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1

Early detection of contagious diseases  

DOEpatents

This invention provides an electronic proximity apparatus and a surveillance method using such an apparatus for alerting individuals that are exposed to a contagious disease. When a person becomes symptomatic and is diagnosed as positive for a given contagious agent, individuals that have recently maintained a threshold proximity with respect to an infected individual are notified and advised to seek immediate medial care. Treatment of individuals in the very early phases of infection (pre-symptomatic) significantly reduces contagiousness of the infected population first exposed to the contagious disease, thus preventing spread of the disease throughout the general population.

Colston, Jr., Billy W. (San Ramon, CA); Milanovich, Fred P. (Lafayette, CA); Estacio, Pedro (Mission San Jose, CA); Chang, John (Walnut Creek, CA)

2011-08-09

2

The effect of travel restrictions on the spread of a moderately contagious disease  

PubMed Central

Background Much research in epidemiology has been focused on evaluating conventional methods of control strategies in the event of an epidemic or pandemic. Travel restrictions are often suggested as an efficient way to reduce the spread of a contagious disease that threatens public health, but few papers have studied in depth the effects of travel restrictions. In this study, we investigated what effect different levels of travel restrictions might have on the speed and geographical spread of an outbreak of a disease similar to severe acute respiratory syndrome (SARS). Methods We used a stochastic simulation model incorporating survey data of travel patterns between municipalities in Sweden collected over 3 years. We tested scenarios of travel restrictions in which travel over distances >50 km and 20 km would be banned, taking into account different levels of compliance. Results We found that a ban on journeys >50 km would drastically reduce the speed and geographical spread of outbreaks, even when compliance is < 100%. The result was found to be robust for different rates of intermunicipality transmission intensities. Conclusion This study supports travel restrictions as an effective way to mitigate the effect of a future disease outbreak. PMID:17166291

Camitz, Martin; Liljeros, Fredrik

2006-01-01

3

Childhood Contagious Diseases  

MedlinePLUS

... or viruses (such as in chickenpox, measles, hand-foot-and-mouth disease, and quite a few others) in droplets ... it is most commonly seen in children. Hand-Foot-and-Mouth Disease Hand-foot-and-mouth disease is a ...

4

Mycoplasmal conjunctivitis in wild songbirds: the spread of a new contagious disease in a mobile host population.  

PubMed Central

A new mycoplasmal conjunctivitis was first reported in wild house finches (Carpodacus mexicanus) in early 1994. The causative agent was identified as Mycoplasma gallisepticum (MG), a nonzoonotic pathogen of poultry that had not been associated with disease in wild songbirds. Since the initial observations of affected house finches in the mid-Atlantic region, the disease has become widespread and has been reported throughout the eastern United States and Canada. By late 1995, mycoplasmal conjunctivitis had spread to an additional species, the American goldfinch (Carduelis tristis). This new disease exemplifies the rapid spread of a pathogen following introduction into a mobile wildlife population and provides lessons that may apply to emerging human diseases. PMID:9126448

Fischer, J. R.; Stallknecht, D. E.; Luttrell, P.; Dhondt, A. A.; Converse, K. A.

1997-01-01

5

The role of contagious disease in udder health  

PubMed Central

Contagious diseases are a threat to animal health and productivity, both nationally and at the farm level. This makes implementation of biosecurity measures to prevent their introduction and spread within countries and farms a necessity. Mastitis is the most common and costly contagious disease affecting dairy farms in the western world. The major mastitis pathogens are endemic in most countries, and biosecurity measures to prevent introduction and transmission must therefore be implemented at farm level. The 40-yr-old mastitis control plan remains a solid foundation to prevent the spread of contagious intramammary infections. Contagious diseases that do not affect the mammary gland directly may have an indirect effect on mastitis. This is true for list A diseases such as foot and mouth disease, for which biosecurity measures may need to be taken at national level, and for other infections with nonmastitis pathogens such as bovine viral diarrhea virus and Mycobacterium avium ssp. paratuberculosis. Maintaining a closed herd decreases the risk of introduction of pathogens that affect udder health directly or indirectly. If animals are purchased, their udder health history should be evaluated and they should be examined and tested for contagious diseases. Transmission of infections by and to humans and nonbovine animals may occur. Contact with visitors and nonbovine animals should therefore be minimized. Because of globalization and heightened consumer awareness, the importance of biosecurity now supersedes individual farms, and increased pressure to control transmission of contagious diseases can be expected at industry or government levels in western countries and elsewhere. PMID:19762787

Barkema, H. W.; Green, M. J.; Bradley, A. J.; Zadoks, R. N.

2009-01-01

6

Invited review: The role of contagious disease in udder health.  

PubMed

Contagious diseases are a threat to animal health and productivity, both nationally and at the farm level. This makes implementation of biosecurity measures to prevent their introduction and spread within countries and farms a necessity. Mastitis is the most common and costly contagious disease affecting dairy farms in the western world. The major mastitis pathogens are endemic in most countries, and biosecurity measures to prevent introduction and transmission must therefore be implemented at farm level. The 40-yr-old mastitis control plan remains a solid foundation to prevent the spread of contagious intramammary infections. Contagious diseases that do not affect the mammary gland directly may have an indirect effect on mastitis. This is true for list A diseases such as foot and mouth disease, for which biosecurity measures may need to be taken at national level, and for other infections with nonmastitis pathogens such as bovine viral diarrhea virus and Mycobacterium avium ssp. paratuberculosis. Maintaining a closed herd decreases the risk of introduction of pathogens that affect udder health directly or indirectly. If animals are purchased, their udder health history should be evaluated and they should be examined and tested for contagious diseases. Transmission of infections by and to humans and nonbovine animals may occur. Contact with visitors and nonbovine animals should therefore be minimized. Because of globalization and heightened consumer awareness, the importance of biosecurity now supersedes individual farms, and increased pressure to control transmission of contagious diseases can be expected at industry or government levels in western countries and elsewhere. PMID:19762787

Barkema, H W; Green, M J; Bradley, A J; Zadoks, R N

2009-10-01

7

Educating Children and Youth To Prevent Contagious Disease. ERIC Digest.  

ERIC Educational Resources Information Center

Twenty-first century contagious diseases require more than basic health lessons to prevent transmission. This Digest examines ways to prevent disease transmission in school settings. Section 1 discusses key concepts in contagion education: all people are potentially contagious; germs that cause diseases are present on many parts of the body; hand…

Grosse, Susan J.

8

Flu is a serious contagious disease. Each year in the United States, on average, more  

E-print Network

Flu is a serious contagious disease. Each year in the United States, on average, more than 200,000 people are hospitalized and 36,000 people die from seasonal flu complications. This flu season could be worse. There is a new and very different flu virus spreading worldwide among people called novel or new

Ferrara, Katherine W.

9

Should Persons with Contagious Diseases Be Barred from School?  

ERIC Educational Resources Information Center

Reviews recent court decisions regarding whether individuals with contagious diseases may be barred from public schools. Devotes specific attention to the issue of whether certain communicable diseases such as tuberculosis and Acquired Immune Deficiency Syndrome (AIDS) can be classified as handicaps and thereby qualify a person for protection…

Roe, Richard L.

1987-01-01

10

What To Do When Contagious Disease Strikes Your School.  

ERIC Educational Resources Information Center

This publication presents 10 documents collected to accompany a seminar entitled "What To Do When Contagious Disease Strikes Your School," presented at the 31st annual convention of the National Organization on Legal Problems of Education in 1985. The materials include (1) an agenda of the seminar listing the speakers, their topics, and the time…

American Bar Association, Chicago, IL.

11

Bovine Spongiform Encephalopathy (BSE) – Infectious, Contagious, Zoonotic or Production Disease?  

Microsoft Academic Search

: In 1986, a new progressive neurological condition similar to scrapie of sheep and goats was recognised in cattle in the United Kingdom (UK), and was named bovine spongiform encephalopathy (BSE). There is an ongoing discussion whether BSE should be classified as infectious, contagious, or zoonotic, and if it fits the definition of a production disease. The objective of this

Marcus G Doherr

2003-01-01

12

Risk and economic consequences of contagious animal disease introduction  

Microsoft Academic Search

Introduction<\\/strong>Within the European Union, epidemics of contagious animal diseases such as Classical Swine Fever (CSF) and Foot-and-Mouth Disease (FMD) are to be eradicated according to strict EU- prescriptions including stamping-out of infected herds, establishment of control and surveillance zones with complete standstill of animals and possible export bans on live animals. Epidemics clearly have a serious impact, in particular on

H. S. Horst

1998-01-01

13

9 CFR 71.14 - Slaughter of poultry or other animals to prevent spread of disease; ascertainment of value and...  

Code of Federal Regulations, 2012 CFR

...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...contagious, infectious, or communicable disease, it becomes necessary to...

2012-01-01

14

9 CFR 71.14 - Slaughter of poultry or other animals to prevent spread of disease; ascertainment of value and...  

Code of Federal Regulations, 2013 CFR

...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...contagious, infectious, or communicable disease, it becomes necessary to...

2013-01-01

15

9 CFR 71.14 - Slaughter of poultry or other animals to prevent spread of disease; ascertainment of value and...  

Code of Federal Regulations, 2014 CFR

...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...contagious, infectious, or communicable disease, it becomes necessary to...

2014-01-01

16

9 CFR 71.14 - Slaughter of poultry or other animals to prevent spread of disease; ascertainment of value and...  

Code of Federal Regulations, 2011 CFR

...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...contagious, infectious, or communicable disease, it becomes necessary to...

2011-01-01

17

9 CFR 71.14 - Slaughter of poultry or other animals to prevent spread of disease; ascertainment of value and...  

Code of Federal Regulations, 2010 CFR

...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...poultry or other animals to prevent spread of disease; ascertainment of value and compensation...contagious, infectious, or communicable disease, it becomes necessary to...

2010-01-01

18

[Highly contagious diseases with human-to-human transmission].  

PubMed

Highly contagious diseases are caused by various biological agents that pose a risk to individuals and may have a potential for public health impact. They result in high mortality and morbidity rates, might cause public panic and therefore require special measures. The pathogens that can be easily disseminated or transmitted from person to person are the riskiest for clinicians (Ebola virus, Marburg virus, Lassa virus, Crimean-Congo hemorrhagic fever virus, Variola major, SARS virus and Yersinia pestis). Human-to-human transmission has not been confirmed for the other biological agents and therefore they pose a very low risk for population. PMID:23386507

Rybka, Aleš; Szanyi, Juraj; Kapla, Jaroslav; Plíšek, Stanislav

2012-12-01

19

Contagious diseases in competitive sport: what are the risks?  

PubMed

Great concern is often expressed over the possibility of contagion among athletes in competitive sports, particularly sports with much person-to-person contact. Human immunodeficiency virus (HIV) is only the most notorious of infectious agents; potentially, other viruses, bacteria, and even fungi may be involved. Because of the concern, however, special attention is paid to HIV and hepatitis B infections. For most of the infections considered, the athlete is more at risk during activities off the playing field than while competing. Inclusion of immunizations against measles and hepatitis B among prematriculation immunization requirements (PIRs) for colleges and universities would eliminate these two diseases from the list of dangers to college athletes and all students. Education, rather than regulations, should remain the cornerstone in considering the risks to athletes from contagious diseases. PMID:11125637

Dorman, J M

2000-11-01

20

The role of the Major Histocompatibility Complex in the spread of contagious cancers.  

PubMed

Major Histocompatibility Complex (MHC) genes play a key role in immune response to infectious diseases, immunosurveillance, and self/nonself recognition. Matching MHC alleles is critical for organ transplantation, while changes in the MHC profile of tumour cells allow effective evasion of the immune response. Two unique cancers have exploited these features to become transmissible. In this review I discuss the functional role of MHC molecules in the emergence and evolution of Devil Facial Tumour Disease (DFTD) and Canine Transmissible Venereal Tumour (CTVT). High levels of genetic diversity at MHC genes play a critical role in protecting populations of vertebrate species from contagious cancer. However, species that have undergone genetic bottlenecks and have lost diversity at MHC genes are at risk of transmissible tumours. Moreover, evolution and selection for tumour variants capable of evading the immune response allow contagious cancers to cross MHC barriers. Transmissible cancers are rare but they can provide unique insights into the genetics and immunology of tumours and organ transplants. PMID:20963591

Belov, Katherine

2011-02-01

21

Contagious caprine pleuropneumonia: new aspects of an old disease.  

PubMed

Contagious caprine pleuropneumonia (CCPP), caused by Mycoplasma capricolum subsp. capripneumoniae, is a serious OIE-listed disease affecting goats in the Middle East, north and east Africa and Asia. Mortality and morbidity rates can be as high as 60% and 90%, respectively, when the disease first enters a territory, invariably through carrier animals. Recent detections of CCPP in Pakistan and Tajikistan are probably the result of improved diagnosis as the disease has been suspected there for many years, while those in Thrace in 2003 and Mauritius in 2009 represent new outbreaks. CCPP was thought to be highly host specific until recent outbreaks in wildlife species including gazelles and gerenuks show that the causative mycoplasma has broader specificity. Diagnosis was hampered by the fastidiousness of the causative mycoplasma but molecular-based tests like PCR have greatly improved detection. Rapid latex agglutination tests that can be performed at the penside are also available for antibody detection. Clinically affected animals respond to a range of antibiotics although it is unlikely that this results in complete elimination of the mycoplasma. Vaccines consisting of saponized organisms have been shown to be protective but the quality and efficacy may be variable. PMID:21951488

Nicholas, R; Churchward, C

2012-06-01

22

What's the Difference Between Infectious and Contagious?  

MedlinePLUS

... contagious . Some infections spread to people from an animal or insect, but are not contagious from another human. Lyme disease is an example: You can't catch it from someone you're hanging out with or pass in the street. It comes from the bite of an infected ...

23

Legal briefing: coerced treatment and involuntary confinement for contagious disease.  

PubMed

This issue's "Legal Briefing" column covers recent legal developments involving coerced treatment and involuntary confinement for contagious disease. Recent high profile court cases involving measles, tuberculosis, human immunodeficiency virus, and especially Ebola, have thrust this topic back into the bioethics and public spotlights. This has reignited debates over how best to balance individual liberty and public health. For example, the Presidential Commission for the Study of Bioethical Issues has officially requested public comments, held open hearings, and published a 90-page report on "ethical considerations and implications" raised by "U.S. public policies that restrict association or movement (such as quarantine)." Broadly related articles have been published in previous issues of The Journal of Clinical Ethics. We categorize recent legal developments on coerced treatment and involuntary confinement into the following six categories: 1. Most Public Health Confinement Is Voluntary 2. Legal Requirements for Involuntary Confinement 3. New State Laws Authorizing Involuntary Confinement 4. Quarantine Must Be as Least Restrictive as Necessary 5. Isolation Is Justified Only as a Last Resort 6. Coerced Treatment after Persistent Noncompliance. PMID:25794297

Pope, Thaddeus Mason; Bughman, Heather Michelle

2015-01-01

24

A Framework for Categorization of the Economic Impacts of Outbreaks of Highly Contagious Livestock Diseases.  

PubMed

A framework for categorization of economic impacts of outbreaks of highly contagious livestock diseases (HCLD) is presented. This framework interprets veterinary measures to control HCLD outbreaks with reference to economic definitions of costs and benefits, and the implications for value losses both for different stakeholders affected and society as a whole. Four cost categories are identified, that is virus control-related direct costs (DC), spread prevention and zoning-related direct consequential costs (DCC), market and price disruption-related costs during (indirect consequential costs, ICC) and after the outbreak (aftermath costs, AC). The framework is used to review existing literature on cost estimation for different stakeholders. This review shows considerable differences between studies, making comparison of results difficult and susceptible to misunderstanding. It is concluded that the framework provides a logical basis for all future analyses of the economic impacts of HCLD. PMID:25382248

Saatkamp, H W; Mourits, M C M; Howe, K S

2014-11-01

25

Epidemiology: Understanding Disease Spread  

NSDL National Science Digital Library

Factors that influence disease spread throughout populations can be explored with the program Epidemiology. Both population and disease characteristics can be modeled over different time periods. The Susceptible- Infected- Recovered (SIR) model enables us to make predictions based on significant variables such as the flow of new susceptibles in to the population, transmission rates, disease deaths, and the duration of the disease. Ebola is used as a model organism and epidemiology is presented from both a microbiological and social perspective. * build epidemiological models of different diseases, design strategies for disease control, and test the effectiveness of these strategies on virtual populations

Marion Fass (Beloit College; Biology)

2006-05-20

26

Supreme Court Holds That Contagious Diseases Are Handicaps.  

ERIC Educational Resources Information Center

Describes a complex case involving termination of a third-grade teacher with recurrent tuberculosis. The United States Supreme Court upheld a circuit court's ruling that the teacher's condition satisfied section 504 of the 1973 Rehabilitation Act protecting handicapped persons against discrimination. Since contagiousness was not addressed, the…

Flygare, Thomas J.

1987-01-01

27

Respiratory-borne Disease Outbreaks in Populations: Contact Networks and the Spread of Disease  

NASA Astrophysics Data System (ADS)

A large class of infectious diseases spread through direct person-to-person contact. Traditional ``compartmental'' modeling in epidemiology assumes that in population groups every individual has an equal chance of spreading the disease to every other. The patterns of these contacts, however, tend to be highly heterogeneous. Explicit models of the patterns of contact among individuals in a community, contact network models, underlie a powerful approach to predicting and controlling the spread of such infectious disease and provide detailed and valuable insight into the fate and control of an outbreak. We use contact network epidemiology to predict the impact of various control policies for both a mildly contagious disease such as SARS and a more highly contagious disease such as smallpox. We demonstrate how integrating these tools into public health decision-making should facilitate more rational strategies for managing newly emerging diseases, bioterrorism and pandemic influenza in situations where empirical data are not yet available to guide decision making.

Pourbohloul, Babak; Meyers, Lauren A.; Newman, Mark E. J.; Skowronski, Danuta M.

2005-03-01

28

Contagious Diseases in Competitive Sport: What Are the Risks?  

ERIC Educational Resources Information Center

Discusses fungal, bacterial, and viral infections that may strike athletes during competition, highlighting possible risks of hepatitis, herpes, and HIV. Athletes generally are more at risk off the playing field than while competing. Requiring immunizations against measles and hepatitis B prior to college admission would eliminate two diseases.…

Dorman, John M.

2000-01-01

29

Contagious Rhythm: Infectious Diseases of 20th Century Musicians  

PubMed Central

Infectious diseases have led to illness and death for many famous musicians, from the classical period to the rock ’n’ roll era. By the 20th century, as public health improved and orchestral composers began living more settled lives, infections among American and European musicians became less prominent. By mid-century, however, seminal jazz musicians famously pursued lifestyles characterized by drug and alcohol abuse. Among the consequences of this risky lifestyle were tuberculosis, syphilis, and chronic viral hepatitis. More contemporary rock musicians have experienced an epidemic of hepatitis C infection and HIV/AIDS related to intravenous drug use and promiscuity. Musical innovation is thus often accompanied by diseases of neglect and overindulgence, particularly infectious illnesses, although risky behavior and associated infectious illnesses tend to decrease as the style matures. PMID:20660936

Sartin, Jeffrey S.

2010-01-01

30

A generic model of contagious disease and its application to human-to-human transmission of avian influenza.  

SciTech Connect

Modeling contagious diseases has taken on greater importance over the past several years as diseases such as SARS and avian influenza have raised concern about worldwide pandemics. Most models developed to consider projected outbreaks have been specific to a single disease. This paper describes a generic System Dynamics contagious disease model and its application to human-to-human transmission of a mutant version of avian influenza. The model offers the option of calculating rates of new infections over time based either on a fixed ''reproductive number'' that is traditional in contagious disease models or on contact rates for different sub-populations and likelihood of transmission per contact. The paper reports on results with various types of interventions. These results suggest the potential importance of contact tracing, limited quarantine, and targeted vaccination strategies as methods for controlling outbreaks, especially when vaccine supplies may initially be limited and the efficacy of anti-viral drugs uncertain.

Hirsch, Gary B.

2007-03-01

31

Global Spread of Infectious Diseases  

E-print Network

We develop simple models for the global spread of infectious diseases, emphasizing human mobility via air travel and the variation of public health infrastructure from region to region. We derive formulas relating the total and peak number of infections in two countries to the rate of travel between them and their respective epidemiological parameters.

S. Hsu; A. Zee

2003-06-25

32

A mechanistic model of infection: why duration and intensity of contacts should be included in models of disease spread  

Microsoft Academic Search

BACKGROUND: Mathematical models and simulations of disease spread often assume a constant per-contact transmission probability. This assumption ignores the heterogeneity in transmission probabilities, e.g. due to the varying intensity and duration of potentially contagious contacts. Ignoring such heterogeneities might lead to erroneous conclusions from simulation results. In this paper, we show how a mechanistic model of disease transmission differs from

Timo Smieszek

2009-01-01

33

Graphing the Spread of Disease  

NSDL National Science Digital Library

Students simulate disease transmission by collecting data based on their proximity to other students. One option for measuring proximity is by having Bluetooth devices "discover" each other. After data is collected, students apply graph theory to analyze it, and summarize their data and findings in lab report format. Students learn real-world engineering applications of graph theory and see how numerous instances of real-world relationships can be more thoroughly understood by applying graph theory. Also, by applying graph theory the students are able to come up with possible solutions to limit the spread of disease. The activity is intended to be part of a computer science curriculum and knowledge of the Java programming language is required. To complete the activity, a computer with Java installed and appropriate editing software is needed.

2014-09-18

34

Cross-border collaboration in the field of highly contagious livestock diseases: a general framework for policy support.  

PubMed

This paper analyses the potential gains and the main challenges for increased cross-border collaboration in the control of highly contagious livestock diseases in regions with cross-border reliance on production and consumption of livestock commodities. The aim of this intensification of cross-border collaboration is to retain the economic advantages of cross-border trade in livestock and livestock commodities while maintaining a low risk of highly contagious livestock diseases. From these two foci, possibilities for future policy making with respect to highly contagious livestock diseases are discussed: peacetime cross-border cooperation to improve the cost-effectiveness of routine veterinary measures and crisis time cross-border harmonization of current disease control strategies. A general disease management framework was used to describe the way in which these two fields are related to and affect the epidemiological system and, consequently, how they impact the stakeholders. In addition to this framework, the importance of a good understanding of influencing factors, that is, the production structure of livestock, was stressed because these factors are important determinants of the frequency and magnitude of highly contagious livestock diseases and their economic impact. The use of the suggested integrated approach was illustrated for the extended cross-border region of the Netherlands and Germany, that is, North Rhine Westphalia and Lower Saxony. For this region, current difficulties in cross-border trade in livestock and livestock commodities and possibilities for future cross-border collaboration were examined. The concepts and ideas presented in this paper should foster future development of cross-border collaboration in animal health control. PMID:23066698

Hop, G E; Mourits, M C M; Oude Lansink, A G J M; Saatkamp, H W

2014-08-01

35

CONTAGIOUS DISEASE MODULE FOR THE JOINT EFFECTS MODEL Mr. Jason Rodriguez, Ms. Karen E. Cheng, Dr. Gene E. McClellan, Dr. David J. Crary, and Dr.  

