysics Data System (ADS)

Guclu, Hasan; Toroczkai, Zoltán

2007-03-01

We presented the basis of a framework to account for the dynamics of contacts in epidemic processes, through the notion of dynamic proximity graphs. By varying the integration time-parameter T, which is the period of infectivity one can give a simple account for some of the differences in the observed contact networks for different diseases, such as smallpox, or AIDS. Our simplistic model also seems to shed some light on the shape of the degree distribution of the measured people-people contact network from the EPISIM data. We certainly do not claim that the simplistic graph integration model above is a good model for dynamic contact graphs. It only contains the essential ingredients for such processes to produce a qualitative agreement with some observations. We expect that further refinements and extensions to this picture, in particular deriving the link-probabilities in the dynamic proximity graph from more realistic contact dynamics should improve the agreement between models and data.

Now and again: the food and beverage industry demonstrates its commitment to a healthy America.

PubMed

Finn, Susan

2005-07-01

There exists a complex relationship between food and health in our society that is intrinsically linked to our obesity epidemic. The food and beverage industry recognizes that it can influence and modify the eating behavior of Americans. The American Council for Fitness and Nutrition was formed in January 2003 as a partnership of food and beverage companies, trade associations, and nutrition advocates that work together to create long-lasting remedies for the obesity epidemic. The American Council for Fitness and Nutrition recognizes that the current American lifestyle contributes to an energy imbalance and, therefore, supports approaches that aim to correct that imbalance. The American Council for Fitness and Nutrition also supports the underrepresented populations that are disproportionately affected by obesity, specifically, the African American and Hispanic American communities. Cooperation between industry, government, and academia will be key in establishing long-term strategies to help consumers make healthy lifestyle choices.

Resurgence of Mumps in Korea

PubMed Central

2015-01-01

Routine vaccination against mumps has markedly reduced its incidence. However, the incidence of mumps continuously has increased since 2007. In 2013, a large mumps epidemic occurred in Korea, and this epidemic is still an ongoing problem. This epidemic occurred primarily in school settings and affected vaccinated adolescents, predominantly male students. The recent resurgence of mumps is caused by multiple factors: suboptimal effectiveness of the current mumps vaccines, use of the Rubini strain vaccine, waning immunity in the absence of natural boosting due to the marked reduction in the mumps incidence, genotype mismatch between the vaccine and circulating mumps virus strains, and environmental conditions that foster intense exposures. Containment of mumps outbreaks is challenging because the sensitivity of diagnostic tests is low among vaccinees and control measures are less efficient because of the inherent nature of the mumps virus. Despite the suboptimal vaccine effectiveness in outbreak settings, maintaining the high vaccine coverage is an important strategy to prevent mumps outbreaks, given that the routine use of mumps vaccines has substantially reduced the incidence of mumps and its complications as compared with that in the pre-vaccine era. In order to control the current mumps epidemic and prevent further outbreaks, we need to better understand the dynamics of mumps among vaccinated populations and the changing epidemiology in Korea. Concerted efforts should be made to systematically monitor the immunization status of the Korean population and to improve diagnosis efficiency. Furthermore, more effective mumps vaccines need to be developed in the future. PMID:25844258

Monitoring the severe acute respiratory syndrome epidemic and assessing effectiveness of interventions in Hong Kong Special Administrative Region

PubMed Central

Chau, P; Yip, P

2003-01-01

Objective: To estimate the infection curve of severe acute respiratory syndrome (SARS) using the back projection method and to assess the effectiveness of interventions. Design: Statistical method. Data: The daily reported number of SARS and interventions taken by Hong Kong Special Administrative Region (HKSAR) up to 24 June 2003 are used. Method: To use a back projection technique to construct the infection curve of SARS in Hong Kong. The estimated epidemic curve is studied to identify the major events and to assess the effectiveness of interventions over the course of the epidemic. Results: The SARS infection curve in Hong Kong is constructed for the period 1 March 2003 to 24 June 2003. Some interventions seem to be effective while others apparently have little or no effect. The infections among the medical and health workers are high. Conclusions: Quarantine of the close contacts of confirmed and suspected SARS cases seems to be the most effective intervention against spread of SARS in the community. Thorough disinfection of the infected area against environmental hazards is helpful. Infections within hospitals can be reduced by better isolation measures and protective equipments. PMID:14573569

Implications of Zika virus and congenital Zika syndrome for the number of live births in Brazil

PubMed Central

Han, Qiuyi C.; Victora, Cesar G.; França, Giovanny V. A.

2018-01-01

An increase in microcephaly, associated with an epidemic of Zika virus (ZIKV) in Brazil, prompted the World Health Organization to declare a Public Health Emergency of International Concern in February 2016. While knowledge on biological and epidemiological aspects of ZIKV has advanced, demographic impacts remain poorly understood. This study uses time-series analysis to assess the impact of ZIKV on births. Data on births, fetal deaths, and hospitalizations due to abortion complications for Brazilian states, from 2010 to 2016, were used. Forecasts for September 2015 to December 2016 showed that 119,095 fewer births than expected were observed, particularly after April 2016 (a reduction significant at 0.05), demonstrating a link between publicity associated with the ZIKV epidemic and the decline in births. No significant changes were observed in fetal death rates. Although no significant increases in hospitalizations were forecasted, after the ZIKV outbreak hospitalizations happened earlier in the gestational period in most states. We argue that postponement of pregnancy and an increase in abortions may have contributed to the decline in births. Also, it is likely that an increase in safe abortions happened, albeit selective by socioeconomic status. Thus, the ZIKV epidemic resulted in a generation of congenital Zika syndrome (CZS) babies that reflect and exacerbate regional and social inequalities. Since ZIKV transmission has declined, it is unlikely that reductions in births will continue. However, the possibility of a new epidemic is real. There is a need to address gaps in reproductive health and rights, and to understand CZS risk to better inform conception decisions. PMID:29844186

The Asian house shrew Suncus murinus as a reservoir and source of human outbreaks of plague in Madagascar

PubMed Central

Rajerison, Minoarisoa; Telfer, Sandra; Savin, Cyril; Carniel, Elisabeth; Duplantier, Jean-Marc

2017-01-01

Identifying key reservoirs for zoonoses is crucial for understanding variation in incidence. Plague re-emerged in Mahajanga, Madagascar in the 1990s but there has been no confirmed case since 1999. Here we combine ecological and genetic data, from during and after the epidemics, with experimental infections to examine the role of the shrew Suncus murinus in the plague epidemiological cycle. The predominance of S. murinus captures during the epidemics, their carriage of the flea vector and their infection with Yersinia pestis suggest they played an important role in the maintenance and transmission of plague. S. murinus exhibit a high but variable resistance to experimental Y. pestis infections, providing evidence of its ability to act as a maintenance host. Genetic analyses of the strains isolated from various hosts were consistent with two partially-linked transmission cycles, with plague persisting within the S. murinus population, occasionally spilling over into the rat and human populations. The recent isolation from a rat in Mahajanga of a Y. pestis strain genetically close to shrew strains obtained during the epidemics reinforces this hypothesis and suggests circulation of plague continues. The observed decline in S. murinus and Xenopsylla cheopis since the epidemics appears to have decreased the frequency of spillover events to the more susceptible rats, which act as a source of infection for humans. Although this may explain the lack of confirmed human cases in recent years, the current circulation of plague within the city highlights the continuing health threat. PMID:29155827

Rapid Development and Use of a Nationwide Training Program for Cholera Management, Haiti, 2010

PubMed Central

Lynch, Michael; Lambert, Yves; Sobel, Jeremy; Domerçant, Jean W.; Khan, Azharul

2011-01-01

When epidemic cholera appeared in Haiti in October 2010, the medical community there had virtually no experience with the disease and needed rapid training as the epidemic spread throughout the country. We developed a set of training materials specific to Haiti and launched a cascading training effort. Through a training-of-trainers course in November 14–15, 2010, and department-level training conducted in French and Creole over the following 3 weeks, 521 persons were trained and equipped to further train staff at the institutions where they worked. After the training, the hospitalized cholera patients’ case-fatality rate dropped from 4% to <2% by mid-December and was <1% by January 2011. Continuing in-service training, monitoring and evaluation, and integration of cholera management into regular clinical training will help sustain this success. PMID:22099112

Global Spread of Hemorrhagic Fever Viruses: Predicting Pandemics.

PubMed

Gonzalez, Jean-Paul; Souris, Marc; Valdivia-Granda, Willy

2018-01-01

As successive epidemics have swept the world, the scientific community has quickly learned from them about the emergence and transmission of communicable diseases. Epidemics usually occur when health systems are unprepared. During an unexpected epidemic, health authorities engage in damage control, fear drives action, and the desire to understand the threat is greatest. As humanity recovers, policy-makers seek scientific expertise to improve their "preparedness" to face future events.Global spread of disease is exemplified by the spread of yellow fever from Africa to the Americas, by the spread of dengue fever through transcontinental migration of mosquitos, by the relentless influenza virus pandemics, and, most recently, by the unexpected emergence of Ebola virus, spread by motorbike and long haul carriers. Other pathogens that are remarkable for their epidemic expansions include the arenavirus hemorrhagic fevers and hantavirus diseases carried by rodents over great geographic distances and the arthropod-borne viruses (West Nile, chikungunya and Zika) enabled by ecology and vector adaptations. Did we learn from the past epidemics? Are we prepared for the worst?The ultimate goal is to develop a resilient global health infrastructure. Besides acquiring treatments, vaccines, and other preventive medicine, bio-surveillance is critical to preventing disease emergence and to counteracting its spread. So far, only the western hemisphere has a large and established monitoring system; however, diseases continue to emerge sporadically, in particular in Southeast Asia and South America, illuminating the imperfections of our surveillance. Epidemics destabilize fragile governments, ravage the most vulnerable populations, and threaten the global community.Pandemic risk calculations employ new technologies like computerized maintenance of geographical and historical datasets, Geographic Information Systems (GIS), Next Generation sequencing, and Metagenomics to trace the molecular changes in pathogens during their emergence, and mathematical models to assess risk. Predictions help to pinpoint the hot spots of emergence, the populations at risk, and the pathogens under genetic evolution. Preparedness anticipates the risks, the needs of the population, the capacities of infrastructure, the sources of emergency funding, and finally, the international partnerships needed to manage a disaster before it occurs. At present, the world is in an intermediate phase of trying to reduce health disparities despite exponential population growth, political conflicts, migration, global trade, urbanization, and major environmental changes due to global warming. For the sake of humanity, we must focus on developing the necessary capacities for health surveillance, epidemic preparedness, and pandemic response.

Modelling virus- and host-limitation in vectored plant disease epidemics.

PubMed

Jeger, M J; van den Bosch, F; Madden, L V

2011-08-01

Models of plant virus epidemics have received less attention than those caused by fungal pathogens. Intuitively, the fact that virus diseases are systemic means that the individual diseased plant can be considered as the population unit which simplifies modelling. However, the fact that a vector is required in the vast majority of cases for virus transmission, means that explicit consideration must be taken of the vector, or, the involvement of the vector in the transmission process must be considered implicitly. In the latter case it is also important that within-plant processes, such as virus multiplication and systemic movement, are taken into account. In this paper we propose an approach based on the linking of transmission at the population level with virus multiplication within plants. The resulting models are parameter-sparse and hence simplistic. However, the range of model outcomes is representative of field observations relating to the apparent limitation of epidemic development in populations of healthy susceptible plants. We propose that epidemic development can be constrained by virus limitation in the early stages of an epidemic when the availability of healthy susceptible hosts is not limiting. There is an inverse relationship between levels of transmission in the population and the mean virus titre/infected plant. In the case of competition between viruses, both virus and host limitation are likely to be important in determining whether one virus can displace another or whether both viruses can co-exist in a plant population. Lotka-Volterra type equations are derived to describe density-dependent competition between two viruses multiplying within plants, embedded within a population level epidemiological model. Explicit expressions determining displacement or co-existence of the viruses are obtained. Unlike the classical Lotka-Volterra competition equations, the co-existence requirement for the competition coefficients to be both less than 1 can be relaxed. Copyright © 2011 Elsevier B.V. All rights reserved.

Distributed intrusion monitoring system with fiber link backup and on-line fault diagnosis functions

NASA Astrophysics Data System (ADS)

Xu, Jiwei; Wu, Huijuan; Xiao, Shunkun

2014-12-01

A novel multi-channel distributed optical fiber intrusion monitoring system with smart fiber link backup and on-line fault diagnosis functions was proposed. A 1× N optical switch was intelligently controlled by a peripheral interface controller (PIC) to expand the fiber link from one channel to several ones to lower the cost of the long or ultra-long distance intrusion monitoring system and also to strengthen the intelligent monitoring link backup function. At the same time, a sliding window auto-correlation method was presented to identify and locate the broken or fault point of the cable. The experimental results showed that the proposed multi-channel system performed well especially whenever any a broken cable was detected. It could locate the broken or fault point by itself accurately and switch to its backup sensing link immediately to ensure the security system to operate stably without a minute idling. And it was successfully applied in a field test for security monitoring of the 220-km-length national borderline in China.

Inflammation and insulin/IGF-1 resistance as the possible link between obesity and neurodegeneration.

PubMed

Spielman, Lindsay J; Little, Jonathan P; Klegeris, Andis

2014-08-15

Obesity is a growing epidemic that contributes to several brain disorders including Alzheimer's, Parkinson's, and Huntington's diseases. Obesity could promote these diseases through several different mechanisms. Here we review evidence supporting the involvement of two recently recognized factors linking obesity with neurodegeneration: the induction of pro-inflammatory cytokines and onset of insulin and insulin-like growth factor 1 (IGF-1) resistance. Excess peripheral pro-inflammatory mediators, some of which can cross the blood brain barrier, may trigger neuroinflammation, which subsequently exacerbates neurodegeneration. Insulin and IGF-1 resistance leads to weakening of neuroprotective signaling by these molecules and can contribute to onset of neurodegenerative diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

World Bank Contribution to Building National HIV/AIDS Monitoring and Evaluation Capacity in Africa: Going beyond Indicator Development and Conceptual Training

ERIC Educational Resources Information Center

Wilson, David

2004-01-01

International commitment to the human immunodeficiency virus-acquired immunodeficiency syndrome (HIV/AIDS) epidemic has grown rapidly in recent years, stimulated by the leadership of the Joint United Nations Programme on HIV/AIDS (UNAIDS) and its cosponsors and supported by a range of new mechanisms. These include the World Bank's Multi-Country…

Data Link Test and Analysis System/TCAS Monitor User's Guide

DOT National Transportation Integrated Search

1991-02-01

This document is a user's guide for the Data Link Test and Analysis System : (DATAS) Traffic Alert and Collision Avoidance System (TCAS) monitor application. : It provides a brief overall hardware description of DATAS configured as a TCAS : Monitor, ...

The world's microbiology laboratories can be a global microbial sensor network.

PubMed

O'Brien, Thomas F; Stelling, John

2014-04-01

The microbes that infect us spread in global and local epidemics, and the resistance genes that block their treatment spread within and between them. All we can know about where they are to track and contain them comes from the only places that can see them, the world's microbiology laboratories, but most report each patient's microbe only to that patient's caregiver. Sensors, ranging from instruments to birdwatchers, are now being linked in electronic networks to monitor and interpret algorithmically in real-time ocean currents, atmospheric carbon, supply-chain inventory, bird migration, etc. To so link the world's microbiology laboratories as exquisite sensors in a truly lifesaving real-time network their data must be accessed and fully subtyped. Microbiology laboratories put individual reports into inaccessible paper or mutually incompatible electronic reporting systems, but those from more than 2,200 laboratories in more than 108 countries worldwide are now accessed and translated into compatible WHONET files. These increasingly web-based files could initiate a global microbial sensor network. Unused microbiology laboratory byproduct data, now from drug susceptibility and biochemical testing but increasingly from new technologies (genotyping, MALDI-TOF, etc.), can be reused to subtype microbes of each genus/species into sub-groupings that are discriminated and traced with greater sensitivity. Ongoing statistical delineation of subtypes from global sensor network data will improve detection of movement into any patient of a microbe or resistance gene from another patient, medical center or country. Growing data on clinical manifestations and global distributions of subtypes can automate comments for patient's reports, select microbes to genotype and alert responders.

Immunomodulatory Role of Diet and Adipokines in Multiple Sclerosis and Its Animal Model

DTIC Science & Technology

2015-09-01

beginning to be elucidated. In this regard, MS has been studied very little. Several recent studies showed that obesity during childhood /young adulthood...confers increased risk of developing MS. Obesity in the past 20 years has become an epidemic in western counties. New evidence suggests a link...between obesity and several autoimmune diseases (Procaccini, Carbone et al. 2011). Obesity is characterized by a low-grade chronic inflammatory state

Cholera: an overview with reference to the Yemen epidemic.

PubMed

Rabaan, Ali A

2018-06-22

Cholera is a secretory diarrhoeal disease caused by infection with Vibrio cholerae, primarily the V. cholerae O1 El Tor biotype. There are approximately 2.9 million cases in 69 endemic countries annually, resulting in 95 000 deaths. Cholera is associated with poor infrastructure and lack of access to sanitation and clean drinking water. The current cholera epidemic in Yemen, linked to spread of V. cholerae O1 (Ogawa serotype), is associated with the ongoing war. This has devastated infrastructure and health services. The World Health Organization had estimated that 172 286 suspected cases arose between 27th April and 19th June 2017, including 1170 deaths. While there are three oral cholera vaccines prequalified by the World Health Organization, there are issues surrounding vaccination campaigns in conflict situations, exacerbated by external factors such as a global vaccine shortage. Major movements of people complicates surveillance and administration of double doses of vaccines. Cholera therapy mainly depends on rehydration, with use of antibiotics in more severe infections. Concerns have arisen about the rise of antibiotic resistance in cholera, due to mobile genetic elements. In this review, we give an overview of cholera epidemiology, virulence, antibiotic resistance, therapy and vaccines, in the light of the ongoing epidemic in Yemen.

Women and AIDS in Zimbabwe: the making of an epidemic.

PubMed

Bassett, M T; Mhloyi, M

1991-01-01

As the AIDS epidemic in Africa assumes major proportions, the need to understand the social context in which heterosexual transmission occurs takes on urgent importance. In this article we explore how the intersection of traditional culture with the colonial legacy and present-day political economy has influenced family structure and sexual relations, and particularly the social position of women. Drawing on Zimbabwe's historical experience, we show how land expropriation, rural impoverishment, and the forcible introduction of male migrant labor fostered new patterns of sexual relations, characterized by multiple partners. Traditional patriarchal values reinterpreted in European law resulted in further subjugation of women as even limited rights to ownership were withdrawn. For many women, sexual relations with men, either within marriage (for the majority) or outside, become inextricably linked to economic and social survival. In this setting, all sexually transmitted diseases became rampant, including genital ulcer, which facilitates transmission of the human immunodeficiency virus (HIV). Intervention programs to halt the spread of AIDS need to take into the account the epidemic's historical roots and social nature. For example, efforts to reduce risk of HIV transmission should seek to expand women's limited options, both technically (e.g., by providing alternatives to condoms) and socially (e.g., by promoting employment).

Factors affecting the HIV/AIDS epidemic: an ecological analysis of global data.

PubMed

Mondal, M N I; Shitan, M

2013-06-01

All over the world the prevalence of Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS) has became a stumbling stone in progress of human civilization and is a huge concern for people worldwide. To determine the social and health factors which contribute to increase the size of HIV epidemic globally. The country level indicators of HIV prevalence rates, are contraceptive prevalence rate, physicians density, proportion of Muslim populations, adolescent fertility rate, and mean year of schooling were compiled of 187 countries from the United Nations (UN) agencies. To extract the major factors from those indicators of the later five categories, backward multiple regression analysis was used as the statistical tool. The national HIV prevalence rate was significantly correlated with almost all the predictors. Backward multiple linear regression analysis identified the proportion of Muslims, physicians density, and adolescent fertility rate are as the three most prominent factors linked with the national HIV epidemic. The findings support the hypotheses that a higher adolescent fertility rate in the population is the adverse effect of premarital and extramarital sex that leads to longer period of sexual activity which increases the risk of HIV infection. On the hand, and cultural restrictions of Muslims and sufficient physicians will decelerate the spread of HIV infections in the society.

Genome sequence analysis of emm89 Streptococcus pyogenes strains causing infections in Scotland, 2010-2016.

PubMed

Beres, Stephen B; Olsen, Randall J; Ojeda Saavedra, Matthew; Ure, Roisin; Reynolds, Arlene; Lindsay, Diane S J; Smith, Andrew J; Musser, James M

2017-12-01

Strains of type emm89 Streptococcus pyogenes have recently increased in frequency as a cause of human infections in several countries in Europe and North America. This increase has been molecular epidemiologically linked with the emergence of a new genetically distinct clone, designated clade 3. We sought to extend our understanding of this epidemic behavior by the genetic characterization of type emm89 strains responsible in recent years for an increased frequency of infections in Scotland. We sequenced the genomes of a retrospective cohort of 122 emm89 strains recovered from patients with invasive and noninvasive infections throughout Scotland during 2010 to 2016. All but one of the 122 emm89 infection isolates are of the recently emerged epidemic clade 3 clonal lineage. The Scotland isolates are closely related to and not genetically distinct from recent emm89 strains from England, they constitute a single genetic population. The clade 3 clone causes virtually all-contemporary emm89 infections in Scotland. These findings add Scotland to a growing list of countries of Europe and North America where, by whole genome sequencing, emm89 clade 3 strains have been demonstrated to be the cause of an ongoing epidemic of invasive infections and to be genetically related due to descent from a recent common progenitor.

HIV epidemic and human rights among men who have sex with men in sub-Saharan Africa: Implications for HIV prevention, care, and surveillance.

PubMed

Abara, Winston E; Garba, Ibrahim

2017-04-01

Recent research has presented evidence that men who have sex with men (MSM) bear a disproportionate burden of HIV and are at increased risk for HIV in sub-Saharan Africa (SSA). However, many countries in SSA have failed to address the needs of MSM in national HIV/AIDS programmes. Furthermore, many MSM face structural barriers to HIV prevention and care, the most significant of which include laws that criminalise male-to-male sexual contact and facilitate stigma and discrimination. This in turn increases the vulnerability of MSM to acquiring HIV and presents barriers to HIV prevention, care, and surveillance. This relationship illustrates the link between human rights, social justice, and health outcomes and presents considerable challenges to addressing the HIV epidemic among MSM in SSA. The response to the HIV epidemic in SSA requires a non-discriminatory human rights approach to all at-risk groups, including MSM. Existing international human rights treaties, to which many SSA countries are signatories, and a 'health in all policies' approach provides a strong basis to reduce structural barriers to HIV prevention, care, surveillance, and research, and to ensure that all populations in SSA, including MSM, have access to the full range of rights that help ensure equal opportunities for health and wellness.

Epidemic and Endemic Malaria Transmission Related to Fish Farming Ponds in the Amazon Frontier

PubMed Central

Barcellos, Christovam; Kitron, Uriel; Camara, Daniel Cardoso Portela; Pereira, Glaucio Rocha; Keppeler, Erlei Cassiano; da Silva-Nunes, Mônica

2015-01-01

Fish farming in the Amazon has been stimulated as a solution to increase economic development. However, poorly managed fish ponds have been sometimes associated with the presence of Anopheles spp. and consequently, with malaria transmission. In this study, we analyzed the spatial and temporal dynamics of malaria in the state of Acre (and more closely within a single county) to investigate the potential links between aquaculture and malaria transmission in this region. At the state level, we classified the 22 counties into three malaria endemicity patterns, based on the correlation between notification time series. Furthermore, the study period (2003–2013) was divided into two phases (epidemic and post-epidemic). Higher fish pond construction coincided both spatially and temporally with increased rate of malaria notification. Within one malaria endemic county, we investigated the relationship between the geolocation of malaria cases (2011–2012) and their distance to fish ponds. Entomological surveys carried out in these ponds provided measurements of anopheline abundance that were significantly associated with the abundance of malaria cases within 100 m of the ponds (P < 0.005; r = 0.39). These results taken together suggest that fish farming contributes to the maintenance of high transmission levels of malaria in this region. PMID:26361330

Perspectives on using remotely-sensed imagery in predictive veterinary epidemiology and global early warning systems.

PubMed

Martin, Vincent; De Simone, Lorenzo; Lubroth, Juan; Ceccato, Pietro; Chevalier, Véronique

2007-11-01

Recent disease epidemics and their spread around the world have illustrated the weaknesses of disease surveillance and early warning systems (EWS), both at national and international levels. These diseases continuously threaten the livestock sector on a worldwide basis, some with major public health impact. EWS and accurate forecasting of new outbreaks of epidemic livestock diseases that may also affect wildlife, and the capacity for spread of such diseases to new areas is an essential pre-requisite to their effective containment and control. Because both the geographical and seasonal distribution of many infectious diseases are linked to climate, the possibility of using climaterelated environmental factors as predictive indicators, in association with regular disease surveillance activities, has proven to be relevant when establishing EWS for climate-related diseases. This article reviews the growing importance of using geographical information systems in predictive veterinary epidemiology and its integration into EWS, with a special focus on Rift Valley fever. It shows that, once fully validated in a country or region, this technology appears highly valuable and could play an increasing role in forecasting major epidemics, providing lead time to national veterinary services to take action to mitigate the impact of the disease in a cost-effective manner.

Nucleocapsid Gene-Mediated Transgenic Resistance Provides Protection Against Tomato spotted wilt virus Epidemics in the Field.

PubMed

Herrero, S; Culbreath, A K; Csinos, A S; Pappu, H R; Rufty, R C; Daub, M E

2000-02-01

ABSTRACT Transformation of plants with the nucleocapsid (N) gene of Tomato spotted wilt tospovirus (TSWV) provides resistance to disease development; however, information is lacking on the response of plants to natural inoculum in the field. Three tobacco cultivars were transformed with the N gene of a dahlia isolate of TSWV (TSWV-D), and plants were evaluated over several generations in the greenhouse. The resistant phenotype was more frequently observed in 'Burley 21' than in 'KY-14' or 'K-326', but highly resistant 'Burley 21' transgenic lines were resistant to only 44% of the heterologous TSWV isolates tested. Advanced generation (R(3) and R(4)) transgenic resistant lines of 'Burley 21' and a 'K-326' F(1) hybrid containing the N genes of two TSWV isolates were evaluated in the field near Tifton, GA, where TSWV is endemic. Disease development was monitored by symptom expression and enzyme-linked immunosorbent assay (ELISA) analysis. Whereas incidence of TSWV infection in 'Burley 21' susceptible controls was 20% in 1996 and 62% in 1997, the mean incidence in transgenic lines was reduced to 4 and 31%, respectively. Three transgenic 'Burley 21' lines were identified that had significantly lower incidence of disease than susceptible controls over the two years of the study. In addition, the rate of disease increase at the onset of the 1997 epidemic was reduced for all the 'Burley 21' transgenic lines compared with the susceptible controls. The 'K-326' F(1) hybrid was as susceptible as the 'K-326' nontransformed control. ELISA analysis demonstrated that symptomless plants from the most resistant 'Burley 21' transgenic lines accumulated detectable nucleocapsid protein, whereas symptomless plants from more susceptible lines did not. We conclude that transgenic resistance to TSWV is effective in reducing incidence of the disease in the field, and that accumulation of transgene protein may be important in broad-spectrum resistance.

Data link test and analysis system/TCAS monitor user's guide

NASA Astrophysics Data System (ADS)

Vandongen, John; Wapelhorst, Leo

1991-02-01

This document is a user's guide for the Data Link Test and Analysis System (DATAS) Traffic Alert and Collision Avoidance System (TCAS) monitor. It provides a brief overall hardware description of DATAS configured as a TCAS monitor, and the applications software.

Socioeconomic and environmental determinants of dengue transmission in an urban setting: An ecological study in Nouméa, New Caledonia.

PubMed

Zellweger, Raphaël M; Cano, Jorge; Mangeas, Morgan; Taglioni, François; Mercier, Alizé; Despinoy, Marc; Menkès, Christophe E; Dupont-Rouzeyrol, Myrielle; Nikolay, Birgit; Teurlai, Magali

2017-04-01

Dengue is a mosquito-borne virus that causes extensive morbidity and economic loss in many tropical and subtropical regions of the world. Often present in cities, dengue virus is rapidly spreading due to urbanization, climate change and increased human movements. Dengue cases are often heterogeneously distributed throughout cities, suggesting that small-scale determinants influence dengue urban transmission. A better understanding of these determinants is crucial to efficiently target prevention measures such as vector control and education. The aim of this study was to determine which socioeconomic and environmental determinants were associated with dengue incidence in an urban setting in the Pacific. An ecological study was performed using data summarized by neighborhood (i.e. the neighborhood is the unit of analysis) from two dengue epidemics (2008-2009 and 2012-2013) in the city of Nouméa, the capital of New Caledonia. Spatial patterns and hotspots of dengue transmission were assessed using global and local Moran's I statistics. Multivariable negative binomial regression models were used to investigate the association between dengue incidence and various socioeconomic and environmental factors throughout the city. The 2008-2009 epidemic was spatially structured, with clusters of high and low incidence neighborhoods. In 2012-2013, dengue incidence rates were more homogeneous throughout the city. In all models tested, higher dengue incidence rates were consistently associated with lower socioeconomic status (higher unemployment, lower revenue or higher percentage of population born in the Pacific, which are interrelated). A higher percentage of apartments was associated with lower dengue incidence rates during both epidemics in all models but one. A link between vegetation coverage and dengue incidence rates was also detected, but the link varied depending on the model used. This study demonstrates a robust spatial association between dengue incidence rates and socioeconomic status across the different neighborhoods of the city of Nouméa. Our findings provide useful information to guide policy and help target dengue prevention efforts where they are needed most.

Fluid fragmentation shapes rain-induced foliar disease transmission

PubMed Central

Gilet, T.; Bourouiba, L.

2015-01-01

Plant diseases represent a growing threat to the global food supply. The factors contributing to pathogen transmission from plant to plant remain poorly understood. Statistical correlations between rainfalls and plant disease outbreaks were reported; however, the detailed mechanisms linking the two were relegated to a black box. In this combined experimental and theoretical study, we focus on the impact dynamics of raindrops on infected leaves, one drop at a time. We find that the deposition range of most of the pathogen-bearing droplets is constrained by a hydrodynamical condition and we quantify the effect of leaf size and compliance on such constraint. Moreover, we identify and characterize two dominant fluid fragmentation scenarios as responsible for the dispersal of most pathogen-bearing droplets emitted from infected leaves: (i) the crescent-moon ejection is driven by the direct interaction between the impacting raindrop and the contaminated sessile drop and (ii) the inertial detachment is driven by the motion imparted to the leaf by the raindrop, leading to catapult-like droplet ejections. We find that at first, decreasing leaf size or increasing compliance reduces the range of pathogen-bearing droplets and the subsequent epidemic onset efficiency. However, this conclusion only applies for the crescent moon ejection. Above a certain compliance threshold a more effective mechanism of contaminated fluid ejection, the inertial detachment, emerges. This compliance threshold is determined by the ratio between the leaf velocity and the characteristic velocity of fluid fragmentation. The inertial detachment mechanism enhances the range of deposition of the larger contaminated droplets and suggests a change in epidemic onset pattern and a more efficient potential of infection of neighbouring plants. Dimensionless parameters and scaling laws are provided to rationalize our observations. Our results link for the first time the mechanical properties of foliage with the onset dynamics of foliar epidemics through the lens of fluid fragmentation. We discuss how the reported findings can inform the design of mitigation strategies acting at the early stage of a foliar disease outbreak. PMID:25652459

The Hungarian congenital malformation monitoring system.

PubMed

Czeizel, A

1978-01-01

The Hungarian Congenital Malformation Monitor has been operating since 1973 in order to detect the temporal and regional clusters of 12 indicator congenital malformations as early as possible. This Monitor takes part in the International Clearinghouse for Birth Defects Monitoring System. Three continuously increasing trends were detected in 1973--1976. They may be connected with the more complete notifications, although the increase of limb reduction deformities are only partly explained by this factor. Transitional (quarterly) significant clusters were observed in the case of anencephaly (1974, IV), spina bifida (1974, II; and 1975, III; 1976, III), cleft lip +/- cleft palate (1974, III). The possibility of three technical biases (changes in diagnosis, notification and evaluation of the given congenital malformation) has to be excluded before accepting the fact of a real epidemic. Subsequently, a case-control epidemiological study by personal interviews and with matched controls has to be performed.

HIITE: HIV-1 incidence and infection time estimator.

PubMed

Park, Sung Yong; Love, Tanzy M T; Kapoor, Shivankur; Lee, Ha Youn

2018-06-15

Around 2.1 million new HIV-1 infections were reported in 2015, alerting that the HIV-1 epidemic remains a significant global health challenge. Precise incidence assessment strengthens epidemic monitoring efforts and guides strategy optimization for prevention programs. Estimating the onset time of HIV-1 infection can facilitate optimal clinical management and identify key populations largely responsible for epidemic spread and thereby infer HIV-1 transmission chains. Our goal is to develop a genomic assay estimating the incidence and infection time in a single cross-sectional survey setting. We created a web-based platform, HIV-1 incidence and infection time estimator (HIITE), which processes envelope gene sequences using hierarchical clustering algorithms and informs the stage of infection, along with time since infection for incident cases. HIITE's performance was evaluated using 585 incident and 305 chronic specimens' envelope gene sequences collected from global cohorts including HIV-1 vaccine trial participants. HIITE precisely identified chronically infected individuals as being chronic with an error less than 1% and correctly classified 94% of recently infected individuals as being incident. Using a mixed-effect model, an incident specimen's time since infection was estimated from its single lineage diversity, showing 14% prediction error for time since infection. HIITE is the first algorithm to inform two key metrics from a single time point sequence sample. HIITE has the capacity for assessing not only population-level epidemic spread but also individual-level transmission events from a single survey, advancing HIV prevention and intervention programs. Web-based HIITE and source code of HIITE are available at http://www.hayounlee.org/software.html. Supplementary data are available at Bioinformatics online.

A text-mining analysis of the public's reactions to the opioid crisis.

PubMed

Glowacki, Elizabeth M; Glowacki, Joseph B; Wilcox, Gary B

2017-07-19

Opioid abuse has become an epidemic in the United States. On August 25, 2016, the former Surgeon General of the United States sent an open letter to care providers asking for their help with combatting this growing health crisis. Social media forums such as Twitter allow for open discussions among the public and up-to-date exchanges of information about timely topics such as opioids. Therefore, the goal of the current study is to identify the public's reactions to the opioid epidemic by identifying the most popular topics tweeted by users. A text miner, algorithmic-driven statistical program was used to capture 73,235 original tweets and retweets posted within a 2-month time span 15 (August 15, 2016, through October 15, 2016). All tweets contained references to "opioids," "turnthetide," or similar keywords. The sets of tweets were then analyzed to identify the most prevalent topics. The most discussed topics had to do with public figures addressing opioid abuse, creating better treatment options for teen addicts, using marijuana as an alternative for managing pain, holding foreign and domestic drug makers accountable for the epidemic, promoting the "Rx for Change" campaign, addressing double standards in the perceptions and treatment of black and white opioid users, and advertising opioid recovery programs. Twitter allows users to find current information, voice their concerns, and share calls for action in response to the opioid epidemic. Monitoring the conversations about opioids that are taking place on social media forums such as Twitter can help public health officials and care providers better understand how the public is responding to this health crisis.

Surveillance lessons from first-wave pandemic (H1N1) 2009, Northern California, USA.

PubMed

Baxter, Roger

2010-03-01

After the appearance of pandemic (H1N1) 2009 in April 2009, influenza activity was monitored within the Kaiser Permanente Northern California division by using laboratory, pharmacy, telephone calls, and utilization (services patients received) data. A combination of testing and utilization data showed a pattern of disease activity, but this pattern may have been affected by public perception of the epidemic.

[Risk management of soybean-related asthma: monitoring and surveillance].

PubMed

Villalbí, Joan R; Carrascal, Dolors; Caylà, Joan A; Rodríguez, Pau; Cruz, M A Jesús; Pintó, Josep M

2011-01-01

Allergen emissions during soybean unloading operations in the Barcelona harbor have caused asthma epidemics. The present article aimed to describe the surveillance and control measures carried out by the public health services. Data were extracted from control systems from 1999 to 2009, with description of the surveillance schemes for allergen emissions, environmental concentrations (with defined reference levels) and for health. Of 95 studies of plant emission, four were above the reference levels, and filters were found to be the most likely cause. Mean environmental concentrations were low but were above the reference levels on 13 days; these levels were related to adverse meteorological conditions and incidents in the plants. No health effects were detected in the panel of patients nor epidemic asthma days. The system detects incidents and has shown its usefulness in protecting public health. Copyright © 2011 SESPAS. Published by Elsevier Espana. All rights reserved.

Remote Sensing Contributions to Prediction and Risk Assessment of Natural Disasters Caused by Large Scale Rift Valley Fever Outbreaks

NASA Technical Reports Server (NTRS)

Anyamba, Assaf; Linthicum, Kenneth J.; Small, Jennifer; Britch, S. C.; Tucker, C. J.

2012-01-01

Remotely sensed vegetation measurements for the last 30 years combined with other climate data sets such as rainfall and sea surface temperatures have come to play an important role in the study of the ecology of arthropod-borne diseases. We show that epidemics and epizootics of previously unpredictable Rift Valley fever are directly influenced by large scale flooding associated with the El Ni o/Southern Oscillation. This flooding affects the ecology of disease transmitting arthropod vectors through vegetation development and other bioclimatic factors. This information is now utilized to monitor, model, and map areas of potential Rift Valley fever outbreaks and is used as an early warning system for risk reduction of outbreaks to human and animal health, trade, and associated economic impacts. The continuation of such satellite measurements is critical to anticipating, preventing, and managing disease epidemics and epizootics and other climate-related disasters.

Emergence of wheat blast in Bangladesh was caused by a South American lineage of Magnaporthe oryzae.

PubMed

Islam, M Tofazzal; Croll, Daniel; Gladieux, Pierre; Soanes, Darren M; Persoons, Antoine; Bhattacharjee, Pallab; Hossain, Md Shaid; Gupta, Dipali Rani; Rahman, Md Mahbubur; Mahboob, M Golam; Cook, Nicola; Salam, Moin U; Surovy, Musrat Zahan; Sancho, Vanessa Bueno; Maciel, João Leodato Nunes; NhaniJúnior, Antonio; Castroagudín, Vanina Lilián; Reges, Juliana T de Assis; Ceresini, Paulo Cezar; Ravel, Sebastien; Kellner, Ronny; Fournier, Elisabeth; Tharreau, Didier; Lebrun, Marc-Henri; McDonald, Bruce A; Stitt, Timothy; Swan, Daniel; Talbot, Nicholas J; Saunders, Diane G O; Win, Joe; Kamoun, Sophien

2016-10-03

In February 2016, a new fungal disease was spotted in wheat fields across eight districts in Bangladesh. The epidemic spread to an estimated 15,000 hectares, about 16 % of the cultivated wheat area in Bangladesh, with yield losses reaching up to 100 %. Within weeks of the onset of the epidemic, we performed transcriptome sequencing of symptomatic leaf samples collected directly from Bangladeshi fields. Reinoculation of seedlings with strains isolated from infected wheat grains showed wheat blast symptoms on leaves of wheat but not rice. Our phylogenomic and population genomic analyses revealed that the wheat blast outbreak in Bangladesh was most likely caused by a wheat-infecting South American lineage of the blast fungus Magnaporthe oryzae. Our findings suggest that genomic surveillance can be rapidly applied to monitor plant disease outbreaks and provide valuable information regarding the identity and origin of the infectious agent.

Amplification of Emerging Viruses in a Bat Colony

PubMed Central

Drexler, Jan Felix; Corman, Victor Max; Wegner, Tom; Tateno, Adriana Fumie; Zerbinati, Rodrigo Melim; Gloza-Rausch, Florian; Seebens, Antje; Müller, Marcel A.

2011-01-01

Bats host noteworthy viral pathogens, including coronaviruses, astroviruses, and adenoviruses. Knowledge on the ecology of reservoir-borne viruses is critical for preventive approaches against zoonotic epidemics. We studied a maternity colony of Myotis myotis bats in the attic of a private house in a suburban neighborhood in Rhineland-Palatinate, Germany, during 2008, 2009, and 2010. One coronavirus, 6 astroviruses, and 1 novel adenovirus were identified and monitored quantitatively. Strong and specific amplification of RNA viruses, but not of DNA viruses, occurred during colony formation and after parturition. The breeding success of the colony was significantly better in 2010 than in 2008, in spite of stronger amplification of coronaviruses and astroviruses in 2010, suggesting that these viruses had little pathogenic influence on bats. However, the general correlation of virus and bat population dynamics suggests that bats control infections similar to other mammals and that they may well experience epidemics of viruses under certain circumstances. PMID:21392436

Conducting HIV Seroprevalence and Behavioral Epidemiology Risk Surveys (SABERS) Among Partner Military Populations.

PubMed

Macera, Caroline A; Ito, Stanley I; Hale, Braden R; Shaffer, Richard A; Thomas, Anne G; Dickieson, Janet

2017-01-01

Characterizing HIV infection and associated risk behaviors within military populations is critical for understanding the epidemic and informing prevention activities. However, the prevalence of HIV and related risk behaviors is often unknown. Further, militaries may not have the systems in place or the staff expertise to conduct HIV surveillance and risk behavior studies. The Department of Defense HIV/AIDS Prevention Program (DHAPP), funded by the President's Emergency Plan for AIDS Relief and the US Department of Defense, provides technical assistance, management and administrative support for HIV/AIDS prevention, care and treatment for approximately 65 partner militaries. Collaborating with partner militaries in conducting Seroprevalence and Behavioral Epidemiology Risk Surveys (SABERS) and using the data to monitor the epidemic and inform activities is a key component of DHAPP. This paper describes the methodology used to plan, adapt, implement and report SABERS studies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Satellite imaging and vector-borne diseases: the approach of the French National Space Agency (CNES).

PubMed

Marechal, Fabienne; Ribeiro, Nathalie; Lafaye, Murielle; Güell, Antonio

2008-11-01

Tele-epidemiology consists in studying human and animal epidemic, the spread of which is closely tied to environmental factors, using data from earth-orbiting satellites. By combining various data originated from satellites such as SPOT (vegetation indexes), Meteosat (winds and cloud masses) and other Earth observation data from Topex/Poseidon and Envisat (wave height, ocean temperature and colour) with hydrology data (number and distribution of lakes, water levels in rivers and reservoirs) and clinical data from humans and animals (clinical cases and serum use), predictive mathematical models can be constructed. A number of such approaches have been tested in the last three years. In Senegal, for example, Rift Valley fever epidemics are being monitored using a predictive model based on the rate at which water holes dry out after the rainy season, which affects the number of mosquito eggs which carry the virus.

Prescription drug abuse: problem, policies, and implications.

PubMed

Phillips, Janice

2013-01-01

This article provides an overview on prescription drug abuse and highlights a number of related legislative bills introduced during the 112th Congress in response to this growing epidemic. Prescription drug abuse has emerged as the nation's fastest growing drug problem. Although prescription drugs have been used effectively and appropriately for decades, deaths from prescription pain medicine in particular have reached epidemic proportions. Bills related to prescription drug abuse introduced during the 112th Congress focus on strengthening provider and consumer education, tracking and monitoring prescription drug abuse, improving data collection on drug overdose fatalities, combating fraud and abuse in Medicare and Medicaid programs, reclassifying drugs to make them more difficult to prescribe and obtain, and enforcing stricter penalties for individuals who operate scam pain clinics and sell pain pills illegitimately. This article underscores the importance of a multifaceted approach to combating prescription drug abuse and concludes with implications for nursing. Copyright © 2013. Published by Mosby, Inc.

Pediatric obesity & type 2 diabetes.

PubMed

Dea, Tara L

2011-01-01

This article focuses on (a) identifying obesity and other risk factors for developing type 2 diabetes, (b) differentiating between pediatric type 1 diabetes and type 2 diabetes, and (c) treating pediatric type 2 diabetes. Obesity has significant implications on a child's health, including an increased risk for insulin resistance and progression to type 2 diabetes. Type 2 diabetes in children, characterized by insulin resistance and relative pancreatic b-cell failure due to the increased demand for insulin production, has now reached epidemic proportions. Longitudinal research on pediatric type 2 diabetes, however, is lacking because this epidemic is relatively new. Treatment of type 2 diabetes in children is focused on lifestyle modification with weight management/increased physical activity, and pharmacological management through oral medication or insulin therapy. Because children with type 2 diabetes are at risk for developing diabetes-related complications earlier in life, they need to be closely monitored for comorbidities.

Network information analysis reveals risk perception transmission in a behaviour-influenza dynamics system.

PubMed

Liao, C-M; You, S-H; Cheng, Y-H

2015-01-01

Influenza poses a significant public health burden worldwide. Understanding how and to what extent people would change their behaviour in response to influenza outbreaks is critical for formulating public health policies. We incorporated the information-theoretic framework into a behaviour-influenza (BI) transmission dynamics system in order to understand the effects of individual behavioural change on influenza epidemics. We showed that information transmission of risk perception played a crucial role in the spread of health-seeking behaviour throughout influenza epidemics. Here a network BI model provides a new approach for understanding the risk perception spread and human behavioural change during disease outbreaks. Our study allows simultaneous consideration of epidemiological, psychological, and social factors as predictors of individual perception rates in behaviour-disease transmission systems. We suggest that a monitoring system with precise information on risk perception should be constructed to effectively promote health behaviours in preparation for emerging disease outbreaks.

Zoonotic viral diseases and the frontier of early diagnosis, control and prevention.

PubMed

Heeney, J L

2006-11-01

Public awareness of the human health risks of zoonotic infections has grown in recent years. Currently, concern of H5N1 flu transmission from migratory bird populations has increased with foci of fatal human cases. This comes on the heels of other major zoonotic viral epidemics in the last decade. These include other acute emerging or re-emerging viral diseases such as severe acute respiratory syndrome (SARS), West-Nile virus, Ebola virus, monkeypox, as well as the more inapparent insidious slow viral and prion diseases. Virus infections with zoonotic potential can become serious killers once they are able to establish the necessary adaptations for efficient human-to-human transmission under circumstances sufficient to reach epidemic proportions. The monitoring and early diagnosis of these potential risks are overlapping frontiers of human and veterinary medicine. Here, current viral zoonotics and evolving threats are reviewed.

Structural and Functional Studies on the Fusion and Attachment Envelope Glycoproteins of Nipah Virus and Hendra Virus

DTIC Science & Technology

2003-01-01

epidemics, caused by Vibrio cholerae have been linked to specific seasons and biogeographical zones. In addition, the population dynamics of V. cholerae in...Climactic warming has directly affected the prevalence of RVFV by prolonging survival rates of the vector involved in disease transmission. 3 Cholera ...climate variability. The study of V. cholerae represents a model system of how climate change affects pathogens (2). Personal human behavior has

Complete Genome Sequences of Two Vesicular Stomatitis New Jersey Viruses Representing the 2012 U.S. Epidemic Strain and Its Closest Relative Endemic Strain from Southern Mexico

PubMed Central

Velazquez-Salinas, Lauro; Pauszek, Steven J.; Verdugo-Rodriguez, Antonio

2018-01-01

ABSTRACT We report here the complete genome sequences of two vesicular stomatitis New Jersey virus (VSNJV) field strains isolated from epithelial lesions from naturally infected animals in Mexico and the United States. The close phylogenetic relationship of these isolates makes them an ideal model for assessing potential genetic factors linked with the emergence of VSNJV in the United States. PMID:29449388

Adenovirus 36 and Obesity: An Overview.

PubMed

Ponterio, Eleonora; Gnessi, Lucio

2015-07-08

There is an epidemic of obesity starting about 1980 in both developed and undeveloped countries definitely associated with multiple etiologies. About 670 million people worldwide are obese. The incidence of obesity has increased in all age groups, including children. Obesity causes numerous diseases and the interaction between genetic, metabolic, social, cultural and environmental factors are possible cofactors for the development of obesity. Evidence emerging over the last 20 years supports the hypothesis that viral infections may be associated with obesity in animals and humans. The most widely studied infectious agent possibly linked to obesity is adenovirus 36 (Adv36). Adv36 causes obesity in animals. In humans, Adv36 associates with obesity both in adults and children and the prevalence of Adv36 increases in relation to the body mass index. In vivo and in vitro studies have shown that the viral E4orf1 protein (early region 4 open reading frame 1, Adv) mediates the Adv36 effect including its adipogenic potential. The Adv36 infection should therefore be considered as a possible risk factor for obesity and could be a potential new therapeutic target in addition to an original way to understand the worldwide rise of the epidemic of obesity. Here, the data indicating a possible link between viral infection and obesity with a particular emphasis to the Adv36 will be reviewed.

Adenovirus 36 and Obesity: An Overview

PubMed Central

Ponterio, Eleonora; Gnessi, Lucio

2015-01-01

There is an epidemic of obesity starting about 1980 in both developed and undeveloped countries definitely associated with multiple etiologies. About 670 million people worldwide are obese. The incidence of obesity has increased in all age groups, including children. Obesity causes numerous diseases and the interaction between genetic, metabolic, social, cultural and environmental factors are possible cofactors for the development of obesity. Evidence emerging over the last 20 years supports the hypothesis that viral infections may be associated with obesity in animals and humans. The most widely studied infectious agent possibly linked to obesity is adenovirus 36 (Adv36). Adv36 causes obesity in animals. In humans, Adv36 associates with obesity both in adults and children and the prevalence of Adv36 increases in relation to the body mass index. In vivo and in vitro studies have shown that the viral E4orf1 protein (early region 4 open reading frame 1, Adv) mediates the Adv36 effect including its adipogenic potential. The Adv36 infection should therefore be considered as a possible risk factor for obesity and could be a potential new therapeutic target in addition to an original way to understand the worldwide rise of the epidemic of obesity. Here, the data indicating a possible link between viral infection and obesity with a particular emphasis to the Adv36 will be reviewed. PMID:26184280

Dyslipidemia, Hypertension and Diabetes Metaflammation. A Unique Mechanism for 3 Risk Factors.

PubMed

Morales-Villegas, E

2014-07-01

The main current threat to the human race is the correlation and synergy between two determining triumvirates of atherosclerosis, cardiovascular disease and death. The first triumvirate is constituted by obesity, metaflammation and insulin resistance; the second triumvirate is constituted by atherogenic dyslipidemia, hypertension and type 2 diabetes mellitus. The etiopathogenic driving force for both triumvirates is the global epidemic of obesity. Metaflammation and insulin resistance are associated with obesity; in turn, insulin resistance determines a high risk for the development of atherogenic dyslipidemia, hypertension and type 2 diabetes mellitus, the three of them being factors responsible for vascular endothelial injury and substrates involved in the genesis of atherosclerosis, cardiovascular disease and death. The present chapter will address both triumvirates. Firstly, the current concepts of obesity, metaflammation and insulin resistance will be reviewed; emphasizing the second (metaflammation) for being a concept that has revolutionized and integrated our understanding of the harmful effects of obesity. Secondly, the impact of insulin resistance in the regulation of intermediary metabolism and endothelial function will be addressed; this will facilitate the understanding of the inextricable link between atherogenic dyslipidemia, hypertension and type 2 diabetes mellitus. Thus, this chapter aims to present to the clinician the best knowledge to link epidemics of obesity and cardiovascular death, through the sequence of metaflammation, insulin resistance and cardiovascular risk factors (mixed dyslipidemia, hypertension and type 2 diabetes mellitus).

The usefulness of school-based syndromic surveillance for detecting malaria epidemics: experiences from a pilot project in Ethiopia.

PubMed

Ashton, Ruth A; Kefyalew, Takele; Batisso, Esey; Awano, Tessema; Kebede, Zelalem; Tesfaye, Gezahegn; Mesele, Tamiru; Chibsa, Sheleme; Reithinger, Richard; Brooker, Simon J

2016-01-09

Syndromic surveillance is a supplementary approach to routine surveillance, using pre-diagnostic and non-clinical surrogate data to identify possible infectious disease outbreaks. To date, syndromic surveillance has primarily been used in high-income countries for diseases such as influenza--however, the approach may also be relevant to resource-poor settings. This study investigated the potential for monitoring school absenteeism and febrile illness, as part of a school-based surveillance system to identify localised malaria epidemics in Ethiopia. Repeated cross-sectional school- and community-based surveys were conducted in six epidemic-prone districts in southern Ethiopia during the 2012 minor malaria transmission season to characterise prospective surrogate and syndromic indicators of malaria burden. Changes in these indicators over the transmission season were compared to standard indicators of malaria (clinical and confirmed cases) at proximal health facilities. Subsequently, two pilot surveillance systems were implemented, each at ten sites throughout the peak transmission season. Indicators piloted were school attendance recorded by teachers, or child-reported recent absenteeism from school and reported febrile illness. Lack of seasonal increase in malaria burden limited the ability to evaluate sensitivity of the piloted syndromic surveillance systems compared to existing surveillance at health facilities. Weekly absenteeism was easily calculated by school staff using existing attendance registers, while syndromic indicators were more challenging to collect weekly from schoolchildren. In this setting, enrolment of school-aged children was found to be low, at 54%. Non-enrolment was associated with low household wealth, lack of parental education, household size, and distance from school. School absenteeism is a plausible simple indicator of unusual health events within a community, such as malaria epidemics, but the sensitivity of an absenteeism-based surveillance system to detect epidemics could not be rigorously evaluated in this study. Further piloting during a demonstrated increase in malaria transmission within a community is recommended.

Heterogeneity in geographical trends of HIV epidemics among key populations in Pakistan: a mathematical modeling study of survey data.

PubMed

Melesse, Dessalegn Y; Shafer, Leigh Anne; Emmanuel, Faran; Reza, Tahira; Achakzai, Baseer K; Furqan, Sofia; Blanchard, James F

2018-06-01

Assessing patterns and trends in new infections is key to better understanding of HIV epidemics, and is best done through monitoring changes in incidence over time. In this study, we examined disparities in geographical trends of HIV epidemics among people who inject drugs (PWIDs), female sex workers (FSWs) and hijra /transgender/male sex workers (H/MSWs), in Pakistan. The UNAIDS Estimation and Projection Package (EPP) mathematical model was used to explore geographical trends in HIV epidemics. Four rounds of mapping and surveillance data collected among key populations (KPs) across 20 cities in Pakistan between 2005-2011 was used for modeling. Empirical estimates of HIV prevalence of each KP in each city were used to fit the model to estimate prevalence and incidence over time. HIV incidence among PWIDs in Pakistan reached its peak in 2011, estimated at 45.3 per 1000 person-years. Incidence was projected to continue to rise from 18.9 in 2015 to 24.3 in 2020 among H/MSWs and from 3.2 in 2015 to 6.3 in 2020 among FSWs. The number of people living with HIV in Pakistan was estimated to steadily increase through at least 2020. HIV incidence peak among PWIDs ranged from 16.2 in 1997 in Quetta to 71.0 in 2010 in Faisalabad (per 1000 person-years). Incidence among H/MSWs may continue to rise through 2020 in all the cities, except in Larkana where it peaked in the early 2000s. In 2015, model estimated incidence among FSWs was 8.1 in Karachi, 6.6 in Larkana, 2.0 in Sukkur and 1.2 in Lahore (per 1000 person-years). There exists significant geographical heterogeneity in patterns and trends of HIV sub-epidemics in Pakistan. Focused interventions and service delivery approaches, different by KP and city, are recommended.

Modelling the effect of wheat canopy architecture as affected by sowing density on Septoria tritici epidemics using a coupled epidemic–virtual plant model

PubMed Central

Baccar, Rim; Fournier, Christian; Dornbusch, Tino; Andrieu, Bruno; Gouache, David; Robert, Corinne

2011-01-01

Background and Aims The relationship between Septoria tritici, a splash-dispersed disease, and its host is complex because of the interactions between the dynamic plant architecture and the vertical progress of the disease. The aim of this study was to test the capacity of a coupled virtual wheat–Septoria tritici epidemic model (Septo3D) to simulate disease progress on the different leaf layers for contrasted sowing density treatments. Methods A field experiment was performed with winter wheat ‘Soissons’ grown at three contrasted densities. Plant architecture was characterized to parameterize the wheat model, and disease dynamic was monitored to compare with simulations. Three simulation scenarios, differing in the degree of detail with which plant variability of development was represented, were defined. Key Results Despite architectural differences between density treatments, few differences were found in disease progress; only the lower-density treatment resulted in a slightly higher rate of lesion development. Model predictions were consistent with field measurements but did not reproduce the higher rate of lesion progress in the low density. The canopy reconstruction scenario in which inter-plant variability was taken into account yielded the best agreement between measured and simulated epidemics. Simulations performed with the canopy represented by a population of the same average plant deviated strongly from the observations. Conclusions It was possible to compare the predicted and measured epidemics on detailed variables, supporting the hypothesis that the approach is able to provide new insights into the processes and plant traits that contribute to the epidemics. On the other hand, the complex and dynamic responses to sowing density made it difficult to test the model precisely and to disentangle the various aspects involved. This could be overcome by comparing more contrasted and/or simpler canopy architectures such as those resulting from quasi-isogenic lines differing by single architectural traits. PMID:21724656

Heterogeneity in geographical trends of HIV epidemics among key populations in Pakistan: a mathematical modeling study of survey data

PubMed Central

Melesse, Dessalegn Y; Shafer, Leigh Anne; Emmanuel, Faran; Reza, Tahira; Achakzai, Baseer K; Furqan, Sofia; Blanchard, James F

2018-01-01

Background Assessing patterns and trends in new infections is key to better understanding of HIV epidemics, and is best done through monitoring changes in incidence over time. In this study, we examined disparities in geographical trends of HIV epidemics among people who inject drugs (PWIDs), female sex workers (FSWs) and hijra/transgender/male sex workers (H/MSWs), in Pakistan. Methods The UNAIDS Estimation and Projection Package (EPP) mathematical model was used to explore geographical trends in HIV epidemics. Four rounds of mapping and surveillance data collected among key populations (KPs) across 20 cities in Pakistan between 2005-2011 was used for modeling. Empirical estimates of HIV prevalence of each KP in each city were used to fit the model to estimate prevalence and incidence over time. Results HIV incidence among PWIDs in Pakistan reached its peak in 2011, estimated at 45.3 per 1000 person-years. Incidence was projected to continue to rise from 18.9 in 2015 to 24.3 in 2020 among H/MSWs and from 3.2 in 2015 to 6.3 in 2020 among FSWs. The number of people living with HIV in Pakistan was estimated to steadily increase through at least 2020. HIV incidence peak among PWIDs ranged from 16.2 in 1997 in Quetta to 71.0 in 2010 in Faisalabad (per 1000 person-years). Incidence among H/MSWs may continue to rise through 2020 in all the cities, except in Larkana where it peaked in the early 2000s. In 2015, model estimated incidence among FSWs was 8.1 in Karachi, 6.6 in Larkana, 2.0 in Sukkur and 1.2 in Lahore (per 1000 person-years). Conclusions There exists significant geographical heterogeneity in patterns and trends of HIV sub-epidemics in Pakistan. Focused interventions and service delivery approaches, different by KP and city, are recommended. PMID:29770215

Implications of Zika virus and congenital Zika syndrome for the number of live births in Brazil.

PubMed

Castro, Marcia C; Han, Qiuyi C; Carvalho, Lucas R; Victora, Cesar G; França, Giovanny V A

2018-06-12

An increase in microcephaly, associated with an epidemic of Zika virus (ZIKV) in Brazil, prompted the World Health Organization to declare a Public Health Emergency of International Concern in February 2016. While knowledge on biological and epidemiological aspects of ZIKV has advanced, demographic impacts remain poorly understood. This study uses time-series analysis to assess the impact of ZIKV on births. Data on births, fetal deaths, and hospitalizations due to abortion complications for Brazilian states, from 2010 to 2016, were used. Forecasts for September 2015 to December 2016 showed that 119,095 fewer births than expected were observed, particularly after April 2016 (a reduction significant at 0.05), demonstrating a link between publicity associated with the ZIKV epidemic and the decline in births. No significant changes were observed in fetal death rates. Although no significant increases in hospitalizations were forecasted, after the ZIKV outbreak hospitalizations happened earlier in the gestational period in most states. We argue that postponement of pregnancy and an increase in abortions may have contributed to the decline in births. Also, it is likely that an increase in safe abortions happened, albeit selective by socioeconomic status. Thus, the ZIKV epidemic resulted in a generation of congenital Zika syndrome (CZS) babies that reflect and exacerbate regional and social inequalities. Since ZIKV transmission has declined, it is unlikely that reductions in births will continue. However, the possibility of a new epidemic is real. There is a need to address gaps in reproductive health and rights, and to understand CZS risk to better inform conception decisions. Copyright © 2018 the Author(s). Published by PNAS.

A Population-Structured HIV Epidemic in Israel: Roles of Risk and Ethnicity

PubMed Central

Grossman, Zehava; Avidor, Boaz; Mor, Zohar; Chowers, Michal; Levy, Itzchak; Shahar, Eduardo; Riesenberg, Klaris; Sthoeger, Zev; Maayan, Shlomo; Shao, Wei; Lorber, Margalit; Olstein-Pops, Karen; Elbirt, Daniel; Elinav, Hila; Asher, Ilan; Averbuch, Diana; Istomin, Valery; Gottesman, Bat Sheva; Kedem, Eynat; Girshengorn, Shirley; Kra-Oz, Zipi; Shemer Avni, Yonat; Radian Sade, Sara; Turner, Dan; Maldarelli, Frank

2015-01-01

Background HIV in Israel started with a subtype-B epidemic among men who have sex with men, followed in the 1980s and 1990s by introductions of subtype C from Ethiopia (predominantly acquired by heterosexual transmission) and subtype A from the former Soviet Union (FSU, most often acquired by intravenous drug use). The epidemic matured over the last 15 years without additional large influx of exogenous infections. Between 2005 and 2013 the number of infected men who have sex with men (MSM) increased 2.9-fold, compared to 1.6-fold and 1.3-fold for intravenous drug users (IVDU) and Ethiopian-origin residents. Understanding contemporary spread is essential for effective public health planning. Methods We analyzed demographic and virologic data from 1,427 HIV-infected individuals diagnosed with HIV-I during 1998–2012. HIV phylogenies were reconstructed with maximum-likelihood and Bayesian methods. Results Subtype-B viruses, but not A or C, demonstrated a striking number of large clusters with common ancestors having posterior probability ≥0.95, including some suggesting presence of transmission networks. Transmitted drug resistance was highest in subtype B (13%). MSM represented a frequent risk factor in cross-ethnic transmission, demonstrated by the presence of Israeli-born with non-B virus infections and FSU immigrants with non-A subtypes. Conclusions Reconstructed phylogenetic trees demonstrated substantial grouping in subtype B, but not in non-MSM subtype-A or in subtype-C, reflecting differences in transmission dynamics linked to HIV transmission categories. Cross-ethnic spread occurred through multiple independent introductions, with MSM playing a prevalent role in the transmission of the virus. Such data provide a baseline to track epidemic trends and will be useful in informing and quantifying efforts to reduce HIV transmission. PMID:26302493

Fluid status monitoring with a wireless network to reduce cardiovascular-related hospitalizations and mortality in heart failure: rationale and design of the OptiLink HF Study (Optimization of Heart Failure Management using OptiVol Fluid Status Monitoring and CareLink).