E-print Network

smallpox and plague. Smallpox and plague are contagious diseases that lead to an additional load on medical at risk. In order to properly defend against an attack involving smallpox or plague, medical planners must

Ray, Jaideep

36

Nosocomial Spread of Viral Disease  

PubMed Central

Viruses are important causes of nosocomial infection, but the fact that hospital outbreaks often result from introduction(s) from community-based epidemics, together with the need to initiate specific laboratory testing, means that there are usually insufficient data to allow the monitoring of trends in incidences. The most important defenses against nosocomial transmission of viruses are detailed and continuing education of staff and strict adherence to infection control policies. Protocols must be available to assist in the management of patients with suspected or confirmed viral infection in the health care setting. In this review, we present details on general measures to prevent the spread of viral infection in hospitals and other health care environments. These include principles of accommodation of infected patients and approaches to good hygiene and patient management. They provide detail on individual viral diseases accompanied in each case with specific information on control of the infection and, where appropriate, details of preventive and therapeutic measures. The important areas of nosocomial infection due to blood-borne viruses have been extensively reviewed previously and are summarized here briefly, with citation of selected review articles. Human prion diseases, which present management problems very different from those of viral infection, are not included. PMID:11432812

Aitken, Celia; Jeffries, Donald J.

2001-01-01

37

Contagious mastitis.  

PubMed

Contagious mastitis is defined. The major mastitis pathogens are Streptococcus agalactiae, Staphylococcus aureus, Corynebacterium bovis, Mycoplasma sp, and Streptococcus dysgalactiae. These pathogens are discussed relative to prevalence, virulence factors, pathology, and control. These control measures include milking time hygiene, segregation, culling, vaccination, and treatment. PMID:8242453

Fox, L K; Gay, J M

1993-11-01

38

Do astrocytes collaborate with neurons in spreading the "infectious" a? and Tau drivers of Alzheimer's disease?  

PubMed

Evidence has begun emerging for the "contagious" and destructive A?42 (amyloid-beta42) oligomers and phosphorylated Tau oligomers as drivers of sporadic Alzheimer's disease (AD), which advances along a pathway starting from the brainstem or entorhinal cortex and leading to cognition-related upper cerebral cortex regions. Seemingly, A?42 oligomers trigger the events generating the neurotoxic Tau oligomers, which may even by themselves spread the characteristic AD neuropathology. It has been assumed that only neurons make and spread these toxic drivers, whereas their associated astrocytes are just janitorial bystanders/scavengers. But this view is likely to radically change since normal human astrocytes freshly isolated from adult cerebral cortex can be induced by exogenous A?25-35, an A?42 proxy, to make and secrete increased amounts of endogenous A?42. Thus, it would seem that the steady slow progression of AD neuropathology along specific cognition-relevant brain networks is driven by both A?42 and phosphorylated Tau oligomers that are variously released from increasing numbers of "contagion-stricken" members of tightly coupled neuron-astrocyte teams. Hence, we surmise that stopping the oversecretion and spread of the two kinds of "contagious" oligomers by such team members, perhaps via a specific CaSR (Ca(2+)-sensing receptor) antagonist like NPS 2143, might effectively treat AD. PMID:24740577

Dal Prà, Ilaria; Chiarini, Anna; Gui, Li; Chakravarthy, Balu; Pacchiana, Raffaella; Gardenal, Emanuela; Whitfield, James F; Armato, Ubaldo

2015-02-01

39

SIR Model for Spread of Disease  

NSDL National Science Digital Library

Using Maple, Mathmatica, or MatLab, learner should be able to develop the SIR Model for the spread of an infectious disease, including the concepts of contact number and herd immunity; to develop a version of Eulers Method for solving a system of differential equations.

David Smith

40

Reversible epigenetic down-regulation of MHC molecules by devil facial tumour disease illustrates immune escape by a contagious cancer  

PubMed Central

Contagious cancers that pass between individuals as an infectious cell line are highly unusual pathogens. Devil facial tumor disease (DFTD) is one such contagious cancer that emerged 16 y ago and is driving the Tasmanian devil to extinction. As both a pathogen and an allograft, DFTD cells should be rejected by the host–immune response, yet DFTD causes 100% mortality among infected devils with no apparent rejection of tumor cells. Why DFTD cells are not rejected has been a question of considerable confusion. Here, we show that DFTD cells do not express cell surface MHC molecules in vitro or in vivo, due to down-regulation of genes essential to the antigen-processing pathway, such as ?2-microglobulin and transporters associated with antigen processing. Loss of gene expression is not due to structural mutations, but to regulatory changes including epigenetic deacetylation of histones. Consequently, MHC class I molecules can be restored to the surface of DFTD cells in vitro by using recombinant devil IFN-?, which is associated with up-regulation of the MHC class II transactivator, a key transcription factor with deacetylase activity. Further, expression of MHC class I molecules by DFTD cells can occur in vivo during lymphocyte infiltration. These results explain why T cells do not target DFTD cells. We propose that MHC-positive or epigenetically modified DFTD cells may provide a vaccine to DFTD. In addition, we suggest that down-regulation of MHC molecules using regulatory mechanisms allows evolvability of transmissible cancers and could affect the evolutionary trajectory of DFTD. PMID:23479617

Siddle, Hannah V.; Kreiss, Alexandre; Tovar, Cesar; Yuen, Chun Kit; Cheng, Yuanyuan; Belov, Katherine; Swift, Kate; Pearse, Anne-Maree; Hamede, Rodrigo; Jones, Menna E.; Skjødt, Karsten; Woods, Gregory M.; Kaufman, Jim

2013-01-01

41

Social Distancing Strategies against Disease Spreading  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

42

Social distancing strategies against disease spreading  

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

43

Spread of epidemic disease on networks  

Microsoft Academic Search

The study of social networks, and in particular the spread of disease on\\u000anetworks, has attracted considerable recent attention in the physics community.\\u000aIn this paper, we show that a large class of standard epidemiological models,\\u000athe so-called susceptible\\/infective\\/removed (SIR) models can be solved exactly\\u000aon a wide variety of networks. In addition to the standard but unrealistic case\\u000aof

M. E. J. Newman

2002-01-01

44

The SIR Model for Spread of Disease  

NSDL National Science Digital Library

Created by Lang Moore and David Smith for the Connected Curriculum Project, the purpose of this module is to develop the SIR Model for the spread of an infectious disease, including the concepts of contact number and herd immunity; to develop a version of Euler's Method for solving a system of differential equations. This is one lesson within a larger set of learning modules hosted by Duke University.

Moore, Lang

45

Disease Spreading Model with Partial Isolation  

NASA Astrophysics Data System (ADS)

The effect of partial isolation has been studied in disease spreading processes using the framework of susceptible-infected-susceptible (SIS) and susceptible-infected-recovered (SIR) models. The partial isolation is introduced by imposing a restriction: each infected individual can probabilistically infect up to a maximum number n of his susceptible neighbors, but not all. It has been observed that the critical values of the spreading rates for endemic states are non-zero in both models and decrease as 1/n with n, on all graphs including scale-free graphs. In particular, the SIR model with n = 2 turned out to be a special case, characterized by a new bond percolation threshold on square lattice.

Chakraborty, Abhijit; Manna, S. S.

2013-08-01

46

Controlling the Spread of Disease in Schools  

PubMed Central

Pandemic and seasonal infectious diseases such as influenza may have serious negative health and economic consequences. Certain non-pharmaceutical intervention strategies – including school closures – can be implemented rapidly as a first line of defense against spread. Such interventions attempt to reduce the effective number of contacts between individuals within a community; yet the efficacy of closing schools to reduce disease transmission is unclear, and closures certainly result in significant economic impacts for caregivers who must stay at home to care for their children. Using individual-based computer simulation models to trace contacts among schoolchildren within a stereotypical school setting, we show how alternative school-based disease interventions have great potential to be as effective as traditional school closures without the corresponding loss of workforce and economic impacts. PMID:22242138

Ridenhour, Benjamin J.; Braun, Alexis; Teyrasse, Thomas; Goldsman, David

2011-01-01

47

Contagious Cancer  

PubMed Central

Although cancer can on occasion be caused by infectious agents such as specific bacteria, parasites, and viruses, it is not generally considered a transmissible disease. In rare circumstances, however, direct communication from one host to another has been documented. The Tasmanian devil is now threatened with extinction in the wild because of a fatal transmissible cancer, devil facial tumor disease (DFTD). Another example is canine transmissible venereal tumor (CTVT or Sticker's sarcoma) in dogs. There is a vast difference in prognosis between these two conditions. DFTD is often fatal within 6 months, whereas most cases of CTVT are eventually rejected by the host dog, who then is conferred lifelong immunity. In man, only scattered case reports exist about such communicable cancers, most often in the setting of organ or hematopoietic stem cell transplants and cancers arising during pregnancy that are transmitted to the fetus. In about one third of cases, transplant recipients develop cancers from donor organs from individuals who were found to harbor malignancies after the transplantation. The fact that two thirds of the time cancer does not develop, along with the fact that cancer very rarely is transmitted from person to person, supports the notion that natural immunity prevents such cancers from taking hold in man. These observations might hold invaluable clues to the immunobiology and possible immunotherapy of cancer. PMID:21212437

2011-01-01

48

Contagious cancer.  

PubMed

Although cancer can on occasion be caused by infectious agents such as specific bacteria, parasites, and viruses, it is not generally considered a transmissible disease. In rare circumstances, however, direct communication from one host to another has been documented. The Tasmanian devil is now threatened with extinction in the wild because of a fatal transmissible cancer, devil facial tumor disease (DFTD). Another example is canine transmissible venereal tumor (CTVT or Sticker's sarcoma) in dogs. There is a vast difference in prognosis between these two conditions. DFTD is often fatal within 6 months, whereas most cases of CTVT are eventually rejected by the host dog, who then is conferred lifelong immunity. In man, only scattered case reports exist about such communicable cancers, most often in the setting of organ or hematopoietic stem cell transplants and cancers arising during pregnancy that are transmitted to the fetus. In about one third of cases, transplant recipients develop cancers from donor organs from individuals who were found to harbor malignancies after the transplantation. The fact that two thirds of the time cancer does not develop, along with the fact that cancer very rarely is transmitted from person to person, supports the notion that natural immunity prevents such cancers from taking hold in man. These observations might hold invaluable clues to the immunobiology and possible immunotherapy of cancer. PMID:21212437

Welsh, James S

2011-01-01

49

Atmospheric Spread of Foot-and-mouth Disease During The Early Phase of The Uk Epidemic 2001  

NASA Astrophysics Data System (ADS)

Foot-and-mouth disease (FMD) is a highly contagious viral disease in cloven-hoofed domesticated and wild animals. The highly contagious nature of FMD is a reflection of the wide range of species which are susceptible, the enormous quantities of virus liberated by infected animals, the range of excretions and secretions which can be infectious, the stability of the virus in the environment, the multiplicity of routes of infection and the very small doses of virus that can initiate infection in susceptible hosts. One of the routes for the spread of the disease is the atmospheric dispersion of virus exhaled by infected animals. Such spread can be rapid and extensive, and it is known in certain circumstances to have occurred over a distance of several hundred kilometres. For the FMD epidemic in UK in 2001, atmospheric dispersion models were applied in real time in order to describe the atmospheric dispersion of virus for the larger outbreaks of the disease. The operational value of such modelling is first of all to identify risk zones, which is helpful to the emergency management. The paper addresses the modelling techniques and presents results related with the epidemic in UK in 2001.

Sørensen, J. H.; Mikkelsen, T.; Astrup, P.; Alexandersen, S.; Donaldson, A. I.

50

Modeling daily flow patterns individuals to characterize disease spread  

SciTech Connect

The effect of an individual's travels throughout a day on the spread of disease is examined using a deterministic SIR model. We determine which spatial and demographic characteristics most contribute to the disease spread and whether the progression of the disease can be slowed by appropriate vaccination of people belonging to a specific location-type.

Smallwood, J. (Jeanine); Hyman, J. M. (James M.); Mirchandani, Pitu B.

2002-11-17

51

25 CFR 167.15 - Control of livestock disease and introduction of livestock.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Control of livestock disease and introduction of livestock. 167...REGULATIONS § 167.15 Control of livestock disease and introduction of livestock...and spread of contagious or infectious disease in the economic interest of the...

2011-04-01

52

25 CFR 167.15 - Control of livestock disease and introduction of livestock.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Control of livestock disease and introduction of livestock. 167...REGULATIONS § 167.15 Control of livestock disease and introduction of livestock...and spread of contagious or infectious disease in the economic interest of the...

2013-04-01

53

25 CFR 167.15 - Control of livestock disease and introduction of livestock.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Control of livestock disease and introduction of livestock. 167...REGULATIONS § 167.15 Control of livestock disease and introduction of livestock...and spread of contagious or infectious disease in the economic interest of the...

2014-04-01

54

25 CFR 167.15 - Control of livestock disease and introduction of livestock.  

Code of Federal Regulations, 2012 CFR

...2011-04-01 true Control of livestock disease and introduction of livestock. 167...REGULATIONS § 167.15 Control of livestock disease and introduction of livestock...and spread of contagious or infectious disease in the economic interest of the...

2012-04-01

55

The Committee Studying Contagious Disease Training for Public Safety Personnel. Report of the Committee on Training of the Criminal Justice Services Board to the Governor and the General Assembly of Virginia. House Document No. 15.  

ERIC Educational Resources Information Center

Through discussion and extensive research, the Committee Studying Contagious Disease Training attempted to address concerns regarding education and training of public safety personnel with regard to human immunodeficiency virus (HIV) and hepatitis B virus (HBV). The committee's findings were based on Occupational Safety and Health Administration…

Virginia State Dept. of Criminal Justice Services, Richmond.

56

Spatial spread of farm animal diseases  

E-print Network

exist, but their relevance to the dynamics of infectious diseases on networks is unclear. To address this, a discrete-time stochastic SIR simulation model of disease on a network was designed and implemented in software. Using this simulation model, a...

Vernon, Matthew Christopher

57

Global Transport Networks and Infectious Disease Spread  

PubMed Central

Air, sea and land transport networks continue to expand in reach, speed of travel and volume of passengers and goods carried. Pathogens and their vectors can now move further, faster and in greater numbers than ever before. Three important consequences of global transport network expansion are infectious disease pandemics, vector invasion events and vector-borne pathogen importation. This review briefly examines some of the important historical examples of these disease and vector movements, such as the global influenza pandemics, the devastating Anopheles gambiae invasion of Brazil and the recent increases in imported Plasmodium falciparum malaria cases. We then outline potential approaches for future studies of disease movement, focussing on vector invasion and vector-borne disease importation. Such approaches allow us to explore the potential implications of international air travel, shipping routes and other methods of transport on global pathogen and vector traffic. PMID:16647974

Tatem, A.J.; Rogers, D.J.; Hay, S.I.

2011-01-01

58

A Computational Model of Mitigating Disease Spread in Spatial Networks  

E-print Network

progression, forest fires, computer viruses 1 #12;I. INTRODUCTION Networks are encountered in a wideA Computational Model of Mitigating Disease Spread in Spatial Networks Taehyong Kim1 , Kang Li1 model is capable of detecting disease progression to initiate processes mitigating infection

Buffalo, State University of New York

59

Marek’s disease virus pathogenesis and latency   

E-print Network

Marek’s Disease virus (MDV) is a highly contagious, widespread and persistent neoplastic ?-herpesvirus causing extensive lymphoblastic tumours in chickens. The virus is shed in feather dust and spread through inhalation. ...

Hunter, Gillian

2012-11-30

60

In vivo infection biology of contagious bovine pleuropneumonia  

E-print Network

Contagious Bovine Pleuropneumonia (CBPP), caused by Mycoplasma mycoides mycoides small colony (MmmSC), is a devastating respiratory disease of cattle in Africa, Asia and the Middle East. Little investigation has been done on molecular disease...

Gull, Tamara Brownsey

2009-05-15

61

? Several foreign animal diseases present a significant threat to the US cattle industry. The status of vaccines for high priority foreign animal diseases of cattle will be presented; including Foot and Mouth Disease, Rift Valley Fever, Rinderpest, Contagious Bovine Pleuropneumonia, and Heartwater  

Microsoft Academic Search

KEY POINTS ? Of the high priority foreign animal diseases of cattle, vaccines are only available in the US for Foot and Mouth Disease. ? Research and development is urgently needed for improved vaccines for FMD, Rift Valley Fever, Contagious Bovine Pleuropneumonia, and Heartwater. OVERVIEW OF THE ISSUE The US has a vaccine bank for Foot and Mouth Disease and

James A. Roth

62

Contagious Pustular Stomatitis, Infectious Labial Dermatitis,  

E-print Network

Contagious ecthyma is a highly contagious, zoonotic, viral skin disease that affects sheep, goats and some other domesticated and wild ruminants. The skin lesions are painful and often occur on the mouth and muzzle, where they can cause anorexia or starvation. Lesions on the udder may result in the abandonment of offspring, and foot lesions can cause transient lameness. Secondary bacterial infections can occur and, in rare cases, the lesions may extend into the internal organs. Severe generalized infections have been described in Boer and Boer cross goats. Although contagious ecthyma usually resolves spontaneously and the mortality rate is generally low, fatality rates up to 10 % have been reported. Most infections in humans are localized and heal spontaneously; however, large, poorly healing lesions can occur in people who are immunosuppressed. Etiology Contagious ecthyma results from infection by the orf virus, a member of the genus Parapoxvirus in the family Poxviridae. Geographic Distribution Contagious ecthyma has been found worldwide in all countries that raise sheep. In the U.S., this disease is seen most often in the Western states. Transmission The orf virus, which is found in skin lesions and scabs, is thought to enter the skin through cuts and abrasions. This virus can be carried by clinically normal sheep as well as sick animals. It can be transmitted by direct contact or on fomites. The orf virus remains viable on the wool and hides for approximately one month after the lesions have healed. It is very resistant to inactivation in the environment and has been recovered from dried crusts after 12 years. Contagious ecthyma vaccines contain live virus and can infect humans. Recently vaccinated animals can also transmit infections to humans. Disinfection The best disinfectants for the poxviruses are detergents, hypochlorite, alkalis, Virkon ® and glutaraldehyde.

Orf Ecthyma Contagiosum; Soremouth Scabby Mouth

2007-01-01

63

Epidemic spreading on uniform networks with two interacting diseases  

NASA Astrophysics Data System (ADS)

In this paper, we consider a pair of homogeneous diseases spreading concurrently on uniform networks based on the SIS model. A new model describing the transmission process of the interacting diseases is established. The influence of the transmission parameters, the interacting parameter and the initial density value of infected nodes on the epidemic spreading is presented by simulating the transmission process of the proposed model. The mathematical expressions of the conditions among the transmission parameters, the interacting parameter and the network parameter when diseases can exist in the network based on the simplified model are presented. Comparing the transmission process of this interacting model under different intervals of the interacting parameter, it is found that the interacting of the two diseases leads to larger scale prevalence with a relatively larger interacting parameter when the infection breaks out.

Feng, Yun; Fan, Qingli; Ma, Lin; Ding, Li

2014-01-01

64

Mathematical analysis of dynamic spread of Pine Wilt disease.  

PubMed

Since its detection in Portugal in 1999, the pinewood nematode Bursaphelenchus xylophilus (Steiner and Buhrer), a causal agent of Pine Wilt Disease, represents a threat to European forestry. Significant amount of money has been spent on its monitoring and eradication. This paper presents mathematical analysis of spread of pine wilt disease using a set of partial differential equations with space (longitude and latitude) and time as parameters of estimated spread of disease. This methodology can be used to evaluate risk of various assumed entry points of disease and make defense plans in advance. In case of an already existing outbreak, it can be used to draw optimal line of defense and plan removal of trees. Optimization constraints are economic loss of removal of susceptible trees as well as budgetary constraints of workforce cost. PMID:25151817

Dimitrijevic, D D; Bacic, J

2013-01-01

65

Modelling power-law spread of infectious diseases  

E-print Network

Short-time human travel behaviour can be well described by a power law with respect to distance. We incorporate this information in space-time models for infectious disease surveillance data to better capture the dynamics of disease spread. Two previously established model classes are extended, which both decompose disease risk additively into endemic and epidemic components: a space-time point process model for individual point-referenced data, and a multivariate time series model for aggregated count data. In both frameworks, the power-law spread is embedded into the epidemic component and its decay parameter is estimated simultaneously with all other unknown parameters using (penalised) likelihood inference. The performance of the new approach is investigated by a re-analysis of individual cases of invasive meningococcal disease in Germany (2002-2008), and count data on influenza in 140 administrative districts of Southern Germany (2001-2008). In both applications, the power-law formulations substantially ...

Meyer, Sebastian

2013-01-01

66

Evaluating the links between climate, disease spread, and amphibian declines  

E-print Network

Evaluating the links between climate, disease spread, and amphibian declines Jason R. Rohra,1 propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused

Rohr, Jason

67

FluPhone study: virtual disease spread using haggle  

Microsoft Academic Search

This paper introduces the FluPhone project, where data collection of human contact, flu-like symptoms and virtual disease spread are experimented using various phones ranging Java phones to Android phones. FluPhone uses Pocket Switched Networks as base and exploits the framework of the Haggle project.

Eiko Yoneki

2011-01-01

68

Factors Affecting the Spread of Disease in Human Populations  

NSDL National Science Digital Library

This resource is a manual for instructing a laboratory exercise in epidemiology.Students use computer simulations to examine the spread of a disease under different conditions in human populations. This exercise is suitable for courses in human health, population ecology, or epidemiology, and could be expanded to apply to general ecology or theoretical ecology courses.

Nancy L. Goodyear (Bainbridge College; )

1998-01-01

69

Spreading of diseases through comorbidity networks across life and gender  

NASA Astrophysics Data System (ADS)

The state of health of patients is typically not characterized by a single disease alone but by multiple (comorbid) medical conditions. These comorbidities may depend strongly on age and gender. We propose a specific phenomenological comorbidity network of human diseases that is based on medical claims data of the entire population of Austria. The network is constructed from a two-layer multiplex network, where in one layer the links represent the conditional probability for a comorbidity, and in the other the links contain the respective statistical significance. We show that the network undergoes dramatic structural changes across the lifetime of patients. Disease networks for children consist of a single, strongly interconnected cluster. During adolescence and adulthood further disease clusters emerge that are related to specific classes of diseases, such as circulatory, mental, or genitourinary disorders. For people over 65 these clusters start to merge, and highly connected hubs dominate the network. These hubs are related to hypertension, chronic ischemic heart diseases, and chronic obstructive pulmonary diseases. We introduce a simple diffusion model to understand the spreading of diseases on the disease network at the population level. For the first time we are able to show that patients predominantly develop diseases that are in close network proximity to disorders that they already suffer. The model explains more than 85% of the variance of all disease incidents in the population. The presented methodology could be of importance for anticipating age-dependent disease profiles for entire populations, and for design and validation of prevention strategies.

Chmiel, Anna; Klimek, Peter; Thurner, Stefan

2014-11-01

70

Spread of Infectious Diseases with a Latent Period  

E-print Network

Infectious diseases spread through human networks. Susceptible-Infected-Removed (SIR) model is one of the epidemic models to describe infection dynamics on a complex network connecting individuals. In the metapopulation SIR model, each node represents a population (group) which has many individuals. In this paper, we propose a modified metapopulation SIR model in which a latent period is taken into account. We call it SIIR model. We divide the infection period into two stages: an infected stage, which is the same as the previous model, and a seriously ill stage, in which individuals are infected and cannot move to the other populations. The two infectious stages in our modified metapopulation SIR model produce a discontinuous final size distribution. Individuals in the infected stage spread the disease like individuals in the seriously ill stage and never recover directly, which makes an effective recovery rate smaller than the given recovery rate.