PubMed

Brachmann, Johannes; Böhm, Michael; Rybak, Karin; Klein, Gunnar; Butter, Christian; Klemm, Hanno; Schomburg, Rolf; Siebermair, Johannes; Israel, Carsten; Sinha, Anil-Martin; Drexler, Helmut

2011-07-01

The Optimization of Heart Failure Management using OptiVol Fluid Status Monitoring and CareLink (OptiLink HF) study is designed to investigate whether OptiVol fluid status monitoring with an automatically generated wireless CareAlert notification via the CareLink Network can reduce all-cause death and cardiovascular hospitalizations in an HF population, compared with standard clinical assessment. Methods Patients with newly implanted or replacement cardioverter-defibrillator devices with or without cardiac resynchronization therapy, who have chronic HF in New York Heart Association class II or III and a left ventricular ejection fraction ≤35% will be eligible to participate. Following device implantation, patients are randomized to either OptiVol fluid status monitoring through CareAlert notification or regular care (OptiLink 'on' vs. 'off'). The primary endpoint is a composite of all-cause death or cardiovascular hospitalization. It is estimated that 1000 patients will be required to demonstrate superiority of the intervention group to reduce the primary outcome by 30% with 80% power. The OptiLink HF study is designed to investigate whether early detection of congestion reduces mortality and cardiovascular hospitalization in patients with chronic HF. The study is expected to close recruitment in September 2012 and to report first results in May 2014.

Safe and effective error rate monitors for SS7 signaling links

NASA Astrophysics Data System (ADS)

Schmidt, Douglas C.

1994-04-01

This paper describes SS7 error monitor characteristics, discusses the existing SUERM (Signal Unit Error Rate Monitor), and develops the recently proposed EIM (Error Interval Monitor) for higher speed SS7 links. A SS7 error monitor is considered safe if it ensures acceptable link quality and is considered effective if it is tolerant to short-term phenomena. Formal criteria for safe and effective error monitors are formulated in this paper. This paper develops models of changeover transients, the unstable component of queue length resulting from errors. These models are in the form of recursive digital filters. Time is divided into sequential intervals. The filter's input is the number of errors which have occurred in each interval. The output is the corresponding change in transmit queue length. Engineered EIM's are constructed by comparing an estimated changeover transient with a threshold T using a transient model modified to enforce SS7 standards. When this estimate exceeds T, a changeover will be initiated and the link will be removed from service. EIM's can be differentiated from SUERM by the fact that EIM's monitor errors over an interval while SUERM's count errored messages. EIM's offer several advantages over SUERM's, including the fact that they are safe and effective, impose uniform standards in link quality, are easily implemented, and make minimal use of real-time resources.

Hydroclimatological And Anthropogenic Drivers For Cholera Spreading

NASA Astrophysics Data System (ADS)

Righetto, Lorenzo; Bertuzzo, Enrico; Mari, Lorenzo; Casagrandi, Renato; Gatto, Marino; Rinaldo, Andrea

2010-05-01

The nature of waterborne diseases, among which cholera has a prominent importance, calls for a better understanding of the link between epidemic spreading, water and climate. To this end, we have developed a framework which involves a network-based description of a river system, connected with local communities which act as nodes of the network. This has allowed us to produce consistent simulations of real case studies. More recent investigations comprise the evaluation of the spreading velocity of an epidemic wave by means of a reaction-diffusion modeling approach. In particular, we have found that both transport processes and epidemiological quantities, such as the basic reproduction number, have a crucial effect in controlling the spreading of the epidemics. We first developed a description of bacterial movement along the network driven by advection and diffusion; afterward, we have included the movement of human populations. This latter model allowed us to establish the conditions that can trigger epidemic waves that start from the coastal region, where bacteria are autochthonous, and travel inland. In particular, our findings suggest that even relatively low values of human diffusion can have the epidemic propagate upstream. The interaction between climate, hydrology and epidemic events is still much debated, since no clear correlation between climatologic and epidemiological phenomena has emerged so far. However, a spatial assessment of hydrological and epidemiological mechanisms could be crucial to understand the evolution of cholera outbreaks. In particular, a hotly debated topic is the understanding of the mechanisms that can generate patterns of cholera incidence that exhibit an intra-annual double peak, as frequently observed in endemic region such as Bangladesh. One of the possible explanations proposed in the literature is that spring droughts cause bacteria concentration in water to rise dramatically, triggering the first peak. On the other hand similar mechanisms can occur during flood recessions in autumn together with major water sanitation system failures and higher population density. We show here the results of an ecohydrological model that couples the dynamics of the disease to a description of both the local water reservoir and of the local river section. The goal of this modeling exercise is to reproduce and understand the mechanisms behind intra-annual cholera incidence dynamics driven by hydrologic variability.

[HIV epidemic: a study among physicians in Vaud].

PubMed

Meystre-Agustoni, G; Van Melle, G; Chave, J P; Martin, J; Billo, N; Glauser, M P; Francioli, P

1990-09-22

A two-phase survey was conducted in the Canton of Vaud among the 1006 registered private practitioners (response rate 98%). The first phase aimed at determining the proportion of these physicians involved in the care of HIV+ persons. The results showed that 43% of the practitioners had been consulted by HIV+ patients. In the second phase, all institutions (hospitals, prisons and IV-drug user rehabilitation and testing centers) and a representative sample of the physicians with HIV+ patients were asked about the transmission category of their HIV+ patients. A mathematical method was used to estimate the true number of known HIV+ individuals by December 1988. Approximately 60% of the HIV+ persons had been seen exclusively by the private practitioners. IV-drug users represented 57% of all HIV+ persons compared to only 27% of the AIDS cases registered in 1988, suggesting that an important change in the transmission categories of AIDS cases is to be expected in the near future. These observations underscore the evolving nature of the HIV epidemic on the one hand, and the crucial role of the private practitioners in the prevention of the HIV infection on the other. This also points to the need for methods specifically designed to monitor HIV and AIDS epidemics respectively.

Laboratory preparedness for detection and monitoring of Shiga toxin 2-producing Escherichia coli O104:H4 in Europe and response to the 2011 outbreak.

PubMed

Rosin, P; Niskanen, T; Palm, D; Struelens, M; Takkinen, J

2013-06-20

A hybrid strain of enteroaggregative and Shiga toxin 2-producing Escherichia coli (EAEC-STEC) serotype O104:H4 strain caused a large outbreak of haemolytic uraemic syndrome and bloody diarrhoea in 2011 in Europe. Two surveys were performed in the European Union (EU) and European Economic Area (EEA) countries to assess their laboratory capabilities to detect and characterise this previously uncommon STEC strain. Prior to the outbreak, 11 of the 32 countries in this survey had capacity at national reference laboratory (NRL) level for epidemic case confirmation according to the EU definition. During the outbreak, at primary diagnostic level, nine countries reported that clinical microbiology laboratories routinely used Shiga toxin detection assays suitable for diagnosis of infections with EAEC-STEC O104:H4, while 14 countries had NRL capacity to confirm epidemic cases. Six months after the outbreak, 22 countries reported NRL capacity to confirm such cases following initiatives taken by NRLs and the European Centre for Disease Prevention and Control (ECDC) Food- and Waterborne Disease and Zoonoses laboratory network. These data highlight the challenge of detection and confirmation of epidemic infections caused by atypical STEC strains and the benefits of coordinated EU laboratory networks to strengthen capabilities in response to a major outbreak.

The Burden of Dengue and the Financial Cost to Colombia, 2010–2012

PubMed Central

Rodríguez, Raúl Castro; Carrasquilla, Gabriel; Porras, Alexandra; Galera-Gelvez, Katia; Yescas, Juan Guillermo Lopez; Rueda-Gallardo, Jorge A.

2016-01-01

Data on the burden of dengue and its economic costs can help guide health policy decisions. However, little reliable information is available for Colombia. We therefore calculated the burden of the disease, expressed in disability-adjusted life years (DALYs), for two scenarios: endemic years (average number of cases in non-epidemic years 2011 and 2012) and an epidemic year (2010, when the highest number of dengue cases was reported in the study period). We also estimated the total economic cost of the disease (U.S. dollars at the average exchange rate for 2012), including indirect costs to households derived from expenses such as preventing entry of mosquitos into the home and costs to government arising from direct, indirect, and prevention and monitoring activities, as well as the direct medical and non-medical costs. In the epidemic year 2010, 1,198.73 DALYs were lost per million inhabitants versus 83.88 in endemic years. The total financial cost of the disease in Colombia from a societal perspective was US$167.8 million for 2010, US$129.9 million for 2011, and US$131.7 million for 2012. The cost of mosquito prevention borne by households was a major cost driver (accounting for 46% of the overall cost in 2010, 62% in 2011, and 64% in 2012). PMID:26928834

The role of Brazilian National Health Information Systems in assessing the impact of Zika virus outbreak.

PubMed

Pavão, Ana Luiza Braz; Barcellos, Christovam; Pedroso, Marcel; Boccolini, Cristiano; Romero, Dália

2017-01-01

The Zika virus (ZIKV) epidemic has become a public health emergency following its association with severe neurological complications. We aim to discuss how the Brazilian National Health Information Systems can help to assess the impact of the ZIKV epidemic on health outcomes potentially related to ZIKV. Health outcomes potentially related to ZIKV infection were described based on a literature review of published studies on ZIKV infection outcomes and on recent protocols developed and published by the Brazilian Ministry of Health for different stages of the life cycle. These outcomes were correlated with the International Classification of Diseases 10th Revision (ICD-10) classification system, as this is the diagnostic classification registered in the Health Information System. A suggested list of 50 clinical manifestations, dispersed into 4 ICD chapters, and their information sources was created to help monitor the ZIKV epidemics and trends. Correlation of these selected ICD-10 codes and the HIS, as well as, a review of the potentialities and limitations of health information systems were performed. The potential of the Health Information System and its underutilization by stakeholders and researchers have been a barrier in diagnosing and reporting ZIKV infection and its complications. The ZIKV outbreak is still a challenge for health practice and the Brazilian Health Information System.

Making a human right to tobacco control: expert and advocacy networks, framing and the right to health.

PubMed

Reubi, David

2012-01-01

This article addresses the proliferation of human rights in international public health over the last 20 years by examining recent attempts at framing the global smoking epidemic as a human rights problem. Rather than advocating in favour or against human rights-based approaches, the article purports to understand how and why such approaches are being articulated and disseminated. First, it argues that the representation of the global smoking epidemic as a human rights issue has been the product of a small, international network of public health experts and lawyers: the human rights and tobacco control collective or community (HTC). The article describes in particular the HTC's membership, its style of thinking and its efforts to articulate and disseminate human rights-based approaches to tobacco control. Second, the article argues that the aim of the HTC when framing tobacco control as a human rights issue was not to generate public attention for and the political will to tackle the global smoking epidemic, as the literature on framing and human rights presupposes. Instead, as the article shows, the HTC framed tobacco control as a human rights problem to tap into the powerful, judicial monitoring and enforceability mechanisms that make up international human rights.

Digital Health Communication and Global Public Influence: A Study of the Ebola Epidemic.

PubMed

Roberts, Hal; Seymour, Brittany; Fish, Sands Alden; Robinson, Emily; Zuckerman, Ethan

2017-01-01

Scientists and health communication professionals expressed frustration over the relationship between misinformation circulating on the Internet and global public perceptions of and responses to the Ebola epidemic originating in West Africa. Using the big data platform Media Cloud, we analyzed all English-language stories about keyword "Ebola" published from 1 July 2014 to 17 November 2014 from the media sets U.S. Mainstream Media, U.S. Regional Media, U.S. Political Blogs, U.S. Popular Blogs, Europe Media Monitor, and Global Voices to understand how social network theory and models of the networked global public may have contributed to health communication efforts. 109,400 stories met our inclusion criteria. The CDC and WHO were the two media sources with the most inlinks (hyperlinks directed to their sites). Twitter was fourth Significantly more public engagement on social media globally was directed toward stories about risks of U.S. domestic Ebola infections than toward stories focused on Ebola infections in West Africa or on science-based information. Corresponding public sentiments about Ebola were reflected in the policy responses of the international community, including violations of the International Health Regulations and the treatment of potentially exposed individuals. The digitally networked global public may have influenced the discourse, sentiment, and response to the Ebola epidemic.

Dynamic and interacting complex networks

NASA Astrophysics Data System (ADS)

Dickison, Mark E.

This thesis employs methods of statistical mechanics and numerical simulations to study some aspects of dynamic and interacting complex networks. The mapping of various social and physical phenomena to complex networks has been a rich field in the past few decades. Subjects as broad as petroleum engineering, scientific collaborations, and the structure of the internet have all been analyzed in a network physics context, with useful and universal results. In the first chapter we introduce basic concepts in networks, including the two types of network configurations that are studied and the statistical physics and epidemiological models that form the framework of the network research, as well as covering various previously-derived results in network theory that are used in the work in the following chapters. In the second chapter we introduce a model for dynamic networks, where the links or the strengths of the links change over time. We solve the model by mapping dynamic networks to the problem of directed percolation, where the direction corresponds to the time evolution of the network. We show that the dynamic network undergoes a percolation phase transition at a critical concentration pc, that decreases with the rate r at which the network links are changed. The behavior near criticality is universal and independent of r. We find that for dynamic random networks fundamental laws are changed: i) The size of the giant component at criticality scales with the network size N for all values of r, rather than as N2/3 in static network, ii) In the presence of a broad distribution of disorder, the optimal path length between two nodes in a dynamic network scales as N1/2, compared to N1/3 in a static network. The third chapter consists of a study of the effect of quarantine on the propagation of epidemics on an adaptive network of social contacts. For this purpose, we analyze the susceptible-infected-recovered model in the presence of quarantine, where susceptible individuals protect themselves by disconnecting their links to infected neighbors with probability w and reconnecting them to other susceptible individuals chosen at random. Starting from a single infected individual, we show by an analytical approach and simulations that there is a phase transition at a critical rewiring (quarantine) threshold wc separating a phase (w < wc) where the disease reaches a large fraction of the population from a phase (w > wc) where the disease does not spread out. We find that in our model the topology of the network strongly affects the size of the propagation and that wc increases with the mean degree and heterogeneity of the network. We also find that wc is reduced if we perform a preferential rewiring, in which the rewiring probability is proportional to the degree of infected nodes. In the fourth chapter, we study epidemic processes on interconnected network systems, and find two distinct regimes. In strongly-coupled network systems, epidemics occur simultaneously across the entire system at a critical value betac. In contrast, in weakly-coupled network systems, a mixed phase exists below betac where an epidemic occurs in one network but does not spread to the coupled network. We derive an expression for the network and disease parameters that allow this mixed phase and verify it numerically. Public health implications of communities comprising these two classes of network systems are also mentioned.

Big Data Usage Patterns in the Health Care Domain: A Use Case Driven Approach Applied to the Assessment of Vaccination Benefits and Risks. Contribution of the IMIA Primary Healthcare Working Group.

PubMed

Liyanage, H; de Lusignan, S; Liaw, S-T; Kuziemsky, C E; Mold, F; Krause, P; Fleming, D; Jones, S

2014-08-15

Generally benefits and risks of vaccines can be determined from studies carried out as part of regulatory compliance, followed by surveillance of routine data; however there are some rarer and more long term events that require new methods. Big data generated by increasingly affordable personalised computing, and from pervasive computing devices is rapidly growing and low cost, high volume, cloud computing makes the processing of these data inexpensive. To describe how big data and related analytical methods might be applied to assess the benefits and risks of vaccines. We reviewed the literature on the use of big data to improve health, applied to generic vaccine use cases, that illustrate benefits and risks of vaccination. We defined a use case as the interaction between a user and an information system to achieve a goal. We used flu vaccination and pre-school childhood immunisation as exemplars. We reviewed three big data use cases relevant to assessing vaccine benefits and risks: (i) Big data processing using crowdsourcing, distributed big data processing, and predictive analytics, (ii) Data integration from heterogeneous big data sources, e.g. the increasing range of devices in the "internet of things", and (iii) Real-time monitoring for the direct monitoring of epidemics as well as vaccine effects via social media and other data sources. Big data raises new ethical dilemmas, though its analysis methods can bring complementary real-time capabilities for monitoring epidemics and assessing vaccine benefit-risk balance.

Big Data Usage Patterns in the Health Care Domain: A Use Case Driven Approach Applied to the Assessment of Vaccination Benefits and Risks

PubMed Central

Liyanage, H.; Liaw, S-T.; Kuziemsky, C.; Mold, F.; Krause, P.; Fleming, D.; Jones, S.

2014-01-01

Summary Background Generally benefits and risks of vaccines can be determined from studies carried out as part of regulatory compliance, followed by surveillance of routine data; however there are some rarer and more long term events that require new methods. Big data generated by increasingly affordable personalised computing, and from pervasive computing devices is rapidly growing and low cost, high volume, cloud computing makes the processing of these data inexpensive. Objective To describe how big data and related analytical methods might be applied to assess the benefits and risks of vaccines. Method: We reviewed the literature on the use of big data to improve health, applied to generic vaccine use cases, that illustrate benefits and risks of vaccination. We defined a use case as the interaction between a user and an information system to achieve a goal. We used flu vaccination and pre-school childhood immunisation as exemplars. Results We reviewed three big data use cases relevant to assessing vaccine benefits and risks: (i) Big data processing using crowd-sourcing, distributed big data processing, and predictive analytics, (ii) Data integration from heterogeneous big data sources, e.g. the increasing range of devices in the “internet of things”, and (iii) Real-time monitoring for the direct monitoring of epidemics as well as vaccine effects via social media and other data sources. Conclusions Big data raises new ethical dilemmas, though its analysis methods can bring complementary real-time capabilities for monitoring epidemics and assessing vaccine benefit-risk balance. PMID:25123718

ID-Viewer: a visual analytics architecture for infectious diseases surveillance and response management in Pakistan.

PubMed

Ali, M A; Ahsan, Z; Amin, M; Latif, S; Ayyaz, A; Ayyaz, M N

2016-05-01

Globally, disease surveillance systems are playing a significant role in outbreak detection and response management of Infectious Diseases (IDs). However, in developing countries like Pakistan, epidemic outbreaks are difficult to detect due to scarcity of public health data and absence of automated surveillance systems. Our research is intended to formulate an integrated service-oriented visual analytics architecture for ID surveillance, identify key constituents and set up a baseline for easy reproducibility of such systems in the future. This research focuses on development of ID-Viewer, which is a visual analytics decision support system for ID surveillance. It is a blend of intelligent approaches to make use of real-time streaming data from Emergency Departments (EDs) for early outbreak detection, health care resource allocation and epidemic response management. We have developed a robust service-oriented visual analytics architecture for ID surveillance, which provides automated mechanisms for ID data acquisition, outbreak detection and epidemic response management. Classification of chief-complaints is accomplished using dynamic classification module, which employs neural networks and fuzzy-logic to categorize syndromes. Standard routines by Center for Disease Control (CDC), i.e. c1-c3 (c1-mild, c2-medium and c3-ultra), and spatial scan statistics are employed for detection of temporal and spatio-temporal disease outbreaks respectively. Prediction of imminent disease threats is accomplished using support vector regression for early warnings and response planning. Geographical visual analytics displays are developed that allow interactive visualization of syndromic clusters, monitoring disease spread patterns, and identification of spatio-temporal risk zones. We analysed performance of surveillance framework using ID data for year 2011-2015. Dynamic syndromic classifier is able to classify chief-complaints to appropriate syndromes with high classification accuracy. Outbreak detection methods are able to detect the ID outbreaks in start of epidemic time zones. Prediction model is able to forecast dengue trend for 20 weeks ahead with nominal normalized root mean square error of 0.29. Interactive geo-spatiotemporal displays, i.e. heat-maps, and choropleth are shown in respective sections. The proposed framework will set a standard and provide necessary details for future implementation of such a system for resource-constrained regions. It will improve early outbreak detection attributable to natural and man-made biological threats, monitor spatio-temporal epidemic trends and provide assurance that an outbreak has, or has not occurred. Advanced analytics features will be beneficial in timely organization/formulation of health management policies, disease control activities and efficient health care resource allocation. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Combining Participatory Influenza Surveillance with Modeling and Forecasting: Three Alternative Approaches.

PubMed

Brownstein, John S; Chu, Shuyu; Marathe, Achla; Marathe, Madhav V; Nguyen, Andre T; Paolotti, Daniela; Perra, Nicola; Perrotta, Daniela; Santillana, Mauricio; Swarup, Samarth; Tizzoni, Michele; Vespignani, Alessandro; Vullikanti, Anil Kumar S; Wilson, Mandy L; Zhang, Qian

2017-11-01

Influenza outbreaks affect millions of people every year and its surveillance is usually carried out in developed countries through a network of sentinel doctors who report the weekly number of Influenza-like Illness cases observed among the visited patients. Monitoring and forecasting the evolution of these outbreaks supports decision makers in designing effective interventions and allocating resources to mitigate their impact. Describe the existing participatory surveillance approaches that have been used for modeling and forecasting of the seasonal influenza epidemic, and how they can help strengthen real-time epidemic science and provide a more rigorous understanding of epidemic conditions. We describe three different participatory surveillance systems, WISDM (Widely Internet Sourced Distributed Monitoring), Influenzanet and Flu Near You (FNY), and show how modeling and simulation can be or has been combined with participatory disease surveillance to: i) measure the non-response bias in a participatory surveillance sample using WISDM; and ii) nowcast and forecast influenza activity in different parts of the world (using Influenzanet and Flu Near You). WISDM-based results measure the participatory and sample bias for three epidemic metrics i.e. attack rate, peak infection rate, and time-to-peak, and find the participatory bias to be the largest component of the total bias. The Influenzanet platform shows that digital participatory surveillance data combined with a realistic data-driven epidemiological model can provide both short-term and long-term forecasts of epidemic intensities, and the ground truth data lie within the 95 percent confidence intervals for most weeks. The statistical accuracy of the ensemble forecasts increase as the season progresses. The Flu Near You platform shows that participatory surveillance data provide accurate short-term flu activity forecasts and influenza activity predictions. The correlation of the HealthMap Flu Trends estimates with the observed CDC ILI rates is 0.99 for 2013-2015. Additional data sources lead to an error reduction of about 40% when compared to the estimates of the model that only incorporates CDC historical information. While the advantages of participatory surveillance, compared to traditional surveillance, include its timeliness, lower costs, and broader reach, it is limited by a lack of control over the characteristics of the population sample. Modeling and simulation can help overcome this limitation as well as provide real-time and long-term forecasting of influenza activity in data-poor parts of the world. ©John S Brownstein, Shuyu Chu, Achla Marathe, Madhav V Marathe, Andre T Nguyen, Daniela Paolotti, Nicola Perra, Daniela Perrotta, Mauricio Santillana, Samarth Swarup, Michele Tizzoni, Alessandro Vespignani, Anil Kumar S Vullikanti, Mandy L Wilson, Qian Zhang. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 01.11.2017.

Implementation of an Alert and Response System in Haiti during the Early Stage of the Response to the Cholera Epidemic

PubMed Central

Santa-Olalla, Patricia; Gayer, Michelle; Magloire, Roc; Barrais, Robert; Valenciano, Marta; Aramburu, Carmen; Poncelet, Jean Luc; Gustavo Alonso, Juan Carlos; Van Alphen, Dana; Heuschen, Florence; Andraghetti, Roberta; Lee, Robert; Drury, Patrick; Aldighieri, Sylvain

2013-01-01

The start of the cholera epidemic in Haiti quickly highlighted the necessity of the implementation of an Alert and Response (A&R) System to complement the existing national surveillance system. The national system had been able to detect and confirm the outbreak etiology but required external support to monitor the spread of cholera and coordinate response, because much of the information produced was insufficiently timely for real-time monitoring and directing of a rapid, targeted response. The A&R System was designed by the Pan American Health Organization/World Health Organization in collaboration with the Haiti Ministry of Health, and it was based on a network of partners, including any institution, structure, or individual that could identify, verify, and respond to alerts. The defined objectives were to (1) save lives through early detection and treatment of cases and (2) control the spread through early intervention at the community level. The operational structure could be broken down into three principle categories: (1) alert (early warning), (2) verification and assessment of the information, and (3) efficient and timely response in coordination with partners to avoid duplication. Information generated by the A&R System was analyzed and interpreted, and the qualitative information was critical in qualifying the epidemic and defining vulnerable areas, particularly because the national surveillance system reported incomplete data for more than one department. The A&R System detected a number of alerts unrelated to cholera and facilitated rapid access to that information. The sensitivity of the system and its ability to react quickly was shown in May of 2011, when an abnormal increase in alerts coming from several communes in the Sud-Est Department in epidemiological weeks (EWs) 17 and 18 were noted and disseminated network-wide and response activities were implemented. The national cholera surveillance system did not register the increase until EWs 21 and 22, and the information did not become available until EWs 23 and 24, when the peak of cases had already been reached. Although many of the partners reporting alerts during the peak of the cholera epidemic have since left Haiti, the A&R System has continued to function as an Early Warning (EWARN) System, and it continues to be developed with recent activities, such as the distribution of cell phones to enhance alert communication. PMID:24106196

Can Emergency Department, Hospital Discharge, and Death Data Be Used to Monitor Burden of Drug Overdose in Rhode Island?

PubMed

Jiang, Yongwen; McDonald, James V; Koziol, Jennifer; McCormick, Meghan; Viner-Brown, Samara; Alexander-Scott, Nicole

Drug overdoses are a growing public health problem in the United States. Rhode Island is also confronted with a serious epidemic of drug overdose deaths and ranks sixth worst in the United States for age-adjusted drug overdose death rate. To monitor trends of drug overdose-related emergency department (ED) visits, hospitalizations, and deaths and classify the drug overdoses by demographics, discharge status, intent, and specific drug involved to plan for health care resource allocation, mental health services, drug abuse treatment, prevention, and policies. Cross-sectional study. The 2005-2014 ED, hospital discharge, and death data were used for this study. Age-adjusted rates were calculated by using age-specific Rhode Island 2010 standard population. Healthcare Cost and Utilization Project cost-to-charge ratios were used to convert total hospital charges to costs. The descriptive analysis was performed. Hospitalizations generally represent the most severe cases; there are substantially fewer cases than are seen in the ED, and their characteristics are different from ED visits. More than half of the ED cases were an unintentional injury by drug overdose, but more than half of the hospital discharge data cases were a suicide/self-inflicted injury by drug overdose. There were typically much more females than males that result in a hospital admission. In Rhode Island, there were 249 drug overdose deaths in 2014. Drug overdose fatalities were more likely to be young, male, white, and those who reside in suburban regions. Nonfatal and fatal drug overdose data are important for understanding the scope, incidence, and breadth of this public health epidemic and can guide overdose intervention efforts. In Rhode Island, policy makers can use drug overdose data to target high-risk subpopulations to reduce overdose injuries and fatalities. The Rhode Island study can be shared with other states. Regardless of the type of drug, overdoses remain a public health crisis in Rhode Island. It is a dynamic epidemic and needs partnership among public health, behavioral health, public safety, clinic, pharmacy, and communities. The ability to track drug overdose in real time will be an essential tool to respond to the constantly evolving drug overdose epidemic in Rhode Island quickly and effectively.

Implementation of an alert and response system in Haiti during the early stage of the response to the cholera epidemic.

PubMed

Santa-Olalla, Patricia; Gayer, Michelle; Magloire, Roc; Barrais, Robert; Valenciano, Marta; Aramburu, Carmen; Poncelet, Jean Luc; Gustavo Alonso, Juan Carlos; Van Alphen, Dana; Heuschen, Florence; Andraghetti, Roberta; Lee, Robert; Drury, Patrick; Aldighieri, Sylvain

2013-10-01

The start of the cholera epidemic in Haiti quickly highlighted the necessity of the implementation of an Alert and Response (A&R) System to complement the existing national surveillance system. The national system had been able to detect and confirm the outbreak etiology but required external support to monitor the spread of cholera and coordinate response, because much of the information produced was insufficiently timely for real-time monitoring and directing of a rapid, targeted response. The A&R System was designed by the Pan American Health Organization/World Health Organization in collaboration with the Haiti Ministry of Health, and it was based on a network of partners, including any institution, structure, or individual that could identify, verify, and respond to alerts. The defined objectives were to (1) save lives through early detection and treatment of cases and (2) control the spread through early intervention at the community level. The operational structure could be broken down into three principle categories: (1) alert (early warning), (2) verification and assessment of the information, and (3) efficient and timely response in coordination with partners to avoid duplication. Information generated by the A&R System was analyzed and interpreted, and the qualitative information was critical in qualifying the epidemic and defining vulnerable areas, particularly because the national surveillance system reported incomplete data for more than one department. The A&R System detected a number of alerts unrelated to cholera and facilitated rapid access to that information. The sensitivity of the system and its ability to react quickly was shown in May of 2011, when an abnormal increase in alerts coming from several communes in the Sud-Est Department in epidemiological weeks (EWs) 17 and 18 were noted and disseminated network-wide and response activities were implemented. The national cholera surveillance system did not register the increase until EWs 21 and 22, and the information did not become available until EWs 23 and 24, when the peak of cases had already been reached. Although many of the partners reporting alerts during the peak of the cholera epidemic have since left Haiti, the A&R System has continued to function as an Early Warning (EWARN) System, and it continues to be developed with recent activities, such as the distribution of cell phones to enhance alert communication.

Fasting for weight loss: an effective strategy or latest dieting trend?

PubMed

Johnstone, A

2015-05-01

With the increasing obesity epidemic comes the search for effective dietary approaches for calorie restriction and weight loss. Here I examine whether fasting is the latest 'fad diet' as portrayed in popular media and discuss whether it is a safe and effective approach or whether it is an idiosyncratic diet trend that promotes short-term weight loss, with no concern for long-term weight maintenance. Fasting has long been used under historical and experimental conditions and has recently been popularised by 'intermittent fasting' or 'modified fasting' regimes, in which a very low-calorie allowance is allowed, on alternate days (ADF) or 2 days a week (5:2 diet), where 'normal' eating is resumed on non-diet days. It is a simple concept, which makes it easy to follow with no difficult calorie counting every other day. This approach does seem to promote weight loss, but is linked to hunger, which can be a limiting factor for maintaining food restriction. The potential health benefits of fasting can be related to both the acute food restriction and chronic influence of weight loss; the long-term effect of chronic food restriction in humans is not yet clear, but may be a potentially interesting future dietary strategy for longevity, particularly given the overweight epidemic. One approach does not fit all in the quest to achieve body weight control, but this could be a dietary strategy for consideration. With the obesity epidemic comes the search for dietary strategies to (i) prevent weight gain, (ii) promote weight loss and (iii) prevent weight regain. With over half of the population of the United Kingdom and other developed countries being collectively overweight or obese, there is considerable pressure to achieve these goals, from both a public health and a clinical perspective. Certainly not one dietary approach will solve these complex problems. Although there is some long-term success with gastric surgical options for morbid obesity, there is still a requirement for dietary approaches for weight management for the overweight and obese population, particularly as invasive interventions carry post-operative risk of death due to complications. Effective dietary interventions are required that promote long-term adherence and sustained beneficial effects on metabolic and disease markers. In general, such interventions need to be palatable and satiating, meet minimal nutritional requirements, promote loss of fat and preserve lean body mass, ensure long-term safety, be simple to administer and monitor and have widespread public health utility. Intermittent fasting or alternate day fasting may be an option for achieving weight loss and maintenance.

Establishment of first engineering specifications for environmental modification to eliminate schistosomiasis epidemic foci in urban areas.