Mizuno, Kanako

2015-01-01

71

The landscape genetics of infectious disease emergence and spread  

PubMed Central

The spread of parasites is inherently a spatial process often embedded in physically complex landscapes. It is therefore not surprising that infectious disease researchers are increasingly taking a landscape genetics perspective to elucidate mechanisms underlying basic ecological processes driving infectious disease dynamics and to understand the linkage between spatially-dependent population processes and the geographic distribution of genetic variation within both hosts and parasites. The increasing availability of genetic information on hosts and parasites when coupled to their ecological interactions can lead to insights for predicting patterns of disease emergence, spread, and control. Here, we review research progress in this area based on four different motivations for the application of landscape genetics approaches: (1) assessing the spatial organization of genetic variation in parasites as a function of environmental variability, (2) using host population genetic structure as a means to parameterize ecological dynamics that indirectly influence parasite populations, e.g. gene flow and movement pathways across heterogeneous landscapes and the concurrent transport of infectious agents, (3) elucidating the temporal and spatial scales of disease processes, and (4) reconstructing and understanding infectious disease invasion. Throughout this review, we emphasise that landscape genetic principles are relevant to infection dynamics across a range of scales from within host dynamics to global geographic patterns and that they can also be applied to unconventional “landscapes” such as heterogeneous contact networks underlying the spread of human and livestock diseases. We conclude by discussing some general considerations and problems for inferring epidemiological processes from genetic data and try to identify possible future directions and applications for this rapidly expanding field. PMID:20618897

Biek, Roman; Real, Leslie A.

2011-01-01

72

Airborne spread of foot-and-mouth disease - model intercomparison  

SciTech Connect

Foot-and-mouth disease is a highly infectious vesicular disease of cloven-hoofed animals caused by foot-and-mouth disease virus. It spreads by direct contact between animals, by animal products (milk, meat and semen), by mechanical transfer on people or fomites and by the airborne route - with the relative importance of each mechanism depending on the particular outbreak characteristics. Over the years a number of workers have developed or adapted atmospheric dispersion models to assess the risk of foot-and-mouth disease virus spread through the air. Six of these models were compared at a workshop hosted by the Institute for Animal Health/Met Office during 2008. A number of key issues emerged from the workshop and subsequent modelling work: (1) in general all of the models predicted similar directions for 'at risk' livestock with much of the remaining differences strongly related to differences in the meteorological data used; (2) determination of an accurate sequence of events is highly important, especially if the meteorological conditions vary substantially during the virus emission period; and (3) differences in assumptions made about virus release, environmental fate, and subsequent infection can substantially modify the size and location of the downwind risk area. Close relationships have now been established between participants, which in the event of an outbreak of disease could be readily activated to supply advice or modelling support.

Gloster, J; Jones, A; Redington, A; Burgin, L; Sorensen, J H; Turner, R; Dillon, M; Hullinger, P; Simpson, M; Astrup, P; Garner, G; Stewart, P; D'Amours, R; Sellers, R; Paton, D

2008-09-04

73

Chikungunya: an emerging and spreading arthropod-borne viral disease.  

PubMed

The virus causing Chikungunya disease was identified over 50 years ago; however, because the disease appeared only in developing countries, little research on it has been done. Research interest in the disease increased after an important epidemiological outbreak occurred in 2005 on the French metropolitan island of La Reunion located in the south-eastern part of the Indian Ocean. In 2007, a smaller outbreak of Chikungunya developed in the north-eastern part of Italy made possible by immigration of a viremic patient from the Indian Ocean area and the enormous population of Aedes albopictus in Italy. Currently, Chikungunya is spreading in Southeast Asian aspects, clinical pictures, diagnosis and treatment of the disease caused by Chikungunya virus. PMID:20009275

Cavrini, Francesca; Gaibani, Paolo; Pierro, Anna Maria; Rossini, Giada; Landini, Maria Paola; Sambri, Vittorio

2009-01-01

74

Pathways of extrapelvic spread of pelvic disease: imaging findings.  

PubMed

The complex extraperitoneal anatomy of the pelvis includes various outlets for the transit of organs and neurovascular structures to the rest of the body. These outlets include the greater sciatic foramen, lesser sciatic foramen, inguinal canal, femoral triangle, obturator canal, anal and genitourinary hiatuses of the pelvic floor, prevesical space, and iliopsoas compartment. All of these structures serve as conduits for the dissemination of malignant and benign inflammatory diseases from the pelvic cavity and into the soft-tissue structures of the abdominal wall, buttocks, and upper thigh. Knowledge of the pelvic anatomy is crucial to understand these patterns of disease spread. Cross-sectional imaging provides important anatomic information and depicts the extent of disease and its involvement of surrounding extrapelvic structures, information that is important for planning surgery and radiation therapy. PMID:21257938

Tan, Cher Heng; Vikram, Raghunandan; Boonsirikamchai, Piyaporn; Faria, Silvana C; Charnsangavej, Chusilp; Bhosale, Priya R

2011-01-01

75

Prevent the Spread of Zoonotic Diseases A zoonotic disease is a disease that can be shared between  

E-print Network

Prevent the Spread of Zoonotic Diseases A zoonotic disease is a disease that can be shared between animals and people. A person may become infected with an animal disease indirectly (from the environment). Examples of zoonotic diseases are rabies, tularemia, brucello- sis, plague, salmonellosis, and West Nile

76

The spread of disease with birth and death on networks  

NASA Astrophysics Data System (ADS)

We introduce a modified epidemic model on regular and scale-free networks. In this model, we consider the birth rate dgr, cure rate ggr, infection rate lgr, and death rates agr and bgr. Through mean-field analysis, we find that on a regular network there is an epidemic threshold lgrc dependent on the parameters dgr, ggr, agr, and bgr, while for a power law degree distribution network the epidemic threshold is absent in the thermodynamic limit. The result is the same as that of the standard SIS model. This reminds us that the structure of the networks plays a very important role in the spreading properties of infectious disease.

Liu, Jingzhou; Tang, Yifa; Yang, Z. R.

2004-08-01

77

The Cost of Simplifying Air Travel When Modeling Disease Spread  

PubMed Central

Background Air travel plays a key role in the spread of many pathogens. Modeling the long distance spread of infectious disease in these cases requires an air travel model. Highly detailed air transportation models can be over determined and computationally problematic. We compared the predictions of a simplified air transport model with those of a model of all routes and assessed the impact of differences on models of infectious disease. Methodology/Principal Findings Using U.S. ticket data from 2007, we compared a simplified “pipe” model, in which individuals flow in and out of the air transport system based on the number of arrivals and departures from a given airport, to a fully saturated model where all routes are modeled individually. We also compared the pipe model to a “gravity” model where the probability of travel is scaled by physical distance; the gravity model did not differ significantly from the pipe model. The pipe model roughly approximated actual air travel, but tended to overestimate the number of trips between small airports and underestimate travel between major east and west coast airports. For most routes, the maximum number of false (or missed) introductions of disease is small (<1 per day) but for a few routes this rate is greatly underestimated by the pipe model. Conclusions/Significance If our interest is in large scale regional and national effects of disease, the simplified pipe model may be adequate. If we are interested in specific effects of interventions on particular air routes or the time for the disease to reach a particular location, a more complex point-to-point model will be more accurate. For many problems a hybrid model that independently models some frequently traveled routes may be the best choice. Regardless of the model used, the effect of simplifications and sensitivity to errors in parameter estimation should be analyzed. PMID:19197382

Lessler, Justin; Kaufman, James H.; Ford, Daniel A.; Douglas, Judith V.

2009-01-01

78

Computational Study of Ventilation and Disease Spread in Poultry Houses  

NASA Astrophysics Data System (ADS)

The air flow in and around poultry houses has been studied numerically with the goal of determining disease spread characteristics and comparing ventilation schemes. A typical manure-belt layer egg production facility is considered. The continuity, momentum, and energy equations are solved for flow both inside and outside poultry houses using the commercial computational fluid dynamics (CFD) code FLUENT. Both simplified two-dimensional and fully three-dimensional geometries are modeled. The spread of virus particles is considered to be analogous to diffusion of a tracer contaminant gas, in this case ammonia. The effect of thermal plumes produced by the hens in the poultry house is also considered. Two ventilation schemes with opposite flow directions are compared. Contours of temperature and ammonia mass fraction for both cases are obtained and compared. The analysis shows that ventilation and air quality characteristics are much better for the case in which the air flow is from bottom to top (enhancing the thermal plume) instead of from top to bottom (fighting the thermal plume) as in most poultry houses. This has implications in air quality control in the event of epidemic outbreaks of avian flu or other infectious diseases.

Cimbala, John; Pawar, Sourabh; Wheeler, Eileen; Lindberg, Darla

2006-11-01

79

Global analysis for spread of infectious diseases via transportation networks.  

PubMed

We formulate an epidemic model for the spread of an infectious disease along with population dispersal over an arbitrary number of distinct regions. Structuring the population by the time elapsed since the start of travel, we describe the infectious disease dynamics during transportation as well as in the regions. As a result, we obtain a system of delay differential equations. We define the basic reproduction number [Formula: see text] as the spectral radius of a next generation matrix. For multi-regional systems with strongly connected transportation networks, we prove that if [Formula: see text] then the disease will be eradicated from each region, while if [Formula: see text] there is a globally asymptotically stable equilibrium, which is endemic in every region. If the transportation network is not strongly connected, then the model analysis shows that numerous endemic patterns can exist by admitting a globally asymptotically stable equilibrium, which may be disease free in some regions while endemic in other regions. We provide a procedure to detect the disease free and the endemic regions according to the network topology and local reproduction numbers. The main ingredients of the mathematical proofs are the inductive applications of the theory of asymptotically autonomous semiflows and cooperative dynamical systems. We visualise stability boundaries of equilibria in a parameter plane to illustrate the influence of the transportation network on the disease dynamics. For a system consisting of two regions, we find that due to spatial heterogeneity characterised by different local reproduction numbers, [Formula: see text] may depend non-monotonically on the dispersal rates, thus travel restrictions are not always beneficial. PMID:24948128

Nakata, Yukihiko; Röst, Gergely

2015-05-01

80

Monogamous networks and the spread of sexually transmitted diseases.  

PubMed

Patterns of sexual mixing and heterogeneity in the number of sexual partners can have a huge effect on the spread of a sexually transmitted disease (STD). The sexual mixing network identifies all partnerships within a population over a given period and is a powerful tool in the study of such infections. Previous models assumed all links within the network to be concurrent active partnerships. We present a novel modelling approach in which we adapt the notion of a sexual contact network to a monogamous population by allowing the nature of the links to change. We use the underlying network to represent potential sexual partnerships, only some of which are active at any one time. Thus serial monogamy can be modelled while maintaining the patterns of mixing displayed by the population. PMID:15094315

Eames, Ken T D; Keeling, Matt J

2004-06-01

81

Does genetic diversity limit disease spread in natural host populations?  

PubMed Central

It is a commonly held view that genetically homogenous host populations are more vulnerable to infection than genetically diverse populations. The underlying idea, known as the ‘monoculture effect,' is well documented in agricultural studies. Low genetic diversity in the wild can result from bottlenecks (that is, founder effects), biparental inbreeding or self-fertilization, any of which might increase the risk of epidemics. Host genetic diversity could buffer populations against epidemics in nature, but it is not clear how much diversity is required to prevent disease spread. Recent theoretical and empirical studies, particularly in Daphnia populations, have helped to establish that genetic diversity can reduce parasite transmission. Here, we review the present theoretical work and empirical evidence, and we suggest a new focus on finding ‘diversity thresholds.' PMID:22713998

King, K C; Lively, C M

2012-01-01

82

Spreading of periodic diseases and synchronization phenomena on networks  

NASA Astrophysics Data System (ADS)

In this paper, we investigate numerically the Susceptible-Infected-Recovered-Susceptible (SIRS) epidemic model on an exponential network generated by a preferential attachment procedure. The discrete SIRS model considers two main parameters: the duration ?0 of the complete infection-recovery cycle and the duration ?I of infection. A permanent source of infection I0 has also been introduced in order to avoid the vanishing of the disease in the SIRS model. The fraction of infected agents is found to oscillate with a period T??0. Simulations reveal that the average fraction of infected agents depends on I0 and ?I/?0. A maximum of synchronization of infected agents, i.e. a maximum amplitude of periodic spreading oscillations, is found to occur when the ratio ?I/?0 is slightly smaller than 1/2. The model is in agreement with the general observation that an outbreak corresponds to high ?I/?0 values.

Ababou, M.; Vandewalle, N.; Moussa, N.; El Bouziani, M.; Ludewig, F.

2013-05-01

83

Drivers of disease emergence and spread: is wildlife to blame?  

PubMed

The global focus on wildlife as a major contributor to emerging pathogens and infectious diseases (EIDs) in humans and domestic animals is not based on field, experimental or dedicated research, but mostly on limited surveys of literature, opinion and the assumption that biodiversity harbours pathogens. The perceived and direct impacts of wildlife, from being a reservoir of certain human and livestock pathogens and as a risk to health, are frequently overstated when compared to the Global burden of disease statistics available from WHO, OIE and FAO. However organisms that evolve in wildlife species can and do spill-over into human landscapes and humans and domestic animal population and, where these organisms adapt to surviving and spreading amongst livestock and humans, these emerging infections can have significant consequences. Drivers for the spill-over of pathogens or evolution of organisms from wildlife reservoirs to become pathogens of humans and domestic animals are varied but almost without exception poorly researched. The changing demographics, spatial distribution and movements, associated landscape modifications (especially agricultural) and behavioural changes involving human and domestic animal populations are probably the core drivers of the apparent increasing trend in emergence of new pathogens and infectious diseases over recent decades. PMID:25005349

Kock, Richard

2014-01-01

84

Contagious cancer: lessons from the devil and the dog.  

PubMed

Cancer is generally defined as uncontrollable growth of cells caused by genetic aberrations and/or environmental factors. Yet contagious cancers also occur. The recent emergence of a contagious cancer in Tasmanian devils has reignited interest in transmissible cancers. Two naturally occurring transmissible cancers are known: devil facial tumour disease and canine transmissible venereal tumour. Both cancers evolved once and have then been transmitted from one individual to another as clonal cell lines. The dog cancer is ancient; having evolved more than 6,000 years ago, while the devil disease was first seen in 1996. In this review I will compare and contrast the two diseases focusing on the life histories of the clonal cell lines, their evolutionary trajectories and the mechanisms by which they have achieved immune tolerance. A greater understanding of these contagious cancers will provide unique insights into the role of the immune system in shaping tumour evolution and may uncover novel approaches for treating human cancer. PMID:22383221

Belov, Katherine

2012-04-01

85

Modeling spatial spread of infectious diseases with a fixed latent period in a spatially continuous domain  

E-print Network

Modeling spatial spread of infectious diseases with a fixed latent period in a spatially continuous, March 2009 Abstract In this paper, with the assumptions that an infectious disease in a population has, the simulations on the PDE model also suggest that the spread speed of the disease indeed coincides with c. We

Linder, Tamás

86

Spatial spread of an emerging infectious disease: conjunctivitis in House Finches.  

PubMed

In this paper we quantify the rate of spread of the newly emerged pathogen Mycoplasma gallisepticum of the House Finch, Carpodacus mexicanus, in its introduced range. We compare and contrast the rapid, yet decelerating, rate of spread of the pathogen with the slower, yet accelerating rate of spread of the introduced host. Comparing the rate of spread of this pathogen to pathogens in terrestrial mammalian hosts, we see that elevation and factors relating to host abundance restrict disease spread, rather than finding any major effects of discrete barriers or anthropogenic movement. We examine the role of seasonality in the rate of spread, finding that the rate and direction of disease spread relates more to seasonality in host movement than to seasonality in disease prevalence. We conclude that asymptomatic carriers are major transmitters of Mycoplasma gallisepticum into novel locations, a finding which may also be true for many other diseases, such as West Nile Virus and avian influenza. PMID:17249229

Hosseini, Parviez R; Dhondt, André A; Dobson, Andy P

2006-12-01

87

Alpha-synuclein spreading in Parkinson’s disease  

PubMed Central

Formation and accumulation of misfolded protein aggregates are a central hallmark of several neurodegenerative diseases. In Parkinson’s disease (PD), the aggregation-prone protein alpha-synuclein (?-syn) is the culprit. In the past few years, another piece of the puzzle has been added with data suggesting that ?-syn may self-propagate, thereby contributing to the progression and extension of PD. Of particular importance, it was the seminal observation of Lewy bodies (LB), a histopathological signature of PD, in grafted fetal dopaminergic neurons in the striatum of PD patients. Consequently, these findings were a conceptual breakthrough, generating the “host to graft transmission” hypothesis, also called the “prion-like hypothesis.” Several in vitro and in vivo studies suggest that ?-syn can undergo a toxic templated conformational change, spread from cell to cell and from region to region, and initiate the formation of “LB–like aggregates,” contributing to the PD pathogenesis. Here, we will review and discuss the current knowledge for such a putative mechanism on the prion-like nature of ?-syn, and discuss about the proper use of the term prion-like. PMID:25565982

Recasens, Ariadna; Dehay, Benjamin

2014-01-01

88

9 CFR 147.27 - Procedures recommended to prevent the spread of disease by artificial insemination of turkeys.  

Code of Federal Regulations, 2012 CFR

...Procedures recommended to prevent the spread of disease by artificial insemination of turkeys...Procedures recommended to prevent the spread of disease by artificial insemination of turkeys...be inseminated. If evidence of active disease is noted after insemination is...

2012-01-01

89

9 CFR 147.27 - Procedures recommended to prevent the spread of disease by artificial insemination of turkeys.  

Code of Federal Regulations, 2013 CFR

...Procedures recommended to prevent the spread of disease by artificial insemination of turkeys...Procedures recommended to prevent the spread of disease by artificial insemination of turkeys...be inseminated. If evidence of active disease is noted after insemination is...

2013-01-01

90

9 CFR 147.27 - Procedures recommended to prevent the spread of disease by artificial insemination of turkeys.  

Code of Federal Regulations, 2011 CFR

...Procedures recommended to prevent the spread of disease by artificial insemination of turkeys...Procedures recommended to prevent the spread of disease by artificial insemination of turkeys...be inseminated. If evidence of active disease is noted after insemination is...

2011-01-01

91

9 CFR 147.27 - Procedures recommended to prevent the spread of disease by artificial insemination of turkeys.  

Code of Federal Regulations, 2014 CFR

...Procedures recommended to prevent the spread of disease by artificial insemination of turkeys...Procedures recommended to prevent the spread of disease by artificial insemination of turkeys...be inseminated. If evidence of active disease is noted after insemination is...

2014-01-01

92

GIS-Based Epidemiological Modeling of an Emerging Forest Disease: Spread of  

E-print Network

247 GIS-Based Epidemiological Modeling of an Emerging Forest Disease: Spread of Sudden Oak Death applied in a GIS to real-world wildland landscapes. In this paper, we present and evaluate a GIS model was implemented (1990-2005) in a GIS to simulate disease spread across California at a spatial

Standiford, Richard B.

93

9 CFR 147.27 - Procedures recommended to prevent the spread of disease by artificial insemination of turkeys.  

Code of Federal Regulations, 2010 CFR

...the spread of disease by artificial insemination of turkeys. 147.27 Section...the spread of disease by artificial insemination of turkeys. (a) The vehicle transporting the insemination crew should be left as far as...

2010-01-01

94

An alternate delivery system improves vaccine performance against foot-and-mouth disease virus (FMDV)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease virus (FMDV) causes vesicular disease of cloven-hoofed animals with severe agricultural and economic implications. One of the most highly infectious and contagious livestock pathogens known, the disease spreads rapidly in naïve populations making it critical to have rapidly ac...

95

Some Similarities between the Spread of an Infectious Disease and Population Growth  

NSDL National Science Digital Library

A simple simulation demonstrates how spread of an infectious disease can result in exponential increase in the number of infected individuals. Discussion questions and a graphing activity develop an understanding of exponential and logistic population growth.

Jennifer Doherty

96

Modelling the initial spread of foot-and-mouth disease through animal movements  

E-print Network

Modelling the initial spread of foot-and-mouth disease through animal movements D. M. Green*, I. Z, as in the 2001 epidemic of foot-and-mouth disease (FMD) in the UK. Here, the movement data are used to construct of England than elsewhere. Keywords: modelling; epidemiology; foot-and-mouth disease 1. INTRODUCTION Control

Kiss, Istvan Zoltan

97

Modeling social response to the spread of an infectious disease  

E-print Network

With the globalization of culture and economic trade, it is increasingly important not only to detect outbreaks of infectious disease early, but also to anticipate the social response to the disease. In this thesis, we use ...

Evans, Jane A. (Jane Amanda)

2012-01-01

98

Spreading of infectious diseases on complex networks with non-symmetric transmission probabilities  

E-print Network

We model the spread of a SIS infection on Small World and random networks using weighted graphs. The entry $w_{ij}$ in the weight matrix W holds information about the transmission probability along the edge joining node $v_i$ and node $v_j$. We use the analogy between the spread of a disease on a network and a random walk performed on this network to derive a master equation describing the dynamics of the process. We find conditions under which an epidemic does not break out and investigate numerically the effect of a non-symmetric weight distribution of the initially infected individual on the dynamics of the disease spread.

Britta Daudert; Bai-Lian Li

2006-11-23

99

Beech bark disease: spatial patterns of thicket formation and disease spread in an aftermath forest in the northeastern  

E-print Network

in the Adirondack Mountains of New York using location and disease severity of beech trees. A bivariate point northern hardwood forests of North America. Key words: Adirondack Mountains, American beech, BBD, beechARTICLE Beech bark disease: spatial patterns of thicket formation and disease spread

Mountrakis, Giorgos

100

Disease Evolution Models, Concepts, and Data Analyses  

E-print Network

the invasion and spread of contagious diseases Wayne M. Getz and James O. Lloyd-Smith 87 Section II popula- tions Wayne M. Getz, James O. Lloyd-Smith, Paul C. Cross, Shirli Bar-David, Philip L. Johnson and dynamic models of infection with internal host structure John K. Kelly 67 Basic methods for modeling

Dieckmann, Ulf

101

Control of the deliberate spread of foot-and-mouth disease virus.  

PubMed

Foot-and-mouth disease (FMD) is one of the most feared of transboundary animal diseases. Accidental or deliberate release of the causative agent can have both direct and indirect effects that result in massive economic losses and disruption. The direct effects of an FMD outbreak include immediate losses to agricultural production and disruption of local economies, while the indirect effects are mainly related to disease control measures such as restriction of market access at local and global levels and the high costs of disease control. To improve the capacity of the European Union (EU) to counter animal bioterrorism threats, AniBioThreat was launched with a special focus on threats to living animals, feed, and food of animal origin. As part of this project, several zoonotic or animal pathogenic agents are considered from different perspectives. FMD virus was selected as one agent to be scrutinized because it is highly contagious and an outbreak can have a severe economic impact. Ways to fight a deliberate outbreak can be demonstrated through the example of FMD. In this article, the virology and epidemiology of FMD virus are discussed with special attention to the related law enforcement aspects. PMID:23971796

Farsang, Attila; Frentzel, Hendrik; Kulcsár, Gábor; Soós, Tibor

2013-09-01

102

Simulation of between-farm transmission of porcine reproductive and respiratory syndrome virus in Ontario, Canada using the North American Animal Disease Spread Model.  

PubMed

Porcine reproductive and respiratory syndrome (PRRS), a viral disease of swine, has major economic impacts on the swine industry. The North American Animal Disease Spread Model (NAADSM) is a spatial, stochastic, farm level state-transition modeling framework originally developed to simulate highly contagious and foreign livestock diseases. The objectives of this study were to develop a model to simulate between-farm spread of a homologous strain of PRRS virus in Ontario swine farms via direct (animal movement) and indirect (sharing of trucks between farms) contacts using the NAADSM and to compare the patterns and extent of outbreak under different simulated conditions. A total of 2552 swine farms in Ontario province were allocated to each census division of Ontario and geo-locations of the farms were randomly generated within the agriculture land of each Census Division. Contact rates among different production types were obtained using pig movement information from four regions in Canada. A total of 24 scenarios were developed involving various direct (movement of infected animals) and indirect (pig transportation trucks) contact parameters in combination with alternating the production type of the farm in which the infection was seeded. Outbreaks were simulated for one year with 1000 replications. The median number of farms infected, proportion of farms with multiple outbreaks and time to reach the peak epidemic were used to compare the size, progression and extent of outbreaks. Scenarios involving spread only by direct contact between farms resulted in outbreaks where the median percentage of infected farms ranged from 31.5 to 37% of all farms. In scenarios with both direct and indirect contact, the median percentage of infected farms increased to a range from 41.6 to 48.6%. Furthermore, scenarios with both direct and indirect contact resulted in a 44% increase in median epidemic size when compared to the direct contact scenarios. Incorporation of both animal movements and the sharing of trucks within the model indicated that the effect of direct and indirect contact may be nonlinear on outbreak progression. The increase of 44% in epidemic size when indirect contact, via sharing of trucks, was incorporated into the model highlights the importance of proper biosecurity measures in preventing transmission of the PRRS virus. Simulation of between-farm spread of the PRRS virus in swine farms has highlighted the relative importance of direct and indirect contact and provides important insights regarding the possible patterns and extent of spread of the PRRS virus in a completely susceptible population with herd demographics similar to those found in Ontario, Canada. PMID:25636969

Thakur, Krishna K; Revie, Crawford W; Hurnik, Daniel; Poljak, Zvonimir; Sanchez, Javier

2015-03-01

103

Evaluating the links between climate, disease spread, and amphibian declines  

PubMed Central

Human alteration of the environment has arguably propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd), and two contrasting hypotheses have been proposed to explain these declines. Positive correlations between global warming and Bd-related declines sparked the chytrid-thermal-optimum hypothesis, which proposes that global warming increased cloud cover in warm years that drove the convergence of daytime and nighttime temperatures toward the thermal optimum for Bd growth. In contrast, the spatiotemporal-spread hypothesis states that Bd-related declines are caused by the introduction and spread of Bd, independent of climate change. We provide a rigorous test of these hypotheses by evaluating (i) whether cloud cover, temperature convergence, and predicted temperature-dependent Bd growth are significant positive predictors of amphibian extinctions in the genus Atelopus and (ii) whether spatial structure in the timing of these extinctions can be detected without making assumptions about the location, timing, or number of Bd emergences. We show that there is spatial structure to the timing of Atelopus spp. extinctions but that the cause of this structure remains equivocal, emphasizing the need for further molecular characterization of Bd. We also show that the reported positive multi-decade correlation between Atelopus spp. extinctions and mean tropical air temperature in the previous year is indeed robust, but the evidence that it is causal is weak because numerous other variables, including regional banana and beer production, were better predictors of these extinctions. Finally, almost all of our findings were opposite to the predictions of the chytrid-thermal-optimum hypothesis. Although climate change is likely to play an important role in worldwide amphibian declines, more convincing evidence is needed of a causal link. PMID:18987318

Rohr, Jason R.; Raffel, Thomas R.; Romansic, John M.; McCallum, Hamish; Hudson, Peter J.

2008-01-01

104

A Branching Model for the Spread of Infectious Animal Diseases in Varying  

E-print Network

A Branching Model for the Spread of Infectious Animal Diseases in Varying Environments Pieter with a stochastic model, describing out- breaks of infectious diseases that have potentially great animal or hu- man. With this branching process, we estimate the probability of extinction and the expected number of infected individuals

Meester, Ronald

105

MATHEMATICAL MODELS OF CONTACT PATTERNS BETWEEN AGE GROUPS FOR PREDICTING THE SPREAD OF INFECTIOUS DISEASES  

PubMed Central

The spread of an infectious disease is sensitive to the contact patterns in the population and to precautions people take to reduce the transmission of the disease. We investigate the impact that different mixing assumptions have on the spread an infectious disease in an age-structured ordinary differential equation model. We consider the impact of heterogeneity in susceptibility and infectivity within the population on the disease transmission. We apply the analysis to the spread of a smallpox-like disease, derive the formula for the reproduction number, R0, and based on this threshold parameter, show the level of human behavioral change required to control the epidemic. We analyze how different mixing patterns can affect the disease prevalence, the cumulative number of new infections, and the final epidemic size. Our analysis indicates that the combination of residual immunity and behavioral changes during a smallpox-like disease outbreak can play a key role in halting infectious disease spread; and that realistic mixing patterns must be included in the epidemic model for the predictions to accurately reflect reality. PMID:24245626

Del Valle, Sara Y.; Hyman, James M.; Chitnis, Nakul

2014-01-01

106

The potential role of wildlife in the spread and control of foot and mouth disease in an extensive livestock management system  

E-print Network

Foot and mouth disease (FMD) is a highly contagious viral infection that affects all Artiodactyls (cloven-hoofed) species. The United States has been free of FMD since 1929, and the entire population of cloven-hoofed species is therefore susceptible...

Highfield, Linda

2009-05-15

107

Chronic Wasting Disease  

USGS Publications Warehouse

Chronic wasting disease (CWD) is an always-fatal, neurological illness occurring in North American cervids (members of the deer family), including white-tailed deer, mule deer, elk and moose. Since its discovery in 1967, CWD has spread geographically and increased in prevalence locally. CWD is contagious; it can be transmitted freely within and among free-ranging populations. It is likely that diseased animals can transmit CWD to healthy animals long before they become clinically ill. Managing CWD in free-ranging populations is extremely difficult, therefore preventative measures designed to reduce the chance for disease spread are critically important.

Richards, Bryan

2007-01-01

108

Multiscale mobility networks and the spatial spreading of infectious diseases.  

PubMed

Among the realistic ingredients to be considered in the computational modeling of infectious diseases, human mobility represents a crucial challenge both on the theoretical side and in view of the limited availability of empirical data. To study the interplay between short-scale commuting flows and long-range airline traffic in shaping the spatiotemporal pattern of a global epidemic we (i) analyze mobility data from 29 countries around the world and find a gravity model able to provide a global description of commuting patterns up to 300 kms and (ii) integrate in a worldwide-structured metapopulation epidemic model a timescale-separation technique for evaluating the force of infection due to multiscale mobility processes in the disease dynamics. Commuting flows are found, on average, to be one order of magnitude larger than airline flows. However, their introduction into the worldwide model shows that the large-scale pattern of the simulated epidemic exhibits only small variations with respect to the baseline case where only airline traffic is considered. The presence of short-range mobility increases, however, the synchronization of subpopulations in close proximity and affects the epidemic behavior at the periphery of the airline transportation infrastructure. The present approach outlines the possibility for the definition of layered computational approaches where different modeling assumptions and granularities can be used consistently in a unifying multiscale framework. PMID:20018697

Balcan, Duygu; Colizza, Vittoria; Gonçalves, Bruno; Hu, Hao; Ramasco, José J; Vespignani, Alessandro

2009-12-22

109

Multiscale mobility networks and the spatial spreading of infectious diseases  

PubMed Central

Among the realistic ingredients to be considered in the computational modeling of infectious diseases, human mobility represents a crucial challenge both on the theoretical side and in view of the limited availability of empirical data. To study the interplay between short-scale commuting flows and long-range airline traffic in shaping the spatiotemporal pattern of a global epidemic we (i) analyze mobility data from 29 countries around the world and find a gravity model able to provide a global description of commuting patterns up to 300 kms and (ii) integrate in a worldwide-structured metapopulation epidemic model a timescale-separation technique for evaluating the force of infection due to multiscale mobility processes in the disease dynamics. Commuting flows are found, on average, to be one order of magnitude larger than airline flows. However, their introduction into the worldwide model shows that the large-scale pattern of the simulated epidemic exhibits only small variations with respect to the baseline case where only airline traffic is considered. The presence of short-range mobility increases, however, the synchronization of subpopulations in close proximity and affects the epidemic behavior at the periphery of the airline transportation infrastructure. The present approach outlines the possibility for the definition of layered computational approaches where different modeling assumptions and granularities can be used consistently in a unifying multiscale framework. PMID:20018697

Balcan, Duygu; Colizza, Vittoria; Gonçalves, Bruno; Hu, Hao; Ramasco, José J.; Vespignani, Alessandro

2009-01-01

110

Modeling the spatial spread of infectious diseases: the GLobal Epidemic and Mobility computational model  

PubMed Central

Here we present the Global Epidemic and Mobility (GLEaM) model that integrates sociodemographic and population mobility data in a spatially structured stochastic disease approach to simulate the spread of epidemics at the worldwide scale. We discuss the flexible structure of the model that is open to the inclusion of different disease structures and local intervention policies. This makes GLEaM suitable for the computational modeling and anticipation of the spatio-temporal patterns of global epidemic spreading, the understanding of historical epidemics, the assessment of the role of human mobility in shaping global epidemics, and the analysis of mitigation and containment scenarios. PMID:21415939

Balcan, Duygu; Gonçalves, Bruno; Hu, Hao; Ramasco, José J.; Colizza, Vittoria

2010-01-01

111

Disease Risk in a Dynamic Environment: The Spread of Tick-Borne Pathogens in Minnesota, USA.  

PubMed

As humans and climate change alter the landscape, novel disease risk scenarios emerge. Understanding the complexities of pathogen emergence and subsequent spread as shaped by landscape heterogeneity is crucial to understanding disease emergence, pinpointing high-risk areas, and mitigating emerging disease threats in a dynamic environment. Tick-borne diseases present an important public health concern and incidence of many of these diseases are increasing in the United States. The complex epidemiology of tick-borne diseases includes strong ties with environmental factors that influence host availability, vector abundance, and pathogen transmission. Here, we used 16 years of case data from the Minnesota Department of Health to report spatial and temporal trends in Lyme disease (LD), human anaplasmosis, and babesiosis. We then used a spatial regression framework to evaluate the impact of landscape and climate factors on the spread of LD. Finally, we use the fitted model, and landscape and climate datasets projected under varying climate change scenarios, to predict future changes in tick-borne pathogen risk. Both forested habitat and temperature were important drivers of LD spread in Minnesota. Dramatic changes in future temperature regimes and forest communities predict rising risk of tick-borne disease. PMID:25281302

Robinson, Stacie J; Neitzel, David F; Moen, Ronald A; Craft, Meggan E; Hamilton, Karin E; Johnson, Lucinda B; Mulla, David J; Munderloh, Ulrike G; Redig, Patrick T; Smith, Kirk E; Turner, Clarence L; Umber, Jamie K; Pelican, Katharine M

2014-10-01

112

Porcine type I interferon rapidly protects swine against challenge with multiple serotypes of foot-and-mouth disease virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hoofed animals that rapidly replicates and spreads within infected animals and into the environment. Vaccines require approximately 7 days to induce protection, but prior to this time vaccinated animals are still suscep...

113

The arrival, establishment and spread of exotic diseases: patterns and predictions  

Microsoft Academic Search

The impact of human activities on the principles and processes governing the arrival, establishment and spread of exotic pathogens is illustrated by vector-borne diseases such as malaria, dengue, chikungunya, West Nile, bluetongue and Crimean–Congo haemorrhagic fevers. Competent vectors, which are commonly already present in the areas, provide opportunities for infection by exotic pathogens that are introduced by travel and trade.

David J. Rogers; Sarah E. Randolph

2010-01-01

114

Predicting the Spread of Plant Disease: Analysis of an Infinite-Dimensional Leslie Matrix Model for  

E-print Network

in plant pop- ulations, o¨omycetes have much in common with fungal pathogens. Their life cycle includes because of its practical importance and because its life cycle attributes are well studied. The host plant, more related to algae than to fungi. Epidemiologically however, with regard to the spread of disease

Powell, James

115

The role of wild animals in the spread of exotic diseases in Australia.  

PubMed

The distributions of the following feral animals are given -- cattle, buffalo, pig, goat, deer, camel, horse, donkey, fox, dog and cat -- and the native dingo. The possible role these and the native rodents, marsupials and monotremes would play should an exotic disease of livestock enter Australia is discussed. It is considered that feral animals would be important in creating foci from which the disease would spread. PMID:1021109

Murray, M D; Snowdon, W A

1976-12-01

116

Catch the wave: prairie dogs assess neighbours’ awareness using contagious displays  

PubMed Central

The jump–yip display of black-tailed prairie dogs (Cynomys ludovicianus) is contagious, spreading through a prairie dog town as ‘the wave’ through a stadium. Because contagious communication in primates serves to assess conspecific social awareness, we investigated whether instigators of jump–yip bouts adjusted their behaviour relative to the response of conspecifics recruited to display bouts. Increased responsiveness of neighbouring town members resulted in bout initiators devoting a significantly greater proportion of time to active foraging. Contagious jump–yips thus function to assess neighbours’ alertness, soliciting social information to assess effective conspecific group size in real time and reveal active probing of conspecific awareness consistent with theory of mind in these group-living rodents. PMID:24403324

Hare, James F.; Campbell, Kevin L.; Senkiw, Robert W.

2014-01-01

117

Catch the wave: prairie dogs assess neighbours' awareness using contagious displays.  

PubMed

The jump-yip display of black-tailed prairie dogs (Cynomys ludovicianus) is contagious, spreading through a prairie dog town as 'the wave' through a stadium. Because contagious communication in primates serves to assess conspecific social awareness, we investigated whether instigators of jump-yip bouts adjusted their behaviour relative to the response of conspecifics recruited to display bouts. Increased responsiveness of neighbouring town members resulted in bout initiators devoting a significantly greater proportion of time to active foraging. Contagious jump-yips thus function to assess neighbours' alertness, soliciting social information to assess effective conspecific group size in real time and reveal active probing of conspecific awareness consistent with theory of mind in these group-living rodents. PMID:24403324

Hare, James F; Campbell, Kevin L; Senkiw, Robert W

2014-02-22

118

Disease properties, geography, and mitigation strategies in a simulation spread of rinderpest across the United States  

PubMed Central

For the past decade, the Food and Agriculture Organization of the United Nations has been working toward eradicating rinderpest through vaccination and intense surveillance by 2012. Because of the potential severity of a rinderpest epidemic, it is prudent to prepare for an unexpected outbreak in animal populations. There is no immunity to the disease among the livestock or wildlife in the United States (US). If rinderpest were to emerge in the US, the loss in livestock could be devastating. We predict the potential spread of rinderpest using a two-stage model for the spread of a multi-host infectious disease among agricultural animals in the US. The model incorporates large-scale interactions among US counties and the small-scale dynamics of disease spread within a county. The model epidemic was seeded in 16 locations and there was a strong dependence of the overall epidemic size on the starting location. The epidemics were classified according to overall size into small epidemics of 100 to 300 animals (failed epidemics), epidemics infecting 3 000 to 30 000 animals (medium epidemics), and the large epidemics infecting around one million beef cattle. The size of the rinderpest epidemics were directly related to the origin of the disease and whether or not the disease moved into certain key counties in high-livestock-density areas of the US. The epidemic size also depended upon response time and effectiveness of movement controls. PMID:21435236

2011-01-01

119

Disinfection of foot-and-mouth disease and African swine fever viruses with citric acid and sodium hypochlorite on birch wood carriers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Transboundary animal disease viruses such as foot-and-mouth disease virus (FMDV) and African swine fever virus (ASFV) are highly contagious and cause severe morbidity and mortality in livestock. Proper disinfection during an outbreak can help prevent virus spread and will shorten the time for contam...

120

Herpes Simplex Virus Type 1 Glycoprotein E Domains Involved in Virus Spread and Disease  

PubMed Central

Herpes simplex virus type 1 (HSV-1) glycoprotein E (gE) functions as an immunoglobulin G (IgG) Fc binding protein and is involved in virus spread. Previously we studied a gE mutant virus that was impaired for IgG Fc binding but intact for spread and another that was normal for both activities. To further evaluate the role of gE in spread, two additional mutant viruses were constructed by introducing linker insertion mutations either outside the IgG Fc binding domain at gE position 210 or within the IgG Fc binding domain at position 380. Both mutant viruses were impaired for spread in epidermal cells in vitro; however, the 380 mutant virus was significantly more impaired and was as defective as gE null virus. gE mutant viruses were inoculated into the murine flank to measure epidermal disease at the inoculation site, travel of virus to dorsal root ganglia, and spread of virus from ganglia back to skin to produce zosteriform lesions. Disease at the inoculation and zosteriform sites was reduced for both mutant viruses, but more so for the 380 mutant virus. Moreover, the 380 mutant virus was highly impaired in its ability to reach the ganglia, as demonstrated by virus culture and real-time quantitative PCR. The results indicate that the domain surrounding amino acid 380 is important for both spread and IgG Fc binding and suggest that this domain is a potential target for antiviral therapy or vaccines. PMID:10888608

Saldanha, Charles E.; Lubinski, John; Martin, Claudia; Nagashunmugam, Thandavarayan; Wang, Liyang; van der Keyl, Harjeet; Tal-Singer, Ruth; Friedman, Harvey M.

2000-01-01

121

New Insights into the Role of MHC Diversity in Devil Facial Tumour Disease  

Microsoft Academic Search

BackgroundDevil facial tumour disease (DFTD) is a fatal contagious cancer that has decimated Tasmanian devil populations. The tumour has spread without invoking immune responses, possibly due to low levels of Major Histocompatibility Complex (MHC) diversity in Tasmanian devils. Animals from a region in north-western Tasmania have lower infection rates than those in the east of the state. This area is

Yuanyuan Cheng; Belinda Wright; Rodrigo Hamede; Laura Levan; Menna Jones; Beata Ujvari; Katherine Belov

2012-01-01

122

Chronic contamination decreases disease spread: a Daphnia–fungus–copper case study  

PubMed Central

Chemical contamination and disease outbreaks have increased in many ecosystems. However, connecting pollution to disease spread remains difficult, in part, because contaminants can simultaneously exert direct and multi-generational effects on several host and parasite traits. To address these challenges, we parametrized a model using a zooplankton–fungus–copper system. In individual-level assays, we considered three sublethal contamination scenarios: no contamination, single-generation contamination (hosts and parasites exposed only during the assays) and multi-generational contamination (hosts and parasites exposed for several generations prior to and during the assays). Contamination boosted transmission by increasing contact of hosts with parasites. However, it diminished parasite reproduction by reducing the size and lifespan of infected hosts. Multi-generational contamination further reduced parasite reproduction. The parametrized model predicted that a single generation of contamination would enhance disease spread (via enhanced transmission), whereas multi-generational contamination would inhibit epidemics relative to unpolluted conditions (through greatly depressed parasite reproduction). In a population-level experiment, multi-generational contamination reduced the size of experimental epidemics but did not affect Daphnia populations without disease. This result highlights the importance of multi-generational effects for disease dynamics. Such integration of models with experiments can provide predictive power for disease problems in contaminated environments. PMID:22593104

Civitello, David J.; Forys, Philip; Johnson, Adam P.; Hall, Spencer R.

2012-01-01

123

Global warming and the potential spread of vector-borne diseases  

SciTech Connect

Climatic factors influence many vector-borne infectious diseases, in addition to demographic, biological, and ecological determinants. The United Nation`s Intergovernmental Panel on Climate Change (IPCC) estimates an unprecedented global rise of 2.0 C by the year 2100. Of major concern is that these changes can affect the spread of many serious infectious diseases, including malaria and dengue fever. Global warming would directly affect disease transmission by shifting the mosquito`s geographic range, increasing reproductive and biting rates, and shortening pathogen incubation period. Human migration and damage to health infrastructures from the projected increase in climate variability and sea level rise could indirectly contribute to disease transmission. A review of this literature, as well as preliminary data from ongoing studies will be presented.

Patz, J. [Johns Hopkins School of Hygiene and Public Health, Baltimore, MD (United States). Dept. of Microbiology and Immunology

1996-12-31

124

Progression of relapsing-remitting demyelinating disease does not require increased TCR affinity or epitope spread.  

PubMed

In this study, we investigate the basis of T cell recognition of myelin that governs the progression from acute symptoms into disease remission, relapse, and chronic progression in a secondary progressive model of demyelinating disease. Until now, the frequency and affinity of myelin-reactive CD4 T cells that elicit relapsing-remitting disease have not been quantified. The micropipette adhesion frequency assay was used to obtain a sensitive and physiologically relevant two-dimensional measurement of frequency and TCR affinity for myelin, as the inherent low affinity does not allow the use of specific peptide:MHC-II tetramers for this purpose. We found the highest affinity and frequency of polyclonal myelin oligodendrocyte glycoprotein-reactive cells infiltrate the CNS during acute disease, whereas affinities during remission, relapse, and chronic disease are not significantly different from each other. Frequency analysis revealed that the vast majority of CNS-infiltrating CD4 T cells are myelin oligodendrocyte glycoprotein reactive at all time points, demonstrating epitope spread is not a predominant factor for disease progression. Furthermore, time points at which mice were symptomatic were characterized by an infiltration of Th17 cells in the CNS, whereas symptom remission showed an enrichment of cells producing IFN-?. Also, the ratio of regulatory T cells to Foxp3(-) CD4 T cells was significantly higher in the CNS at remission than during acute disease. The results of this study indicate that a high frequency of T cells specific for a single myelin Ag, rather than increased TCR affinity or epitope spread, governs the transition from acute symptoms through remission, relapse, and chronic disease states. PMID:25267971

Kersh, Anna E; Edwards, Lindsay J; Evavold, Brian D

2014-11-01

125

Enhanced Antiviral Activity Against Foot-and-Mouth Disease Virus by the Combination of Bovine Type 1 and 2 Interferons  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease virus (FMDV) is the most contagious pathogen of cloven-hoofed animals including swine and bovines. The emergency control of outbreaks is dependent on rapid protection and prevention of spread of the infection. Human adenovirus type 5 expressing porcine interferon alpha (Ad5-pI...

126

Cellular Changes Induced by Adenovirus Vaccine Vectors Expressing Foot-and-Mouth Disease Virus Structural and Nonstructural Proteins  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease virus (FMDV) is the most contagious pathogen of cloven-hoofed animals including swine and bovines. The emergency control of outbreaks is dependent on rapid protection and prevention of virus spread. Adenovirus-based FMD subunit vaccines containing the coding region of viral ca...

127

Contagious bovine pleuropneumonia (CBPP) in the Maasai ecosystem of south-western Kenya: Evaluation of seroprevalence, risk factors and vaccine safety and efficacy.   

E-print Network

Contagious bovine pleuropneumonia (CBPP) is a bovine bacterial disease of major economic importance in sub-Saharan Africa. Vaccination has been recommended to control the disease in endemic areas such as the Maasai ...

Mtui-Malamsha, Niwael Jesse

2009-01-01

128

Analytical Modelling of the Spread of Disease in Confined and Crowded Spaces  

E-print Network

Since 1927, models describing the spread of disease have mostly been of the SIR-compartmental type, based on the assumption that populations are homogeneous and well-mixed. The aim of this work is to analyse the implications that arise by taking crowd behaviour explicitly into account. Starting with a microscopic model of pedestrian movement in confined spaces, we show how both the rate of infection as well as the walking speed will depend on the local crowd density around an infected individual. The combined effect is that the rate of infection at a population scale will have an analytically tractable non-linear dependency on crowd density. As an illustrative and simple example, we will model the spread of Influenza in a simple corridor with uni-directional crowd flow and compare our new model with a state-of-the-art model, which will highlight the regime in which current models do not produce credible results.