PubMed

Kong, Shibo; Tan, Xiaodong; Deng, Zhiqing; Xie, Yaofei; Yang, Fen; Zheng, Zengwang

2017-08-01

Snail control is a key link in schistosomiasis control, but no unified methods for eliminating snails have been produced to date. This study was conducted to explore an engineering method for eliminating Oncomelania hupensis applicable to urban areas. The engineering specifications were established using the Delphi method. An engineering project based on these specifications was conducted in Hankou marshland to eliminate snails, including the transformation of the beach surface and ditches. Molluscicide was used as a supplement. The snail control effect was evaluated by field investigation. The engineering results fulfilled the requirements of the design. The snail density decreased to 0/0.11m 2 , and the snail area dropped to 0m 2 after the project. There was a statistically significant difference in the number of frames with snails before and after the project (P<0.05). Snails were completely eliminated through one year of continuous monitoring, and no new snails were found after a flood disaster. This study demonstrates that engineering specifications for environmental modification were successfully established. Environmental modification, mainly through beach and ditch remediation, can completely change the environment of Oncomelania breeding. This method of environmental modification combined with mollusciciding was highly effective at eliminating snails. Copyright © 2017 Elsevier B.V. All rights reserved.

From Creutzfeldt-Jakob disease to the mad cow epidemic.

PubMed

Sternbach, G; Dibble, C L; Varon, J

1997-01-01

Hans-Gerhard Creutzfeldt and Alfons Jakob independently authored clinical and pathologic descriptions of a new syndrome in the 1920s. This syndrome, which subsequently came to be named after them, was characterized by dementia, motor and coordination abnormalities, a fatal course, and pathologic findings of diffuse spongiform neuronal degeneration. Although it appeared for many years to be little more than a medical curiosity, Creutzfeldt-Jakob disease attained widespread attention by its pathologic similarity to kuru and bovine spongiform encephalopathy, "mad cow disease." Because there are sporadic, familial, and iatrogenic forms of Creutzfeldt-Jakob disease, it is considered to have both genetic and infectious aspects. Although its causation has for some time been ascribed to "slow viruses," the etiology of Creutzfeldt-Jakob disease is currently thought to be due to prions, small proteinaceous infectious particles that have genetic encoding. The debate regarding whether the appearance of atypical Creutzfeldt-Jakob disease can be linked to the epidemic of "mad cow disease" is currently unresolved.

Quarantine-generated phase transition in epidemic spreading

NASA Astrophysics Data System (ADS)

Lagorio, C.; Dickison, M.; Vazquez, F.; Braunstein, L. A.; Macri, P. A.; Migueles, M. V.; Havlin, S.; Stanley, H. E.

2011-02-01

We study the critical effect of quarantine on the propagation of epidemics on an adaptive network of social contacts. For this purpose, we analyze the susceptible-infected-recovered model in the presence of quarantine, where susceptible individuals protect themselves by disconnecting their links to infected neighbors with probability w and reconnecting them to other susceptible individuals chosen at random. Starting from a single infected individual, we show by an analytical approach and simulations that there is a phase transition at a critical rewiring (quarantine) threshold wc separating a phase (w

Quarantine generated phase transition in epidemic spreading

NASA Astrophysics Data System (ADS)

Dicksion, Mark; Lagorio, Cecilia; Vazquez, F.; Braunstein, L.; Macri, P. A.; Migueles, M. V.; Havlin, S.; Stanley, H. E.

2011-03-01

We study the critical effect of quarantine on the propagation of epidemics on an adaptive network of social contacts. For this purpose, we analyze the susceptible-infected-recovered (SIR) model in the presence of quarantine, where susceptible individuals protect themselves by disconnecting their links to infected neighbors with probability w, and reconnecting them to other susceptible individuals chosen at random. Starting from a single infected individual, we show by an analytical approach and simulations that there is a phase transition at a critical rewiring (quarantine) threshold wc separating a phase (w =wc) where the disease does not spread out. We find that in our model the topology of the network strongly affects the size of the propagation, and that wc increases with the mean degree and heterogeneity of the network. We also find that wc is reduced if we perform a preferential rewiring, in which the rewiring probability is proportional to the degree of infected nodes.

Anthropogenically driven environmental changes shift the ecological dynamics of hemorrhagic fever with renal syndrome

PubMed Central

Yang, Jing; Tan, Hua; Huang, Shanqian; Cui, Yujun; Dong, Lu; Ma, Chaofeng; Ma, Changan; Zhou, Sen; Wu, Xiaoxu; Zhang, Yanyun; Wang, Jingjun; Yang, Ruifu; Stenseth, Nils Chr.; Xu, Bing

2017-01-01

Zoonoses are increasingly recognized as an important burden on global public health in the 21st century. High-resolution, long-term field studies are critical for assessing both the baseline and future risk scenarios in a world of rapid changes. We have used a three-decade-long field study on hantavirus, a rodent-borne zoonotic pathogen distributed worldwide, coupled with epidemiological data from an endemic area of China, and show that the shift in the ecological dynamics of Hantaan virus was closely linked to environmental fluctuations at the human-wildlife interface. We reveal that environmental forcing, especially rainfall and resource availability, exert important cascading effects on intra-annual variability in the wildlife reservoir dynamics, leading to epidemics that shift between stable and chaotic regimes. Our models demonstrate that bimodal seasonal epidemics result from a powerful seasonality in transmission, generated from interlocking cycles of agricultural phenology and rodent behavior driven by the rainy seasons. PMID:28141833

[A prognostic assessment of louse-borne typhus (Rickettsia prowazekii infection) in Russia].

PubMed

Onishchenko, G G; Lukin, E P; Syskova, T G

1997-01-01

From the 1950s to 1974 R.prowazekii infection was registered on the territory of Russia, mainly in the form of Brill's disease, represented by some individual cases in the focus of infection. In 0.25% of all of cases rickettsiosis was linked with group outbreaks of the family character (14 events), reflecting the epidemic form of the disease. From 1974 until the present time the correlation between the sources of infection and the infestation of the population with lice dropped below the critical level, ensuring the transmission of the infective agent among the susceptible human population. This led to the steady disappearance of rickettsiosis (a decrease in the number of rickettsiosis cases from several thousand in the 60s to less than 100 in 1991) due to natural demographic processes. After the disintegration of the USSR, the migration of the population from some regions, especially from those where military conflicts took place, did not affect this process. The return of the epidemic form of rickettsiosis in Russia is impossible.

Strategies for Reversing the Effects of Metabolic Disorders Induced as a Consequence of Developmental Programming

PubMed Central

Vickers, M. H.; Sloboda, D. M.

2012-01-01

Obesity and the metabolic syndrome have reached epidemic proportions worldwide with far-reaching health care and economic implications. The rapid increase in the prevalence of these disorders suggests that environmental and behavioral influences, rather than genetic causes, are fueling the epidemic. The developmental origins of health and disease hypothesis has highlighted the link between the periconceptual, fetal, and early infant phases of life and the subsequent development of metabolic disorders in later life. In particular, the impact of poor maternal nutrition on susceptibility to later life metabolic disease in offspring is now well documented. Several studies have now shown, at least in experimental animal models, that some components of the metabolic syndrome, induced as a consequence of developmental programming, are potentially reversible by nutritional or targeted therapeutic interventions during windows of developmental plasticity. This review will focus on critical windows of development and possible therapeutic avenues that may reduce metabolic and obesogenic risk following an adverse early life environment. PMID:22783205

Prevention and Control Strategies to Counter ZIKA Epidemic

PubMed Central

Rather, Irfan A.; Kumar, Sanjay; Bajpai, Vivek K.; Lim, Jeongheui; Park, Yong-Ha

2017-01-01

ZIKA virus (ZIKA) has now become a global phenomenon. Since 2007, evidence of ZIKA transmission has been reported over 72 countries and territories. The transmission of ZIKA has made World Health Organization to categorize the situation under the ambit of a health emergency. This situation is serious because there appears to be a highly tangible link between infection during pregnancy and the occurrence of microcephaly and Guillain–Barré syndrome. In the context of this emergency situation, this review article intends to discuss the prevention and control strategies such as avoiding travel to infected area, being careful from mosquito bites, take precautions to reduce the risk of sexual transmission, and seek medical care for any acute illness with rash or fever. This review is an attempt to analyze the results of those campaigns, keeping in view the variables and constants that affect any such measures. Furthermore, this article will suggest proactive measures that can be employed to effectively combat the epidemic transmission of the ZIKA. PMID:28293228

Melamine nephrotoxicity: an emerging epidemic in an era of globalization.

PubMed

Bhalla, Vivek; Grimm, Paul C; Chertow, Glenn M; Pao, Alan C

2009-04-01

Recent outbreaks of nephrolithiasis and acute kidney injury among children in China have been linked to ingestion of milk-based infant formula contaminated with melamine. These cases provide evidence in humans for the nephrotoxicity of melamine, which previously had been described only in animals. The consequences of this outbreak are already severe and will likely continue to worsen. Herein we summarize the global impact of the melamine milk contamination, the reemergence of melamine-tainted animal feed, and potential mechanisms of melamine nephrotoxicity. Large-scale epidemiologic studies are necessary to further characterize this disease and to assess its potential long-term sequelae. This epidemic of environmental kidney disease highlights the morbidity associated with adulterated food products available in today's global marketplace and reminds us of the unique vulnerability of the kidney to environmental insults. Melamine is the latest in a growing list of diverse potentially toxic compounds about which nephrologists and other health-care providers responsible for the diagnosis and management of kidney disease must now be aware.

Disease ecology and the global emergence of zoonotic pathogens.

PubMed

Wilcox, Bruce A; Gubler, Duane J

2005-09-01

The incidence and frequency of epidemic transmission of zoonotic diseases, both known and newly recognized, has increased dramatically in the past 30 years. It is thought that this dramatic disease emergence is primarily the result of the social, demographic, and environmental transformation that has occurred globally since World War II. However, the causal linkages have not been elucidated. Investigating emerging zoonotic pathogens as an ecological phenomenon can provide significant insights as to why some of these pathogens have jumped species and caused major epidemics in humans. A review of concepts and theory from biological ecology and of causal factors in disease emergence previously described suggests a general model of global zoonotic disease emergence. The model links demographic and societal factors to land use and land cover change whose associated ecological factors help explain disease emergence. The scale and magnitude of these changes are more significant than those associated with climate change, the effects of which are largely not yet understood. Unfortunately, the complex character and non-linear behavior of the human-natural systems in which host-pathogen systems are embedded makes specific incidences of disease emergence or epidemics inherently difficult to predict. Employing a complex systems analytical approach, however, may show how a few key ecological variables and system properties, including the adaptive capacity of institutions, explains the emergence of infectious diseases and how an integrated, multi-level approach to zoonotic disease control can reduce risk.

Oral Delivery of Probiotics Expressing Dendritic Cell-Targeting Peptide Fused with Porcine Epidemic Diarrhea Virus COE Antigen: A Promising Vaccine Strategy against PEDV.

PubMed

Wang, Xiaona; Wang, Li; Huang, Xuewei; Ma, Sunting; Yu, Meiling; Shi, Wen; Qiao, Xinyuan; Tang, Lijie; Xu, Yigang; Li, Yijing

2017-10-25

Porcine epidemic diarrhea virus (PEDV), an enteric coronavirus, is the causative agent of porcine epidemic diarrhea (PED) that damages intestinal epithelial cells and results in severe diarrhea and dehydration in neonatal suckling pigs with up to 100% mortality. The oral vaccine route is reported as a promising approach for inducing protective immunity against PEDV invasion. Furthermore, dendritic cells (DCs), professional antigen-presenting cells, link humoral and cellular immune responses for homeostasis of the intestinal immune environment. In this study, in order to explore an efficient oral vaccine against PEDV infection, a mucosal DC-targeting oral vaccine was developed using Lactobacillus casei to deliver the DC-targeting peptide (DCpep) fused with the PEDV core neutralizing epitope (COE) antigen. This probiotic vaccine could efficiently elicit secretory immunoglobulin A (SIgA)-based mucosal and immunoglobulin G (IgG)-based humoral immune responses via oral vaccination in vivo. Significant differences ( p < 0.05) in the immune response levels were observed between probiotics expressing the COE-DCpep fusion protein and COE antigen alone, suggesting better immune efficiency of the probiotics vaccine expressing the DC-targeting peptide fused with PEDV COE antigen. This mucosal DC-targeting oral vaccine delivery effectively enhances vaccine antigen delivery efficiency, providing a useful strategy to induce efficient immune responses against PEDV infection.

The evolution of chronic opioid therapy and recognizing addiction.

PubMed

Daum, Akiva M; Berkowitz, Oren; Renner, John A

2015-05-01

Chronic pain is one of the most common complaints in the United States. Opioids have become a frequently prescribed treatment for patients with chronic nonmalignant pain. Concurrently, opioid use disorders have risen to epidemic levels. Studies investigating iatrogenic opioid addiction have been of limited quality. Aberrant drug-related behaviors may be warning signs of impending addiction. Proper screening and close monitoring are essential for managing patients on opioids for chronic nonmalignant pain.

What Makes a Message Stick? The Role of Content and Context in Social Media Epidemics

DTIC Science & Technology

2013-09-23

First, we propose visual memes , or frequently re-posted short video segments, for detecting and monitoring latent video interactions at scale. Content...interactions (such as quoting, or remixing, parts of a video). Visual memes are extracted by scalable detection algorithms that we develop, with...high accuracy. We further augment visual memes with text, via a statistical model of latent topics. We model content interactions on YouTube with

Fluid status monitoring with a wireless network to reduce cardiovascular-related hospitalizations and mortality in heart failure: rationale and design of the OptiLink HF Study (Optimization of Heart Failure Management using OptiVol Fluid Status Monitoring and CareLink)

PubMed Central

Brachmann, Johannes; Böhm, Michael; Rybak, Karin; Klein, Gunnar; Butter, Christian; Klemm, Hanno; Schomburg, Rolf; Siebermair, Johannes; Israel, Carsten; Sinha, Anil-Martin; Drexler, Helmut

2011-01-01

Aims The Optimization of Heart Failure Management using OptiVol Fluid Status Monitoring and CareLink (OptiLink HF) study is designed to investigate whether OptiVol fluid status monitoring with an automatically generated wireless CareAlert notification via the CareLink Network can reduce all-cause death and cardiovascular hospitalizations in an HF population, compared with standard clinical assessment. Methods Patients with newly implanted or replacement cardioverter-defibrillator devices with or without cardiac resynchronization therapy, who have chronic HF in New York Heart Association class II or III and a left ventricular ejection fraction ≤35% will be eligible to participate. Following device implantation, patients are randomized to either OptiVol fluid status monitoring through CareAlert notification or regular care (OptiLink ‘on' vs. ‘off'). The primary endpoint is a composite of all-cause death or cardiovascular hospitalization. It is estimated that 1000 patients will be required to demonstrate superiority of the intervention group to reduce the primary outcome by 30% with 80% power. Conclusion The OptiLink HF study is designed to investigate whether early detection of congestion reduces mortality and cardiovascular hospitalization in patients with chronic HF. The study is expected to close recruitment in September 2012 and to report first results in May 2014. ClinicalTrials.gov Identifier: NCT00769457 PMID:21555324

A platform to integrate climate information and rural telemedicine in Malawi

NASA Astrophysics Data System (ADS)

Lowe, R.; Chadza, T.; Chirombo, J.; Fonda, C.; Muyepa, A.; Nkoloma, M.; Pietrosemoli, E.; Radicella, S. M.; Tompkins, A. M.; Zennaro, M.

2012-04-01

It is commonly accepted that climate plays a role in the transmission of many infectious diseases, particularly those transmitted by mosquitoes such as malaria, which is one of the most important causes of mortality and morbidity in developing countries. Due to time lags involved in the climate-disease transmission system, lagged observed climate variables could provide some predictive lead for forecasting disease epidemics. This lead time could be extended by using forecasts of the climate in disease prediction models. This project aims to implement a platform for the dissemination of climate-driven disease risk forecasts, using a telemedicine approach. A pilot project has been established in Malawi, where a 162 km wireless link has been installed, spanning from Blantyre City to remote health facilities in the district of Mangochi in the Southern region, bordering Lake Malawi. This long Wi-Fi technology allows rural health facilities to upload real-time disease cases as they occur to an online health information system (DHIS2); a national medical database repository administered by the Ministry of Health. This technology provides a real-time data logging system for disease incidence monitoring and facilitates the flow of information between local and national levels. This platform allows statistical and dynamical disease prediction models to be rapidly updated with real-time climate and epidemiological information. This permits health authorities to target timely interventions ahead of an imminent increase in malaria incidence. By integrating meteorological and health information systems in a statistical-dynamical prediction model, we show that a long-distance Wi-Fi link is a practical and inexpensive means to enable the rapid analysis of real-time information in order to target disease prevention and control measures and mobilise resources at the local level.

A sewage disposal failure as a cause of ascariasis and giardiasis epidemic in a family.

PubMed

Totkova, A; Klobusicky, M; Holkova, R; Valent, M; Stojkovicova, H

2004-01-01

In monitoring the incidence of intestinal parasites in children and employees of a nursery the authors examined 31 children with 8 (25.81%) and 16 employees with 3 (18.75%) positive results. The authors wanted to examine also the family members of 8 positive children and 3 positive employees but except from the cleaner's family, (Ascaris lumburicoides, Enterobius vermicularis and Entamoeba coli) nobody accepted the offer. All 8 members of a large family except for Patient 1 (a cleaner) and her grandson were without clinical and laboratory findings. They constitute 3 independent families who lived in 1st category flats. On August 31 there was an extensive sewage disposal failure in the ground floor flat of Family II and the flat was flooded by sewage. All family members worked solidarily on cleaning and also the members of Family IV who are friends of Family II. As shown by clinical symptoms of 'virosis', during the pre-patent period and after an outbreak within 73-78 days, laboratory findings of the family members demonstrated a severe family infection equal to a epidemic of intestinal parasitosis. Ascaris lumbricoides was diagnosed in 8 family members (61.54%) and Giardia intestinalis in 7 family members (53.85%) involved in cleaning. Enterobius vermicularis was found in 2 and Etamoeba coli in 1 family member. In monitored persons, in extreme hygienic conditions during the failure and later, a mass contraction arose on the basis of infection. The fact, that family epidemic arose subsequently, proved, in contrast to sporadic findings in children and adults, a 6.4 and 3.3 times higher incidence of Ascaris lumbricoides and a 5.6 and 8.6 times higher incidence of Giardia intestinalis. The authors discus the reasons of incidence and also preventive measures in population. (Tab. 3, Ref. 29.).

Genotypic and Functional Impact of HIV-1 Adaptation to Its Host Population during the North American Epidemic

PubMed Central

Carlson, Jonathan M.; Chan, Benjamin; Chopera, Denis R.; Brumme, Chanson J.; Markle, Tristan J.; Martin, Eric; Shahid, Aniqa; Anmole, Gursev; Mwimanzi, Philip; Nassab, Pauline; Penney, Kali A.; Rahman, Manal A.; Milloy, M.-J.; Schechter, Martin T.; Markowitz, Martin; Carrington, Mary; Walker, Bruce D.; Wagner, Theresa; Buchbinder, Susan; Fuchs, Jonathan; Koblin, Beryl; Mayer, Kenneth H.; Harrigan, P. Richard; Brockman, Mark A.; Poon, Art F. Y.; Brumme, Zabrina L.

2014-01-01

HLA-restricted immune escape mutations that persist following HIV transmission could gradually spread through the viral population, thereby compromising host antiviral immunity as the epidemic progresses. To assess the extent and phenotypic impact of this phenomenon in an immunogenetically diverse population, we genotypically and functionally compared linked HLA and HIV (Gag/Nef) sequences from 358 historic (1979–1989) and 382 modern (2000–2011) specimens from four key cities in the North American epidemic (New York, Boston, San Francisco, Vancouver). Inferred HIV phylogenies were star-like, with approximately two-fold greater mean pairwise distances in modern versus historic sequences. The reconstructed epidemic ancestral (founder) HIV sequence was essentially identical to the North American subtype B consensus. Consistent with gradual diversification of a “consensus-like” founder virus, the median “background” frequencies of individual HLA-associated polymorphisms in HIV (in individuals lacking the restricting HLA[s]) were ∼2-fold higher in modern versus historic HIV sequences, though these remained notably low overall (e.g. in Gag, medians were 3.7% in the 2000s versus 2.0% in the 1980s). HIV polymorphisms exhibiting the greatest relative spread were those restricted by protective HLAs. Despite these increases, when HIV sequences were analyzed as a whole, their total average burden of polymorphisms that were “pre-adapted” to the average host HLA profile was only ∼2% greater in modern versus historic eras. Furthermore, HLA-associated polymorphisms identified in historic HIV sequences were consistent with those detectable today, with none identified that could explain the few HIV codons where the inferred epidemic ancestor differed from the modern consensus. Results are therefore consistent with slow HIV adaptation to HLA, but at a rate unlikely to yield imminent negative implications for cellular immunity, at least in North America. Intriguingly, temporal changes in protein activity of patient-derived Nef (though not Gag) sequences were observed, suggesting functional implications of population-level HIV evolution on certain viral proteins. PMID:24762668

Elevation and cholera: an epidemiological spatial analysis of the cholera epidemic in Harare, Zimbabwe, 2008-2009

PubMed Central

2012-01-01

Background In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009. Methods We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs. Results This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%. Conclusion This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and sanitation in endemic areas. Furthermore, elevation information, among other risk factors, could help to spatially orientate cholera control interventions during an epidemic. PMID:22708576

Taking forward a 'One Health' approach for turning the tide against the Middle East respiratory syndrome coronavirus and other zoonotic pathogens with epidemic potential.

PubMed

Zumla, Alimuddin; Dar, Osman; Kock, Richard; Muturi, Matthew; Ntoumi, Francine; Kaleebu, Pontiano; Eusebio, Macete; Mfinanga, Sayoki; Bates, Matthew; Mwaba, Peter; Ansumana, Rashid; Khan, Mishal; Alagaili, Abdulaziz N; Cotten, Matthew; Azhar, Esam I; Maeurer, Markus; Ippolito, Giuseppe; Petersen, Eskild

2016-06-01

The appearance of novel pathogens of humans with epidemic potential and high mortality rates have threatened global health security for centuries. Over the past few decades new zoonotic infectious diseases of humans caused by pathogens arising from animal reservoirs have included West Nile virus, Yellow fever virus, Ebola virus, Nipah virus, Lassa Fever virus, Hanta virus, Dengue fever virus, Rift Valley fever virus, Crimean-Congo haemorrhagic fever virus, severe acute respiratory syndrome coronavirus, highly pathogenic avian influenza viruses, Middle East Respiratory Syndrome Coronavirus, and Zika virus. The recent Ebola Virus Disease epidemic in West Africa and the ongoing Zika Virus outbreak in South America highlight the urgent need for local, regional and international public health systems to be be more coordinated and better prepared. The One Health concept focuses on the relationship and interconnectedness between Humans, Animals and the Environment, and recognizes that the health and wellbeing of humans is intimately connected to the health of animals and their environment (and vice versa). Critical to the establishment of a One Health platform is the creation of a multidisciplinary team with a range of expertise including public health officers, physicians, veterinarians, animal husbandry specialists, agriculturalists, ecologists, vector biologists, viral phylogeneticists, and researchers to co-operate, collaborate to learn more about zoonotic spread between animals, humans and the environment and to monitor, respond to and prevent major outbreaks. We discuss the unique opportunities for Middle Eastern and African stakeholders to take leadership in building equitable and effective partnerships with all stakeholders involved in human and health systems to take forward a 'One Health' approach to control such zoonotic pathogens with epidemic potential. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Coherence of Influenza Surveillance Data across Different Sources and Age Groups, Beijing, China, 2008-2015.

PubMed

Wu, Zhenyu; Sun, Xiaoyu; Chu, Yanhui; Sun, Jingyi; Qin, Guoyou; Yang, Lin; Qin, Jingning; Xiao, Zheng; Ren, Jian; Qin, Di; Wang, Xiling; Zheng, Xueying

2016-01-01

Influenza is active during the winter and spring in the city of Beijing, which has a typical temperate climate with four clear distinct seasons. The clinical and laboratory surveillance data for influenza have been used to construct critical indicators for influenza activities in the community, and previous studies have reported varying degrees of association between laboratory-confirmed influenza specimens and outpatient consultation rates of influenza-like illness in subtropical cities. However, few studies have reported on this issue for cities in temperate regions, especially in developing countries. Furthermore, the mechanism behind age-specific seasonal epidemics remains unresolved, although it has been widely discussed. We utilized a wavelet analysis method to monitor the coherence of weekly percentage of laboratory-confirmed influenza specimens with the weekly outpatient consultation rates of influenza-like illness in Beijing, China. We first examined the seasonal pattern of laboratory-confirmed cases of influenza A (subtyped into seasonal A(H1N1) and A(H3N2) and pandemic virus A(H1N1) pdm09) and influenza B separately within the period from 2008-2015; then, we detected the coherence of clinical and laboratory surveillance data in this district, specially examining weekly time series of age-specific epidemics of influenza-like illnesses in the whole study period for three age categories (age 0-5, 5-15 and 25-60). We found that influenza A and B were both active in winter but were not always seasonally synchronous in Beijing. Synchronization between age ranges was found in most epidemic peaks from 2008-2015. Our findings suggested that peaks of influenza-like illness in individuals aged 0-5 and 5-15 years consistently appeared ahead of those of adults, implying the possibility that schoolchildren may lead epidemic fluctuations.

Concern about the Expanding Prescription Drug Epidemic: A Survey of Licensed Prescribers and Dispensers.

PubMed

Wright, R Eric; Reed, Nia; Carnes, Neal; Kooreman, Harold E

2016-01-01

Prescription drug misuse and abuse has reached epidemic levels in the U.S., and stands as a leading cause of death. As the primary gatekeepers to the medications contributing to this epidemic, it is critical to understand the views of licensed health care professionals. In this study, we examine health care professionals' concern regarding prescription drug abuse in their communities and the impact their concern has had on their prescribing and dispensing practices. An online survey of licensed health care providers. Conducted in Indiana. This study was a state-wide evaluation of Indiana's prescription drug monitoring program. The questionnaire asked respondents how concerned they were about prescription drug abuse in their community. Variation in the level of concern was examined using ordinary least squares regression and information about the respondents' demographic background and clinical experience. In addition, we used logistic regression to examine whether concern was associated with changing prescribing and/or dispensing behavior. The majority of providers indicated they were "moderately" or "extremely concerned" about prescription drug abuse in their communities. The level of concern, however, varied significantly by profession, with pharmacists, physicians, nurse practitioners/physician assistants being more concerned than dentists. Additional analyses indicate that providers with higher levels of concern were those who also reported recently changing their prescribing and/or dispensing behavior. The voluntary nature and geographical focus of the study limits the generalizability of the findings. Concern about prescription drug abuse is generally high across the major health care professions; however, a significant minority of providers, particularly among dentists, expressed little or no concern about the epidemic. Increasing health care providers' general level of concern about prescription drug abuse may be an effective public health tool for encouraging voluntary reductions in prescribing and/or dispensing controlled substances.

[Facing the HIV/AIDS epidemic in Mexico: the response of the health sector].

PubMed

Gutiérrez, Juan Pablo; López-Zaragoza, José Luis; Valencia-Mendoza, Atanacio; Pesqueira, Eduardo; Ponce-de-León, Samuel; Bertozzi, Stefano M

2004-01-01

To analyze the challenges and accomplishments of the Mexican health system as it faced the HIV/AIDS epidemic over the 20 years since discovery of the virus. A review of the relevant literature was done. The topics revised were: HIV/AIDS epidemiology, the early response of the health system and civil society, prevention and risk behaviors, care and treatment, and financing and resources allocation. In Mexico a rapid initial public response surely contributed to containing any early spread of the epidemic to select populations; whether that spread will continue to be contained is an open question. Sexual risk practices remain high not only among traditional risk populations but also among youth. Even though the epidemic remains concentrated in Mexico, principally among MSM and IDU, only 13% of public HIV prevention funds are directed to key populations at especially high risk of becoming infected or infecting others. In recent years antiretroviral coverage has increased rapidly with funding increasing from 30 to 367 million pesos from 2001 to 2003 and coverage now approaching 100%. Of all health spending on HIV/AIDS in the public sector, 82.4% is spent by the social security institutes and 17.6% by the Ministry of Health. The former provides medical care to about half of PLHA while the latter, in addition to caring for the other half, supports the large majority of prevention expenses. One of the challenges faced by the health system which has largely achieved universal antiretroviral coverage is how to provide quality care with appropriate monitoring, promotion of adherence and recognition and treatment of resistance and adverse effects--without dramatically increasing costs.

Effect of Intermediate Hosts on Emerging Zoonoses.

PubMed

Cui, Jing-An; Chen, Fangyuan; Fan, Shengjie

2017-08-01

Most emerging zoonotic pathogens originate from animals. They can directly infect humans through natural reservoirs or indirectly through intermediate hosts. As a bridge, an intermediate host plays different roles in the transmission of zoonotic pathogens. In this study, we present three types of pathogen transmission to evaluate the effect of intermediate hosts on emerging zoonotic diseases in human epidemics. These types are identified as follows: TYPE 1, pathogen transmission without an intermediate host for comparison; TYPE 2, pathogen transmission with an intermediate host as an amplifier; and TYPE 3, pathogen transmission with an intermediate host as a vessel for genetic variation. In addition, we established three mathematical models to elucidate the mechanisms underlying zoonotic disease transmission according to these three types. Stability analysis indicated that the existence of intermediate hosts increased the difficulty of controlling zoonotic diseases because of more difficult conditions to satisfy for the disease to die out. The human epidemic would die out under the following conditions: TYPE 1: [Formula: see text] and [Formula: see text]; TYPE 2: [Formula: see text], [Formula: see text], and [Formula: see text]; and TYPE 3: [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] Simulation with similar parameters demonstrated that intermediate hosts could change the peak time and number of infected humans during a human epidemic; intermediate hosts also exerted different effects on controlling the prevalence of a human epidemic with natural reservoirs in different periods, which is important in addressing problems in public health. Monitoring and controlling the number of natural reservoirs and intermediate hosts at the right time would successfully manage and prevent the prevalence of emerging zoonoses in humans.

An HIV Epidemic Model Based on Viral Load Dynamics: Value in Assessing Empirical Trends in HIV Virulence and Community Viral Load

PubMed Central

Herbeck, Joshua T.; Mittler, John E.; Gottlieb, Geoffrey S.; Mullins, James I.

2014-01-01

Trends in HIV virulence have been monitored since the start of the AIDS pandemic, as studying HIV virulence informs our understanding of HIV epidemiology and pathogenesis. Here, we model changes in HIV virulence as a strictly evolutionary process, using set point viral load (SPVL) as a proxy, to make inferences about empirical SPVL trends from longitudinal HIV cohorts. We develop an agent-based epidemic model based on HIV viral load dynamics. The model contains functions for viral load and transmission, SPVL and disease progression, viral load trajectories in multiple stages of infection, and the heritability of SPVL across transmissions. We find that HIV virulence evolves to an intermediate level that balances infectiousness with longer infected lifespans, resulting in an optimal SPVL∼4.75 log10 viral RNA copies/mL. Adaptive viral evolution may explain observed HIV virulence trends: our model produces SPVL trends with magnitudes that are broadly similar to empirical trends. With regard to variation among studies in empirical SPVL trends, results from our model suggest that variation may be explained by the specific epidemic context, e.g. the mean SPVL of the founding lineage or the age of the epidemic; or improvements in HIV screening and diagnosis that results in sampling biases. We also use our model to examine trends in community viral load, a population-level measure of HIV viral load that is thought to reflect a population's overall transmission potential. We find that community viral load evolves in association with SPVL, in the absence of prevention programs such as antiretroviral therapy, and that the mean community viral load is not necessarily a strong predictor of HIV incidence. PMID:24945322

Error monitoring issues for common channel signaling

NASA Astrophysics Data System (ADS)

Hou, Victor T.; Kant, Krishna; Ramaswami, V.; Wang, Jonathan L.