Goscé, Lara; Johansson, Anders

2013-01-01

129

How Long Is Mono Contagious?  

MedlinePLUS

TeensHealth from Nemours for Parents for Kids for Teens Teens Home Body Mind Sexual Health Food & Fitness Diseases & Conditions Infections Q&A School & Jobs Drugs & Alcohol Staying Safe Recipes En Español Making a change - Use this tool ...

130

Spread of infectious diseases in a hyperbolic reaction-diffusion susceptible-infected-removed model  

NASA Astrophysics Data System (ADS)

A one-dimensional hyperbolic reaction-diffusion model of epidemics is developed to describe the dynamics of diseases spread occurring in an environment where three kinds of individuals mutually interact: the susceptibles, the infectives, and the removed. It is assumed that the disease is transmitted from the infected population to the susceptible one according to a nonlinear convex incidence rate. The model, based upon the framework of extended thermodynamics, removes the unphysical feature of instantaneous diffusive effects, which is typical of parabolic models. Linear stability analyses are performed to study the nature of the equilibrium states against uniform and nonuniform perturbations. Emphasis is given to the occurrence of Hopf and Turing bifurcations, which break the temporal and the spatial symmetry of the system, respectively. The existence of traveling wave solutions connecting two steady states is also discussed. The governing equations are also integrated numerically to validate the analytical results and to characterize the spatiotemporal evolution of diseases.

Barbera, Elvira; Consolo, Giancarlo; Valenti, Giovanna

2013-11-01

131

Development of loop-mediated isothermal amplification test for the diagnosis of contagious agalactia in goats.  

PubMed

Contagious agalactia is a highly infectious disease affecting sheep and goats, mainly caused by Mycoplasma agalactiae. Although various tests are available for diagnosis of contagious agalactia, none of them is credited with the capacity to provide rapid and cost-effective diagnosis. This article reports the development of loop-mediated isothermal amplification (LAMP) test targeting the p40 gene of M. agalactiae, for the diagnosis of classical contagious agalactia. Optimum amplification was obtained at 58 °C in 70 min. The developed test was found to be 100-fold more sensitive than PCR and detected up to 20-fg level of DNA. The test was also superior to conventional PCR in detecting from artificially contaminated milk, i.e. 10(4)-fold more sensitive. The developed LAMP test could detect up to 10 cfu/ml of artificially contaminated milk, indicating its potential for being developed as a field test for rapid and sensitive diagnosis. PMID:25616985

Rekha, Valsala; Rana, Rajneesh; Thomas, Prasad; Viswas, Konasagara Nagaleekar; Singh, Vijendra Pal; Agarwal, Rajesh Kumar; Arun, Thachappully Remesh; Karthik, Kumaragurubaran; Sophia, Inbaraj

2015-03-01

132

Ebola virus disease in southern Sudan: hospital dissemination and intrafamilial spread  

PubMed Central

Between 31 July and 6 October 1979, 34 cases of Ebola virus disease (22 of which were fatal) occurred among five families in a rural district of southern Sudan; the disease was introduced into four of the families from a local hospital. Chains of secondary spread within the family units, accounting for 29 cases resulted from direct physical contact with an infected person. Among all persons with such contact in the family setting, those who provided nursing care had a 5.1-fold increased risk of infection, emphasizing the importance of intimate contact in the spread of this disease. The absence of illness among persons who were exposed to cases in confined spaces, but without physical contact, confirmed previous impressions that there is no risk of airborne transmission. While the ecology of Ebola virus is unknown, the presence of anti-Ebola antibodies in the sera of 18% of persons who were unassociated with the outbreak suggests that the region is an endemic focus of Ebola virus activity. PMID:6370486

Baron, Roy C.; McCormick, Joseph B.; Zubeir, Osman A.

1983-01-01

133

A lateral flow protein microarray for rapid determination of contagious bovine pleuropneumonia status in bovine serum  

Microsoft Academic Search

Novel analytical methods for a next generation of diagnostic devices combine attributes from sensitive, accurate, fast, simple and multiplexed analysis methods. Here, we describe a possible contribution to these by the application of a lateral flow microarray where a panel of recombinant protein antigens was used to differentiate bovine serum samples in the context of the lung disease contagious bovine

Jesper Gantelius; Carl Hamsten; Maja Neiman; Jochen M. Schwenk; Anja Persson; Helene Andersson-Svahn

2010-01-01

134

Sexually transmitted diseases in Ethiopia. Social factors contributing to their spread and implications for developing countries.  

PubMed Central

Sexually transmitted diseases in developing countries are causing concern to those responsible for their control and eradication. To gain a better understanding of the problems involved in a country struggling with development, the economic and psychosocial factors influencing the spread of STD in Ethiopia have been studied. Increased migration and urbanisation and the changing role of women have led to a rise in prostitution. Thus changes in the social structure--particularly in relation to the education and employment of women--and improved medical services are essential for the long-term control of STD. PMID:6895708

Plorde, D S

1981-01-01

135

Molecular drivers and cortical spread of lateral entorhinal cortex dysfunction in preclinical Alzheimer’s disease  

PubMed Central

The entorhinal cortex has been implicated in the early stages of Alzheimer’s disease, which is characterized by changes in the tau protein and in the cleaved fragments of the amyloid precursor protein (APP). We used a high-resolution functional magnetic resonance imaging (fMRI) variant that can map metabolic defects in patients and mouse models to address basic questions about entorhinal cortex pathophysiology. The entorhinal cortex is divided into functionally distinct regions, the medial entorhinal cortex (MEC) and the lateral entorhinal cortex (LEC), and we exploited the high-resolution capabilities of the fMRI variant to ask whether either of them was affected in patients with preclinical Alzheimer’s disease. Next, we imaged three mouse models of disease to clarify how tau and APP relate to entorhinal cortex dysfunction and to determine whether the entorhinal cortex can act as a source of dysfunction observed in other cortical areas. We found that the LEC was affected in preclinical disease, that LEC dysfunction could spread to the parietal cortex during preclinical disease and that APP expression potentiated tau toxicity in driving LEC dysfunction, thereby helping to explain regional vulnerability in the disease. PMID:24362760

Khan, Usman A; Liu, Li; Provenzano, Frank A; Berman, Diego E; Profaci, Caterina P; Sloan, Richard; Mayeux, Richard; Duff, Karen E; Small, Scott A

2014-01-01

136

CD28 Costimulatory Blockade Exacerbates Disease Severity and Accelerates Epitope Spreading in a Virus-Induced Autoimmune Disease  

PubMed Central

Theiler's murine encephalomyelitis virus (TMEV) is a natural mouse pathogen which causes a lifelong persistent infection of the central nervous system (CNS) accompanied by T-cell-mediated myelin destruction leading to chronic, progressive hind limb paralysis. TMEV-induced demyelinating disease (TMEV-IDD) is considered to be a highly relevant animal model for the human autoimmune disease multiple sclerosis (MS), which is thought to be initiated as a secondary consequence of a virus infection. Although TMEV-IDD is initiated by virus-specific CD4+ T cells targeting CNS-persistent virus, CD4+ T-cell responses against self myelin protein epitopes activated via epitope spreading contribute to chronic disease pathogenesis. We thus examined the ability of antibodies directed against B7 costimulatory molecules to regulate this chronic virus-induced immunopathologic process. Contrary to previous studies showing that blockade of B7-CD28 costimulatory interactions inhibit the initiation of experimental autoimmune encephalomyelitis, treatment of SJL mice at the time of TMEV infection with murine CTLA-4 immunoglobulin or a combination of anti-B7-1 and anti-B7-2 antibodies significantly enhanced clinical disease severity. Costimulatory blockade inhibited early TMEV-specific T-cell and antibody responses critical in clearing peripheral virus infection. The inhibition of virus-specific immune responses led to significantly increased CNS viral titers resulting in increased damage to myelin-producing oligodendrocytes. Following clearance of the costimulatory antagonists, epitope spreading to myelin epitopes was accelerated as a result of the increased availability of myelin epitopes leading to a more severe chronic disease course. Our results raise concern about the potential use of B7-CD28 costimulatory blockade to treat human autoimmune diseases potentially associated with acute or persistent virus infections. PMID:10954534

Neville, Katherine L.; Dal Canto, Mauro C.; Bluestone, Jeffrey A.; Miller, Stephen D.

2000-01-01

137

Spread of a disease and its effect on population dynamics in an eco-epidemiological system  

NASA Astrophysics Data System (ADS)

In this paper, an eco-epidemiological model with simple law of mass action and modified Holling type II functional response has been proposed and analyzed to understand how a disease may spread among natural populations. The proposed model is a modification of the model presented by Upadhyay et al. (2008) [1]. Existence of the equilibria and their stability analysis (linear and nonlinear) has been studied. The dynamical transitions in the model have been studied by identifying the existence of backward Hopf-bifurcations and demonstrated the period-doubling route to chaos when the death rate of predator (?1) and the growth rate of susceptible prey population (r) are treated as bifurcation parameters. Our studies show that the system exhibits deterministic chaos when some control parameters attain their critical values. Chaotic dynamics is depicted using the 2D parameter scans and bifurcation analysis. Possible implications of the results for disease eradication or its control are discussed.

Upadhyay, Ranjit Kumar; Roy, Parimita

2014-12-01

138

Transmission of Chronic Wasting Disease in Wisconsin White-Tailed Deer: Implications for Disease Spread and Management  

PubMed Central

Few studies have evaluated the rate of infection or mode of transmission for wildlife diseases, and the implications of alternative management strategies. We used hunter harvest data from 2002 to 2013 to investigate chronic wasting disease (CWD) infection rate and transmission modes, and address how alternative management approaches affect disease dynamics in a Wisconsin white-tailed deer population. Uncertainty regarding demographic impacts of CWD on cervid populations, human and domestic animal health concerns, and potential economic consequences underscore the need for strategies to control CWD distribution and prevalence. Using maximum-likelihood methods to evaluate alternative multi-state deterministic models of CWD transmission, harvest data strongly supports a frequency-dependent transmission structure with sex-specific infection rates that are two times higher in males than females. As transmissible spongiform encephalopathies are an important and difficult-to-study class of diseases with major economic and ecological implications, our work supports the hypothesis of frequency-dependent transmission in wild deer at a broad spatial scale and indicates that effective harvest management can be implemented to control CWD prevalence. Specifically, we show that harvest focused on the greater-affected sex (males) can result in stable population dynamics and control of CWD within the next 50 years, given the constraints of the model. We also provide a quantitative estimate of geographic disease spread in southern Wisconsin, validating qualitative assessments that CWD spreads relatively slowly. Given increased discovery and distribution of CWD throughout North America, insights from our study are valuable to management agencies and to the general public concerned about the impacts of CWD on white-tailed deer populations. PMID:24658535

Jennelle, Christopher S.; Henaux, Viviane; Wasserberg, Gideon; Thiagarajan, Bala; Rolley, Robert E.; Samuel, Michael D.

2014-01-01

139

Analytical Modelling of the Spread of Disease in Confined and Crowded Spaces  

NASA Astrophysics Data System (ADS)

Since 1927 and until recently, most models describing the spread of disease have been of compartmental type, based on the assumption that populations are homogeneous and well-mixed. Recent models have utilised agent-based models and complex networks to explicitly study heterogeneous interaction patterns, but this leads to an increasing computational complexity. Compartmental models are appealing because of their simplicity, but their parameters, especially the transmission rate, are complex and depend on a number of factors, which makes it hard to predict how a change of a single environmental, demographic, or epidemiological factor will affect the population. Therefore, in this contribution we propose a middle ground, utilising crowd-behaviour research to improve compartmental models in crowded situations. We show how both the rate of infection as well as the walking speed depend on the local crowd density around an infected individual. The combined effect is that the rate of infection at a population scale has an analytically tractable non-linear dependency on crowd density. We model the spread of a hypothetical disease in a corridor and compare our new model with a typical compartmental model, which highlights the regime in which current models may not produce credible results.

Goscé, Lara; Barton, David A. W.; Johansson, Anders

2014-05-01

140

Predictive Modelling of Contagious Deforestation in the Brazilian Amazon  

PubMed Central

Tropical forests are diminishing in extent due primarily to the rapid expansion of agriculture, but the future magnitude and geographical distribution of future tropical deforestation is uncertain. Here, we introduce a dynamic and spatially-explicit model of deforestation that predicts the potential magnitude and spatial pattern of Amazon deforestation. Our model differs from previous models in three ways: (1) it is probabilistic and quantifies uncertainty around predictions and parameters; (2) the overall deforestation rate emerges “bottom up”, as the sum of local-scale deforestation driven by local processes; and (3) deforestation is contagious, such that local deforestation rate increases through time if adjacent locations are deforested. For the scenarios evaluated–pre- and post-PPCDAM (“Plano de Ação para Proteção e Controle do Desmatamento na Amazônia”)–the parameter estimates confirmed that forests near roads and already deforested areas are significantly more likely to be deforested in the near future and less likely in protected areas. Validation tests showed that our model correctly predicted the magnitude and spatial pattern of deforestation that accumulates over time, but that there is very high uncertainty surrounding the exact sequence in which pixels are deforested. The model predicts that under pre-PPCDAM (assuming no change in parameter values due to, for example, changes in government policy), annual deforestation rates would halve between 2050 compared to 2002, although this partly reflects reliance on a static map of the road network. Consistent with other models, under the pre-PPCDAM scenario, states in the south and east of the Brazilian Amazon have a high predicted probability of losing nearly all forest outside of protected areas by 2050. This pattern is less strong in the post-PPCDAM scenario. Contagious spread along roads and through areas lacking formal protection could allow deforestation to reach the core, which is currently experiencing low deforestation rates due to its isolation. PMID:24204776

Rosa, Isabel M. D.; Purves, Drew; Souza, Carlos; Ewers, Robert M.

2013-01-01

141

Weather, host and vector — their interplay in the spread of insect-borne animal virus diseases  

PubMed Central

The spread of insect-borne animal virus diseases is influenced by a number of factors. Hosts migrate, move or are conveyed over long distances: vectors are carried on the wind for varying distances in search of hosts and breeding sites; weather and climate affect hosts and vectors through temperature, moisture and wind. As parasites of host and vector, viruses are carried by animals, birds and insects, and their spread can be correlated with the migration of hosts and the carriage of vectors on winds associated with the movements of the Intertropical Convergence Zone (ITCZ) and warm winds to the north and south of the limits of the ITCZ. The virus is often transmitted from a local cycle to a migratory cycle and back again. Examples of insect-borne virus diseases and their spread are analysed. Japanese, Murray Valley, Western equine, Eastern equine and St Louis encephalitis represent viruses transmitted by mosquito—bird or pig cycles. The areas experiencing infection with these viruses can be divided into a number of zones: A, B, C, D, E and F. In zone A there is a continuous cycle of virus in host and vector throughout the year; in zone B, there is an upsurge in the cycle during the wet season, but the cycle continues during the dry season; there is movement of infected vectors between and within zones A and B on the ITCZ and the virus is introduced to zone C by infected vectors on warm winds; persistence may occur in zone C if conditions are right. In zone D, virus is introduced each year by infected vectors on warm winds and the arrival of the virus coincides with the presence of susceptible nestling birds and susceptible piglets. The disappearance of virus occurs at the time when migrating mosquitoes and birds are returning to warmer climates. The virus is introduced to zone E only on occasions every 5-10 years when conditions are suitable. Infected hosts introduced to zone F do not lead to circulation of virus, since the climate is unsuitable for vectors. Zones A, B and C correspond to endemic and zones D and E to epidemic conditions. Similar zones can be recognized for African horse sickness, bluetongue, Ibaraki disease and bovine ephemeral fever — examples of diseases transmitted in a midge-mammal cycle. In zones A and B viruses are transported by infected midges carried on the wind in association with the movement of ITCZ and undergo cycles in young animals. In these zones and in zone C there is a continual movement of midges on the warm wind between one area and another, colonizing new sites or reinforcing populations of midges already present. Virus is introduced at times into fringe areas (zones D and E) and, as there is little resistance in the host, gives rise to clinical signs of disease. In some areas there is persistence during adverse conditions; in others, the virus is carried back to the endemic zones by infected midges or vectors. Examples of viruses maintained in a mosquito/biting fly—mammal cycle are Venezuelan equine encephalitis and vesicular stomatitis. These viruses enter a migratory cycle from a local cycle and the vectors in the migratory cycle are carried over long distances on the wind. Further examples of virus spread by movement of vectors include West Nile, Rift Valley fever, yellow fever, epizootic haemorrhagic disease of deer and Akabane viruses. In devising means of control it is essential to decide the relationship of host, vector and virus and the nature of the zone in which the area to be controlled lies. Because of the continual risk of reintroduction of infected vectors, it is preferable to protect the host by dipping, spraying or by vaccination rather than attempting to eliminate the local population of insects. PMID:6131919

Sellers, R. F.

1980-01-01

142

Controlling wildlife fungal disease spread: in vitro efficacy of disinfectants against Batrachochytrium dendrobatidis and Mucor amphibiorum.  

PubMed

Chytridiomycosis in amphibians, and mucormycosis in the platypus Ornithorhynchus anatinus and amphibians, are serious fungal diseases affecting these aquatic taxa. In Tasmania, Australia, the fungi that cause these diseases overlap in range along with Phytophthora cinnamomi (Pc), an invasive fungal plant pathogen. To identify disinfectants that may be useful to reduce anthropogenic spread of these fungi to uninfected wilderness areas, for example by bush walkers and forestry or fire-fighting operations, we tested 3 disinfectants and a fire-fighting foam against Mucor amphibiorum (Ma) and tested 1 disinfectant and the foam against Batrachochytrium dendrobatidis (Bd). Combining the present study with previous work we found Bd was more susceptible to all 4 chemicals than Ma. Phytoclean, a disinfectant used at 2 to 10% for 30 s to control Pc, killed cultures of Bd at 0.075% and Ma at 5%, when also applied for 30 s. The disinfectant F10sc was not effective against Ma at standard exposures, but previous work shows Bd is killed at 0.03% with a 1 min exposure. Path-X is effective against Bd at 0.001% with a 30 s exposure and killed Ma at 1% with a 5 min exposure. Forexpan S, a foam added to water at 0.1 to 1% to control forest fires, killed Bd but not Ma when used at 1% for 2 min. Therefore, Phytoclean and Path-X have broader efficacy, although Path-X has not been trialled against Pc. Interestingly a positive mating strain of Ma (from a platypus) was more resistant to disinfectants than a negative strain (from a frog). Current protocols against Pc that involve high concentrations (10%) of Phytoclean are likely to reduce spread of pathogenic wildlife fungi, which is important for protecting biodiversity. PMID:22691980

Webb, Rebecca; Philips, Annie; Speare, Rick; Connolly, Joanne; Berger, Lee

2012-06-13

143

Avian influenza shedding patterns in waterfowl: implications for surveillance, environmentaltransmission, and disease spread  

USGS Publications Warehouse

Despite the recognized importance of fecal/oral transmission of low pathogenic avian influenza (LPAI) via contaminated wetlands, little is known about the length, quantity, or route of AI virus shed by wild waterfowl. We used published laboratory challenge studies to evaluate the length and quantity of low pathogenic (LP) and highly pathogenic (HP) virus shed via oral and cloacal routes by AI-infected ducks and geese, and how these factors might influence AI epidemiology and virus detection. We used survival analysis to estimate the duration of infection(from virus inoculation to the last day virus was shed) and nonlinear models to evaluate temporal patterns in virus shedding. We found higher mean virus titer and longer median infectious period for LPAI-infected ducks (1011.5 days in oral and cloacal swabs) than HPAI-infected ducks(5 days) and geese (7.5 days). Based on the median bird infectious dose, we found that environmental contamination is two times higher for LPAI- than HPAI-infectious ducks, which implies that susceptible birds may have a higher probability of infection during LPAI than HP AIoutbreaks. Less environmental contamination during the course of infection and previously documented shorter environmental persistence for HPAI than LPAI suggest that the environment is a less favorable reservoir for HPAI. The longer infectious period, higher virus titers, and subclinical infections with LPAI viruses favor the spread of these viruses by migratory birds in comparison to HPAI. Given the lack of detection of HPAI viruses through worldwide surveillance,we suggest monitoring for AI should aim at improving our understanding of AI dynamics (inparticular, the role of the environment and immunity) using long-term comprehensive live bird, serologic, and environmental sampling at targeted areas. Our findings on LPAI and HPAIshedding patterns over time provide essential information to parameterize environmental transmission and virus spread in predictive epizootio logic models of disease risks. ?? Wildlife Disease Association 2011.

Henaux, V.; Samuel, M.D.

2011-01-01

144

The Risk of Disease to Great Apes: Simulating Disease Spread in Orang-Utan (Pongo pygmaeus wurmbii) and Chimpanzee (Pan troglodytes schweinfurthii) Association Networks  

PubMed Central

All great ape species are endangered, and infectious diseases are thought to pose a particular threat to their survival. As great ape species vary substantially in social organisation and gregariousness, there are likely to be differences in susceptibility to disease types and spread. Understanding the relation between social variables and disease is therefore crucial for implementing effective conservation measures. Here, we simulate the transmission of a range of diseases in a population of orang-utans in Sabangau Forest (Central Kalimantan) and a community of chimpanzees in Budongo Forest (Uganda), by systematically varying transmission likelihood and probability of subsequent recovery. Both species have fission-fusion social systems, but differ considerably in their level of gregariousness. We used long-term behavioural data to create networks of association patterns on which the spread of different diseases was simulated. We found that chimpanzees were generally far more susceptible to the spread of diseases than orang-utans. When simulating different diseases that varied widely in their probability of transmission and recovery, it was found that the chimpanzee community was widely and strongly affected, while in orang-utans even highly infectious diseases had limited spread. Furthermore, when comparing the observed association network with a mean-field network (equal contact probability between group members), we found no major difference in simulated disease spread, suggesting that patterns of social bonding in orang-utans are not an important determinant of susceptibility to disease. In chimpanzees, the predicted size of the epidemic was smaller on the actual association network than on the mean-field network, indicating that patterns of social bonding have important effects on susceptibility to disease. We conclude that social networks are a potentially powerful tool to model the risk of disease transmission in great apes, and that chimpanzees are particularly threatened by infectious disease outbreaks as a result of their social structure. PMID:24740263

Carne, Charlotte; Semple, Stuart; Morrogh-Bernard, Helen; Zuberbühler, Klaus; Lehmann, Julia

2014-01-01

145

Homogenization, sex, and differential motility predict spread of chronic wasting disease in mule deer in southern Utah.  