1994-04-01

Motivated by field data which showed a large number of link changeovers and incidences of link oscillations between in-service and out-of-service states in common channel signaling (CCS) networks, a number of analyses of the link error monitoring procedures in the SS7 protocol were performed by the authors. This paper summarizes the results obtained thus far and include the following: (1) results of an exact analysis of the performance of the error monitoring procedures under both random and bursty errors; (2) a demonstration that there exists a range of error rates within which the error monitoring procedures of SS7 may induce frequent changeovers and changebacks; (3) an analysis of the performance ofthe SS7 level-2 transmission protocol to determine the tolerable error rates within which the delay requirements can be met; (4) a demonstration that the tolerable error rate depends strongly on various link and traffic characteristics, thereby implying that a single set of error monitor parameters will not work well in all situations; (5) some recommendations on a customizable/adaptable scheme of error monitoring with a discussion on their implementability. These issues may be particularly relevant in the presence of anticipated increases in SS7 traffic due to widespread deployment of Advanced Intelligent Network (AIN) and Personal Communications Service (PCS) as well as for developing procedures for high-speed SS7 links currently under consideration by standards bodies.

Real-Time Distributed Embedded Oscillator Operating Frequency Monitoring

NASA Technical Reports Server (NTRS)

Pollock, Julie; Oliver, Brett; Brickner, Christopher

2012-01-01

A document discusses the utilization of embedded clocks inside of operating network data links as an auxiliary clock source to satisfy local oscillator monitoring requirements. Modem network interfaces, typically serial network links, often contain embedded clocking information of very tight precision to recover data from the link. This embedded clocking data can be utilized by the receiving device to monitor the local oscillator for tolerance to required specifications, often important in high-integrity fault-tolerant applications. A device can utilize a received embedded clock to determine if the local or the remote device is out of tolerance by using a single link. The local device can determine if it is failing, assuming a single fault model, with two or more active links. Network fabric components, containing many operational links, can potentially determine faulty remote or local devices in the presence of multiple faults. Two methods of implementation are described. In one method, a recovered clock can be directly used to monitor the local clock as a direct replacement of an external local oscillator. This scheme is consistent with a general clock monitoring function whereby clock sources are clocking two counters and compared over a fixed interval of time. In another method, overflow/underflow conditions can be used to detect clock relationships for monitoring. These network interfaces often provide clock compensation circuitry to allow data to be transferred from the received (network) clock domain to the internal clock domain. This circuit could be modified to detect overflow/underflow conditions of the buffering required and report a fast or slow receive clock, respectively.

Warmth and legitimacy beliefs contextualize adolescents' negative reactions to parental monitoring.

PubMed

LaFleur, Laura K; Zhao, Yinan; Zeringue, Megan M; Laird, Robert D

2016-08-01

This study sought to identify conditions under which parents' monitoring behaviors are most strongly linked to adolescents' negative reactions (i.e., feelings of being controlled and invaded). 242 adolescents (49.2% male; M age = 15.4 years) residing in the United States of America reported parental monitoring and warmth, and their own feelings of being controlled and invaded and beliefs in the legitimacy of parental authority. Analyses tested whether warmth and legitimacy beliefs moderate and/or suppress the link between parents' monitoring behaviors and adolescents' negative reactions. Monitoring was associated with more negative reactions, controlling for legitimacy beliefs and warmth. More monitoring was associated with more negative reactions only at weaker levels of legitimacy beliefs, and at lower levels of warmth. The link between monitoring and negative reactions is sensitive to the context within which monitoring occurs with the strongest negative reactions found in contexts characterized by low warmth and weak legitimacy beliefs. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Molecular epidemiology of newly acquired hepatitis C infections in England 2008-2011: genotype, phylogeny and mutation analysis.

PubMed

May, Shoshanna; Ngui, Siew Lin; Collins, Sarah; Lattimore, Sam; Ramsay, Mary; Tedder, Richard S; Ijaz, Samreen

2015-03-01

Analysis of laboratory testing data collected through the Sentinel Surveillance programme has provided a method for identifying individuals who have recently acquired their hepatitis C virus (HCV) infection. Access to samples from these individuals provided a rare opportunity to undertake molecular characterization studies. To describe the epidemiology and genetic diversity of hepatitis C in recent seroconverter infections and to predict how this will impact on HCV treatment and control. One hundred and forty seven samples were available from individuals, identified to have recently acquired their HCV infection. Genotype determination with additional phylogenetic analysis was carried out on NS5B sequences. Analysis across the NS3 region investigated the presence of antiviral resistance mutations. Where possible, molecular data was linked to demographic and risk/behavioural factor information. The majority of new infections occurred in males with a mean age of 37 years. The most commonly observed genotypes were 1a (49%) and 3a (42%) and injecting drug use (58%) was the most common risk factor. Genotype distribution differed between persons who inject drugs and those with other risk factors suggesting two possible epidemics. Phylogenetic analysis indicated possible transmission networks within specific risk groups. Amino acid changes associated with antiviral resistance were noted in the NS3 region in some samples. Continued surveillance of linked molecular, virological, demographic and epidemiological information on recently acquired infections will contribute to understanding the on-going HCV epidemic in England. Copyright © 2015 Elsevier B.V. All rights reserved.

Regulation of Food Intake, Energy Balance, and Body Fat Mass: Implications for the Pathogenesis and Treatment of Obesity

PubMed Central

Guyenet, Stephan J.

2012-01-01

Context: Obesity has emerged as one of the leading medical challenges of the 21st century. The resistance of this disorder to effective, long-term treatment can be traced to the fact that body fat stores are subject to homeostatic regulation in obese individuals, just as in lean individuals. Because the growing obesity epidemic is linked to a substantial increase in daily energy intake, a key priority is to delineate how mechanisms governing food intake and body fat content are altered in an obesogenic environment. Evidence Acquisition: We considered all relevant published research and cited references that represented the highest quality evidence available. Where space permitted, primary references were cited. Evidence Synthesis: The increase of energy intake that has fueled the U.S. obesity epidemic is linked to greater availability of highly rewarding/palatable and energy-dense food. Obesity occurs in genetically susceptible individuals and involves the biological defense of an elevated body fat mass, which may result in part from interactions between brain reward and homeostatic circuits. Inflammatory signaling, accumulation of lipid metabolites, or other mechanisms that impair hypothalamic neurons may also contribute to the development of obesity and offer a plausible mechanism to explain the biological defense of elevated body fat mass. Conclusions: Despite steady research progress, mechanisms underlying the resistance to fat loss once obesity is established remain incompletely understood. Breakthroughs in this area may be required for the development of effective new obesity prevention and treatment strategies. PMID:22238401

Link Performance Analysis and monitoring - A unified approach to divergent requirements

NASA Astrophysics Data System (ADS)

Thom, G. A.

Link Performance Analysis and real-time monitoring are generally covered by a wide range of equipment. Bit Error Rate testers provide digital link performance measurements but are not useful during real-time data flows. Real-time performance monitors utilize the fixed overhead content but vary widely from format to format. Link quality information is also present from signal reconstruction equipment in the form of receiver AGC, bit synchronizer AGC, and bit synchronizer soft decision level outputs, but no general approach to utilizing this information exists. This paper presents an approach to link tests, real-time data quality monitoring, and results presentation that utilizes a set of general purpose modules in a flexible architectural environment. The system operates over a wide range of bit rates (up to 150 Mbs) and employs several measurement techniques, including P/N code errors or fixed PCM format errors, derived real-time BER from frame sync errors, and Data Quality Analysis derived by counting significant sync status changes. The architecture performs with a minimum of elements in place to permit a phased update of the user's unit in accordance with his needs.

Spatial distribution and ecological environment analysis of great gerbil in Xinjiang Plague epidemic foci based on remote sensing

NASA Astrophysics Data System (ADS)

Gao, Mengxu; Li, Qun; Cao, Chunxiang; Wang, Juanle

2014-03-01

Yersinia pestis (Plague bacterium) from great gerbil was isolated in 2005 in Xinjiang Dzungarian Basin, which confirmed the presence of the plague epidemic foci. This study analysed the spatial distribution and suitable habitat of great gerbil based on the monitoring data of great gerbil from Chinese Center for Disease Control and Prevention, as well as the ecological environment elements obtained from remote sensing products. The results showed that: (1) 88.5% (277/313) of great gerbil distributed in the area of elevation between 200 and 600 meters. (2) All the positive points located in the area with a slope of 0-3 degree, and the sunny tendency on aspect was not obvious. (3) All 313 positive points of great gerbil distributed in the area with an average annual temperature from 5 to 11 °C, and 165 points with an average annual temperature from 7 to 9 °C. (4) 72.8% (228/313) of great gerbil survived in the area with an annual precipitation of 120-200mm. (5) The positive points of great gerbil increased correspondingly with the increasing of NDVI value, but there is no positive point when NDVI is higher than 0.521, indicating the suitability of vegetation for great gerbil. This study explored a broad and important application for the monitoring and prevention of plague using remote sensing and geographic information system.

Genetic diversity of environmental Vibrio cholerae O1 strains isolated in Northern Vietnam.

PubMed

Takemura, Taichiro; Murase, Kazunori; Maruyama, Fumito; Tran, Thi Luong; Ota, Atsushi; Nakagawa, Ichiro; Nguyen, Dong Tu; Ngo, Tu Cuong; Nguyen, Thi Hang; Tokizawa, Asako; Morita, Masatomo; Ohnishi, Makoto; Nguyen, Binh Minh; Yamashiro, Tetsu

2017-10-01

Cholera epidemics have been recorded periodically in Vietnam during the seventh cholera pandemic. Since cholera is a water-borne disease, systematic monitoring of environmental waters for Vibrio cholerae presence is important for predicting and preventing cholera epidemics. We conducted monitoring, isolation, and genetic characterization of V. cholerae strains in Nam Dinh province of Northern Vietnam from Jul 2013 to Feb 2015. In this study, four V. cholerae O1 strains were detected and isolated from 110 analyzed water samples (3.6%); however, none of them carried the cholera toxin gene, ctxA, in their genomes. Whole genome sequencing and phylogenetic analysis revealed that the four O1 isolates were separated into two independent clusters, and one of them diverged from a common ancestor with pandemic strains. The analysis of pathogenicity islands (CTX prophage, VPI-I, VPI-II, VSP-I, and VSP-II) indicated that one strain (VNND_2014Jun_6SS) harbored an unknown prophage-like sequence with high homology to vibriophage KSF-1 phi and VCY phi, identified from Bangladesh and the USA, respectively, while the other three strains carried tcpA gene with a distinct sequence demonstrating a separate clonal lineage. These results suggest that the aquatic environment can harbor highly divergent V. cholera strains and serve as a reservoir for multiple V. cholerae virulence-associated genes which may be exchanged via mobile genetic elements. Therefore, continuous monitoring and genetic characterization of V. cholerae strains in the environment should contribute to the early detection of the sources of infection and prevention of cholera outbreaks as well as to understanding the natural ecology and evolution of V. cholerae. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Using web search query data to monitor dengue epidemics: a new model for neglected tropical disease surveillance.

PubMed

Chan, Emily H; Sahai, Vikram; Conrad, Corrie; Brownstein, John S

2011-05-01

A variety of obstacles including bureaucracy and lack of resources have interfered with timely detection and reporting of dengue cases in many endemic countries. Surveillance efforts have turned to modern data sources, such as Internet search queries, which have been shown to be effective for monitoring influenza-like illnesses. However, few have evaluated the utility of web search query data for other diseases, especially those of high morbidity and mortality or where a vaccine may not exist. In this study, we aimed to assess whether web search queries are a viable data source for the early detection and monitoring of dengue epidemics. Bolivia, Brazil, India, Indonesia and Singapore were chosen for analysis based on available data and adequate search volume. For each country, a univariate linear model was then built by fitting a time series of the fraction of Google search query volume for specific dengue-related queries from that country against a time series of official dengue case counts for a time-frame within 2003-2010. The specific combination of queries used was chosen to maximize model fit. Spurious spikes in the data were also removed prior to model fitting. The final models, fit using a training subset of the data, were cross-validated against both the overall dataset and a holdout subset of the data. All models were found to fit the data quite well, with validation correlations ranging from 0.82 to 0.99. Web search query data were found to be capable of tracking dengue activity in Bolivia, Brazil, India, Indonesia and Singapore. Whereas traditional dengue data from official sources are often not available until after some substantial delay, web search query data are available in near real-time. These data represent valuable complement to assist with traditional dengue surveillance.

Genetic evolution of low pathogenecity H9N2 Avian influenza viruses in Tunisia: acquisition of new mutations

PubMed Central

2011-01-01

Background Since the end of 2009, H9N2 has emerged in Tunisia causing several epidemics in poultry industry resulting in major economic losses. To monitor variations of Influenza viruses during the outbreaks, Tunisian H9N2 virus isolates were identified and genetically characterized. Methods The genomic RNA segments of Tunisian H9N2 strains were subjected to RT-PCR amplifications followed by sequencing analysis. Results Phylogenetic analysis demonstrated that A/Ck/TUN/12/10 and A/Migratory Bird/TUN/51/10 viruses represent multiple reassortant lineages, with genes coming from Middle East strains, and share the common ancestor Qa/HK/G1/97 isolate which has contributed internal genes of H5N1 virus circulating in Asia. Some of the internal genes seemed to have undergone broad reassortments with other influenza subtypes. Deduced amino acid sequences of the hemagglutinin (HA) gene showed the presence of additional glycosylation site and Leu at position 234 indicating to binding preference to α (2, 6) sialic acid receptors, indicating their potential to directly infect humans. The Hemagglutinin cleavage site motif sequence is 333 PARSSR*GLF341 which indicates the low pathogenicity nature of the Tunisian H9N2 strains and the potential to acquire the basic amino acids required for the highly pathogenic strains. Their neuraminidase protein (NA) carried substitutions in the hemadsorption (HB) site, similar to those of other avian H9N2 viruses from Asia, Middle Eastern and human pandemic H2N2 and H3N2 that bind to α -2, 6 -linked receptors. Two avian virus-like aa at positions 661 (A) and 702 (K), similar to H5N1 strains, were identified in the polymerase (PB2) protein. Likewise, matrix (M) protein carried some substitutions which are linked with increasing replication in mammals. In addition, H9N2 strain recently circulating carried new polymorphism, "GSEV" PDZ ligand (PL) C-terminal motif in its non structural (NS) protein. Two new aa substitutions (I) and (V), that haven't been previously reported, were identified in the polymerase and matrix proteins, respectively. Nucleoprotein and non-structural protein carried some substitutions similar to H5N1 strains. Conclusion Considering these new mutations, the molecular basis of tropism, host responses and enhanced virulence will be defined and studied. Otherwise, Continuous monitoring of viral genetic changes throughout the year is warranted to monitor variations of Influenza viruses in the field. PMID:21992186

The Burden of Dengue and the Financial Cost to Colombia, 2010-2012.

PubMed

Castro Rodríguez, Raúl; Carrasquilla, Gabriel; Porras, Alexandra; Galera-Gelvez, Katia; Lopez Yescas, Juan Guillermo; Rueda-Gallardo, Jorge A

2016-05-04

Data on the burden of dengue and its economic costs can help guide health policy decisions. However, little reliable information is available for Colombia. We therefore calculated the burden of the disease, expressed in disability-adjusted life years (DALYs), for two scenarios: endemic years (average number of cases in non-epidemic years 2011 and 2012) and an epidemic year (2010, when the highest number of dengue cases was reported in the study period). We also estimated the total economic cost of the disease (U.S. dollars at the average exchange rate for 2012), including indirect costs to households derived from expenses such as preventing entry of mosquitos into the home and costs to government arising from direct, indirect, and prevention and monitoring activities, as well as the direct medical and non-medical costs. In the epidemic year 2010, 1,198.73 DALYs were lost per million inhabitants versus 83.88 in endemic years. The total financial cost of the disease in Colombia from a societal perspective was US$167.8 million for 2010, US$129.9 million for 2011, and US$131.7 million for 2012. The cost of mosquito prevention borne by households was a major cost driver (accounting for 46% of the overall cost in 2010, 62% in 2011, and 64% in 2012). © The American Society of Tropical Medicine and Hygiene.

Non-toxigenic environmental Vibrio cholerae O1 strain from Haiti provides evidence of pre-pandemic cholera in Hispaniola.

PubMed

Azarian, Taj; Ali, Afsar; Johnson, Judith A; Jubair, Mohammad; Cella, Eleonora; Ciccozzi, Massimo; Nolan, David J; Farmerie, William; Rashid, Mohammad H; Sinha-Ray, Shrestha; Alam, Meer T; Morris, J Glenn; Salemi, Marco

2016-10-27

Vibrio cholerae is ubiquitous in aquatic environments, with environmental toxigenic V. cholerae O1 strains serving as a source for recurrent cholera epidemics and pandemic disease. However, a number of questions remain about long-term survival and evolution of V. cholerae strains within these aquatic environmental reservoirs. Through monitoring of the Haitian aquatic environment following the 2010 cholera epidemic, we isolated two novel non-toxigenic (ctxA/B-negative) Vibrio cholerae O1. These two isolates underwent whole-genome sequencing and were investigated through comparative genomics and Bayesian coalescent analysis. These isolates cluster in the evolutionary tree with strains responsible for clinical cholera, possessing genomic components of 6 th and 7 th pandemic lineages, and diverge from "modern" cholera strains around 1548 C.E. [95% HPD: 1532-1555]. Vibrio Pathogenicity Island (VPI)-1 was present; however, SXT/R391-family ICE and VPI-2 were absent. Rugose phenotype conversion and vibriophage resistance evidenced adaption for persistence in aquatic environments. The identification of V. cholerae O1 strains in the Haitian environment, which predate the first reported cholera pandemic in 1817, broadens our understanding of the history of pandemics. It also raises the possibility that these and similar environmental strains could acquire virulence genes from the 2010 Haitian epidemic clone, including the cholera toxin producing CTXϕ.

Alkaline peptone water enrichment with a dipstick test to quickly detect and monitor cholera outbreaks.

PubMed

Bwire, Godfrey; Orach, Christopher Garimoi; Abdallah, Dauda; Debes, Amanda Kay; Kagirita, Atek; Ram, Malathi; Sack, David A

2017-11-21

Detection, confirmation and monitoring of cholera outbreaks in many developing countries including Uganda is a big challenge due to lack of the required resources and the time the test takes. Culture method which takes 24-48 h to get the feedback and requires highly skilled laboratory staff plus other complex resources is the standard test. This study evaluated the new cholera rapid detection method that relies on Crystal VC dipsticks after enrichment with alkaline peptone water (APW) against the culture method for monitoring the progress of cholera outbreaks in rural setting. We conducted the study between March and June 2015. Fresh stool samples and rectal swabs were incubated in 1% APW for 6 h at room temperature before testing with RDT following the manufacturer's instruction. The same stool sample was cultured to isolate V. cholerae in the standard manner. We also reviewed patient registers to epidemiologically describe the cholera epidemic. We tested stool from 102 consenting suspected cholera patients reporting during daytime at Bwera Hospital (n = 69), Kilembe Mines Hospital (n = 4) and Kinyabwama Health Centre (n = 29). Ninety one (91) samples were positive and nine samples were negative according to both methods. One (1) sample was positive only by dipstick and one sample was positive only by culture (sensitivity of 99%, specificity of 90%, Positive Predictive Value of 99% and Negative Predictive Value of 90%). Overall, 146 suspected cholera cases and two deaths, (case fatality rate of 1.36%) were recorded during the study period. Among the cases aged 1-9 years, 63% (50/79) were males while in those aged 20-49 years, 76% (34/45) were females. Our findings showed that the modified dipstick test after enrichment with 1% APW had high level of accuracy in detection of V. cholerae and is quick, affordable alternative cholera outbreak monitoring tool in resource constrained settings. However, culture method should remain for cholera epidemic confirmation, for monitoring of antibiotic sensitivity and for production of pure isolates for molecular characterization. Further studies should be done to better understand the observed age and sex case distribution, in Kasese district.

Modeling the influence of information on the coevolution of contact networks and the dynamics of infectious diseases

NASA Astrophysics Data System (ADS)

Zhang, Haifeng; Small, Michael; Fu, Xinchu; Sun, Guiquan; Wang, Binghong

2012-09-01

Outbreaks of infectious diseases may awaken the awareness of individuals, consequently, they may adjust their contact patterns according to the perceived risk from disease. In this paper, we assume that individuals make decisions on breaking or recovering links according to the information of diseases spreading which they have acquired. They will reduce some links when diseases are prevalent and have high risks; otherwise, they will recover some original links when the diseases are controlled or present minimal risk. Under such an assumption, we study the effects of information of diseases on the contact patterns within the population and on the dynamics of epidemics. By extensive simulations and theoretical analysis, we find that, due to the time-delayed information of diseases, both the density of the disease and the topology of the network vary with time in a periodic form. Our results indicate that the quality of information available to individuals can have an important effect on the spreading of infectious diseases and implications for related problems.

Genetic analysis of West Nile virus isolates from an outbreak in Idaho, United States, 2006-2007.

PubMed

Grinev, Andriyan; Chancey, Caren; Añez, Germán; Ball, Christopher; Winkelman, Valerie; Williamson, Phillip; Foster, Gregory A; Stramer, Susan L; Rios, Maria

2013-09-23

West Nile virus (WNV) appeared in the U.S. in 1999 and has since become endemic, with yearly summer epidemics causing tens of thousands of cases of serious disease over the past 14 years. Analysis of WNV strains isolated during the 2006-2007 epidemic seasons demonstrates that a new genetic variant had emerged coincidentally with an intense outbreak in Idaho during 2006. The isolates belonging to the new variant carry a 13 nt deletion, termed ID-Δ13, located at the variable region of the 3'UTR, and are genetically related. The analysis of deletions and insertions in the 3'UTR of two major lineages of WNV revealed the presence of conserved repeats and two indel motifs in the variable region of the 3'UTR. One human and two bird isolates from the Idaho 2006-2007 outbreaks were sequenced using Illumina technology and within-host variability was analyzed. Continued monitoring of new genetic variants is important for public health as WNV continues to evolve.

Climate and Non-Climate Drivers of Dengue Epidemics in Southern Coastal Ecuador

PubMed Central

Stewart-Ibarra, Anna M.; Lowe, Rachel

2013-01-01

We report a statistical mixed model for assessing the importance of climate and non-climate drivers of interannual variability in dengue fever in southern coastal Ecuador. Local climate data and Pacific sea surface temperatures (Oceanic Niño Index [ONI]) were used to predict dengue standardized morbidity ratios (SMRs; 1995–2010). Unobserved confounding factors were accounted for using non-structured yearly random effects. We found that ONI, rainfall, and minimum temperature were positively associated with dengue, with more cases of dengue during El Niño events. We assessed the influence of non-climatic factors on dengue SMR using a subset of data (2001–2010) and found that the percent of households with Aedes aegypti immatures was also a significant predictor. Our results indicate that monitoring the climate and non-climate drivers identified in this study could provide some predictive lead for forecasting dengue epidemics, showing the potential to develop a dengue early-warning system in this region. PMID:23478584

The molecular epidemiology of variant CJD

PubMed Central

Mackay, Graham A; Knight, Richard SG; Ironside, James W

2011-01-01

The emergence of the novel prion diseases bovine spongiform encephalopathy (BSE) and, subsequently, variant Creutzfeldt-Jakob disease (vCJD) in epidemic forms has attracted much scientific attention. The oral transmission of these disorders, the causative relationship of vCJD to BSE and the resistance of the transmissible agents in both disorders to conventional forms of decontamination has caused great public health concern. The size of the still emerging vCJD epidemic is thankfully much lower than some early published estimates. This paper reviews current knowledge of the factors that influence the development of vCJD: the properties of the infectious agent; the route of inoculation and individual susceptibility factors. The current epidemiological data are reviewed, along with relevant animal transmission studies. In terms of genetic susceptibility, the best characterised is the common single nucleotide polymorphism at codon 129 of prion protein gene. Current biomarkers and future areas of research will be discussed. These issues are important in informing precautionary measures and the ongoing monitoring of vCJD. PMID:21915360

Early warnings of the potential for malaria transmission in Rural Africa using the Hydrology, Entomology and Malaria Transmission Simulator (HYDREMATS)

NASA Astrophysics Data System (ADS)

Yamana, T. K.; Eltahir, E. A.

2010-12-01

Early warnings of malaria transmission allow health officials to better prepare for future epidemics. Monitoring rainfall is recognized as an important part of malaria early warning systems, as outlined by the Roll Back Malaria Initiative. The Hydrology, Entomology and Malaria Simulator (HYDREMATS) is a mechanistic model that relates rainfall to malaria transmission, and could be used to provide early warnings of malaria epidemics. HYDREMATS is used to make predictions of mosquito populations and vectorial capacity for 2005, 2006, and 2007 in Banizoumbou village in western Niger. HYDREMATS is forced by observed rainfall, followed by a rainfall prediction based on the seasonal mean rainfall for a period two or four weeks into the future. Predictions made using this method provided reasonable estimates of mosquito populations and vectorial capacity, two to four weeks in advance. The predictions were significantly improved compared to those made when HYDREMATS was forced with seasonal mean rainfall alone.

The Critical Role of Early Dengue Surveillance and Limitations of Clinical Reporting – Implications for Non-Endemic Countries

PubMed Central

Kao, Jui-Hung; Chen, Chaur-Dong; Chu, Yin-Hsia; Cheng, Hau-Yuan; Liu, Jien-Wei; Shih, Fuh-Yuan; Shu, Pei-Yun; Lin, Chien-Chou; Tsai, Wu-Hsiung; Ku, Chia-Chi; Ho, Chi-Kung; King, Chwan-Chuen

2016-01-01

The increasing dengue burden and epidemic severity worldwide have highlighted the need to improve surveillance. In non-endemic areas such as Taiwan, where outbreaks start mostly with imported cases from Southeast Asia, a closer examination of surveillance dynamics to detect cases early is necessary. To evaluate problems with dengue surveillance and investigate the involvement of different factors at various epidemic stages, we investigated 632 laboratory-confirmed indigenous dengue cases in Kaohsiung City, Taiwan during 2009–2010. The estimated sensitivity of clinical surveillance was 82.4% (521/632). Initially, the modified serological surveillance (targeting only the contacts of laboratory-confirmed dengue cases) identified clinically unrecognized afebrile cases in younger patients who visited private clinics and accounted for 30.4% (35/115) of the early-stage cases. Multivariate regression indicated that hospital/medical center visits [Adjusted Odds Ratio (aOR): 11.6, 95% confidence interval (CI): 6.3–21.4], middle epidemic stage [aOR: 2.4 (1.2–4.7)], fever [aOR: 2.3 (2.3–12.9)], and musculo-articular pain [aOR: 1.9 (1.05–3.3)] were significantly associated with clinical reporting. However, cases with pruritus/rash [aOR: 0.47 (0.26–0.83)] and diarrhea [aOR: 0.47 (0.26–0.85)] were underreported. In conclusion, multiple factors contributed to dengue surveillance problems. To prevent a large-scale epidemic and minimize severe dengue cases, there is a need for integrated surveillance incorporating entomological, clinical, serological, and virological surveillance systems to detect early cases, followed by immediate prevention and control measures and continuous evaluation to ensure effectiveness. This effort will be particularly important for an arbovirus, such as Zika virus, with a high asymptomatic infection ratio. For dengue- non-endemic countries, we recommend serological surveillance be implemented in areas with high Aedes mosquito indices or many breeding sites. Syndromic surveillance, spatial analysis and monitoring changes in epidemiological characteristics using a geographical information system, as well as epidemic prediction models involving epidemiological, meteorological and environmental variables will be helpful for early risk communication to increase awareness. PMID:27501302

Fluid fragmentation shapes rain-induced foliar disease transmission.

PubMed

Gilet, T; Bourouiba, L

2015-03-06

Plant diseases represent a growing threat to the global food supply. The factors contributing to pathogen transmission from plant to plant remain poorly understood. Statistical correlations between rainfalls and plant disease outbreaks were reported; however, the detailed mechanisms linking the two were relegated to a black box. In this combined experimental and theoretical study, we focus on the impact dynamics of raindrops on infected leaves, one drop at a time. We find that the deposition range of most of the pathogen-bearing droplets is constrained by a hydrodynamical condition and we quantify the effect of leaf size and compliance on such constraint. Moreover, we identify and characterize two dominant fluid fragmentation scenarios as responsible for the dispersal of most pathogen-bearing droplets emitted from infected leaves: (i) the crescent-moon ejection is driven by the direct interaction between the impacting raindrop and the contaminated sessile drop and (ii) the inertial detachment is driven by the motion imparted to the leaf by the raindrop, leading to catapult-like droplet ejections. We find that at first, decreasing leaf size or increasing compliance reduces the range of pathogen-bearing droplets and the subsequent epidemic onset efficiency. However, this conclusion only applies for the crescent moon ejection. Above a certain compliance threshold a more effective mechanism of contaminated fluid ejection, the inertial detachment, emerges. This compliance threshold is determined by the ratio between the leaf velocity and the characteristic velocity of fluid fragmentation. The inertial detachment mechanism enhances the range of deposition of the larger contaminated droplets and suggests a change in epidemic onset pattern and a more efficient potential of infection of neighbouring plants. Dimensionless parameters and scaling laws are provided to rationalize our observations. Our results link for the first time the mechanical properties of foliage with the onset dynamics of foliar epidemics through the lens of fluid fragmentation. We discuss how the reported findings can inform the design of mitigation strategies acting at the early stage of a foliar disease outbreak. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Porcine Epidemic Diarrhea Virus 3C-Like Protease-Mediated Nucleocapsid Processing: Possible Link to Viral Cell Culture Adaptability.

PubMed

Jaru-Ampornpan, Peera; Jengarn, Juggragarn; Wanitchang, Asawin; Jongkaewwattana, Anan

2017-01-15

Porcine epidemic diarrhea virus (PEDV) causes severe diarrhea and high mortality rates in newborn piglets, leading to massive losses to the swine industry worldwide during recent epidemics. Intense research efforts are now focusing on defining viral characteristics that confer a growth advantage, pathogenicity, or cell adaptability in order to better understand the PEDV life cycle and identify suitable targets for antiviral or vaccine development. Here, we report a unique phenomenon of PEDV nucleocapsid (N) cleavage by the PEDV-encoded 3C-like protease (3Cpro) during infection. The identification of the 3Cpro cleavage site at the C terminus of N supported previous observations that PEDV 3Cpro showed a substrate requirement slightly different from that of severe acute respiratory syndrome coronavirus (SARS-CoV) 3Cpro and revealed a greater flexibility in its substrate recognition site. This cleavage motif is present in the majority of cell culture-adapted PEDV strains but is missing in emerging field isolates. Remarkably, reverse-genetics-derived cell culture-adapted PEDV AVCT12 harboring uncleavable N displayed growth retardation in Vero E6-APN cells compared to the wild-type virus. These observations altogether shed new light on the investigation and characterization of the PEDV nucleocapsid protein and its possible link to cell culture adaptation. Recurrent PEDV outbreaks have resulted in enormous economic losses to swine industries worldwide. To gain the upper hand in combating this disease, it is necessary to understand how this virus replicates and evades host immunity. Characterization of viral proteins provides important clues to mechanisms by which viruses survive and spread. Here, we characterized an intriguing phenomenon in which the nucleocapsids of some PEDV strains are proteolytically processed by the virally encoded main protease. Growth retardation in recombinant PEDV carrying uncleavable N suggests a replication advantage provided by the cleavage event, at least in the cell culture system. These findings may direct us to a more complete understanding of PEDV replication and pathogenicity. Copyright © 2017 American Society for Microbiology.