PubMed

Chronic wasting disease (CWD) is an infectious prion disease that affects mule deer, along with other Cervids. It is a slow-developing, fatal disease which is rare in the free-ranging deer population of Utah. We present a sex-structured, spatial model for the spread of CWD over heterogeneous landscapes, incorporating both horizontal and environmental transmission pathways. To connect the local movement of deer to the regional spread of CWD, we use ecological diffusion with motility coefficients estimated from mule deer movement data. Ecological diffusion allows for aggregation of populations in desirable habitats and therefore allows for an interaction between density dependent disease transmission and landscape structure. The major innovation presented is use of homogenization to accelerate simulations of disease spread in southeastern Utah, from the La Sal Mountains near Moab to the Abajo Mountains near Monticello. The homogenized model provides accuracy while maintaining fidelity to small-scale habitat effects on deer distribution, including differential aggregation in land cover types with high residence times, with errors comparable to the order parameter measuring separation of small and large scales ([Formula: see text] in this case). We use the averaged coefficients from the homogenized model to explore asymptotic invasion speed and the impact of current population size on disease spread in southeastern Utah. PMID:23846241

Garlick, Martha J; Powell, James A; Hooten, Mevin B; MacFarlane, Leslie R

2014-08-01

146

Pharmacodynamics of Antimicrobials against Mycoplasma mycoides mycoides Small Colony, the Causative Agent of Contagious Bovine Pleuropneumonia  

PubMed Central

Background Mycoplasma mycoides subspecies mycoides Small Colony (MmmSC) is the causative agent of Contagious Bovine Pleuropneumonia (CBPP), a disease of substantial economic importance in sub-Saharan Africa. Failure of vaccination to curtail spread of this disease has led to calls for evaluation of the role of antimicrobials in CBPP control. Three major classes of antimicrobial are effective against mycoplasmas, namely tetracyclines, fluoroquinolones and macrolides. Therefore, the objectives of this study were to determine the effector kinetics of oxytetracycline, danofloxacin and tulathromycin against two MmmSC field strains in artificial medium and adult bovine serum. Methods Minimum inhibitory concentrations (MIC) were determined for oxytetracycline, danofloxacin and tulathromycin against MmmSC strains B237 and Tan8 using a macrodilution technique, and time-kill curves were constructed for various multiples of the MIC over a 24 hour period in artificial medium and serum. Data were fitted to sigmoid Emax models to obtain 24 hour-area under curve/MIC ratios for mycoplasmastasis and, where appropriate, for mycoplasmacidal activity and virtual mycoplasmal elimination. Results Minimum inhibitory concentrations against B237 were 20-fold higher, 2-fold higher and approximately 330-fold lower in serum than in artificial medium for oxytetracycline, danofloxacin and tulathromycin, respectively. Such differences were mirrored in experiments using Tan8. Oxytetracycline was mycoplasmastatic against both strains in both matrices. Danofloxacin elicited mycoplasmacidal activity against B237 and virtual elimination of Tan8; similar maximum antimycoplasmal effects were observed in artificial medium and serum. Tulathromycin effected virtual elimination of B237 but was mycoplasmastatic against Tan8 in artificial medium. However, this drug was mycoplasmastatic against both strains in the more physiologically relevant matrix of serum. Conclusions Oxytetracycline, danofloxacin and tulathromycin are all suitable candidates for further investigation as potential treatments for CBPP. This study also highlights the importance of testing drug activity in biological matrices as well as artificial media. PMID:22952911

Mitchell, John D.; McKellar, Quintin A.; McKeever, Declan J.

2012-01-01

147

Lymphangitic spread from the appendiceal adenocarcinoma to the ileocecal valve, mimicking Crohn’s disease  

PubMed Central

Due to the anatomical peculiarity of the appendix, diagnosis of tumors arising from this area can be challenging by clinicoradiologic means. We report a case of a rare primary appendiceal signet ring carcinoma with an uncommon presentation. An 86-year-old woman was admitted to our hospital with subacute epigastric pain. Computed tomography demonstrated bowel wall thickening with fat stranding in the ileocecal region. The leading diagnostic consideration was inflammatory bowel disease. Upon colonoscopy, a swollen, distorted ileocecal valve was identified. The remaining colon was otherwise unremarkable. Extensive biopsy sampling of the ileocecal region and colon was performed. A lymphangitic signet ring carcinoma within the ileocecal region was diagnosed on biopsy; there was no dysplasia or carcinoma of the remaining biopsies. By cytomorphology and immunoprofile, a lymphangitic signet ring carcinoma of appendiceal origin was the primary consideration, further confirmed upon subsequent laparotomy. This case represents an unusual pattern of appendiceal tumor spread with localized, lymphangitic involvement, creating a milieu which closely simulates Crohn’s disease on imaging modalities. PMID:25717258

Murdock, Tricia; Lim, Nicholas; Zenali, Maryam

2015-01-01

148

Birth and death of links control disease spreading in empirical contact networks  

NASA Astrophysics Data System (ADS)

We investigate what structural aspects of a collection of twelve empirical temporal networks of human contacts are important to disease spreading. We scan the entire parameter spaces of the two canonical models of infectious disease epidemiology--the Susceptible-Infectious-Susceptible (SIS) and Susceptible-Infectious-Removed (SIR) models. The results from these simulations are compared to reference data where we eliminate structures in the interevent intervals, the time to the first contact in the data, or the time from the last contact to the end of the sampling. The picture we find is that the birth and death of links, and the total number of contacts over a link, are essential to predict outbreaks. On the other hand, the exact times of contacts between the beginning and end, or the interevent interval distribution, do not matter much. In other words, a simplified picture of these empirical data sets that suffices for epidemiological purposes is that links are born, is active with some intensity, and die.

Holme, Petter; Liljeros, Fredrik

2014-05-01

149

Modelling bovine babesiosis: a tool to simulate scenarios for pathogen spread and to test control measures for the disease.  

PubMed

Tick-borne diseases are of increasing concern in many countries, particularly as a consequence of changes in land use and climate. Ticks are vectors of numerous pathogens (viruses, bacteria, protozoa) that can be harmful to humans and animals. In the context of animal health, bovine babesiosis poses a recurrent threat to cattle herds. In this study, we use a modeling approach to investigate the spread of babesiosis and evaluate control measures. A previously developed tick population dynamics model (here, Ixodes ricinus) is coupled with a pathogen spread model (here, the protozoan Babesia divergens), which describes pathogen spread in a dairy herd through the following processes: transmission, acquisition, transovarial transmission, transstadial persistence, and clearance of the pathogen. An assessment of the simulated B. divergens prevalence levels in ticks and cattle in the context of existing knowledge and data suggested that the model provides a realistic representation of pathogen spread. The model was then used to evaluate the influence of host density and the effect of acaricides on B. divergens prevalence in cattle. Increasing deer density results in an increase in prevalence in cattle whereas increasing cattle stocking rate results in a slight decrease. A potential increase in deer density would thus have an amplification effect on disease spread due to the increase in the number of infected ticks. Regular use of acaricides produces a reduction in pathogen prevalence in cattle. This model could be adapted to other tick-borne diseases. PMID:22341037

Hoch, Thierry; Goebel, Julien; Agoulon, Albert; Malandrin, Laurence

2012-09-15

150

Minimal Contagious Sets in Random Regular Graphs  

NASA Astrophysics Data System (ADS)

The bootstrap percolation (or threshold model) is a dynamic process modelling the propagation of an epidemic on a graph, where inactive vertices become active if their number of active neighbours reach some threshold. We study an optimization problem related to it, namely the determination of the minimal number of active sites in an initial configuration that leads to the activation of the whole graph under this dynamics, with and without a constraint on the time needed for the complete activation. This problem encompasses in special cases many extremal characteristics of graphs like their independence, decycling or domination number, and can also be seen as a packing problem of repulsive particles. We use the cavity method (including the effects of replica symmetry breaking), an heuristic technique of statistical mechanics many predictions of which have been confirmed rigorously in the recent years. We have obtained in this way several quantitative conjectures on the size of minimal contagious sets in large random regular graphs, the most striking being that 5-regular random graph with a threshold of activation of 3 (resp. 6-regular with threshold 4) have contagious sets containing a fraction (resp. ) of the total number of vertices. Equivalently these numbers are the minimal fraction of vertices that have to be removed from a 5-regular (resp. 6-regular) random graph to destroy its 3-core. We also investigated Survey Propagation like algorithmic procedures for solving this optimization problem on single instances of random regular graphs.

Guggiola, Alberto; Semerjian, Guilhem

2015-01-01

151

Hand, Foot and Mouth Disease in China: Patterns of Spread and Transmissibility during 2008-2009  

PubMed Central

Background Large outbreaks of hand, foot and mouth disease (HFMD) were observed in both 2008 and 2009 in China. Methods Using the national surveillance data since May 2, 2008, epidemiological characteristics of the outbreaks are summarized, and the transmissibility of the disease and the effects of potential risk factors were evaluated via a susceptible-infectious-recovered transmission model. Results Children of 1.0–2.9 years were the most susceptible group to HFMD (odds ratios [OR] > 2.3 as compared to other age groups). Infant cases had the highest incidences of severe disease (ORs > 1.4) and death (ORs > 2.4), as well as the longest delay from symptom onset to diagnosis (2.3 days). Males were more susceptible to HFMD than females (OR=1.56 [95% confidence interval=1.56, 1.57]). An one day delay in diagnosis was associated with increases in the odds of severe disease by 40.3% [38.7%, 41.9%] and in the odds of death by 53.7% [43.6%, 64.5%]. Compared to Coxsackie A16, enterovirus (EV) 71 is more strongly associated with severe disease (OR=15.6 [13.4, 18.1]) and death (OR=40.7 [13.0, 127.3]). The estimated local effective reproductive numbers among prefectures ranged from 1.4 to 1.6 (median=1.4) in spring and stayed below 1.2 in other seasons. A higher risk of transmission was associated with temperatures in the range of 70-80F, higher relative humidity, wind speed, precipitation, population density, and the periods in which schools were open. Conclusion HFMD is a moderately transmittable infectious disease, mainly among pre-school children. EV71 was responsible for most severe cases and fatalities. Mixing of asymptomatically infected children in schools might have contributed to the spread of HFMD. Timely diagnosis may be a key to reducing the high mortality rate in infants. PMID:21968769

Wang, Yu; Feng, Zijian; Yang, Yang; Self, Steve; Gao, Yongjun; Longini, Ira M.; Wakefield, Jon; Zhang, Jing; Wang, Liping; Chen, Xi; Yao, Lena; Stanaway, Jeffrey D.; Wang, Zijun; Yang, Weizhong

2011-01-01

152

Trichothecene-Genotypes Play a Role in Fusarium Head Blight Disease Spread and Trichothecene Accumulation in Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

In the current study, we evaluated the impact of the observed North American evolutionary shift in the Fusarium graminearum complex on disease spread, kernel damage, and trichothecene accumulation in resistant and susceptible wheat genotypes. Four inocula were prepared using composites of F. gramin...

153

Modeling the Effect of Herd Immunity and Contagiousness in Mitigating a Smallpox Outbreak.  

PubMed

The smallpox antiviral tecovirimat (Arestvyr) has recently been purchased by the U.S. Strategic National Stockpile. Given significant uncertainty regarding both the contagiousness of smallpox in a contemporary outbreak and the efficiency of a mass vaccination campaign, vaccine prophylaxis alone may be unable to control a smallpox outbreak following a bioterror attack. Here, we present the results of a compartmental epidemiological model that identifies conditions under which tecovirimat is required to curtail the epidemic by exploring how the interaction between contagiousness and prophylaxis coverage of the affected population affects the ability of the public health response to control a large-scale smallpox outbreak. Each parameter value in the model is based on published empirical data. We describe contagiousness parametrically using a novel method of distributing an assumed R-value over the disease course based on the relative rates of daily viral shedding from human and animal studies of cognate orthopoxvirus infections. Our results suggest that vaccination prophylaxis is sufficient to control the outbreak when caused either by a minimally contagious virus or when a very high percentage of the population receives prophylaxis. As vaccination coverage of the affected population decreases below 70%, vaccine prophylaxis alone is progressively less capable of controlling outbreaks, even those caused by a less contagious virus (R0 less than 4). In these scenarios, tecovirimat treatment is required to control the outbreak (total number of cases under an order of magnitude more than the number of initial infections). The first study to determine the relative importance of smallpox prophylaxis and treatment under a range of highly uncertain epidemiological parameters, this work provides public health decision-makers with an evidence-based guide for responding to a large-scale smallpox outbreak. PMID:25480757

Graeden, Ellie; Fielding, Russel; Steinhouse, Kyle E; Rubin, Ilan N

2014-12-01

154

Laboratory generation of new parthenogenetic lineages supports contagious parthenogenesis in Artemia  

PubMed Central

Contagious parthenogenesis—a process involving rare functional males produced by a parthenogenetic lineage which mate with coexisting sexual females resulting in fertile parthenogenetic offspring—is one of the most striking mechanisms responsible for the generation of new parthenogenetic lineages. Populations of the parthenogenetic diploid brine shrimp Artemia produce fully functional males in low proportions. The evolutionary role of these so-called Artemia rare males is, however, unknown. Here we investigate whether new parthenogenetic clones could be obtained in the laboratory by mating these rare males with sexual females. We assessed the survival and sex ratio of the hybrid ovoviviparous offspring from previous crosses between rare males and females from all Asiatic sexual species, carried out cross-mating experiments between F1 hybrid individuals to assess their fertility, and estimated the viability and the reproductive mode of the resulting F2 offspring. Molecular analysis confirmed the parentage of hybrid parthenogenetic F2. Our study documents the first laboratory synthesis of new parthenogenetic lineages in Artemia and supports a model for the contagious spread of parthenogenesis. Our results suggest recessive inheritance but further experiments are required to confirm the likelihood of the contagious parthenogenesis model. PMID:25024909

Amat, Francisco; Hontoria, Francisco; Gómez, Africa

2014-01-01

155

Herpes Simplex Virus Type 1 Glycoprotein E Domains Involved in Virus Spread and Disease  

Microsoft Academic Search

Herpes simplex virus type 1 (HSV-1) glycoprotein E (gE) functions as an immunoglobulin G (IgG) Fc bind- ing protein and is involved in virus spread. Previously we studied a gE mutant virus that was impaired for IgG Fc binding but intact for spread and another that was normal for both activities. To further evaluate the role of gE in spread,

CHARLES E. SALDANHA; JOHN LUBINSKI; CLAUDIA MARTIN; THANDAVARAYAN NAGASHUNMUGAM; LIYANG WANG; HARJEET VAN DER KEYL; RUTH TAL-SINGER; HARVEY M. FRIEDMAN

2000-01-01

156

Connectivity of the American Agricultural Landscape: Assessing the National Risk of Crop Pest and Disease Spread  

NSDL National Science Digital Library

More than two-thirds of cropland in the United States is devoted to the production of just four crop speciesâ??maize, wheat, soybeans, and cottonâ??raising concerns that homogenization of the American agricultural landscape could facilitate widespread disease and pest outbreaks, compromising the national food supply. As a new component in national agricultural risk assessment, we employed a graph-theoretic approach to examine the connectivity of these crops across the United States. We used county crop acreage to evaluate the landscape resistance to transmissionâ??the degree to which host availability limits spread in any given regionâ??for pests or pathogens dependent on each crop. For organisms that can disperse under conditions of lower host availability, maize and soybean are highly connected at a national scale, compared with the more discrete regions of wheat and cotton production. Determining the scales at which connectivity becomes disrupted for organisms with different dispersal abilities may help target rapid-response regions and the development of strategic policies to enhance agricultural landscape heterogeneity.

Karen Garrett (Kansas State University; Department of Plant Pathology)

2009-02-01

157

Climate Change, Extreme Weather Events, and Fungal Disease Emergence and Spread  

NASA Technical Reports Server (NTRS)

Empirical evidence from multiple sources show the Earth has been warming since the late 19th century. More recently, evidence for this warming trend is strongly supported by satellite data since the late 1970s from the cryosphere, atmosphere, oceans, and land that confirms increasing temperature trends and their consequences (e.g., reduced Arctic sea ice, rising sea level, ice sheet mass loss, etc.). At the same time, satellite observations of the Sun show remarkably stable solar cycles since the late 1970s, when direct observations of the Sun's total solar irradiance began. Numerical simulation models, driven in part by assimilated satellite data, suggest that future-warming trends will lead to not only a warmer planet, but also a wetter and drier climate depending upon location in a fashion consistent with large-scale atmospheric processes. Continued global warming poses new opportunities for the emergence and spread of fungal disease, as climate systems change at regional and global scales, and as animal and plant species move into new niches. Our contribution to this proceedings is organized thus: First, we review empirical evidence for a warming Earth. Second, we show the Sun is not responsible for the observed warming. Third, we review numerical simulation modeling results that project these trends into the future, describing the projected abiotic environment of our planet in the next 40 to 50 years. Fourth, we illustrate how Rift Valley fever outbreaks have been linked to climate, enabling a better understanding of the dynamics of these diseases, and how this has led to the development of an operational predictive outbreak model for this disease in Africa. Fifth, We project how this experience may be applicable to predicting outbreaks of fungal pathogens in a warming world. Lastly, we describe an example of changing species ranges due to climate change, resulting from recent warming in the Andes and associated glacier melt that has enabled amphibians to colonize higher elevation lakes, only to be followed shortly by the emergence of fungal disease in the new habitats.

Tucker, Compton J.; Yager, Karina; Anyamba, Assaf; Linthicum, Kenneth J.

2011-01-01

158

Contagiousness under antiretroviral therapy and stigmatization toward people with HIV.  

PubMed

Perceived contagiousness is a major dimension underlying HIV-related stigmatization. Antiretroviral therapy (ART) can diminish contagiousness by reducing viral load levels in HIV-infected individuals. To test the assumption that reductions in contagiousness can lead to a decrease in stigmatizing reactions, we conducted an experimental online study. A sample of 752 participants (50.9% female) read a short vignette depicting an HIV-positive individual with either a high or a low viral load and were either given or not given information about the association between viral load and contagiousness. Subsequently, participants were asked to rate their willingness to stigmatize this individual by responding to two measures of social and physical distance. Differences between the low and the high viral load information groups and the combined no-information groups (forming a quasi-control group) were analyzed using analysis of covariance (ANCOVA), controlling for gender and baseline perceptions of contagiousness. The covariates, perceived contagiousness at baseline and gender, were associated with social and physical distancing, but the viral load/information factor was only significant in physical distancing. Planned contrast analyses confirmed that physical distancing in the informed group was lower in the low viral load condition compared to the high viral load condition and to the control group. We thus found evidence for the significant role of perceived contagiousness in the HIV-related stigma and were able to experimentally demonstrate the potential of ART to reduce HIV-related stigmatization by lowering viral load and contagiousness, when these changes are accompanied by a decreased perception of contagiousness. PMID:24779483

Drewes, Jochen; Kleiber, Dieter

2014-01-01

159

Coupling multi-agent model and GIS to simulate pine wood nematode disease spread in ZheJiang Province, China  

NASA Astrophysics Data System (ADS)

A coupled method based on multi-agent model, remote sensing and GIS is described to simulate the forest disease spread. The coupled model focuses on the temporal dynamics of the Bursaphelenchus xylophilus population at the landscape scale. Each individual is modeled as an autonomous agent who behaves according to a set of rules including spreading in the landscape, feeding on Pinus massoniana, sheltering in forest edges and dying, constrained by terrain, land cover and other variables. The model parameters are derived from remote sensing data and field measurements. Ten factors, including damage degree of Pinus Massoniana, altitude and slope, are helped to build the transfer rules. The main outputs are the dynamic disease distribution maps and survived pine population. Our method is applied and validated in DingHai distinct, Zhou Shan city of Zhejiang Province. Three Landsat TM images from the year 1991 to 2006 are used for the pine information extraction. The extracted pine distribution map is used to compare with the simulated surviving pine map. The results show that the coupled model can produce reasonable results and be used as a virtual experiment tool. However, it is difficult to simulate the human activities to help or prevent disease spread and the long fly behavior of insect vectors. Therefore, there still exists some difference between the simulated results and the real data. At the next step, those factors will be considered.

Huang, Huaguo; Wang, Lei; Zhang, XiaoLi; Luo, YouQing; Zhao, Liqiong

2008-10-01

160

Be-CoDiS: An epidemiological model to predict the risk of human diseases spread worldwide. Application to the 2014 Ebola Virus Disease epidemic  

E-print Network

Ebola virus disease is a lethal human and primate disease that currently requires a particular attention from the national and international health authorities due to important outbreaks concurring in some Western African countries and possible spread to other continents, which has already occurred in the USA and Spain. Regarding the emergency of this situation, there is a need of development of decision tools to help the authorities to focus their efforts in important factors that can help to eradicate Ebola. Mathematical modeling and, more precisely, epidemiological modeling can help to predict the possible evolution of the Ebola outbreaks and to give some recommendations in the region to be prioritized for surveillance. In this work, we present a first formulation of a new spatial-temporal epidemiological model, called Be-CoDiS (Between-COuntries Disease Spread), based on the combination of a deterministic Individual-Based model (modelling the interaction between countries, considered as individual) for be...

Benjamin, Ivorra; Diène, Ngom

2014-01-01

161

Contagious Yawning and Seasonal Climate Variation  

PubMed Central

Recent evidence suggests that yawning is a thermoregulatory behavior. To explore this possibility further, the frequency of contagious yawning in humans was measured while outdoors in a desert climate in the United States during two distinct temperature ranges and seasons (winter: 22°C; early summer: 37°C). As predicted, the proportion of pedestrians who yawned in response to seeing pictures of people yawning differed significantly between the two conditions (winter: 45%; summer: 24%). Across conditions yawning occurred at lower ambient temperatures, and the tendency to yawn during each season was associated with the length of time spent outside prior to being tested. Participants were more likely to yawn in the milder climate after spending long periods of time outside, while prolonged exposure to ambient temperatures at or above body temperature was associated with reduced yawning. This is the first report to show that the incidence of yawning in humans is associated with seasonal climate variation, further demonstrating that yawn-induced contagion effects can be mediated by factors unrelated to individual social characteristics or cognitive development. PMID:21960970

Gallup, Andrew C.; Eldakar, Omar Tonsi

2011-01-01

162

Active surveillance of the aquatic environment for potential prediction, prevention and spread of water borne disease: the cholera paradigm  

NASA Astrophysics Data System (ADS)

Based on results of ecological and epidemiological studies, occurrence and spread of certain diseases are more fully understood. Cholera is a major waterborne disease, that is relatively easily treatable and clearly preventable, yet tens of thousands die each year worldwide. A dose dependent disease, the infectious dose can vary from 103-106, depending on health status of the victim. Historically, cholera has been shown to spread from person to person. Furthermore, the disease is caused predominantly via ingestion of contaminated water and most of the outbreaks that have been recorded worldwide originated in a coastal region. Using appropriate detection methods, Vibrio cholerae can be isolated from samples collected from ponds, rivers, estuaries, and coastal waters globally. The populations of V. cholerae may vary in numbers during different seasons of the year. It is important to have a clear understanding of the distribution of the causative agent in the environment as such information can assist public health officials in taking action to prevent outbreaks of cholera. Thus an effective monitoring program is critical, particularly in light of climate change with temperature extremes more likely to be occurring. Based on a predictive model and results of ground truth data, temperature has been found to be a factor in the increase of V. cholerae in the environment. Correlation was observed with occurrence of cholera and both temperature and salinity. More recent research indicates additional factors need to be considered in predicting cholera epidemics, including the hydrology and disease dynamics.

Huq, A.; Colwell, R.

2011-12-01

163

A tale of two tumours: Comparison of the immune escape strategies of contagious cancers?  

PubMed Central

The adaptive immune system should prevent cancer cells passing from one individual to another, in much the same way that it protects against pathogens. However, in rare cases cancer cells do not die within a single individual, but successfully pass between individuals, escaping the adaptive immune response and becoming a contagious cancer. There are two naturally occurring contagious cancers, Devil Facial Tumour Disease (DFTD), found in Tasmanian devils, and Canine Transmissible Venereal Tumour (CTVT), found in dogs. Despite sharing an ability to pass as allografts, these cancers have a very different impact on their hosts. While DFTD causes 100% mortality among infected devils and has had a devastating impact on the devil population, CTVT co-exists with its host in a manner that does not usually cause death of the dog. Although immune evasion strategies for CTVT have been defined, why DFTD is not rejected as an allograft is not understood. We have made progress in revealing mechanisms of immune evasion for DFTD both in vitro and in vivo, and here we compare how DFTD and CTVT interact with their respective hosts and avoid rejection. Our findings highlight factors that may be important for the evolution of contagious cancers and cancer more generally. Perhaps most importantly, this work has opened up important areas for future research, including the effect of epigenetic factors on immune escape mechanisms and the basis of a vaccine strategy that may protect Tasmanian devils against DFTD. PMID:23200636

Siddle, Hannah V.; Kaufman, Jim

2013-01-01

164

A tale of two tumours: comparison of the immune escape strategies of contagious cancers.  