Socioeconomic and environmental determinants of dengue transmission in an urban setting: An ecological study in Nouméa, New Caledonia

PubMed Central

Zellweger, Raphaël M.; Cano, Jorge; Mangeas, Morgan; Taglioni, François; Mercier, Alizé; Despinoy, Marc; Menkès, Christophe E.; Dupont-Rouzeyrol, Myrielle

2017-01-01

Background Dengue is a mosquito-borne virus that causes extensive morbidity and economic loss in many tropical and subtropical regions of the world. Often present in cities, dengue virus is rapidly spreading due to urbanization, climate change and increased human movements. Dengue cases are often heterogeneously distributed throughout cities, suggesting that small-scale determinants influence dengue urban transmission. A better understanding of these determinants is crucial to efficiently target prevention measures such as vector control and education. The aim of this study was to determine which socioeconomic and environmental determinants were associated with dengue incidence in an urban setting in the Pacific. Methodology An ecological study was performed using data summarized by neighborhood (i.e. the neighborhood is the unit of analysis) from two dengue epidemics (2008–2009 and 2012–2013) in the city of Nouméa, the capital of New Caledonia. Spatial patterns and hotspots of dengue transmission were assessed using global and local Moran’s I statistics. Multivariable negative binomial regression models were used to investigate the association between dengue incidence and various socioeconomic and environmental factors throughout the city. Principal findings The 2008–2009 epidemic was spatially structured, with clusters of high and low incidence neighborhoods. In 2012–2013, dengue incidence rates were more homogeneous throughout the city. In all models tested, higher dengue incidence rates were consistently associated with lower socioeconomic status (higher unemployment, lower revenue or higher percentage of population born in the Pacific, which are interrelated). A higher percentage of apartments was associated with lower dengue incidence rates during both epidemics in all models but one. A link between vegetation coverage and dengue incidence rates was also detected, but the link varied depending on the model used. Conclusions This study demonstrates a robust spatial association between dengue incidence rates and socioeconomic status across the different neighborhoods of the city of Nouméa. Our findings provide useful information to guide policy and help target dengue prevention efforts where they are needed most. PMID:28369149

Achieving universal access and moving towards elimination of new HIV infections in Cambodia

PubMed Central

Vun, Mean Chhi; Fujita, Masami; Rathavy, Tung; Eang, Mao Tang; Sopheap, Seng; Sovannarith, Samreth; Chhorvann, Chhea; Vanthy, Ly; Sopheap, Oum; Welle, Emily; Ferradini, Laurent; Sedtha, Chin; Bunna, Sok; Verbruggen, Robert

2014-01-01

Introduction In the mid-1990s, Cambodia faced one of the fastest growing HIV epidemics in Asia. For its achievement in reversing this trend, and achieving universal access to HIV treatment, the country received a United Nations millennium development goal award in 2010. This article reviews Cambodia’s response to HIV over the past two decades and discusses its current efforts towards elimination of new HIV infections. Methods A literature review of published and unpublished documents, including programme data and presentations, was conducted. Results and discussion Cambodia classifies its response to one of the most serious HIV epidemics in Asia into three phases. In Phase I (1991–2000), when adult HIV prevalence peaked at 1.7% and incidence exceeded 20,000 cases, a nationwide HIV prevention programme targeted brothel-based sex work. Voluntary confidential counselling and testing and home-based care were introduced, and peer support groups of people living with HIV emerged. Phase II (2001–2011) observed a steady decline in adult prevalence to 0.8% and incidence to 1600 cases by 2011, and was characterized by: expanding antiretroviral treatment (coverage reaching more than 80%) and continuum of care; linking with tuberculosis and maternal and child health services; accelerated prevention among key populations, including entertainment establishment-based sex workers, men having sex with men, transgender persons, and people who inject drugs; engagement of health workers to deliver quality services; and strengthening health service delivery systems. The third phase (2012–2020) aims to attain zero new infections by 2020 through: sharpening responses to key populations at higher risk; maximizing access to community and facility-based testing and retention in prevention and care; and accelerating the transition from vertical approaches to linked/integrated approaches. Conclusions Cambodia has tailored its prevention strategy to its own epidemic, established systematic linkages across different services and communities, and achieved nearly universal coverage of HIV services nationwide. Still, the programme must continually (re)prioritize the most effective and efficient interventions, strengthen synergies between programmes, contribute to health system strengthening, and increase domestic funding so that the gains of the previous two decades are sustained, and the goal of zero new infections is reached. PMID:24950749

Transfusion-Transmitted Dengue and Associated Clinical Symptoms During the 2012 Epidemic in Brazil

PubMed Central

Sabino, Ester C.; Loureiro, Paula; Lopes, Maria Esther; Capuani, Ligia; McClure, Christopher; Chowdhury, Dhuly; Di-Lorenzo-Oliveira, Claudia; Oliveira, Lea C.; Linnen, Jeffrey M.; Lee, Tzong-Hae; Gonçalez, Thelma; Brambilla, Donald; Kleinman, Steve; Busch, Michael P.; Custer, Brian

2016-01-01

Background. A linked donor-recipient study was conducted during epidemics in 2 cities in Brazil to investigate transfusion-transmitted (TT) dengue virus (DENV) by DENV RNA–positive donations. Methods. During February–June 2012, samples were collected from donors and recipients and retrospectively tested for DENV RNA by transcription-mediated amplification. Recipient chart review, using a case (DENV positive)–control (DENV negative and not known to be exposed) design, was conducted to assess symptoms. Results. Of 39 134 recruited blood donors, DENV-4 viremia was confirmed in 0.51% of donations from subjects in Rio de Janeiro and 0.80% of subjects in Recife. Overall, 42 DENV RNA–positive units were transfused into 35 recipients. Of these, 16 RNA-positive units transfused into 16 susceptible recipients were identified as informative: 5 cases were considered probable TT cases, 1 possible TT case, and 10 nontransmissions. The TT rate was 37.5% (95% confidence interval [CI], 15.2%–64.6%), significantly higher than the viremia rate of 0.93% (95% CI, .11%–3.34%) in nonexposed recipients (P < .0001). Chart review did not find significant differences between cases and controls in symptoms or mortality. Conclusions. During a large epidemic of DENV-4 infection in Brazil, >0.5% of donations were RNA positive, and approximately one third of components resulted in TT. However, no significant clinical differences were evident between RNA-positive and RNA-negative recipients. PMID:26908780

Epidemic keratoconjunctivitis outbreak at a tertiary referral eye care clinic.

PubMed

Montessori, V; Scharf, S; Holland, S; Werker, D H; Roberts, F J; Bryce, E

1998-08-01

An outbreak of epidemic keratoconjunctivitis (EKC) occurred at a tertiary referral eye care clinic between late September and mid-November 1995. Before the outbreak, instruments were cleaned with 70% isopropyl alcohol and handwashing between patients was not routine. Infection control measures were implemented when the outbreak was recognized in mid-October. Control measures included triaging suspected cases to a separate waiting area, cohorting cases to a specific examining room, endorsing the use of gloves and handwashing during examinations of patients, and cleaning instruments with a buffered bleach solution. Thirty-six cases were diagnosed before the infection control measures were taken, and 3 cases were seen after the control measures were taken. Also, numerous secondary cases occurred in the community. No additional cases were diagnosed from DEcember to February 25, 1996. Acquisition of the infection was linked to visits to 4 of 20 physicians in the eye clinic with 61% of cases associated with visits to 1 of those 4 physicians. The use of diagnostic lenses applied directly to the eye was associated with infection (odds ratio = 2.83, 95% confidence interval = 0.79 to 10.4), although this did not reach statistical significance. The use of tonometers, ophthalmic solutions, or laser therapy was not associated with infection, and all environmental cultures were negative. This outbreak emphasizes the need for implementation of routine infection control guidelines to prevent nosocomial transmission of epidemic keratoconjunctivitis and stresses the need for appropriate disinfection of instruments.

Size matters: concurrency and the epidemic potential of HIV in small networks.

PubMed

Carnegie, Nicole Bohme; Morris, Martina

2012-01-01

Generalized heterosexual epidemics are responsible for the largest share of the global burden of HIV. These occur in populations that do not have high rates of partner acquisition, and research suggests that a pattern of fewer, but concurrent, partnerships may be the mechanism that provides the connectivity necessary for sustained transmission. We examine how network size affects the impact of concurrency on network connectivity. We use a stochastic network model to generate a sample of networks, varying the size of the network and the level of concurrency, and compare the largest components for each scenario to the asymptotic expected values. While the threshold for the growth of a giant component does not change, the transition is more gradual in the smaller networks. As a result, low levels of concurrency generate more connectivity in small networks. Generalized HIV epidemics are by definition those that spread to a larger fraction of the population, but the mechanism may rely in part on the dynamics of transmission in a set of linked small networks. Examples include rural populations in sub-Saharan Africa and segregated minority populations in the US, where the effective size of the sexual network may well be in the hundreds, rather than thousands. Connectivity emerges at lower levels of concurrency in smaller networks, but these networks can still be disconnected with small changes in behavior. Concurrency remains a strategic target for HIV combination prevention programs in this context.

Modeling the Epidemiology of Cholera to Prevent Disease Transmission in Developing Countries

PubMed Central

MUKANDAVIRE, ZINDOGA; MORRIS, J. GLENN

2015-01-01

Cholera remains an important global cause of morbidity and mortality, which is capable of causing periodic epidemic disease. A number of mathematical models have been developed to help in understanding the dynamics of cholera outbreaks and for use as a tool in planning interventions, including vaccination campaigns. We have explored the utility of models in assessing the spread of cholera in the recent epidemics in Zimbabwe and Haiti. In both instances, a mathematical model was formulated and fitted to cumulative cholera cases to estimate the basic reproductive number ℜ0, and the partial reproductive numbers reflecting potential differences in environmental-to-human versus human-to-human transmission were quantified. In Zimbabwe, estimated ℜ0 for the epidemic using aggregated data at the national level was 1.15; in Haiti, it was 1.55. However, when calculated at a provincial/departmental level, estimated basic reproductive numbers were highly heterogeneous, with a range of 1.11 to 2.72 in Zimbabwe and 1.06 to 2.63 in Haiti. Our models suggest that the underlying patterns of cholera transmission varied widely from region to region, with a corresponding variation in the amenability of outbreaks to control measures such as immunization. These data underscore the heterogeneity of transmission dynamics, potentially linked to differences in environment, socio-economic conditions, and cultural practices. They also highlight the potential utility of these types of models in guiding development of public health intervention strategies. PMID:26185087

Methodologic limitations of prescription opioid safety research and recommendations for improving the evidence base.

PubMed

Ranapurwala, Shabbar I; Naumann, Rebecca B; Austin, Anna E; Dasgupta, Nabarun; Marshall, Stephen W

2018-06-03

The ongoing opioid epidemic has claimed more than a quarter million Americans' lives over the past 15 years. The epidemic began with an escalation of prescription opioid deaths and has now evolved to include secondary waves of illicit heroin and fentanyl deaths, while the deaths due to prescription opioid overdoses are still increasing. In response, the Centers for Disease Control and Prevention (CDC) moved to limit opioid prescribing with the release of opioid prescribing guidelines for chronic noncancer pain in March 2016. The guidelines represent a logical and timely federal response to this growing crisis. However, CDC acknowledged that the evidence base linking opioid prescribing to opioid use disorders and overdose was grades 3 and 4. Motivated by the need to strengthen the evidence base, this review details limitations of the opioid safety studies cited in the CDC guidelines with a focus on methodological limitations related to internal and external validity. Internal validity concerns were related to poor confounding control, variable misclassification, selection bias, competing risks, and potential competing interventions. External validity concerns arose from the use of limited source populations, historical data (in a fast-changing epidemic), and issues with handling of cancer and acute pain patients' data. We provide a nonexhaustive list of 7 recommendations to address these limitations in future opioid safety studies. Strengthening the opioid safety evidence base will aid any future revisions of the CDC guidelines and enhance their prevention impact. Copyright © 2018 John Wiley & Sons, Ltd.

Within-farm transmission dynamics of foot and mouth disease as revealed by the 2001 epidemic in Great Britain.

PubMed

Chis Ster, Irina; Dodd, Peter J; Ferguson, Neil M

2012-08-01

This paper uses statistical and mathematical models to examine the potential impact of within-farm transmission dynamics on the spread of the 2001 foot and mouth disease (FMD) outbreak in Great Britain. We partly parameterize a simple within farm transmission model using data from experimental studies of FMD pathogenesis, embed this model within an existing between-farm transmission model, and then estimate unknown parameters (such as the species-specific within-farm reproduction number) from the 2001 epidemic case data using Markov Chain Monte-Carlo (MCMC) methods. If the probability of detecting an infected premises depends on farm size and species mix then the within-farm species specific basic reproduction ratios for baseline models are estimated to be 21 (16, 25) and 14 (10, 19) for cattle and sheep, respectively. Alternatively, if detection is independent of farm size, then the corresponding estimates are 49 (41, 61) and 10 (1.4, 21). Both model variants predict that the average fraction of total farm infectiousness accumulated prior to detection of infection on an IP is about 30-50% in cattle or mixed farms. The corresponding estimate for sheep farms depended more on the detection model, being 65-80% if detection was linked to the farms' characteristics, but only 25% if not. We highlighted evidence which reinforces the role of within-farm dynamics in contributing to the long tail of the 2001 epidemic. Copyright © 2012 Elsevier B.V. All rights reserved.

[Five years of cholera surveillance in Ivory Coast during social and political crisis, 2001 to 2005].

PubMed

Ekra, K D; Attoh-Touré, H; Bénié, B V J; Coulibaly, D; Koutouan, M G; Aka, L N; Dagnan, S N; Coulibaly, A; Douba, A; Tiembré, I; Odéhouri-Koudou, P; Tagliante-Saracino, J

2009-05-01

For an efficient struggle against infectious diseases with epidemic potential, the Cdte d'Ivoire set up a precocious alert system in 2001 with a main objective: to detect epidemics of cholera, measles, yellow fever and meningitis and to provide necessary information for their control and their prevention. During the 2001 to 2005 period, the country was marked by military and political crisis which occurred in 2002; the country had to face up to a reappearance of cholera. How did it evolve in such a context? The question was to describe the performances of the system and the evolution of cholera from weekly data collected by the centers of epidemiological monitoring in health districts. The cases and declared deaths were compiled and the indicators of morbidity and mortality were then studied according to time site and individual features on the period of 2001 to 2005. From 2001 to 2005, 11,874 cases were notified with 564 deaths and a lethal rate of 4.7%. In 2001, from the initial source of infection, the civil jail, the epidemic of cholera disseminated itself through visitors in the whole city of Abidjan where 3250 cases were notified. Out of city, 20 outbreaks have been declared with a total of 3010 cases. The yearly highest impact, 37 living cases/100,000 inhabitants recorded in 2001, decreased regularly until 2005 with 0.2 living cases/100,000. After 2002, outbreaks were located mainly in the half south of the country which welcomed displaced populations from the north, preferably in transition or settling zones near the front line. The lethal rate in Abidjan (2.3%) was less important than that of other health districts (8.6%). The lethal rate globally increased as the impact decreased. Vibrio cholerae was responsible for the epidemics. The group of 15 years old and over was the most affected (12.69 living cases/100,000) whereas the highest lethal rate appeared in the group under 5 years old (6.6%). The reappearance and constant cholera epidemics in Côte d'Ivoire are due to bad general hygiene conditions, insufficient supply of drinking water from wells or packaged, concentration of populations in the south of the country due to war and uncontrolled development of the poor and unsanitary precarious boroughs. Outburst during the dry season is a warning signal of an important epidemic during the raining season especially in poor urban areas. The precocious alert system has permitted to detect the epidemics, to follow up their evolution and to orientate the struggle against cholera in Côte d'Ivoire.

A three-variable chaotic system for the epidemic of bubonic plague in Bombay by the end of the 19th century and its coupling to the epizootics of the two main species of rats

NASA Astrophysics Data System (ADS)

Mangiarotti, Sylvain

2016-04-01

A plague epidemic broke out in Bombay by the end of the 19th century. A committee was first appointed by the Bombay City [1] in order to stop the epidemic before the rain season started. Unfortunately, the disease could not be stopped and the epidemic became endemic. After several years, another Advisory Committee [2] was appointed that tried to investigate the causes of plague in all possible directions. An impressing quantity of information was gathered during the period 1907-1911 and published. In particular, it was noticed that the epidemic was systematically preceded by epizootics of rats. For this reason, the populations of the main species of rodents were systematically monitored. This data set is revisited here by using a multivariate version of the global modeling technique [3]. The aim of this technique is to obtain a set of Ordinary Differential Equations directly from time series. Three observational time series are considered: the number of person died of bubonic plague per half month (1), and the number of captured infected black rats Mus rattus (2) and brown rats Mus decumanus (3). Several models are obtained, all based on the same algebraic basic structure. These models are, either directly chaotic, or close to chaos (chaos could easily be obtained by tuning one model parameter). The algebraic structure of the simplest model obtained is analyzed in more details. Surprisingly, it is found that the interpretation of the coupling between the three variables can be done term by term. This interpretation is in quite good coherence with the conclusions of the Advisory Committee published one hundred years ago. This structure also shows that the human action to slow down the disease during this period was obviously effective, although insufficient to stop the epidemic drastically. This result suggests that the global modeling technique can be a powerful tool to detect causal couplings in epidemiology, and, more generally, among observational variables from any dynamical networks. The possibility to apply the technique to other diseases (such as Ebola) and to detect couplings to climatic conditions will also be evoked. [1] Gatacre W. F., 1897. Report on the bubonic plague in Bombay. [2] Plague Research Commission, 1907. The epidemiological observations made by the commission in Bombay city. J. of Hygiene, 7, 724-798. [3] Mangiarotti S., Coudret R., Drapeau L. & Jarlan L., 2012. Polynomial search and Global modelling: two algorithms for modeling chaos. Physical Review E, 86(4), 046205. [4] Mangiarotti S. 2015. Low dimensional chaotic models for the plague epidemic in Bombay (1896-1911). Chaos Solitons and Fractals, 81, 184-196.

Vaginal Electrohysterography: The Design and Preliminary Evaluation of a Novel Device for Uterine Contraction Monitoring in an Ovine Model

PubMed Central

SUNWOO, Nate; HWANG, Karin; BLAKEMORE, Karin; AINA-MUMUNEY, Abimbola

2016-01-01

Objective Tocodynamometry is the most common method of labor evaluation but most clinicians would agree it has limited utility before 26 weeks gestation. The obesity epidemic has further reduced our ability to accurately detect uterine contractions using the tocodynamometer at any gestational age. We sought to design and test a novel contraction monitor that bypasses the maternal abdomen. Methods An optimized version of an intravaginal electrohysterographic ring device was tested in an ovine model. The device and its methodology as well as the tocodynamometer were validated against the current gold standard uterine activity monitor, the intrauterine pressure catheter in 6 sheep at varying gestational ages. Results Both the intravaginal ring device and the tocodynamometer correlated well with IUPC, r = 0.69 and 0.73 respectively (p<0.001). The number of contractions detected by each monitor remained similar even after accounting for confounders. Conclusions These results suggest that uterine activity can be monitored from the vaginal interface in an ovine model and offers an alternative clinical tool for the detection of contractions in situations in which tocodynamometry would be ineffective or intrauterine monitoring inappropriate. PMID:26458732

[Current situation of soil-transmitted nematodiasis monitoring in China and working keys in future].

PubMed

Chen, Ying-dan; Zang, Wei

2015-04-01

Soil-transmitted nematodiasis is widely epidemic in rural areas in China. It was showed that the infection rate of soil-transmitted nematodes was 19.56% while the overall number of persons infected was 129,000,000, which was supported by the results of the National Survey of Current Situation of Major Human Parasitic Diseases in China in 2005 published by former Ministry of Health. Therefore, soil-transmitted nematodiasis was included in the national infectious diseases and pathogenic media monitoring system by Chinese Center for Disease Control and Prevention in 2006, and subsequently 22 monitoring spots were established nationwide. From 2006 to 2013, the human infection rate of intestinal nematodes in national monitoring spots decreased from 20.88% to 3.12%, which showed a declining trend year by year. Meanwhile, the infection rates of Ascaris lumbricoides, Trichuris trichiura, hookworm, Enterobius vermicularis decreased from 10.10%, 5.88%, 8.88%, 10.00% in 2006 to 0.76%, 0.42%, 2.04%, 6.78% in 2013 respectively. In this paper, the current situation of soil-transmitted nematodiasis is overviewed based on a summary of the 8 years' monitoring work, as well as the experiences, challenges and key of monitoring work in the future.

Monitoring the tobacco use epidemic V: The environment: factors that influence tobacco use.

PubMed

Farrelly, Matthew C

2009-01-01

This environment paper (V of V) summarizes important surveillance and evaluation systems that monitor influences on tobacco use such as smoke-free laws and other legislation, excise taxes, mass media, and a broad range of tobacco control activities, discusses their strengths and weaknesses, and makes recommendations for enhancement. We summarize and expand on the recommendations from the Environment Working Group of the National Tobacco Monitoring, Research, and Evaluation Workshop prioritized surveillance needs. This group rank-ordered surveillance needs various environmental influences, considering both the perceived importance of each environmental influence and the adequacy of the current surveillance systems. Based on this ranking and subsequent discussion, the group identified key priorities for enhancement. The group arrived at two key priorities: (1) develop and implement a national system for local tobacco control ordinance surveillance, and (2) develop and implement a comprehensive program monitoring system that is used by all states and supported by all funding agencies. Other environmental influences recommended for priority monitoring include cigarette prices and tobacco countermarketing. Systematic surveillance and monitoring of key program inputs and outputs and environmental influences is central to understand the effectiveness and cost-effectiveness of tobacco control efforts.

Prediction, Assessment of the Rift Valley Fever Activity in East and Southern Africa 2006-2008 and Possible Vector Control Strategies

DTIC Science & Technology

2010-01-01

and Hygiene INTRODUCTION Rift Valley fever ( RVF ) is a mosquito-borne viral disease with pronounced health and economic impacts on domestic...animals and humans in much of sub-Saharan Africa. 1 The eco- nomic loss from RVF in East Africa is estimated to exceed $60 million because of disruption in...morbidity and mortality in humans. The RVF epizootics and epidemics are closely linked to the occurrence of the warm phase of the El Niño/Southern

Ethical issues in human prion diseases.

PubMed

Tabrizi, S J; Elliott, C L; Weissmann, C

2003-01-01

Prion diseases or transmissible spongiform encephalopathies are a group of closely related transmissible neurodegenerative conditions of humans and animals, all of which are incurable. In recent years, they have captured public attention with the emergence of the bovine spongiform encephalopathy (BSE) epidemic in Europe, and more recently with the appearance of variant CJD (vCJD) in humans, a novel form of Creutzfeldt-Jakob disease (CJD) that is linked to dietary exposure to BSE. In this chapter, we outline ethical questions posed by research, diagnostic procedures and therapy in the field of prion diseases.

[New infectious diseases in Finland--caused by climate change?].

PubMed

Vapalahti, Olli; Ruuhela, Reija; Henttonen, Heikki

2012-01-01

Although the appearance and spreading of most new infectious diseases are likely to be due to globalization or socio-economic changes, the occurrence of tick-, insect- and rodent-borne infections is at least partially dependent on climate variability and change. Climate influences the distribution and life cycle of vectors of arthropod-borne viruses as well as viral evolution and efficacy of transmission. The natural circulation of many pathogens and the development of epidemics are dependent on complex ecological factors, such as biodiversity and predator-prey cycles that in turn are indirectly linked to climate.

[Design and implementation of field questionnaire survey system of taeniasis/cysticercosis].

PubMed

Huan-Zhang, Li; Jing-Bo, Xue; Men-Bao, Qian; Xin-Zhong, Zang; Shang, Xia; Qiang, Wang; Ying-Dan, Chen; Shi-Zhu, Li

2018-04-17

A taeniasis/cysticercosis information management system was designed to achieve the dynamic monitoring of the epidemic situation of taeniasis/cysticercosis and improve the intelligence level of disease information management. The system includes three layer structures (application layer, technical core layer, and data storage layer) and designs a datum transmission and remote communication system of traffic information tube in Browser/Server architecture. The system is believed to promote disease datum collection. Additionally, the system may provide the standardized data for convenience of datum analysis.

Genome Sequence of a Monoreassortant H1N1 Swine Influenza Virus Isolated from a Pig in Hungary

PubMed Central

Bányai, Krisztián; Kovács, Eszter; Tóth, Ádám György; Biksi, Imre; Szentpáli-Gavallér, Katalin; Bálint, Ádám; Dencső, László

2012-01-01

The genome of a porcine H1N1 influenza A strain is reported in this study. The strain proved to be a monoreassortant strain with a typical porcine N1 gene on the genetic backbone of the pandemic H1N1 influenza A virus strain. Monitoring of descendants of the pandemic 2009 H1N1 strain is needed because of concerns that more-virulent strains may emerge in forthcoming epidemic seasons. PMID:23118459

Optimizing care for the obese patient in interventional radiology

PubMed Central

Aberle, Dwight; Charles, Hearns; Hodak, Steven; O’Neill, Daniel; Oklu, Rahmi; Deipolyi, Amy R.

2017-01-01

With the rising epidemic of obesity, interventional radiologists are treating increasing numbers of obese patients, as comorbidities associated with obesity preclude more invasive treatments. These patients are at heightened risk of vascular and oncologic disease, both of which often require interventional radiology care. Obese patients pose unique challenges in imaging, technical feasibility, and periprocedural monitoring. This review describes the technical and clinical challenges posed by this population, with proposed methods to mitigate these challenges and optimize care. PMID:28082253

EVALUATION OF AN ENZYME-LINKED IMMUNOSORBENT ASSAY FOR BIOLOGICAL MONITORING OF 3-PHENOXYBENZOIC ACID IN URINE

EPA Science Inventory

Abstract describes the development of an enzyme-linked immunosorbent assay (ELISA) method for monitoring 2,4-dichlorophenoxyacetic acid (2,4-D exposures). The ELISA is compared with a gas chromatograhy/mass spectrometry procedure. ELISA method development steps and comparative ...

Assessment of Overlap of Phylogenetic Transmission Clusters and Communities in Simple Sexual Contact Networks: Applications to HIV-1

PubMed Central

Villandre, Luc; Günthard, Huldrych F.; Kouyos, Roger; Stadler, Tanja

2016-01-01

Background Transmission patterns of sexually-transmitted infections (STIs) could relate to the structure of the underlying sexual contact network, whose features are therefore of interest to clinicians. Conventionally, we represent sexual contacts in a population with a graph, that can reveal the existence of communities. Phylogenetic methods help infer the history of an epidemic and incidentally, may help detecting communities. In particular, phylogenetic analyses of HIV-1 epidemics among men who have sex with men (MSM) have revealed the existence of large transmission clusters, possibly resulting from within-community transmissions. Past studies have explored the association between contact networks and phylogenies, including transmission clusters, producing conflicting conclusions about whether network features significantly affect observed transmission history. As far as we know however, none of them thoroughly investigated the role of communities, defined with respect to the network graph, in the observation of clusters. Methods The present study investigates, through simulations, community detection from phylogenies. We simulate a large number of epidemics over both unweighted and weighted, undirected random interconnected-islands networks, with islands corresponding to communities. We use weighting to modulate distance between islands. We translate each epidemic into a phylogeny, that lets us partition our samples of infected subjects into transmission clusters, based on several common definitions from the literature. We measure similarity between subjects’ island membership indices and transmission cluster membership indices with the adjusted Rand index. Results and Conclusion Analyses reveal modest mean correspondence between communities in graphs and phylogenetic transmission clusters. We conclude that common methods often have limited success in detecting contact network communities from phylogenies. The rarely-fulfilled requirement that network communities correspond to clades in the phylogeny is their main drawback. Understanding the link between transmission clusters and communities in sexual contact networks could help inform policymaking to curb HIV incidence in MSMs. PMID:26863322

Estimating Coextinction Risks from Epidemic Tree Death: Affiliate Lichen Communities among Diseased Host Tree Populations of Fraxinus excelsior

PubMed Central

Jönsson, Mari T.; Thor, Göran

2012-01-01

At least 10% of the world’s tree species are threatened with extinction and pathogens are increasingly implicated in tree threats. Coextinction and threats to affiliates as a consequence of the loss or decline of their host trees is a poorly understood phenomenon. Ash dieback is an emerging infectious disease causing severe dieback of common ash Fraxinus excelsior throughout Europe. We utilized available empirical data on affiliate epiphytic lichen diversity (174 species and 17,800 observations) among 20 ash dieback infected host tree populations of F. excelsior on the island Gotland in the Baltic Sea, Sweden. From this, we used structured scenario projections scaled with empirical data of ash dieback disease to generate probabilistic models for estimating local and regional lichen coextinction risks. Average coextinction probabilities (Ā) were 0.38 (95% CI ±0.09) for lichens occurring on F. excelsior and 0.14 (95% CI ±0.03) when considering lichen persistence on all tree species. Ā was strongly linked to local disease incidence levels and generally increasing with lichen host specificity to F. excelsior and decreasing population size. Coextinctions reduced affiliate community viability, with significant local reductions in species richness and shifts in lichen species composition. Affiliates were projected to become locally extirpated before their hosts, illuminating the need to also consider host tree declines. Traditionally managed open wooded meadows had the highest incidence of ash dieback disease and significantly higher proportions of affiliate species projected to go extinct, compared with unmanaged closed forests and semi-open grazed sites. Most cothreatened species were not previously red-listed, which suggest that tree epidemics cause many unforeseen threats to species. Our analysis shows that epidemic tree deaths represent an insidious, mostly overlooked, threat to sessile affiliate communities in forested environments. Current conservation and management strategies must account for secondary extinctions associated with epidemic tree death. PMID:23049840

Effect of the interconnected network structure on the epidemic threshold.

PubMed

Wang, Huijuan; Li, Qian; D'Agostino, Gregorio; Havlin, Shlomo; Stanley, H Eugene; Van Mieghem, Piet

2013-08-01

Most real-world networks are not isolated. In order to function fully, they are interconnected with other networks, and this interconnection influences their dynamic processes. For example, when the spread of a disease involves two species, the dynamics of the spread within each species (the contact network) differs from that of the spread between the two species (the interconnected network). We model two generic interconnected networks using two adjacency matrices, A and B, in which A is a 2N×2N matrix that depicts the connectivity within each of two networks of size N, and B a 2N×2N matrix that depicts the interconnections between the two. Using an N-intertwined mean-field approximation, we determine that a critical susceptible-infected-susceptible (SIS) epidemic threshold in two interconnected networks is 1/λ(1)(A+αB), where the infection rate is β within each of the two individual networks and αβ in the interconnected links between the two networks and λ(1)(A+αB) is the largest eigenvalue of the matrix A+αB. In order to determine how the epidemic threshold is dependent upon the structure of interconnected networks, we analytically derive λ(1)(A+αB) using a perturbation approximation for small and large α, the lower and upper bound for any α as a function of the adjacency matrix of the two individual networks, and the interconnections between the two and their largest eigenvalues and eigenvectors. We verify these approximation and boundary values for λ(1)(A+αB) using numerical simulations, and determine how component network features affect λ(1)(A+αB). We note that, given two isolated networks G(1) and G(2) with principal eigenvectors x and y, respectively, λ(1)(A+αB) tends to be higher when nodes i and j with a higher eigenvector component product x(i)y(j) are interconnected. This finding suggests essential insights into ways of designing interconnected networks to be robust against epidemics.

Investigating the association between HIV/AIDS and recent fertility patterns in Kenya.