PubMed

The adaptive immune system should prevent cancer cells passing from one individual to another, in much the same way that it protects against pathogens. However, in rare cases cancer cells do not die within a single individual, but successfully pass between individuals, escaping the adaptive immune response and becoming a contagious cancer. There are two naturally occurring contagious cancers, Devil Facial Tumour Disease (DFTD), found in Tasmanian devils, and Canine Transmissible Venereal Tumour (CTVT), found in dogs. Despite sharing an ability to pass as allografts, these cancers have a very different impact on their hosts. While DFTD causes 100% mortality among infected devils and has had a devastating impact on the devil population, CTVT co-exists with its host in a manner that does not usually cause death of the dog. Although immune evasion strategies for CTVT have been defined, why DFTD is not rejected as an allograft is not understood. We have made progress in revealing mechanisms of immune evasion for DFTD both in vitro and in vivo, and here we compare how DFTD and CTVT interact with their respective hosts and avoid rejection. Our findings highlight factors that may be important for the evolution of contagious cancers and cancer more generally. Perhaps most importantly, this work has opened up important areas for future research, including the effect of epigenetic factors on immune escape mechanisms and the basis of a vaccine strategy that may protect Tasmanian devils against DFTD. PMID:23200636

Siddle, Hannah V; Kaufman, Jim

2013-09-01

165

The Earth Institute, Columbia University18 19 the spread of many diseases in africa  

E-print Network

temperatures warm. Bacterial meningitis can spread rapidly in the dusty dry season in the semi-arid belt in insecticide to kill mosquitoes or stockpiling meningitis vaccine. "Seasonal forecasting is not just gauges. Malaria and meningitis alone kill thousands of people each year across sub-Saharan Africa

166

Using Friends as Sensors to Detect Global-Scale Contagious Outbreaks  

PubMed Central

Recent research has focused on the monitoring of global–scale online data for improved detection of epidemics, mood patterns, movements in the stock market political revolutions, box-office revenues, consumer behaviour and many other important phenomena. However, privacy considerations and the sheer scale of data available online are quickly making global monitoring infeasible, and existing methods do not take full advantage of local network structure to identify key nodes for monitoring. Here, we develop a model of the contagious spread of information in a global-scale, publicly-articulated social network and show that a simple method can yield not just early detection, but advance warning of contagious outbreaks. In this method, we randomly choose a small fraction of nodes in the network and then we randomly choose a friend of each node to include in a group for local monitoring. Using six months of data from most of the full Twittersphere, we show that this friend group is more central in the network and it helps us to detect viral outbreaks of the use of novel hashtags about 7 days earlier than we could with an equal-sized randomly chosen group. Moreover, the method actually works better than expected due to network structure alone because highly central actors are both more active and exhibit increased diversity in the information they transmit to others. These results suggest that local monitoring is not just more efficient, but also more effective, and it may be applied to monitor contagious processes in global–scale networks. PMID:24718030

Garcia-Herranz, Manuel; Moro, Esteban; Cebrian, Manuel; Christakis, Nicholas A.; Fowler, James H.

2014-01-01

167

Genetic diversity and mutation of avian paramyxovirus serotype 1 (Newcastle disease virus) in wild birds and evidence for intercontinental spread.  

PubMed

Avian paramyxovirus serotype 1 (APMV-1), or Newcastle disease virus, is the causative agent of Newcastle disease, one of the most economically important diseases for poultry production worldwide and a cause of periodic epizootics in wild birds in North America. In this study, we examined the genetic diversity of APMV-1 isolated from migratory birds sampled in Alaska, Japan, and Russia and assessed the evidence for intercontinental virus spread using phylogenetic methods. Additionally, we predicted viral virulence using deduced amino acid residues for the fusion protein cleavage site and estimated mutation rates for the fusion gene of class I and class II migratory bird isolates. All 73 isolates sequenced as part of this study were most closely related to virus genotypes previously reported for wild birds; however, five class II genotype I isolates formed a monophyletic clade exhibiting previously unreported genetic diversity, which met criteria for the designation of a new sub-genotype. Phylogenetic analysis of wild-bird isolates provided evidence for intercontinental virus spread, specifically viral lineages of APMV-1 class II genotype I sub-genotypes Ib and Ic. This result supports migratory bird movement as a possible mechanism for the redistribution of APMV-1. None of the predicted deduced amino acid motifs for the fusion protein cleavage site of APMV-1 strains isolated from migratory birds in Alaska, Japan, and Russia were consistent with those of previously identified virulent viruses. These data therefore provide no support for these strains contributing to the emergence of avian pathogens. The estimated mutation rates for fusion genes of class I and class II wild-bird isolates were faster than those reported previously for non-virulent APMV-1 strains. Collectively, these findings provide new insight into the diversity, spread, and evolution of APMV-1 in wild birds. PMID:23807743

Ramey, Andrew M; Reeves, Andrew B; Ogawa, Haruko; Ip, Hon S; Imai, Kunitoshi; Bui, Vuong Nghia; Yamaguchi, Emi; Silko, Nikita Y; Afonso, Claudio L

2013-12-01

168

Genetic diversity and mutation of avian paramyxovirus serotype 1 (Newcastle disease virus) in wild birds and evidence for intercontinental spread  

USGS Publications Warehouse

Avian paramyxovirus serotype 1 (APMV-1), or Newcastle disease virus, is the causative agent of Newcastle disease, one of the most economically important diseases for poultry production worldwide and a cause of periodic epizootics in wild birds in North America. In this study, we examined the genetic diversity of APMV-1 isolated from migratory birds sampled in Alaska, Japan, and Russia and assessed the evidence for intercontinental virus spread using phylogenetic methods. Additionally, we predicted viral virulence using deduced amino acid residues for the fusion protein cleavage site and estimated mutation rates for the fusion gene of class I and class II migratory bird isolates. All 73 isolates sequenced as part of this study were most closely related to virus genotypes previously reported for wild birds; however, five class II genotype I isolates formed a monophyletic clade exhibiting previously unreported genetic diversity, which met criteria for the designation of a new sub-genotype. Phylogenetic analysis of wild-bird isolates provided evidence for intercontinental virus spread, specifically viral lineages of APMV-1 class II genotype I sub-genotypes Ib and Ic. This result supports migratory bird movement as a possible mechanism for the redistribution of APMV-1. None of the predicted deduced amino acid motifs for the fusion protein cleavage site of APMV-1 strains isolated from migratory birds in Alaska, Japan, and Russia were consistent with those of previously identified virulent viruses. These data therefore provide no support for these strains contributing to the emergence of avian pathogens. The estimated mutation rates for fusion genes of class I and class II wild-bird isolates were faster than those reported previously for non-virulent APMV-1 strains. Collectively, these findings provide new insight into the diversity, spread, and evolution of APMV-1 in wild birds.

Ramey, Andy M.; Reeves, Andrew; Ogawa, Haruko; Ip, Hon S.; Imai, Kunitoshi; Bui, V. N.; Yamaguchi, Emi; Silko, N. Y.; Afonso, C.L.

2013-01-01

169

9 CFR 71.3 - Interstate movement of diseased animals and poultry generally prohibited.  

Code of Federal Regulations, 2010 CFR

...known to exist in the United States: foot-and-mouth disease, rinderpest, African...atrophic rhinitis, contagious ecthyma, foot rot, infectious keratitis, ram...actinobacillosis, contagious ecthyma, foot rot, and shipping fever:...

2010-01-01

170

The spread of zoonoses and other infectious diseases through the international trade of animals and animal products.  

PubMed

For trade purposes, ever increasing quantities of food animals and animal products that are transported more rapidly than ever before are contributing to the spread of zoonoses and are creating threats on a permanent basis. Most countries in south-eastern Europe, the Mediterranean and the Middle East are increasing imports of food animals and meat and products of animal origin. They can become potential sources of zoonotic and other infectious diseases if controls are not performed under the most effective conditions. Developing countries with their organisational weakness are particularly vulnerable to fraudulent international trade practices of animals and animal products. To prevent such risks, the World Trade Organization, the World Organisation for Animal Health and their member countries support the measures stipulated in the Sanitary and Phytosanitary Agreement which targets the liberalisation of trade in animals and animal products under specific conditions while protecting public health and national economies. Vigilance must be exercised and appropriate inspection made at points of entry by veterinary and other authorities to ensure the strict implementation of international and national regulations. National legislation, appropriate infrastructures and the respect of international regulations can become barriers to avoid animal trade, contributing to the spread of zoonotic and other infectious diseases. PMID:20411486

Seimenis, Aristarhos M

2008-01-01

171

A Comparison of Dynamics in Two Models for the Spread of a Vector-Borne Disease.  

PubMed

In 2007, bluetongue virus (BTV) was introduced to both Denmark (DK) and the United Kingdom (UK). For this reason, simulation models were built to predict scenarios for future incursions. The DK and UK models have a common description of within-herd dynamics, but differ greatly in their descriptions of between-herd spread, one using an explicit representation of vector dispersal, the other a transmission kernel. Here, we compare model predictions for the dynamics of bluetongue in the UK, based on the 2007 incursion and vaccination rollout in 2008. We demonstrate how an agent-based model shows greater sensitivity to the level of vaccine uptake and has lower variability compared with a kernel-based model. However, a model using a transmission kernel requires less detailed data and is often faster. PMID:25056842

Graesbøll, K; Sumner, T; Enøe, C; Christiansen, L E; Gubbins, S

2014-07-24

172

The network of sheep movements within Great Britain: network properties and their implications for infectious disease spread  

PubMed Central

During the 2001 foot and mouth disease epidemic in the UK, initial dissemination of the disease to widespread geographical regions was attributed to livestock movement, especially of sheep. In response, recording schemes to provide accurate data describing the movement of large livestock in Great Britain (GB) were introduced. Using these data, we reconstruct directed contact networks within the sheep industry and identify key epidemiological properties of these networks. There is clear seasonality in sheep movements, with a peak of intense activity in August and September and an associated high risk of a large epidemic. The high correlation between the in and out degree of nodes favours disease transmission. However, the contact networks were largely dissasortative: highly connected nodes mostly connect to nodes with few contacts, effectively slowing the spread of disease. This is a result of bipartite-like network properties, with most links occurring between highly active markets and less active farms. When comparing sheep movement networks (SMNs) to randomly generated networks with the same number of nodes and node degrees, despite structural differences (such as disassortativity and higher frequency of even path lengths in the SMNs), the characteristic path lengths within the SMNs are close to values computed from the corresponding random networks, showing that SMNs have ‘small-world’-like properties. Using the network properties, we show that targeted biosecurity or surveillance at highly connected nodes would be highly effective in preventing a large and widespread epidemic. PMID:16971335

Kiss, Istvan Z; Green, Darren M; Kao, Rowland R

2006-01-01

173

Contagious ecthyma in mountain goat of coastal British Columbia.  

PubMed

Contagious ecthyma has been reported previously from mountain goat (Oreamnos americanus) in one restricted area of eastern British Columbia. A second focus of infection is reported for mountain goat from western British Columbia. Diagnosis was based on appearance of lesions at necropsy, histopathology and demonstration of poxvirus with the electron microscope. The epizootiology of this infection in mountain goat is discussed briefly. PMID:559107

Hebert, D M; Samuel, W M; Smith, G W

1977-04-01

174

Disease risk mitigation: the equivalence of two selective mixing strategies on aggregate contact patterns and resulting epidemic spread.  

PubMed

The personal choices affecting the transmission of infectious diseases include the number of contacts an individual makes, and the risk-characteristics of those contacts. We consider whether these different choices have distinct implications for the course of an epidemic. We also consider whether choosing contact mitigation (how much to mix) and affinity mitigation (with whom to mix) strategies together has different epidemiological effects than choosing each separately. We use a set of differential equation compartmental models of the spread of disease, coupled with a model of selective mixing. We assess the consequences of varying contact or affinity mitigation as a response to disease risk. We do this by comparing disease incidence and dynamics under varying contact volume, contact type, and both combined across several different disease models. Specifically, we construct a change of variables that allows one to transition from contact mitigation to affinity mitigation, and vice versa. In the absence of asymptomatic infection we find no difference in the epidemiological impacts of the two forms of disease risk mitigation. Furthermore, since models that include both mitigation strategies are underdetermined, varying both results in no outcome that could not be reached by choosing either separately. Which strategy is actually chosen then depends not on their epidemiological consequences, but on the relative cost of reducing contact volume versus altering contact type. Although there is no fundamental epidemiological difference between the two forms of mitigation, the social cost of alternative strategies can be very different. From a social perspective, therefore, whether one strategy should be promoted over another depends on economic not epidemiological factors. PMID:25150459

Morin, Benjamin R; Perrings, Charles; Levin, Simon; Kinzig, Ann

2014-12-21

175

Infectious Disease and Climate Change: Is Climate Change Responsible for the Spread of West Nile Virus?  

NSDL National Science Digital Library

Temperature increases associated with global climate change have led to concerns that infectious diseases common in warmer tropical and subtropical climates may become more common in warming middle altitudes. In this problem-based learning module, learners investigate the connections between disease and climate change. Additional resources and activities are also provided. This module was developed to be used in the Earth System Science Education Alliance (ESSEA) courses for middle and high school teachers and is also available to teachers to adapt for general classroom use.

176

Spread of Sugarcane yellow leaf virus in initially disease-free sugarcane is linked to rainfall and host resistance in the humid tropical environment of Guadeloupe  

Microsoft Academic Search

Sugarcane yellow leaf virus, the causal agent of yellow leaf, is transmitted from plant to plant by aphids. Understanding and evaluating the epidemic\\u000a risks due to spread of yellow leaf by aphids is an important feature for sugarcane production. Four distinct sugarcane trials\\u000a were set up with disease-free plants to study the relationship between spread of yellow leaf, the vector

Jean Heinrich Daugrois; Carine Edon-Jock; Sandrine Bonoto; Jean Vaillant; Philippe Rott

2011-01-01

177

Predicting ectotherm disease vector spread—benefits from multidisciplinary approaches and directions forward  

NASA Astrophysics Data System (ADS)

The occurrence of ectotherm disease vectors outside of their previous distribution area and the emergence of vector-borne diseases can be increasingly observed at a global scale and are accompanied by a growing number of studies which investigate the vast range of determining factors and their causal links. Consequently, a broad span of scientific disciplines is involved in tackling these complex phenomena. First, we evaluate the citation behaviour of relevant scientific literature in order to clarify the question "do scientists consider results of other disciplines to extend their expertise?" We then highlight emerging tools and concepts useful for risk assessment. Correlative models (regression-based, machine-learning and profile techniques), mechanistic models (basic reproduction number R 0) and methods of spatial regression, interaction and interpolation are described. We discuss further steps towards multidisciplinary approaches regarding new tools and emerging concepts to combine existing approaches such as Bayesian geostatistical modelling, mechanistic models which avoid the need for parameter fitting, joined correlative and mechanistic models, multi-criteria decision analysis and geographic profiling. We take the quality of both occurrence data for vector, host and disease cases, and data of the predictor variables into consideration as both determine the accuracy of risk area identification. Finally, we underline the importance of multidisciplinary research approaches. Even if the establishment of communication networks between scientific disciplines and the share of specific methods is time consuming, it promises new insights for the surveillance and control of vector-borne diseases worldwide.

Thomas, Stephanie Margarete; Beierkuhnlein, Carl

2013-05-01

178

Predicting ectotherm disease vector spread--benefits from multidisciplinary approaches and directions forward.  

PubMed

The occurrence of ectotherm disease vectors outside of their previous distribution area and the emergence of vector-borne diseases can be increasingly observed at a global scale and are accompanied by a growing number of studies which investigate the vast range of determining factors and their causal links. Consequently, a broad span of scientific disciplines is involved in tackling these complex phenomena. First, we evaluate the citation behaviour of relevant scientific literature in order to clarify the question "do scientists consider results of other disciplines to extend their expertise?" We then highlight emerging tools and concepts useful for risk assessment. Correlative models (regression-based, machine-learning and profile techniques), mechanistic models (basic reproduction number R0) and methods of spatial regression, interaction and interpolation are described. We discuss further steps towards multidisciplinary approaches regarding new tools and emerging concepts to combine existing approaches such as Bayesian geostatistical modelling, mechanistic models which avoid the need for parameter fitting, joined correlative and mechanistic models, multi-criteria decision analysis and geographic profiling. We take the quality of both occurrence data for vector, host and disease cases, and data of the predictor variables into consideration as both determine the accuracy of risk area identification. Finally, we underline the importance of multidisciplinary research approaches. Even if the establishment of communication networks between scientific disciplines and the share of specific methods is time consuming, it promises new insights for the surveillance and control of vector-borne diseases worldwide. PMID:23532546

Thomas, Stephanie Margarete; Beierkuhnlein, Carl

2013-05-01

179

Spread of Creutzfeldt-Jakob disease virus along visual pathways after intraocular inoculation  

Microsoft Academic Search

Summary We studied the targeting of spongiform lesions within the visual pathways after intraocular injection with the Fujisaki strain of Creutzfeldt-Jakob disease (CJD) virus. The first lesions were observed 18 weeks postinoculation in the most superficial layer of the superior colliculus and in the lateral geniculate body contralateral to the side of the inoculation. Asymmetrical lesions in the superior colliculus

P. P. Liberski; R. Yanagihara; C. J. Gibbs Jr; D. C. Gajdusek

1990-01-01

180

Key Node Selection for Containing Infectious Disease Spread Using Particle Swarm Optimization  

E-print Network

weeks, as an effort to block a rising wave of seasonal influenza. The economic cost is high when of infectious diseases. Considering the cost in manpower and limited screening machines available, we face, feasible direct interventions include non-pharmaceutical interventions [6] and health-care interventions

Wong, Limsoon

181

The African buffalo: a villain for inter-species spread of infectious diseases in southern Africa.  

PubMed

The African buffalo (Syncerus caffer) is a large wild bovid which until recently ranged across all but the driest parts of sub-Saharan Africa, and their local range being limited to about 20 km from surface water. They are of high ecological value due to their important role as bulk feeders in the grazing hierarchy. They also have high economic value, because they are one of the sought after 'Big Five' in the eco-tourism industry. In Africa, buffaloes have been recognised for some time as an important role player in the maintenance and transmission of a variety of economically important livestock diseases at the wildlife and/or livestock interface. These include African strains of foot-and-mouth disease (FMD), Corridor disease (theileriosis), bovine tuberculosis and bovine brucellosis. For a number of other diseases of veterinary importance, African buffaloes may also serve as amplifier or incidental host, whereby infection with the causative pathogens may cause severe clinical signs such as death or abortion as in the case of anthrax and Rift Valley fever, or remain mild or subclinical for example heartwater. The long term health implications of most of those infections on the buffalo at a population level is usually limited, and they do not pose a threat on the population's survival. Because of their ability to harbour and transmit important diseases to livestock, their sustainable future in ecotourism, trade and transfrontier conservation projects become complex and costly and reliable diagnostic tools are required to monitor these infections in buffalo populations. PMID:23327373

Michel, Anita L; Bengis, Roy G

2012-01-01

182

Mycoplasma agalactiae, an Etiological Agent of Contagious Agalactia in Small Ruminants: A Review  

PubMed Central

Mycoplasma agalactiae is one of the causal agents of classical contagious agalactia (CA), a serious, economically important but neglected enzootic disease of small ruminants. It occurs in many parts of the world and most notably in the Mediterranean Basin. Following the infection common complications are septicaemia, mastitis, arthritis, pleurisy, pneumonia, and keratoconjunctivitis. Primary or tentative diagnosis of the organism is based upon clinical signs. Various serological tests, namely, growth precipitation, immunofluorescence, complement fixation test, haemagglutination inhibition, agglutination, immunodiffusion, enzyme immunoassays, immunoelectrophoresis, blotting techniques, and others, are available. Molecular tools seem to be much more sensitive, specific, and faster and help to differentiate various strains. The real-time PCR, multiplex PCR, quantitative PCR, PCR-RFLP, MLST, and gene probes, complementary to segments of chromosomal DNA or 16S ribosomal RNA (rRNA), have strengthened the diagnosis of M. agalactiae. Both live attenuated and adjuvant (alum precipitated or saponified) inactivated vaccines are available with greater use of inactivated ones due to lack of side effects. The present review discusses the etiology, epidemiology, pathogenesis, and clinical signs of contagious agalactia in small ruminants along with trends and advances in its diagnosis, treatment, vaccination, prevention, and control strategies that will help in countering this disease. PMID:25097796

Kumar, Amit; Rahal, Anu; Verma, Amit Kumar

2014-01-01

183

Spread of Vector-borne Diseases and Neglect of Leishmaniasis, Europe  

PubMed Central

The risk for reintroduction of some exotic vector-borne diseases in Europe has become a hot topic, while the reality of others is neglected at the public health policy level. Leishmaniasis is endemic in all southern countries of Europe, with ?700 autochthonous human cases reported each year (3,950 if Turkey is included). Asymptomatic cases have been estimated at 30–100/1 symptomatic case, and leishmaniasis has up to 25% seroprevalence in domestic dogs. Even though leishmaniasis is essentially associated with Leishmania infantum and visceral leishmaniasis, new species, such as L. donovani and L. tropica, might colonize European sand fly vectors. Drug-resistant L. infantum strains might be exported outside Europe through dogs. Despite this possibility, no coordinated surveillance of the disease exists at the European level. In this review of leishmaniasis importance in Europe, we would like to bridge the gap between research and surveillance and control. PMID:18598618

Campino, Lenea; Cañavate, Carmen; Dedet, Jean-Pierre; Gradoni, Luigi; Soteriadou, Ketty; Mazeris, Apostolos; Ozbel, Yusuf; Boelaert, Marleen

2008-01-01

184

Spreading of pathology in neurodegenerative diseases: a focus on human studies  

PubMed Central

The progression of many neurodegenerative diseases is thought to be driven by the template-directed misfolding, seeded aggregation and cell–cell transmission of characteristic disease-related proteins, leading to the sequential dissemination of pathological protein aggregates. Recent evidence strongly suggests that the anatomical connections made by neurons — in addition to the intrinsic characteristics of neurons, such as morphology and gene expression profile — determine whether they are vulnerable to degeneration in these disorders. Notably, this common pathogenic principle opens up opportunities for pursuing novel targets for therapeutic interventions for these neurodegenerative disorders. We review recent evidence that supports the notion of neuron–neuron protein propagation, with a focus on neuropathological and positron emission tomography imaging studies in humans. PMID:25588378

Brettschneider, Johannes; Del Tredici, Kelly; Lee, Virginia M.-Y.; Trojanowski, John Q.

2015-01-01

185

Comparative effects of avoidance and vaccination in disease spread on a dynamic small-world network  

NASA Astrophysics Data System (ADS)

Dynamic small-world contact networks have fixed short range links and time-varying stochastic long range links. They are used to model mobile populations or as minimal models for traditional small-world networks. Here we study the relative effects of vaccinations and avoidance of infected individuals in a susceptible-infected-recovered (SIR) epidemic model on a dynamic small-world network. We derive the critical mobility required for an outbreak to occur as a function of the disease’s infectivity, recovery rate, avoidance rate, and vaccination rate. We also derive an expression that allows us to calculate the amount of vaccination and/or avoidance necessary to prevent an epidemic. Calculated quantities show excellent agreement with simulations.