PubMed

Magadi, Monica Akinyi; Agwanda, Alfred O

2010-07-01

Findings from previous studies linking the HIV/AIDS epidemic and fertility of populations have remained inconclusive. In sub-Saharan Africa, demographic patterns point to the epidemic resulting in fertility reduction. However, evidence from the 2003 Kenya Demographic and Health Survey (KDHS) has revealed interesting patterns, with regions most adversely affected with HIV/AIDS showing the clearest reversal trend in fertility decline. While there is suggestive evidence that fertility behaviour in some parts of sub-Saharan Africa has changed in relation to the HIV/AIDS epidemic, more rigorous empirical analysis is necessary to better understand this relationship. In this paper, we examine individual and contextual community HIV/AIDS factors associated with fertility patterns in Kenya, paying particular attention to possible mechanisms of the association. Multilevel models are applied to the 2003 KDHS, introducing various proximate fertility determinants in successive stages, to explore possible mechanisms through which HIV/AIDS may be associated with fertility. The results corroborate findings from earlier studies of the fertility inhibiting effect of HIV among infected women. HIV-infected women have 40 percent lower odds of having had a recent birth than their uninfected counterparts of similar background characteristics. Further analysis suggests an association between HIV/AIDS and fertility that exists through proximate fertility determinants relating to sexual exposure, breastfeeding duration, and foetal loss. While HIV/AIDS may have contributed to reduced fertility, mainly through reduced sexual exposure, there is evidence that it has contributed to increased fertility, through reduced breastfeeding and increased desire for more children resulting from increased infant/child mortality (i.e. a replacement phenomenon). In communities at advanced stages of the HIV/AIDS epidemic, it is possible that infant/child mortality has reached appreciably high levels where the impact of replacement and reduced breastfeeding duration is substantial enough to result in a reversal of fertility decline. This provides a plausible explanation for the patterns observed in regions with particularly high HIV prevalence in Kenya. Crown Copyright 2010. Published by Elsevier Ltd. All rights reserved.

Effect of the interconnected network structure on the epidemic threshold

NASA Astrophysics Data System (ADS)

Wang, Huijuan; Li, Qian; D'Agostino, Gregorio; Havlin, Shlomo; Stanley, H. Eugene; Van Mieghem, Piet

2013-08-01

Most real-world networks are not isolated. In order to function fully, they are interconnected with other networks, and this interconnection influences their dynamic processes. For example, when the spread of a disease involves two species, the dynamics of the spread within each species (the contact network) differs from that of the spread between the two species (the interconnected network). We model two generic interconnected networks using two adjacency matrices, A and B, in which A is a 2N×2N matrix that depicts the connectivity within each of two networks of size N, and B a 2N×2N matrix that depicts the interconnections between the two. Using an N-intertwined mean-field approximation, we determine that a critical susceptible-infected-susceptible (SIS) epidemic threshold in two interconnected networks is 1/λ1(A+αB), where the infection rate is β within each of the two individual networks and αβ in the interconnected links between the two networks and λ1(A+αB) is the largest eigenvalue of the matrix A+αB. In order to determine how the epidemic threshold is dependent upon the structure of interconnected networks, we analytically derive λ1(A+αB) using a perturbation approximation for small and large α, the lower and upper bound for any α as a function of the adjacency matrix of the two individual networks, and the interconnections between the two and their largest eigenvalues and eigenvectors. We verify these approximation and boundary values for λ1(A+αB) using numerical simulations, and determine how component network features affect λ1(A+αB). We note that, given two isolated networks G1 and G2 with principal eigenvectors x and y, respectively, λ1(A+αB) tends to be higher when nodes i and j with a higher eigenvector component product xiyj are interconnected. This finding suggests essential insights into ways of designing interconnected networks to be robust against epidemics.

The role of socioeconomic status in longitudinal trends of cholera in Matlab, Bangladesh, 1993-2007.

PubMed

Root, Elisabeth Dowling; Rodd, Joshua; Yunus, Mohammad; Emch, Michael

2013-01-01

There has been little evidence of a decline in the global burden of cholera in recent years as the number of cholera cases reported to WHO continues to rise. Cholera remains a global threat to public health and a key indicator of lack of socioeconomic development. Overall socioeconomic development is the ultimate solution for control of cholera as evidenced in developed countries. However, most research has focused on cross-county comparisons so that the role of individual- or small area-level socioeconomic status (SES) in cholera dynamics has not been carefully studied. Reported cases of cholera in Matlab, Bangladesh have fluctuated greatly over time and epidemic outbreaks of cholera continue, most recently with the introduction of a new serotype into the region. The wealth of longitudinal data on the population of Matlab provides a unique opportunity to explore the impact of socioeconomic status and other demographic characteristics on the long-term temporal dynamics of cholera in the region. In this population-based study we examine which factors impact the initial number of cholera cases in a bari at the beginning of the 0139 epidemic and the factors impacting the number of cases over time. Cholera data were derived from the ICDDR,B health records and linked to socioeconomic and geographic data collected as part of the Matlab Health and Demographic Surveillance System. Longitudinal zero-inflated Poisson (ZIP) multilevel regression models are used to examine the impact of environmental and socio-demographic factors on cholera counts across baris. Results indicate that baris with a high socioeconomic status had lower initial rates of cholera at the beginning of the 0139 epidemic (γ(01) = -0.147, p = 0.041) and a higher probability of reporting no cholera cases (α(01) = 0.156, p = 0.061). Populations in baris characterized by low SES are more likely to experience higher cholera morbidity at the beginning of an epidemic than populations in high SES baris.

Transmission of drug-susceptible and drug-resistant tuberculosis and the critical importance of airborne infection control in the era of HIV infection and highly active antiretroviral therapy rollouts.

PubMed

Shenoi, Sheela V; Escombe, A Roderick; Friedland, Gerald

2010-05-15

Comprehensive and successful tuberculosis (TB) care and treatment must incorporate effective airborne infection-control strategies. This is particularly and critically important for health care workers and all persons with or at risk of human immunodeficiency virus (HIV) infection. Past and current outbreaks and epidemics of drug-susceptible, multidrug-resistant, and extensively drug-resistant TB have been fueled by HIV infection, with high rates of morbidity and mortality and linked to the absence or limited application of airborne infection-control strategies in both resource-rich and resource-limited settings. Airborne infection-control strategies are available--grouped into administrative, environmental, and personal protection categories--and have been shown to be associated with decreases in nosocomial transmission of TB; their efficacy has not been fully demonstrated, and their implementation is extremely limited, particularly in resource-limited settings. New research and resources are required to fully realize the potential benefits of infection control in the era of TB and HIV epidemics.

Quarantine-generated phase transition in epidemic spreading.

PubMed

Lagorio, C; Dickison, M; Vazquez, F; Braunstein, L A; Macri, P A; Migueles, M V; Havlin, S; Stanley, H E

2011-02-01

We study the critical effect of quarantine on the propagation of epidemics on an adaptive network of social contacts. For this purpose, we analyze the susceptible-infected-recovered model in the presence of quarantine, where susceptible individuals protect themselves by disconnecting their links to infected neighbors with probability w and reconnecting them to other susceptible individuals chosen at random. Starting from a single infected individual, we show by an analytical approach and simulations that there is a phase transition at a critical rewiring (quarantine) threshold w(c) separating a phase (w

Diet modification for treatment and prevention of obesity.

PubMed

Ness-Abramof, Rosane; Apovian, Caroline M

2006-02-01

The obesity epidemic is best explained by global lifestyle alterations favoring weight gain in a susceptible population. The consumption of calorically dense foods, increased portion sizes, and a decrease in workplace and leisure physical activity most likely accounts for the increase in overweight and obesity worldwide. The cornerstone of overweight and obesity therapy is dietary intervention, but unfortunately most patients eventually regain the weight lost through diet alone. The search for a macronutrient composition that may enhance and help maintain weight loss has brought an abundance of fad diets into the lay literature. According to the available data, weight loss and maintenance of weight loss are dictated by total caloric intake, and not by macronutrient composition. There is epidemiologic data linking sugar-sweetened beverages to adult and childhood obesity, and an inverse relationship between dairy intake and overweight and obesity has also been observed. More research is needed to elucidate mechanisms explaining these relationships. Further research should focus on permanent lifestyle changes that may reverse this growing epidemic. This review will focus on current practices for the dietary management of obesity and to promote weight maintenance.

Colonialism, Biko and AIDS: reflections on the principle of beneficence in South African medical ethics.

PubMed

Braude, Hillel David

2009-06-01

This paper examines the principle of beneficence in the light of moral and epistemological concerns that have crystallized in the South African context around clinical care. Three examples from the South African experience affecting the development of bioethics are examined: medical colonialism, the death in detention of Steve Biko, and the HIV/AIDS epidemic. Michael Gelfand's book [(1948). The sick African: a clinical study. Cape Town: Stewart Printing Company.] on African medical conditions captures the ambiguous nature of colonial medicine that linked genuine medical treatment with the civilizing mission. Biko's death was a key historical event that deeply implicated the medical profession under apartheid. The present HIV/AIDS epidemic presents the gravest social and political crisis for South African society. All three experiences influence the meaning and relevance of beneficence as a bioethics principle in the South African context. This paper argues for a South African bioethics informed by a critical humanism that takes account of the colonial past, and that does not model itself on an "original wound" or negation, but on positive care-giving practices.

A modified anthrax toxin-based enzyme-linked immunospot assay reveals robust T cell responses in symptomatic and asymptomatic Ebola virus exposed individuals.

PubMed

Herrera, Bobby Brooke; Hamel, Donald J; Oshun, Philip; Akinsola, Rolake; Akanmu, Alani S; Chang, Charlotte A; Eromon, Philomena; Folarin, Onikepe; Adeyemi, Kayode T; Happi, Christian T; Lu, Yichen; Ogunsola, Folasade; Kanki, Phyllis J

2018-05-01

Ebola virus (EBOV) caused more than 11,000 deaths during the 2013-2016 epidemic in West Africa without approved vaccines or immunotherapeutics. Despite its high lethality in some individuals, EBOV infection can produce little to no symptoms in others. A better understanding of the immune responses in individuals who experienced minimally symptomatic and asymptomatic infection could aid the development of more effective vaccines and antivirals against EBOV and related filoviruses. Between August and November 2017, blood samples were collected from 19 study participants in Lagos, Nigeria, including 3 Ebola virus disease (EVD) survivors, 10 individuals with documented close contact with symptomatic EVD patients, and 6 control healthcare workers for a cross-sectional serosurvey and T cell analysis. The Lagos samples, as well as archived serum collected from healthy individuals living in surrounding areas of the 1976 Democratic Republic of Congo (DRC) epidemic, were tested for EBOV IgG using commercial enzyme-linked immunosorbent assays (ELISAs) and Western blots. We detected antibodies in 3 out of 3 Lagos survivors and identified 2 seropositive individuals not known to have ever been infected. Of the DRC samples tested, we detected antibodies in 9 out of 71 (12.7%). To characterize the T cell responses in the Lagos samples, we developed an anthrax toxin-based enzyme-linked immunospot (ELISPOT) assay. The seropositive asymptomatic individuals had T cell responses against EBOV nucleoprotein, matrix protein, and glycoprotein 1 that were stronger in magnitude compared to the survivors. Our data provide further evidence of EBOV exposure in individuals without EVD-like illness and, for the first time, demonstrate that these individuals have T cell responses that are stronger in magnitude compared to severe cases. These findings suggest that T cell immunity may protect against severe EVD, which has important implications for vaccine development.

Measure of robustness for complex networks

NASA Astrophysics Data System (ADS)

Youssef, Mina Nabil

Critical infrastructures are repeatedly attacked by external triggers causing tremendous amount of damages. Any infrastructure can be studied using the powerful theory of complex networks. A complex network is composed of extremely large number of different elements that exchange commodities providing significant services. The main functions of complex networks can be damaged by different types of attacks and failures that degrade the network performance. These attacks and failures are considered as disturbing dynamics, such as the spread of viruses in computer networks, the spread of epidemics in social networks, and the cascading failures in power grids. Depending on the network structure and the attack strength, every network differently suffers damages and performance degradation. Hence, quantifying the robustness of complex networks becomes an essential task. In this dissertation, new metrics are introduced to measure the robustness of technological and social networks with respect to the spread of epidemics, and the robustness of power grids with respect to cascading failures. First, we introduce a new metric called the Viral Conductance (VCSIS ) to assess the robustness of networks with respect to the spread of epidemics that are modeled through the susceptible/infected/susceptible (SIS) epidemic approach. In contrast to assessing the robustness of networks based on a classical metric, the epidemic threshold, the new metric integrates the fraction of infected nodes at steady state for all possible effective infection strengths. Through examples, VCSIS provides more insights about the robustness of networks than the epidemic threshold. In addition, both the paradoxical robustness of Barabasi-Albert preferential attachment networks and the effect of the topology on the steady state infection are studied, to show the importance of quantifying the robustness of networks. Second, a new metric VCSIR is introduced to assess the robustness of networks with respect to the spread of susceptible/infected/recovered (SIR) epidemics. To compute VCSIR, we propose a novel individual-based approach to model the spread of SIR epidemics in networks, which captures the infection size for a given effective infection rate. Thus, VCSIR quantitatively integrates the infection strength with the corresponding infection size. To optimize the VCSIR metric, a new mitigation strategy is proposed, based on a temporary reduction of contacts in social networks. The social contact network is modeled as a weighted graph that describes the frequency of contacts among the individuals. Thus, we consider the spread of an epidemic as a dynamical system, and the total number of infection cases as the state of the system, while the weight reduction in the social network is the controller variable leading to slow/reduce the spread of epidemics. Using optimal control theory, the obtained solution represents an optimal adaptive weighted network defined over a finite time interval. Moreover, given the high complexity of the optimization problem, we propose two heuristics to find the near optimal solutions by reducing the contacts among the individuals in a decentralized way. Finally, the cascading failures that can take place in power grids and have recently caused several blackouts are studied. We propose a new metric to assess the robustness of the power grid with respect to the cascading failures. The power grid topology is modeled as a network, which consists of nodes and links representing power substations and transmission lines, respectively. We also propose an optimal islanding strategy to protect the power grid when a cascading failure event takes place in the grid. The robustness metrics are numerically evaluated using real and synthetic networks to quantify their robustness with respect to disturbing dynamics. We show that the proposed metrics outperform the classical metrics in quantifying the robustness of networks and the efficiency of the mitigation strategies. In summary, our work advances the network science field in assessing the robustness of complex networks with respect to various disturbing dynamics.

Geographic variation in sexual behavior can explain geospatial heterogeneity in the severity of the HIV epidemic in Malawi.

PubMed

Palk, Laurence; Blower, Sally

2018-02-09

In sub-Saharan Africa, where ~ 25 million individuals are infected with HIV and transmission is predominantly heterosexual, there is substantial geographic variation in the severity of epidemics. This variation has yet to be explained. Here, we propose that it is due to geographic variation in the size of the high-risk group (HRG): the group with a high number of sex partners. We test our hypothesis by conducting a geospatial analysis of data from Malawi, where ~ 13% of women and ~ 8% of men are infected with HIV. We used georeferenced HIV testing and behavioral data from ~ 14,000 participants of a nationally representative population-level survey: the 2010 Malawi Demographic and Health Survey (MDHS). We constructed gender-stratified epidemic surface prevalence (ESP) maps by spatially smoothing and interpolating the HIV testing data. We used the behavioral data to construct gender-stratified risk maps that reveal geographic variation in the size of the HRG. We tested our hypothesis by fitting gender-stratified spatial error regression (SER) models to the MDHS data. The ESP maps show considerable geographic variation in prevalence: 1-29% (women), 1-20% (men). Risk maps reveal substantial geographic variation in the size of the HRG: 0-40% (women), 16-58% (men). Prevalence and the size of the HRG are highest in urban centers. However, the majority of HIV-infected individuals (~75% of women, ~ 80% of men) live in rural areas, as does most of the HRG (~ 80% of women, ~ 85% of men). We identify a significant (P < 0.001) geospatial relationship linking the size of the HRG with prevalence: the greater the size, the higher the prevalence. SER models show HIV prevalence in women is expected to exceed the national average in districts where > 20% of women are in the HRG. Most importantly, the SER models show that geographic variation in the size of the HRG can explain a substantial proportion (73% for women, 67% for men) of the geographic variation in epidemic severity. Taken together, our results provide substantial support for our hypothesis. They provide a potential mechanistic explanation for the geographic variation in the severity of the HIV epidemic in Malawi and, potentially, in other countries in sub-Saharan Africa.

Trends in parent-child correlations of childhood body mass index during the development of the obesity epidemic.

PubMed

Ajslev, Teresa A; Ängquist, Lars; Silventoinen, Karri; Baker, Jennifer L; Sørensen, Thorkild I A

2014-01-01

The intergenerational resemblance in body mass index may have increased during the development of the obesity epidemic due to changes in environment and/or expression of genetic predisposition. This study investigates trends in intergenerational correlations of childhood body mass index (BMI; kg/m2) during the emergence of the obesity epidemic. The study population was derived from the Copenhagen School Health Records Register, which includes height and weight measurements since birth year 1930. Mothers and fathers with BMIs available at ages 7 (n = 25,923 and n = 20,972) or 13 years (n = 26,750 and n = 21,397), respectively, were linked through the civil registration system introduced in 1968 to their children with BMIs available at age 7 years. Age- and sex-specific BMI z-scores were calculated. Correlations were estimated across eight intervals of child birth years (1952-1989) separately by sex. Trends in these correlations were examined. Whereas the mother-child correlations reflected the biological relationship, a likely decline in the assignment of non-biological fathers through the registration system across time must be considered when interpreting the father-child correlations. The BMI correlations between mothers and sons ranged from 0.29-0.36 and they decreased marginally, albeit significantly across time at ages 7-7 years (-0.002/year, p = 0.006), whereas those at 13-7 years remained stable (<0.0004/year, p = 0.96). Mother-daughter correlations ranged from 0.30-0.34, and they were stable at ages 7-7 years (0.0001/year, p = 0.84) and at 13-7 years (0.0004/year, p = 0.56). In contrast, father-son correlations increased significantly during this period, both at ages 7-7 (0.002/year, p = 0.007) and at ages 13-7 years (0.003/year, p<0.001), whereas the increase in father-daughter correlations were insignificant both at ages 7-7 (0.001/year, p = 0.37) and at ages 13-7 years (0.001/year, p = 0.18). During the obesity epidemics development, the intergenerational resemblance with mothers remained stable, whereas the father-child BMI resemblance increased, possibly reflecting changes in family relationships, and unlikely to have influenced the epidemic.

Priority actions for addressing the obesity epidemic in England.

PubMed

Watson, Fiona; Taylor, Anna; Rayner, Mike; Lobstein, Tim; Hinks, Robin

2018-04-01

To prioritise policy actions for government to improve the food environment and contribute to reduced obesity and related diseases. Cross-sectional study applying the Food Environment Policy Index (Food EPI) in two stages. First, the evidence on all relevant policies was compiled, through an Internet search of government documents, and reviewed for accuracy and completeness by government officials. Second, independent experts were brought together to identify critical gaps and prioritise actions to fill those gaps, through a two-stage rating process. England. A total of seventy-three independent experts from forty-one organisations were involved in the exercise. The top priority policy actions for government identified were: (i) control the advertising of unhealthy foods to children; (ii) implement the levy on sugary drinks; (iii) reduce the sugar, fat and salt content in processed foods (leading to an energy reduction); (iv) monitor school and nursery food standards; (v) prioritise health and the environment in the 25-year Food and Farming Plan; (vi) adopt a national food action plan; (vii) monitor the food environment; (viii) apply buying standards to all public institutions; (ix) strengthen planning laws to discourage less healthy food offers; and (x) evaluate food-related programmes and policies. Applying the Food EPI resulted in agreement on the ten priority actions required to improve the food environment. The Food EPI has proved to be a useful tool in developing consensus for action to address the obesity epidemic among a broad group of experts in a complex legislative environment.

Insecticide susceptibility of Aedes aegypti populations from Senegal and Cape Verde Archipelago.

PubMed

Dia, Ibrahima; Diagne, Cheikh Tidiane; Ba, Yamar; Diallo, Diawo; Konate, Lassana; Diallo, Mawlouth

2012-10-22

Two concomitant dengue 3 (DEN-3) epidemics occurred in Cape Verde Archipelago and Senegal between September and October 2009. Aedes aegypti was identified as the vector of these epidemics as several DEN-3 virus strains were isolated from this species in both countries. The susceptibility to pyrethroids, organochlorine, organophosphates and carbamate was investigated in two field strains of Aedes aegypti from both countries using WHO diagnostic bioassay kits in order to monitor their the current status of insecticide susceptibility. The two tested strains were highly resistant to DDT. The Cape Verde strain was found to be susceptible to all others tested insecticides except for propoxur 0.1%, which needs further investigation. The Dakar strain was susceptible to fenitrothion 1% and permethrin 0.75%, but displayed reduced susceptibility to deltamethrin, lambda-cyhalothrin and propoxur. As base-line results, our observations stress a careful management of insecticide use for the control of Ae. aegypti. Indeed, they indicate that DDT is no longer efficient for the control of Ae. aegypti populations in Cape Verde and Dakar and further suggest a thorough follow-up of propoxur susceptibility status in both sites and that of deltamethrin and lambda-cyhalothrin in Ae. aegypti populations in Dakar. Thus, regular monitoring of susceptibility is greatly needed as well as the knowing if this observed resistance/susceptibility is focal or not and for observed resistance, the use of biochemical methods is needed with detailed comparison of resistance levels over a large geographic area. Aedes aegypti, Insecticides, Susceptibility, Cape Verde, Senegal.

Inter-satellite links for satellite autonomous integrity monitoring

NASA Astrophysics Data System (ADS)

Rodríguez-Pérez, Irma; García-Serrano, Cristina; Catalán Catalán, Carlos; García, Alvaro Mozo; Tavella, Patrizia; Galleani, Lorenzo; Amarillo, Francisco

2011-01-01

A new integrity monitoring mechanisms to be implemented on-board on a GNSS taking advantage of inter-satellite links has been introduced. This is based on accurate range and Doppler measurements not affected neither by atmospheric delays nor ground local degradation (multipath and interference). By a linear combination of the Inter-Satellite Links Observables, appropriate observables for both satellite orbits and clock monitoring are obtained and by the proposed algorithms it is possible to reduce the time-to-alarm and the probability of undetected satellite anomalies.Several test cases have been run to assess the performances of the new orbit and clock monitoring algorithms in front of a complete scenario (satellite-to-satellite and satellite-to-ground links) and in a satellite-only scenario. The results of this experimentation campaign demonstrate that the Orbit Monitoring Algorithm is able to detect orbital feared events when the position error at the worst user location is still under acceptable limits. For instance, an unplanned manoeuvre in the along-track direction is detected (with a probability of false alarm equals to 5 × 10-9) when the position error at the worst user location is 18 cm. The experimentation also reveals that the clock monitoring algorithm is able to detect phase jumps, frequency jumps and instability degradation on the clocks but the latency of detection as well as the detection performances strongly depends on the noise added by the clock measurement system.

Population-Level Immune-Mediated Adaptation in HIV-1 Polymerase during the North American Epidemic

PubMed Central

Kinloch, Natalie N.; MacMillan, Daniel R.; Le, Anh Q.; Cotton, Laura A.; Bangsberg, David R.; Buchbinder, Susan; Carrington, Mary; Fuchs, Jonathan; Harrigan, P. Richard; Koblin, Beryl; Kushel, Margot; Markowitz, Martin; Mayer, Kenneth; Milloy, M. J.; Schechter, Martin T.; Wagner, Theresa; Walker, Bruce D.; Carlson, Jonathan M.; Poon, Art F. Y.

2015-01-01

ABSTRACT Human leukocyte antigen (HLA) class I-associated polymorphisms in HIV-1 that persist upon transmission to HLA-mismatched hosts may spread in the population as the epidemic progresses. Transmission of HIV-1 sequences containing such adaptations may undermine cellular immune responses to the incoming virus in future hosts. Building upon previous work, we investigated the extent of HLA-associated polymorphism accumulation in HIV-1 polymerase (Pol) through comparative analysis of linked HIV-1/HLA class I genotypes sampled during historic (1979 to 1989; n = 338) and modern (2001 to 2011; n = 278) eras from across North America (Vancouver, BC, Canada; Boston, MA; New York, NY; and San Francisco, CA). Phylogenies inferred from historic and modern HIV-1 Pol sequences were star-like in shape, with an inferred most recent common ancestor (epidemic founder virus) sequence nearly identical to the modern North American subtype B consensus sequence. Nevertheless, modern HIV-1 Pol sequences exhibited roughly 2-fold-higher patristic (tip-to-tip) genetic distances than historic sequences, with HLA pressures likely driving ongoing diversification. Moreover, the frequencies of published HLA-associated polymorphisms in individuals lacking the selecting HLA class I allele was on average ∼2.5-fold higher in the modern than in the historic era, supporting their spread in circulation, though some remained stable in frequency during this time. Notably, polymorphisms restricted by protective HLA alleles appear to be spreading to a greater relative extent than others, though these increases are generally of modest absolute magnitude. However, despite evidence of polymorphism spread, North American hosts generally remain at relatively low risk of acquiring an HIV-1 polymerase sequence substantially preadapted to their HLA profiles, even in the present era. IMPORTANCE HLA class I-restricted cytotoxic T-lymphocyte (CTL) escape mutations in HIV-1 that persist upon transmission may accumulate in circulation over time, potentially undermining host antiviral immunity to the transmitted viral strain. We studied >600 experimentally collected HIV-1 polymerase sequences linked to host HLA information dating back to 1979, along with phylogenetically reconstructed HIV-1 sequences dating back to the virus' introduction into North America. Overall, our results support the gradual spread of many—though not all—HIV-1 polymerase immune escape mutations in circulation over time. This is consistent with recent observations from other global regions, though the extent of polymorphism accumulation in North America appears to be lower than in populations with high seroprevalence, older epidemics, and/or limited HLA diversity. Importantly, the risk of acquiring an HIV-1 polymerase sequence at transmission that is substantially preadapted to one's HLA profile remains relatively low in North America, even in the present era. PMID:26559841

The Topological Weighted Centroid (TWC): A topological approach to the time-space structure of epidemic and pseudo-epidemic processes

NASA Astrophysics Data System (ADS)

Buscema, Massimo; Massini, Giulia; Sacco, Pier Luigi

2018-02-01

This paper offers the first systematic presentation of the topological approach to the analysis of epidemic and pseudo-epidemic spatial processes. We introduce the basic concepts and proofs, at test the approach on a diverse collection of case studies of historically documented epidemic and pseudo-epidemic processes. The approach is found to consistently provide reliable estimates of the structural features of epidemic processes, and to provide useful analytical insights and interpretations of fragmentary pseudo-epidemic processes. Although this analysis has to be regarded as preliminary, we find that the approach's basic tenets are strongly corroborated by this first test and warrant future research in this vein.

"They accept me, because I was one of them": formative qualitative research supporting the feasibility of peer-led outreach for people who use drugs in Dakar, Senegal.

PubMed

Stengel, Camille May; Mane, Famara; Guise, Andrew; Pouye, Magath; Sigrist, Monika; Rhodes, Tim

2018-02-27

Peer outreach harm reduction initiatives are being developed with and for people who use drugs in Dakar, Senegal. This is in response to growing injecting drug use across the West Africa region and linked emerging epidemics of HIV and hepatitis C. We undertook formative qualitative research to explore the feasibility and potential of peer outreach in this context and in particular how outreach could be linked to fostering community-level processes of change. We undertook a total of 44 semi-structured qualitative interviews. Thirty-four interviews were with people who used drugs (comprised of 25 participants who had injected at least once in their life) and included 11 peer educators who delivered "awareness-raising" harm reduction activities. We also interviewed 10 service providers involved in the planning and monitoring of peer outreach initiatives. We used thematic analysis to identify key characteristics of how peer-led outreach is being delivered, beneficiary need, and the nature of the social networks in which the awareness-raising activities operate. Through interviews with peer educators, people who use drugs, and service providers, four main overlapping themes are identified as follows: peer educators as a bridge to responsibilization through awareness-raising activities, awareness-raising activities as an enactment of recovery, awareness raising through social network diffusion, and the contexts and constraints of peer outreach engagement through awareness-raising activities. The study results suggest that peer education is on a trajectory to develop into a central role for harm reduction interventions in Dakar, Senegal. This research shows how peer education is bound in processes of responsibilization and self-change, which link to varying possibilities for risk reduction or recovery. For peer education to achieve a range of significant goals, broader structural and system changes should be implemented in the region. We caution that without such changes, awareness-raising activities and the role of peer educators may instead become part of state- and agency-sponsored processes of seeking to responsibilize individuals for health and harm reduction.

Focus expansion and stability of the spread parameter estimate of the power law model for dispersal gradients

PubMed Central

Gent, David H.; Mehra, Lucky K.; Christie, David; Magarey, Roger

2017-01-01

Empirical and mechanistic modeling indicate that pathogens transmitted via aerially dispersed inoculum follow a power law, resulting in dispersive epidemic waves. The spread parameter (b) of the power law model, which is an indicator of the distance of the epidemic wave front from an initial focus per unit time, has been found to be approximately 2 for several animal and plant diseases over a wide range of spatial scales under conditions favorable for disease spread. Although disease spread and epidemic expansion can be influenced by several factors, the stability of the parameter b over multiple epidemic years has not been determined. Additionally, the size of the initial epidemic area is expected to be strongly related to the final epidemic extent for epidemics, but the stability of this relationship is also not well established. Here, empirical data of cucurbit downy mildew epidemics collected from 2008 to 2014 were analyzed using a spatio-temporal model of disease spread that incorporates logistic growth in time with a power law function for dispersal. Final epidemic extent ranged from 4.16 ×108 km2 in 2012 to 6.44 ×108 km2 in 2009. Current epidemic extent became significantly associated (P < 0.0332; 0.56 < R2 < 0.99) with final epidemic area beginning near the end of April, with the association increasing monotonically to 1.0 by the end of the epidemic season in July. The position of the epidemic wave-front became exponentially more distant with time, and epidemic velocity increased linearly with distance. Slopes from the temporal and spatial regression models varied with about a 2.5-fold range across epidemic years. Estimates of b varied substantially ranging from 1.51 to 4.16 across epidemic years. We observed a significant b ×time (or distance) interaction (P < 0.05) for epidemic years where data were well described by the power law model. These results suggest that the spread parameter b may not be stable over multiple epidemic years. However, b ≈ 2 may be considered the lower limit of the distance traveled by epidemic wave-fronts for aerially transmitted pathogens that follow a power law dispersal function. PMID:28649473

Fast tracking the vaccine licensure process to control an epidemic of serogroup B meningococcal disease in New Zealand.

PubMed

Lennon, Diana; Jackson, Catherine; Wong, Sharon; Horsfall, Maraekura; Stewart, Joanna; Reid, Stewart

2009-08-15

Epidemics of serogroup B meningococcal disease are rare. Strain-specific outer membrane vesicle vaccines, which are not marketed, are the only current tool for control. A correlate of protection is ill defined, but published data suggest that measured serum bactericidal antibody levels parallel efficacy. Even infants can mount a strain-specific antibody response to a strain-specific vaccine. New Zealand's epidemic (1991-2007; peak rate [in 2001], 17.4 cases per 100,000 persons) was dominated by a single strain. After a 5-year search (1996-2001) for a manufacturer for a strain-specific outer membrane vesicle vaccine, a fast-tracked research program (2002-2004) determined the safety and immunogenicity of vaccine in infants (2 age groups: 6-10 weeks and 6-8 months), children (age, 16-24 months), and school-aged children (age, 8-12 years) after an adult trial. The vaccine was reactogenic, compared with control vaccines (meningococcal C conjugate and routine infant vaccines), but retention was high. Three vaccine doses produced antibody levels (measured by serum bactericidal assay) that were considered to be adequate for public health intervention. However, in young infants, a fourth dose was required to achieve levels equivalent to those achieved by other age groups. Provisional licensure by New Zealand's MedSafe was based on serological criteria strengthened by bridged safety data from studies of the parent outer membrane vesicle vaccine, independent assessment of manufacturing quality, and a clear plan for safety monitoring and effectiveness evaluation after licensure.

Evaluation of the indirect fluorescent antibody test as a diagnostic tool for East Coast fever in eastern Zambia.

PubMed

Billiouw, M; Brandt, J; Vercruysse, J; Speybroeck, N; Marcotty, T; Mulumba, M; Berkvens, D

2005-02-28

Serological surveys using the schizont indirect fluorescence antibody test (IFAt) are routinely carried out to monitor the Theileria parva infection prevalence. The present study evaluates the diagnostic accuracy of the IFAt in eastern Zambia, where the transmission of T. parva is highly seasonal. The data set resulted from a sentinel herd (n = 105 animals) study carried out between 1995 and 2000 and was split into an epidemic period, during which the majority of the cattle became infected, and an endemic period with seasonal disease incidence in calves. In the epidemic period the T. parva seroprevalence followed closely the build up of the herd immunity. In the endemic period the seroprevalence fluctuates considerably although most of the animals had been infected. Overall, the diagnostic sensitivity of the IFA test was 55% at cut-off titre 1:40 and 28% at cut-off 1:160. The specificity of the test was 86 and 95%, respectively. A logistic regression model demonstrates that the sensitivity is significantly lower when the T. parva transmission is low (p < 0.01). The analysis of receiver operator characteristic curves classifies the test as moderately accurate (area under the curve, AUC = 0.79) during the epidemic period and less accurate in the endemic period (AUC = 0.63). Neonatal serology surveys yield a better estimate of the infection prevalence. The sensitivity of the neonatal test was 73% at cut-off titre 1:40 and 24% at cut-off 1:160.

Paradox of vaccination: is vaccination really effective against avian flu epidemics?

PubMed

Iwami, Shingo; Suzuki, Takafumi; Takeuchi, Yasuhiro

2009-01-01

Although vaccination can be a useful tool for control of avian influenza epidemics, it might engender emergence of a vaccine-resistant strain. Field and experimental studies show that some avian influenza strains acquire resistance ability against vaccination. We investigated, in the context of the emergence of a vaccine-resistant strain, whether a vaccination program can prevent the spread of infectious disease. We also investigated how losses from immunization by vaccination imposed by the resistant strain affect the spread of the disease. We designed and analyzed a deterministic compartment model illustrating transmission of vaccine-sensitive and vaccine-resistant strains during a vaccination program. We investigated how the loss of protection effectiveness impacts the program. Results show that a vaccination to prevent the spread of disease can instead spread the disease when the resistant strain is less virulent than the sensitive strain. If the loss is high, the program does not prevent the spread of the resistant strain despite a large prevalence rate of the program. The epidemic's final size can be larger than that before the vaccination program. We propose how to use poor vaccines, which have a large loss, to maximize program effects and describe various program risks, which can be estimated using available epidemiological data. We presented clear and simple concepts to elucidate vaccination program guidelines to avoid negative program effects. Using our theory, monitoring the virulence of the resistant strain and investigating the loss caused by the resistant strain better development of vaccination strategies is possible.

Evolution of Monitoring and Evaluation of AIDS Response in Ukraine: Laying the Groundwork for Evidence-Based Health Care.

PubMed

Dumchev, Kostyantyn; Varetska, Olga; Kuzin, Ihor

2017-07-01

Once facing the most severe HIV epidemic in Eastern Europe, Ukraine has built an elaborate Monitoring and Evaluation (M&E) system to track the response to AIDS. This system was developed using recommendations and input from multiple international expert organizations and donors and, at the current stage, serves as a best practice model in many areas. The present paper aims to provide a comprehensive overview of the evolution of the M&E system in Ukraine since its inception. Notable achievements and challenges are described and illustrated by epidemiological data and the recommendations for future development are discussed. Unique experiences and advances in M&E in Ukraine may be useful to other countries facing similar epidemiological, structural or methodological issues.

Improving Decision-Making Activities for Meningitis and Malaria

NASA Astrophysics Data System (ADS)

Ceccato, P.; Trzaska, S.; Perez, C.; Kalashnikova, O. V.; del Corral, J.; Cousin, R.; Blumenthal, M. B.; Connor, S.; Thomson, M. C.

2012-12-01

Public health professionals are increasingly concerned about the potential impact that climate variability and change can have on infectious disease. The International Research Institute for Climate and Society (IRI) is developing new products to increase the public health community's capacity to understand, use, and demand the appropriate climate data and climate information to mitigate the public health impacts of climate on infectious disease, in particular Meningitis and Malaria. In this paper we present the new and improved products that have been developed for monitoring dust, temperature, rainfall and vectorial capacity model for monitoring and forecasting risks of Meningitis and Malaria epidemics. We also present how the products have been integrated into a knowledge system (IRI Data Library Map room, SERVIR) to support the use of climate and environmental information in climate-sensitive health decision-making.

Interplay of node connectivity and epidemic rates in the dynamics of epidemic networks

DOE PAGES

Kostova, Tanya

2010-07-09

We present and analyze a discrete-time susceptible-infected epidemic network model which represents each host as a separate entity and allows heterogeneous hosts and contacts. We establish a necessary and sufficient condition for global stability of the disease-free equilibrium of the system (defined as epidemic controllability) which defines the epidemic reproduction number of the network. When this condition is not fulfilled, we show that the system has a unique, locally stable equilibrium. As a result, we further derive sufficient conditions for epidemic controllability in terms of the epidemic rates and the network topology.

Periodic re-emergence of endemic strains with strong epidemic potential-a proposed explanation for the 2004 Indonesian dengue epidemic.

PubMed

Ong, Swee Hoe; Yip, Jin Teen; Chen, Yen Liang; Liu, Wei; Harun, Syahrial; Lystiyaningsih, Erlin; Heriyanto, Bambang; Beckett, Charmagne G; Mitchell, Wayne P; Hibberd, Martin L; Suwandono, Agus; Vasudevan, Subhash G; Schreiber, Mark J

2008-03-01

Indonesia experienced a severe dengue epidemic in the first quarter of 2004 with 58,301 cases and 658 deaths reported to the WHO. All four dengue virus (DENV) serotypes were detected, with DENV-3 the predominant strain. To ascertain the molecular epidemiology of the DENV associated with the epidemic, complete genomes of 15 isolates were sequenced from patient serum collected in Jakarta during the epidemic, and two historical DENV-3 isolates from previous epidemics in 1988 and 1998 were selectively sequenced for comparative studies. Phylogenetic trees for all four serotypes indicate the viruses are endemic strains that have been circulating in Indonesia for a few decades. Whole-genome phylogeny showed the 2004 DENV-3 isolates share high similarity with those isolated in 1998 during a major epidemic in Sumatra. Together these subtype I DENV-3 strains form a Sumatran-Javan clade with demonstrated epidemic potential. No newly-acquired amino acid mutations were found while comparing genomes from the two epidemics. This suggests re-emergence of little-changed endemic strains as causative agents of the epidemic in 2004. Notably, the molecular evidence rules out change in the viral genomes as the trigger of the epidemic.

Modeling household and community transmission of Ebola virus disease: Epidemic growth, spatial dynamics and insights for epidemic control

PubMed Central

Kiskowski, Maria; Chowell, Gerardo

2016-01-01

The mechanisms behind the sub-exponential growth dynamics of the West Africa Ebola virus disease epidemic could be related to improved control of the epidemic and the result of reduced disease transmission in spatially constrained contact structures. An individual-based, stochastic network model is used to model immediate and delayed epidemic control in the context of social contact networks and investigate the extent to which the relative role of these factors may be determined during an outbreak. We find that in general, epidemics quickly establish a dynamic equilibrium of infections in the form of a wave of fixed size and speed traveling through the contact network. Both greater epidemic control and limited community mixing decrease the size of an infectious wave. However, for a fixed wave size, epidemic control (in contrast with limited community mixing) results in lower community saturation and a wave that moves more quickly through the contact network. We also found that the level of epidemic control has a disproportionately greater reductive effect on larger waves, so that a small wave requires nearly as much epidemic control as a larger wave to end an epidemic. PMID:26399855

Modeling household and community transmission of Ebola virus disease: Epidemic growth, spatial dynamics and insights for epidemic control.

PubMed

Kiskowski, Maria; Chowell, Gerardo

2016-01-01

The mechanisms behind the sub-exponential growth dynamics of the West Africa Ebola virus disease epidemic could be related to improved control of the epidemic and the result of reduced disease transmission in spatially constrained contact structures. An individual-based, stochastic network model is used to model immediate and delayed epidemic control in the context of social contact networks and investigate the extent to which the relative role of these factors may be determined during an outbreak. We find that in general, epidemics quickly establish a dynamic equilibrium of infections in the form of a wave of fixed size and speed traveling through the contact network. Both greater epidemic control and limited community mixing decrease the size of an infectious wave. However, for a fixed wave size, epidemic control (in contrast with limited community mixing) results in lower community saturation and a wave that moves more quickly through the contact network. We also found that the level of epidemic control has a disproportionately greater reductive effect on larger waves, so that a small wave requires nearly as much epidemic control as a larger wave to end an epidemic.

Integrating malaria surveillance with climate data for outbreak detection and forecasting: the EPIDEMIA system.

PubMed

Merkord, Christopher L; Liu, Yi; Mihretie, Abere; Gebrehiwot, Teklehaymanot; Awoke, Worku; Bayabil, Estifanos; Henebry, Geoffrey M; Kassa, Gebeyaw T; Lake, Mastewal; Wimberly, Michael C

2017-02-23

Early indication of an emerging malaria epidemic can provide an opportunity for proactive interventions. Challenges to the identification of nascent malaria epidemics include obtaining recent epidemiological surveillance data, spatially and temporally harmonizing this information with timely data on environmental precursors, applying models for early detection and early warning, and communicating results to public health officials. Automated web-based informatics systems can provide a solution to these problems, but their implementation in real-world settings has been limited. The Epidemic Prognosis Incorporating Disease and Environmental Monitoring for Integrated Assessment (EPIDEMIA) computer system was designed and implemented to integrate disease surveillance with environmental monitoring in support of operational malaria forecasting in the Amhara region of Ethiopia. A co-design workshop was held with computer scientists, epidemiological modelers, and public health partners to develop an initial list of system requirements. Subsequent updates to the system were based on feedback obtained from system evaluation workshops and assessments conducted by a steering committee of users in the public health sector. The system integrated epidemiological data uploaded weekly by the Amhara Regional Health Bureau with remotely-sensed environmental data freely available from online archives. Environmental data were acquired and processed automatically by the EASTWeb software program. Additional software was developed to implement a public health interface for data upload and download, harmonize the epidemiological and environmental data into a unified database, automatically update time series forecasting models, and generate formatted reports. Reporting features included district-level control charts and maps summarizing epidemiological indicators of emerging malaria outbreaks, environmental risk factors, and forecasts of future malaria risk. Successful implementation and use of EPIDEMIA is an important step forward in the use of epidemiological and environmental informatics systems for malaria surveillance. Developing software to automate the workflow steps while remaining robust to continual changes in the input data streams was a key technical challenge. Continual stakeholder involvement throughout design, implementation, and operation has created a strong enabling environment that will facilitate the ongoing development, application, and testing of the system.

Monitoring the fitness of antiviral-resistant influenza strains during an epidemic: A mathematical modeling study

PubMed Central

Leung, Kathy; Lipsitch, Marc; Yuen, Kwok Yung; Wu, Joseph T

2017-01-01

Summary Background Antivirals (e.g. oseltamivir) are important for mitigating influenza epidemics. In 2007, an oseltamivir-resistant seasonal A(H1N1) strain emerged and spread to global fixation within one year. This showed that antiviral-resistant (AVR) strains can be intrinsically more transmissible than their contemporaneous antiviral-sensitive (AVS) counterpart. Surveillance of AVR fitness is therefore essential. Methods We define the fitness of AVR strains as their reproductive number relative to their co-circulating AVS counterparts. We develop a simple method for real-time estimation of AVR fitness from surveillance data. This method requires only information on generation time without other specific details regarding transmission dynamics. We first use simulations to validate this method by showing that it yields unbiased and robust fitness estimates in most epidemic scenarios. We then apply this method to two retrospective case studies and one hypothetical case study. Findings We estimate that (i) the oseltamivir-resistant A(H1N1) strain that emerged in 2007 was 4% (3–5%) more transmissible than its oseltamivir-sensitive predecessor and (ii) the oseltamivir-resistant pandemic A(H1N1) strain that emerged and circulated in Japan during 2013–2014 was 24% (17–30%) less transmissible than its oseltamivir-sensitive counterpart. We show that in the event of large-scale antiviral interventions during a pandemic with co-circulation of AVS and AVR strains, our method can be used to inform optimal use of antivirals by monitoring intrinsic AVR fitness and drug pressure on the AVS strain. Conclusions We have developed a simple method that can be easily integrated into contemporary influenza surveillance systems to provide reliable estimates of AVR fitness in real time. Funding Research Fund for the Control of Infectious Disease (09080792) and a commissioned grant from the Health and Medical Research Fund from the Government of the Hong Kong Special Administrative Region, Harvard Center for Communicable Disease Dynamics from the National Institute of General Medical Sciences (grant no. U54 GM088558), Area of Excellence Scheme of the Hong Kong University Grants Committee (grant no. AoE/M-12/06). PMID:27914853

[The characteristics of epidemic influenza A and B virus strains circulating in Russia during the 2007-2008 season].

PubMed

Ivanova, V T; Trushakova, S V; Oskerko, T A; Shevchenko, E S; Kolobukhina, L V; Vartanian, R V; Beliakova, N V; Iatsyshina, S B; Feodoritova, E L; Zueva, N D; Burtseva, E I

2009-01-01

In 2007-2008 in Russia, the epidemic upsurge of influenza morbidity was caused by the active circulation of influenza A(H1N1, A(H3N2), and B viruses. The center for Ecology and Epidemiology of Influenza studied 334 epidemic strains. The results of a comparative study of the svirus specificity of commercial test systems (AmpliSens Influenza virus A/B and AmpliSens Influenza virus A/H5N1) for the polymerase chain reaction diagnosis and virological assays, including virus isolation, revealed their high correlation, which confirms that they may be expensively used to monitor the circulation of influenza viruses in the Russian Federation. All the strains were isolated in the MDCK cell culture. Influenza A(H1N1) viruses (n = 127) were antigenic variants of the reference strains A/Solomon Islands/3/06 and A/Brisbane/59107. Influenza A(H3N2) viruses (n = 49) were antigenic variants of the reference strains A/Wisconsin/67/05 and A/Brisbane/10/08. One hundred and fifty seven Influenza B strains were drift variants of the reference strains B/Florida/4/06 and B/Shanghai/361/02 of lineage B/Yamagata/16/88 and one strain, a variant of Malaysia/2506/04 related to lineage B/victoria/2/87. The isolates interacted actively with human 0(I) blood group erythrocytes and much more weakly with chicken ones. All study influenza A(H1N1) viruses (n = 74) preserved their sensitivity to rimantadine while 24 (77%) of the 31 study influenza A(H3N2) virus strains were resistant. A study of the time course of changes in the generation of antibodies in the donor sera obtained in Moscow and the Moscow Region in different periods of the epidemic process revealed an increase in antibodies to the reference influenza A and B virus strains circulating in this period.

[Multiple Ebola virus haemorrhagic fever outbreaks in Gabon, from October 2001 to April 2002].

PubMed

Nkoghe, D; Formenty, P; Leroy, E M; Nnegue, S; Edou, S Y Obame; Ba, J Iba; Allarangar, Y; Cabore, J; Bachy, C; Andraghetti, R; de Benoist, A C; Galanis, E; Rose, A; Bausch, D; Reynolds, M; Rollin, P; Choueibou, C; Shongo, R; Gergonne, B; Koné, L M; Yada, A; Roth, C; Mve, M Toung

2005-09-01

Outbreaks of Ebola virus haemorrhagic fever have been reported from 1994 to 1996 in the province of Ogooué Ivindo, a forest zone situated in the Northeast of Gabon. Each time, the great primates had been identified as the initial source of human infection. End of November 2001 a new alert came from this province, rapidly confirmed as a EVHV outbreak. The response was given by the Ministry of Health with the help of an international team under the aegis of WHO. An active monitoring system was implemented in the three districts hit by the epidemic (Zadié, Ivindo and Mpassa) to organize the detection of cases and their follow-up. A case definition has been set up, the suspected cases were isolated at hospital, at home or in lazarets and serological tests were performed. These tests consisted of the detection of antigen or specific IgG and the RT-PCR. A classification of cases was made according to the results of biological tests, clinical and epidemiological data. The contact subjects were kept watch over for 21 days. 65 cases were recorded among which 53 deaths. The first human case, a hunter died on the 28th of October 2001. The epidemic spreads over through family transmission and nosocomial contamination. Four distinct primary foci have been identified together with an isolated case situated in the South East of Gabon, 580 km away from the epicenter. Deaths happened within a delay of 6 days. The last death has been recorded on the 22nd of March 2002 and the end of the outbreak was declared on the 6th of May 2002. The epidemic spreads over the Gabon just next. Unexplained deaths of animals had been mentionned in the nearby forests as soon as August 2001: great primates and cephalophus. Samples taken from their carcasses confirmed a concomitant animal epidemic.

HIV/AIDS in Costa Rica: epidemiological and sociological features, 1993.

PubMed

Mata, L; Ramírez, G; Quesada, J

1995-01-01

Acquired immunodeficiency syndrome (AIDS) was first detected in Costa Rica in 1983. For four years most known cases were in hemophiliac men. Thereafter, AIDS in homosexual and bisexual men predominated. By December 31 of 1993, 563 persons had been diagnosed with the syndrome, 71% of them homosexual and bisexual men, 10% heterosexual men and women, 6% hemophiliacs, 2% intravenous drug abusers (IVDA's), 2% women and men who had blood transfusions, 1.4% infants born to HIV-infected mothers and 7% unknown. The epidemics in homosexual/bisexual men and in heterosexual women and men are rising; cases in infants and in persons who received blood or coagulation factors, are stagnant. The steady increase in AIDS among women is linked to exposure to bisexual partners. The moderate nature of the national epidemic reflects, in part, the low incidence of IVDA, the universal screening of blood donors for antibodies to the human immunodeficiency virus (HIV) since 1985, and the prompt banning of unsafe coagulation factors. The projection of AIDS for the year 2000 is 2,304 cases (606 accumulated incidence per million inhabitants). A national educational campaign, radio and television programs and other preventive actions, apparently did not influence the rate of receptive anal intercourse without condom (about 80%) during 9 years of the epidemic. Persons with HIV/AIDS often are deprived of social and medical benefits or are subjected to harassment and exploitation by the health sector. More efficient prevention must target children, adolescents and adults in reproductive age, to promote safer lifestyles, through education and counseling effected through primary health care.

Survey of American food trends and the growing obesity epidemic.

PubMed

Shao, Qin; Chin, Khew-Voon

2011-06-01

The rapid rise in the incidence of obesity has emerged as one of the most pressing global public health issues in recent years. The underlying etiological causes of obesity, whether behavioral, environmental, genetic, or a combination of several of them, have not been completely elucidated. The obesity epidemic has been attributed to the ready availability, abundance, and overconsumption of high-energy content food. We determined here by Pearson's correlation the relationship between food type consumption and rising obesity using the loss-adjusted food availability data from the United States Department of Agriculture (USDA) Economic Research Services (ERS) as well as the obesity prevalence data from the Behavioral Risk Factor Surveillance System (BRFSS) and the National Health and Nutrition Examination Survey (NHANES) at the Centers for Disease Control and Prevention (CDC). Our analysis showed that total calorie intake and consumption of high fructose corn syrup (HFCS) did not correlate with rising obesity trends. Intake of other major food types, including chicken, dairy fats, salad and cooking oils, and cheese also did not correlate with obesity trends. However, our results surprisingly revealed that consumption of corn products correlated with rising obesity and was independent of gender and race/ethnicity among population dynamics in the U.S. Therefore, we were able to demonstrate a novel link between the consumption of corn products and rising obesity trends that has not been previously attributed to the obesity epidemic. This correlation coincides with the introduction of bioengineered corns into the human food chain, thus raising a new hypothesis that should be tested in molecular and animal models of obesity.

Survey of American food trends and the growing obesity epidemic

PubMed Central

Shao, Qin

2011-01-01

The rapid rise in the incidence of obesity has emerged as one of the most pressing global public health issues in recent years. The underlying etiological causes of obesity, whether behavioral, environmental, genetic, or a combination of several of them, have not been completely elucidated. The obesity epidemic has been attributed to the ready availability, abundance, and overconsumption of high-energy content food. We determined here by Pearson's correlation the relationship between food type consumption and rising obesity using the loss-adjusted food availability data from the United States Department of Agriculture (USDA) Economic Research Services (ERS) as well as the obesity prevalence data from the Behavioral Risk Factor Surveillance System (BRFSS) and the National Health and Nutrition Examination Survey (NHANES) at the Centers for Disease Control and Prevention (CDC). Our analysis showed that total calorie intake and consumption of high fructose corn syrup (HFCS) did not correlate with rising obesity trends. Intake of other major food types, including chicken, dairy fats, salad and cooking oils, and cheese also did not correlate with obesity trends. However, our results surprisingly revealed that consumption of corn products correlated with rising obesity and was independent of gender and race/ethnicity among population dynamics in the U.S. Therefore, we were able to demonstrate a novel link between the consumption of corn products and rising obesity trends that has not been previously attributed to the obesity epidemic. This correlation coincides with the introduction of bioengineered corns into the human food chain, thus raising a new hypothesis that should be tested in molecular and animal models of obesity. PMID:21779530

The rate of co-infection for piglet diarrhea viruses in China and the genetic characterization of porcine epidemic diarrhea virus and porcine kobuvirus.

PubMed

Zhao, Z-P; Yang, Z; Lin, W-D; Wang, W-Y; Yang, J; Jin, W-J; Qin, A-J

2016-03-01

Piglet diarrhea epidemics result in major economic losses for the swine industry. Four viruses are closely linked to porcine diarrhea: porcine kobuvirus (PKV), porcine epidemic diarrhea virus (PEDV), porcine transmissible gastroenteritis virus (TGEV), and porcine rotavirus (PRoV). We have conducted an epidemiology study to determine the frequency of infection and co-infection with these viruses in China, and characterized the genetic variation of the isolated PEDV and PKV strains. Stool and intestinal samples (n = 314) were collected from piglets with diarrhea in China from years 2012 to 2014. RT-PCR was used to detect PKV, PEDV, TGEV, and PRoV. Phylogenetic relationships between reference strains and the isolated PEDV and PKV strains were determined based on the M and 3D gene sequence. The rates of infection with PKV, PEDV, TGEV and PRoV were 29.9%, 24.2%, 1.91%, and 0.31%, respectively. Co-infections with PKV and the other three viruses were very common. Co-infection of PKV and PEDV was detected in 15.0% (47/314) of the samples. Phylogenetic analysis of the PKV 3D gene indicated that there were some phylogenetic differences in the PKV strains across regions within China. However, according to the PEDV M gene, strains clustered into three groups and the primary group was distinct from the vaccine strain CV777. This study provides insights in to the prevalence of diarrhea viruses and their prevention and control in China.

Social Network Clustering and the Spread of HIV/AIDS Among Persons Who Inject Drugs in 2 Cities in the Philippines.

PubMed

Verdery, Ashton M; Siripong, Nalyn; Pence, Brian W

2017-09-01

The Philippines has seen rapid increases in HIV prevalence among people who inject drugs. We study 2 neighboring cities where a linked HIV epidemic differed in timing of onset and levels of prevalence. In Cebu, prevalence rose rapidly from below 1% to 54% between 2009 and 2011 and remained high through 2013. In nearby Mandaue, HIV remained below 4% through 2011 then rose rapidly to 38% by 2013. We hypothesize that infection prevalence differences in these cities may owe to aspects of social network structure, specifically levels of network clustering. Building on previous research, we hypothesize that higher levels of network clustering are associated with greater epidemic potential. Data were collected with respondent-driven sampling among men who inject drugs in Cebu and Mandaue in 2013. We first examine sample composition using estimators for population means. We then apply new estimators of network clustering in respondent-driven sampling data to examine associations with HIV prevalence. Samples in both cities were comparable in composition by age, education, and injection locations. Dyadic needle-sharing levels were also similar between the 2 cities, but network clustering in the needle-sharing network differed dramatically. We found higher clustering in Cebu than Mandaue, consistent with expectations that higher clustering is associated with faster epidemic spread. This article is the first to apply estimators of network clustering to empirical respondent-driven samples, and it offers suggestive evidence that researchers should pay greater attention to network structure's role in HIV transmission dynamics.

Using a Social Network Strategy to Distribute HIV Self-Test Kits to African American and Latino MSM.

PubMed

Lightfoot, Marguerita A; Campbell, Chadwick K; Moss, Nicholas; Treves-Kagan, Sarah; Agnew, Emily; Kang Dufour, Mi-Suk; Scott, Hyman; Sa'id, Aria M; Lippman, Sheri A

2018-05-04

Men who have sex with men (MSM) continue to be disproportionately impacted globally by the HIV epidemic. Studies suggest that HIV Self-testing (HIVST) is highly acceptable among MSM. Social network strategies to increase testing are effective in reaching MSM, particularly MSM of color, who may not otherwise test. We tested a social-network based strategy to distribute HIVST kits to African American and Latino MSM. This study was conducted in Alameda County, California a large, urban/suburban county with an HIV epidemic mirroring the national HIV epidemic. From January 2016 to March 2017, 30 AAMSM, LMSM, and Transgender women were trained as peer recruiters and asked to distribute five self-test kits to MSM social network members and support those who test positive in linking to care. Testers completed an online survey following their test. We compared peer-distributed HIVST testing outcomes to outcomes from Alameda County's targeted, community-based HIV testing programs using chi-squared tests. Peers distributed HIVST to 143 social and sexual network members, of whom 110 completed the online survey. Compared to MSM who utilized the County's sponsored testing programs, individuals reached through the peer-based self-testing strategy were significantly more likely to have never tested for HIV (3.51% vs. 0.41%, p<0.01) and to report a positive test result (6.14% vs 1.49%, p<0.01). Findings suggest that a network-based strategy for self-test distribution is a promising intervention to increase testing uptake and reduce undiagnosed infections among African American and Latino MSM.

The investigation of using 5G millimeter-wave communications links for environmental monitoring

NASA Astrophysics Data System (ADS)

Han, Congzheng

2017-04-01

There has been significantly increasing recognition that millimeter waves from 30 GHz to 300 GHz as carriers for future 5G cellular networks. This is good for high speed, line-of-sight communication, potentially using very densely deployed infrastructure involving many small cells. High resolution, continuous and accurate monitoring of environmental conditions, such as rainfall and water vapor are of great important to meteorology, hydrology (e.g. flood warning), agriculture, environmental policy (e.g. pollution regulation) and weather forecasting. We have built a 28GHz measurement link at our research institute in central Beijing, China. This work will study the potential of using millimeter wave based wireless links to monitor environmental conditions including rainfall and water vapor.

[Zika virus infection during pregnancy].

PubMed

Picone, O; Vauloup-Fellous, C; D'Ortenzio, E; Huissoud, C; Carles, G; Benachi, A; Faye, A; Luton, D; Paty, M-C; Ayoubi, J-M; Yazdanpanah, Y; Mandelbrot, L; Matheron, S

2016-05-01

A Zika virus epidemic is currently ongoing in the Americas. This virus is linked to congenital infections with potential severe neurodevelopmental dysfunction. However, incidence of fetal infection and whether this virus is responsible of other fetal complications are still unknown. National and international public health authorities recommend caution and several prevention measures. Declaration of Zika virus infection is now mandatory in France. Given the available knowledge on Zika virus, we suggest here a review of the current recommendations for management of pregnancy in case of suspicious or infection by Zika virus in a pregnant woman. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Asymptotically inspired moment-closure approximation for adaptive networks

NASA Astrophysics Data System (ADS)

Shkarayev, Maxim; Shaw, Leah

2012-02-01

Adaptive social networks, in which nodes and network structure co-evolve, are often described using a mean-field system of equations for the density of node and link types. These equations constitute an open system due to dependence on higher order topological structures. We propose a moment-closure approximation based on the analytical description of the system in an asymptotic regime. We apply the proposed approach to two examples of adaptive networks: recruitment to a cause model and epidemic spread model. We show a good agreement between the improved mean-field prediction and simulations of the full network system.

Asymptotically inspired moment-closure approximation for adaptive networks

NASA Astrophysics Data System (ADS)

Shkarayev, Maxim

2013-03-01

Dynamics of adaptive social networks, in which nodes and network structure co-evolve, are often described using a mean-field system of equations for the density of node and link types. These equations constitute an open system due to dependence on higher order topological structures. We propose a systematic approach to moment closure approximation based on the analytical description of the system in an asymptotic regime. We apply the proposed approach to two examples of adaptive networks: recruitment to a cause model and adaptive epidemic model. We show a good agreement between the mean-field prediction and simulations of the full network system.

Asymptotically inspired moment-closure approximation for adaptive networks

NASA Astrophysics Data System (ADS)

Shkarayev, Maxim S.; Shaw, Leah B.

2013-11-01

Adaptive social networks, in which nodes and network structure coevolve, are often described using a mean-field system of equations for the density of node and link types. These equations constitute an open system due to dependence on higher-order topological structures. We propose a new approach to moment closure based on the analytical description of the system in an asymptotic regime. We apply the proposed approach to two examples of adaptive networks: recruitment to a cause model and adaptive epidemic model. We show a good agreement between the improved mean-field prediction and simulations of the full network system.

Dynamics of Cholera Outbreaks in Great Lakes Region of Africa, 1978–2008

PubMed Central

Nkoko, Didier Bompangue; Giraudoux, Patrick; Plisnier, Pierre-Denis; Tinda, Annie Mutombo; Piarroux, Martine; Sudre, Bertrand; Horion, Stephanie; Tamfum, Jean-Jacques Muyembe; Ilunga, Benoît Kebela

2011-01-01

Cholera outbreaks have occurred in Burundi, Rwanda, Democratic Republic of Congo, Tanzania, Uganda, and Kenya almost every year since 1977–1978, when the disease emerged in these countries. We used a multiscale, geographic information system–based approach to assess the link between cholera outbreaks, climate, and environmental variables. We performed time-series analyses and field investigations in the main affected areas. Results showed that cholera greatly increased during El Niño warm events (abnormally warm El Niños) but decreased or remained stable between these events. Most epidemics occurred in a few hotspots in lakeside areas, where the weekly incidence of cholera varied by season, rainfall, fluctuations of plankton, and fishing activities. During lull periods, persistence of cholera was explained by outbreak dynamics, which suggested a metapopulation pattern, and by endemic foci around the lakes. These links between cholera outbreaks, climate, and lake environments need additional, multidisciplinary study. PMID:22099090

Gastrointestinal Issues in the Assessment and Management of the Obese Patient

PubMed Central

Hussain, Zulfiqar

2007-01-01

As the obesity epidemic spreads across the world, physicians of all specialties will be called on to participate in the management of this condition. Gastroenterologists are no exception and can expect, in the future, to play a major role in all aspects of the care of the obese patient. Thus, gastroenterologists must learn to recognize, prevent, and treat gastrointestinal disorders related to obesity, and they must have an understanding of the risks and benefits of various management strategies. Gastroenterologists may also be called upon to assist in the evaluation and management of liver and gastrointestinal problems that have developed following bariatric surgery. When treating these problems, a thorough understanding of the anatomic and physiologic perturbations associated with a given procedure is essential, as is the knowledge of which complications are linked to weight loss and which are linked to a specific surgical approach. PMID:21960865