Stone, Thomas E.; Jones, Matthew M.; McKay, Susan R.

2010-12-01

186

MedyMyst: Orientation at O.R.B. Introduction to the six types of pathogens, Koch's Postulates, disease spread, disease prevention measures, and the immune system.  

NSDL National Science Digital Library

This is a problem-based learning adventure game that engages the player in the role of scientist, historian, and detective. Students get an introduction to infectious diseases and pathogens. At the beginning, the student is presented with a problem that must be solved. During the mission, students conduct field and laboratory investigations with the aid of the MedMyst characters. Each mission can be played within one class period (approximately 30 to 45 minutes) and the knowledge gained from each mission will help students understand how infectious diseases are spread. We recommend that Mission One be played first because it covers the basics and serves as an orientation to the concepts and the characters. However, any of the missions may be chosen to follow Mission One. Each mission is a self-contained problem and may be played without reliance on the other missions. Also available in Spanish.

Center for Technology in Teaching and Learning

2011-09-28

187

Disease properties, geography, and mitigation strategies in a simulation spread of rinderpest across the United States  

Microsoft Academic Search

For the past decade, the Food and Agriculture Organization of the United Nations has been working toward eradicating rinderpest\\u000a through vaccination and intense surveillance by 2012. Because of the potential severity of a rinderpest epidemic, it is prudent\\u000a to prepare for an unexpected outbreak in animal populations. There is no immunity to the disease among the livestock or wildlife\\u000a in

Carrie Manore; Benjamin McMahon; Jeanne Fair; James M Hyman; Mac Brown; Montiago LaBute

2011-01-01

188

The SIS Model of Epidemic Spreading in a Hierarchical Social Network  

NASA Astrophysics Data System (ADS)

The phenomenon of epidemic spreading in a population with a hierarchical structure of interpersonal interactions is described and investigated numerically. The SIS model with temporal immunity to a disease and a time of incubation is used. In our model spatial localization of individuals belonging to different social groups, effectiveness of different interpersonal interactions and the mobility of a contemporary community are taken into account. The structure of interpersonal connections is based on a scale-free network. The influence of the structure of the social network on typical relations characterizing the spreading process, like a range of epidemic and epidemic curves, is discussed. The probability that endemic state occurs is also calculated. Surprisingly it occurs, that less contagious diseases has greater chance to survive. The influence of preventive vaccinations on the spreading process is investigated and critical range of vaccinations that is sufficient for the suppression of an epidemic is calculated. Our results of numerical calculations are compared with the solutions of the master equation for the spreading process, and good agreement is found.

Grabowski, A.; Kosinski, R. A.

2005-05-01

189

Broad and fine-scale genetic analysis of white-tailed deer populations: estimating the relative risk of chronic wasting disease spread  

PubMed Central

Chronic wasting disease is a transmissible spongiform encephalopathy of cervids, similar to sheep scrapie that has only recently been detected in wild populations of white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus hemionus) in western Canada. Relatively little is known about local transmission dynamics of the disease or the potential for long-distance spread. We analysed the population genetic structure of over 2000 white-tailed deer sampled from Alberta, British Columbia, and Saskatchewan using microsatellite profiles and mtDNA sequencing to assess the relative risk of disease spread. There was very little differentiation among subpopulations and a weak trend of increasing differentiation with geographic distance. This suggests that the potential for long-distance disease spread through the dispersal of infected individuals is possible, yet the risk of spread should gradually diminish with distance from infection foci. Within subpopulations, females were more related than expected by chance (R > 0) within a radius of approximately 500 m. Sex-biased philopatry and social interactions among related females may facilitate local disease transmission within social groups. Local herd reduction may therefore be an effective tool for reducing the disease prevalence when implemented at the appropriate spatial scale. PMID:25567957

Cullingham, Catherine I; Merrill, Evelyn H; Pybus, Margo J; Bollinger, Trent K; Wilson, Gregory A; Coltman, David W

2011-01-01

190

Broad and fine-scale genetic analysis of white-tailed deer populations: estimating the relative risk of chronic wasting disease spread.  

PubMed

Chronic wasting disease is a transmissible spongiform encephalopathy of cervids, similar to sheep scrapie that has only recently been detected in wild populations of white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus hemionus) in western Canada. Relatively little is known about local transmission dynamics of the disease or the potential for long-distance spread. We analysed the population genetic structure of over 2000 white-tailed deer sampled from Alberta, British Columbia, and Saskatchewan using microsatellite profiles and mtDNA sequencing to assess the relative risk of disease spread. There was very little differentiation among subpopulations and a weak trend of increasing differentiation with geographic distance. This suggests that the potential for long-distance disease spread through the dispersal of infected individuals is possible, yet the risk of spread should gradually diminish with distance from infection foci. Within subpopulations, females were more related than expected by chance (R > 0) within a radius of approximately 500 m. Sex-biased philopatry and social interactions among related females may facilitate local disease transmission within social groups. Local herd reduction may therefore be an effective tool for reducing the disease prevalence when implemented at the appropriate spatial scale. PMID:25567957

Cullingham, Catherine I; Merrill, Evelyn H; Pybus, Margo J; Bollinger, Trent K; Wilson, Gregory A; Coltman, David W

2011-01-01

191

International trade and the spread of animal diseases: assessing the risks.  

PubMed

Decisions about managing animal and zoonotic disease risks associated with the international trade in animals and animal products are inevitably made in the face of varying degrees of uncertainty. The risk analysis framework of the Office International des Epizooties (OIE: World organisation for animal health) provides a structured approach that facilitates the identification, assessment, management and communication of these risks. By ensuring that an analysis is transparent and subjected to scientific review, stakeholders and trading partners can be assured that a reasonable level of objectivity is obtained, that the measures adopted are appropriate and that international obligations, outlined in the Agreement on the Application of Sanitary and Phytosanitary Measures of the World Trade Organization, are fulfilled. PMID:20429068

Murray, N

2006-01-01

192

Alveolar echinococcosis-spreading disease challenging clinicians: A case report and literature review  

PubMed Central

Human alveolar echinococcosis (AE) is a potentially deadly disease; recent studies have shown that the endemic area of Echinococcus multilocularis, its causative agent, is larger than previously known. This disease has low prevalence and remains underreported in Europe. Emerging clinical data show that diagnostic difficulties are still common. We report on a 76-year old patient suffering from AE lesions restricted to the left lobe of the liver who underwent a curative extended left hemihepatectomy. Prior to the resection a liver biopsy under the suspicion of an atypical malignancy was performed. After the intervention he developed a pseudoaneurysm of the hepatic artery that was successfully coiled. Surprisingly, during surgery, the macroscopic appearance of the tumour revealed a growth pattern that was rather typical for cystic echinococcosis (CE), i.e., a gross tumour composed of multiple large vesicles with several centimeters in diameter. In addition, there were neither extensive adhesions nor infiltrations of the neighboring pancreas and diaphragm as was expected from previous imaging results. The unexpected diagnosis of AE was confirmed by definite histopathology, specific polymerase chain reaction and serology results. This is a rare case of unusual macroscopic presentation of AE that posed immense diagnostic challenges and had an eventful course. To our knowledge this is the first case of an autochthonous infection in this particular geographic area of Germany, the federal state of Saxony. This report may provide new hints for an expanding area of risk for AE and emphasizes the risk of complications in the scope of diagnostic procedures and the limitations of modern radiological imaging. PMID:23864792

Atanasov, Georgi; Benckert, Christoph; Thelen, Armin; Tappe, Dennis; Frosch, Matthias; Teichmann, Dieter; Barth, Thomas FE; Wittekind, Christian; Schubert, Stefan; Jonas, Sven

2013-01-01

193

A predictable sequential determinant spreading cascade invariably accompanies progression of experimental autoimmune encephalomyelitis: a basis for peptide-specific therapy after onset of clinical disease  

PubMed Central

The development of autoimmune disease is accompanied by the acquired recognition of new self-determinants, a process commonly referred to as determinant spreading. In this study, we addressed the question of whether determinant spreading is pathogenic for progression of chronic- relapsing experimental autoimmune encephalomyelitis (EAE), a disease with many similarities to multiple sclerosis (MS). Our approach involved a systematic epitope mapping of responses to myelin proteolipid protein (PLP) as well as assaying responses to known encephalitogenic determinants of myelin basic protein (MBP 87-89) and myelin oligodendrocyte glycoprotein (MOG 92-106) at various times after induction of EAE in (SWR X SJL)F1 mice immunized with PLP 139-151. We found that the order in which new determinants are recognized during the course of disease follows a predictable sequential pattern. At monthly intervals after immunization with p139-151, responses to PLP 249-273, MBP 87-99, and PLP 137-198 were sequentially accumulated in al mice examined. Three lines of evidence showed that determinant spreading is pathogenic for disease progression: (a) spreading determinants mediate passive transfer of acute EAE in naive (SWR X SJL)F1 recipients; (b) an invariant relationship exists between the development of relapse/progression and the spreading of recognition to new immunodominant encephalitogenic determinants; and (c) after EAE onset, the induction of peptide-specific tolerance to spreading but not to nonspreading encephalitogenic determinants prevents subsequent progression of EAE. Thus, the predictability of acquired self- determinant recognition provides a basis for sequential determinant- specific therapeutic intervention after onset of the autoimmune disease process. PMID:8666934

1996-01-01

194

Immunizing against Prejudice: Effects of Disease Protection on Attitudes toward out-Groups  

E-print Network

Contemporary interpersonal biases are partially derived from psychological mechanisms that evolved to protect people against the threat of contagious disease. This behavioral immune system effectively promotes disease ...

Ackerman, Joshua

195

Presence of Contagious Yawning in Children with Autism Spectrum Disorder  

PubMed Central

Most previous studies suggest diminished susceptibility to contagious yawning in children with autism spectrum disorder (ASD). However, it could be driven by their atypical attention to the face. To test this hypothesis, children with ASD and typically developing (TD) children were shown yawning and control movies. To ensure participants' attention to the face, an eye tracker controlled the onset of the yawning and control stimuli. Results demonstrated that both TD children and children with ASD yawned more frequently when they watched the yawning stimuli than the control stimuli. It is suggested therefore that the absence of contagious yawning in children with ASD, as reported in previous studies, might relate to their weaker tendency to spontaneously attend to others' faces. PMID:23970970

Kikuchi, Yukiko; Akechi, Hironori; Tojo, Yoshikuni; Osanai, Hiroo; Hasegawa, Toshikazu

2013-01-01

196

Contagious crying beyond the first days of life.  

PubMed

Newborns cry in response to another newborn cry and researchers agree that these are the very early signs of empathy development. Yet, little is known about the development of these affect sharing reactions in infancy, beyond the very first few days after birth. The aim of this study is to investigate the presence of contagious cry phenomenon in infancy. Infants aged 1-, 3-, 6-, and 9-month-old were presented with the sound of another infant cry vocalizations. Their emotional reactions were recorded in terms of vocal (presence of vocal distress, latency, and intensity) and facial (anger and sadness) expressions of emotions. Results show that during the presentation of a pain cry sound, 1, 3, 6, and 9 months old infants manifest increased vocal and facial expressions of distress. These affect sharing reactions do not decrease with age. Both boys and girls manifest similar levels of contagious crying reactions. The results are discussed in terms of early empathy development. PMID:20362341

Geangu, Elena; Benga, Oana; Stahl, Daniel; Striano, Tricia

2010-06-01

197

Changing social contact patterns under tropical weather conditions relevant for the spread of infectious diseases.  

PubMed

Weather conditions and social contact patterns provide some clues to understanding year-round influenza epidemics in the tropics. Recent studies suggest that contact patterns may direct influenza transmission in the tropics as critically as the aerosol channel in temperate regions. To examine this argument, we analysed a representative nationwide survey dataset of contact diaries with comprehensive weather data in Taiwan. Methods we used included model-free estimated relative changes in reproduction number, R 0; relative changes in the number of contacts; and model-based estimated relative changes in mean contacts using zero-inflated negative binomial regression models. Overall, social contact patterns clearly differ by demographics (such as age groups), personal idiosyncrasies (such as personality and happiness), and social institutions (such as the division of weekdays and weekend days). Further, weather conditions also turn out to be closely linked to contact patterns under various circumstances. Fleeting contacts, for example, tend to diminish when it rains hard on weekdays, while physical contacts also decrease during weekend days with heavy rain. Frequent social contacts on weekdays and under good weather conditions, including high temperature and low absolute humidity, all might facilitate the transmission of infectious diseases in tropical regions. PMID:24725605

Chan, T-C; Fu, Y-C; Hwang, J-S

2015-01-01

198

On the Origin and Spread of the Scab Disease of Apple: Out of Central Asia  

PubMed Central

Background Venturia inaequalis is an ascomycete fungus responsible for apple scab, a disease that has invaded almost all apple growing regions worldwide, with the corresponding adverse effects on apple production. Monitoring and predicting the effectiveness of intervention strategies require knowledge of the origin, introduction pathways, and population biology of pathogen populations. Analysis of the variation of genetic markers using the inferential framework of population genetics offers the potential to retrieve this information. Methodology/Principal Findings Here, we present a population genetic analysis of microsatellite variation in 1,273 strains of V. inaequalis representing 28 orchard samples from seven regions in five continents. Analysis of molecular variance revealed that most of the variation (88%) was distributed within localities, which is consistent with extensive historical migrations of the fungus among and within regions. Despite this shallow population structure, clustering analyses partitioned the data set into separate groups corresponding roughly to geography, indicating that each region hosts a distinct population of the fungus. Comparison of the levels of variability among populations, along with coalescent analyses of migration models and estimates of genetic distances, was consistent with a scenario in which the fungus emerged in Central Asia, where apple was domesticated, before its introduction into Europe and, more recently, into other continents with the expansion of apple growing. Across the novel range, levels of variability pointed to multiple introductions and all populations displayed signatures of significant post-introduction increases in population size. Most populations exhibited high genotypic diversity and random association of alleles across loci, indicating recombination both in native and introduced areas. Conclusions/Significance Venturia inaequalis is a model of invasive phytopathogenic fungus that has now reached the ultimate stage of the invasion process with a broad geographic distribution and well-established populations displaying high genetic variability, regular sexual reproduction, and demographic expansion. PMID:18197265

Gladieux, Pierre; Zhang, Xiu-Guo; Afoufa-Bastien, Damien; Valdebenito Sanhueza, Rosa-Maria; Sbaghi, Mohamed; Le Cam, Bruno

2008-01-01

199

Ti plasmids from Agrobacterium characterize rootstock clones that initiated a spread of crown gall disease in Mediterranean countries.  

PubMed

Crown gall caused by Agrobacterium is one of the predominant diseases encountered in rose cultures. However, our current knowledge of the bacterial strains that invade rose plants and the way in which they spread is limited. Here, we describe the integrated physiological and molecular analyses of 30 Agrobacterium isolates obtained from crown gall tumors and of several reference strains. Characterization was based on the determination of the biovar, analysis of 16S ribosomal DNA restriction fragment length polymorphisms by PCR (PCR-RFLP), elucidation of the opine type, and PCR-RFLP analysis of genes involved in virulence and oncogenesis. This study led to the classification of rose isolates into seven groups with common chromosome characteristics and seven groups with common Ti plasmid characteristics. Altogether, the rose isolates formed 14 independent groups, with no specific association of plasmid- and chromosome-encoded traits. The predominant Ti plasmid characteristic was that 16 of the isolates induced the production of the uncommon opine succinamopine, while the other 14 were nopaline-producing isolates. With the exception of one, all succinamopine Ti plasmids belonged to the same plasmid group. Conversely, the nopaline Ti plasmids belonged to five groups, one of these containing seven isolates. We showed that outbreaks of disease provoked by the succinamopine-producing isolates in different countries and nurseries concurred with a common origin of specific rootstock clones. Similarly, groups of nopaline-producing isolates were associated with particular rootstock clones. These results strongly suggest that the causal agent of crown gall disease in rose plants is transmitted via rootstock material. PMID:10473434

Pionnat, S; Keller, H; Héricher, D; Bettachini, A; Dessaux, Y; Nesme, X; Poncet, C

1999-09-01

200

Ti Plasmids from Agrobacterium Characterize Rootstock Clones That Initiated a Spread of Crown Gall Disease in Mediterranean Countries  

PubMed Central

Crown gall caused by Agrobacterium is one of the predominant diseases encountered in rose cultures. However, our current knowledge of the bacterial strains that invade rose plants and the way in which they spread is limited. Here, we describe the integrated physiological and molecular analyses of 30 Agrobacterium isolates obtained from crown gall tumors and of several reference strains. Characterization was based on the determination of the biovar, analysis of 16S ribosomal DNA restriction fragment length polymorphisms by PCR (PCR-RFLP), elucidation of the opine type, and PCR-RFLP analysis of genes involved in virulence and oncogenesis. This study led to the classification of rose isolates into seven groups with common chromosome characteristics and seven groups with common Ti plasmid characteristics. Altogether, the rose isolates formed 14 independent groups, with no specific association of plasmid- and chromosome-encoded traits. The predominant Ti plasmid characteristic was that 16 of the isolates induced the production of the uncommon opine succinamopine, while the other 14 were nopaline-producing isolates. With the exception of one, all succinamopine Ti plasmids belonged to the same plasmid group. Conversely, the nopaline Ti plasmids belonged to five groups, one of these containing seven isolates. We showed that outbreaks of disease provoked by the succinamopine-producing isolates in different countries and nurseries concurred with a common origin of specific rootstock clones. Similarly, groups of nopaline-producing isolates were associated with particular rootstock clones. These results strongly suggest that the causal agent of crown gall disease in rose plants is transmitted via rootstock material. PMID:10473434

Pionnat, Sandrine; Keller, Harald; Héricher, Delphine; Bettachini, Andrée; Dessaux, Yves; Nesme, Xavier; Poncet, Christine

1999-01-01

201

POST-HURRICANE ANALYSIS OF CITRUS CANKER II: PREDICTIVE MODEL ESTIMATION OF DISEASE SPREAD AND AREA POTENTIALLY IMPACTED BY VARIOUS ERADICATION PROTOCOLS FOLLOWING CATASTROPHIC WEATHER EVENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The affect of 2005 Hurricane Wilma on the dissemination of Xanthomonas axonopodis pv. citri (Xac), the cause of Asiatic citrus canker (ACC), and subsequent disease development was examined and predictions for the areas into which Xac was likely to have spread from known sources of infection was deve...

202

Re-assessing the likelihood of airborne spread of foot-and-mouth disease at the start of the 1967-1968 UK foot-and-mouth disease epidemic.  

PubMed Central

The likelihood of airborne spread of foot-and-mouth disease at the start of the 1967-1968 epidemic is re-assessed in the light of current understanding of airborne disease spread. The findings strongly confirm those made at the time that airborne virus was the most likely cause of the rapid early development of the disease out to 60 km from the source. This conclusion is reached following a detailed epidemiological, meteorological and modelling study using original records and current modelling techniques. The role played by 'lee waves' as the mechanism for the spread is investigated. It is thought that they played little part in influencing the development of the epidemic. A number of lessons learned from the work are drawn, identifying the need for further research on the quantity and characteristics of airborne virus. The results are also used to illustrate what advice would have been available to disease controllers if the outbreak had occurred in 2004. PMID:16181495

Gloster, J.; Freshwater, A.; Sellers, R. F.; Alexandersen, S.

2005-01-01

203

Contagious Yawning and the Frontal Lobe: An fMRI Study  

PubMed Central

We conducted a slow event-related fMRI experiment with naïve subjects’ passively viewing yawn and various other control videos along with correlative behavioral testing. Specifically associated with the viewing of the contagious yawn was an area of activation in the ventromedial prefrontal cortex. These findings suggest a role for the prefrontal cortex in the processing of contagious yawning, while demonstrating a unique automaticity in the processing of contagious motor programs which take place independently of mirror neuron networks. PMID:20357471

Nahab, Fatta B.; Hattori, Noriaki; Saad, Ziad S.; Hallett, Mark

2014-01-01

204

Brief Report: Does Eye Contact Induce Contagious Yawning in Children with Autism Spectrum Disorder?  

Microsoft Academic Search

Individuals with autism spectrum disorder (ASD) reportedly fail to show contagious yawning, but the mechanism underlying the\\u000a lack of contagious yawning is still unclear. The current study examined whether instructed fixation on the eyes modulates\\u000a contagious yawning in ASD. Thirty-one children with ASD, as well as 31 age-matched typically developing (TD) children, observed\\u000a video clips of either yawning or control

Atsushi Senju; Yukiko Kikuchi; Hironori Akechi; Toshikazu Hasegawa; Yoshikuni Tojo; Hiroo Osanai

2009-01-01

205

RAPID SPREAD OF RATOON STUNTING DISEASE DURING MANUAL HARVESTING OF SUGARCANE AND THE EFFECT OF KNIFE CLEANING ON THE RATE OF SPREAD  

Microsoft Academic Search

In a field experiment, spreader plants of variety N13 in­ fected with ratoon stunting disease were interplanted with healthy plants of indicator variety NC0376. When cane knives were not disinfected during manual harvesting, 62% ofstalks ofNC0376 down-row from the spreader plants were found to be infected after one harvest, and almost all the stalks were infected after three harvests. This

R. A. BAILEY; S. A. TOUGH

206

Optimizing Hybrid Spreading in Metapopulations  

E-print Network

Epidemic spreading phenomena are ubiquitous in nature and society. Examples include the spreading of diseases, information, and computer viruses. Epidemics can spread by \\textit{local spreading}, where infected nodes can only infect a limited set of direct target nodes and \\textit{global spreading}, where an infected node can infect every other node. In reality, many epidemics spread using a hybrid mixture of both types of spreading. In this study we develop a theoretical framework for studying hybrid epidemics, and examine the optimum balance between spreading mechanisms in terms of achieving the maximum outbreak size. In a metapopulation, made up of many weakly connected subpopulations, we show that one can calculate an optimal tradeoff between local and global spreading which will maximise the extent of the epidemic. As an example we analyse the 2008 outbreak of the Internet worm Conficker, which uses hybrid spreading to propagate through the internet. Our results suggests that the worm would have been eve...

Zhang, Changwang; Cox, Ingemar J; Chain, Benjamin M

2014-01-01

207

Fatal transmission of contagious caprine pleuropneumonia to an Arabian oryx (Oryx leucoryx).  

PubMed

Contagious caprine pleuropneumonia (CCPP) is an infectious respiratory disease mainly affecting domestic goats. As CCPP has never been documented in grazing antelopes (subfamily hippotraginae), they were not considered susceptible. Mycoplasma capricolum subspecies capripneumoniae (Mccp) was isolated from pleural liquid collected during the necropsy of a severely emaciated Arabian oryx with mild nasal discharge. The Mccp isolate was then genotyped using a multilocus sequence scheme; the sequence type was identical to the Mccp strain previously identified in a sand gazelle from a nearby enclosure. This case shows for the first time that members of the hippotraginae subfamily, here the Arabian oryx, can be affected by CCPP. In addition, genotyping shows that the oryx was most probably infected, at a distance, by sand gazelles. PMID:25069622

Chaber, A L; Lignereux, L; Al Qassimi, M; Saegerman, C; Manso-Silván, L; Dupuy, V; Thiaucourt, F

2014-09-17

208

Contagious ecthyma in bighorn sheep and mountain goat in western Canada.  

PubMed

Contagious ecthyma (CE) is reported in bighorn sheep (Ovis c. canadensis) from several national parks in western Canada and in moutain goat (Oreamnos americanus) from Kootenay National Park, British Columbia. (This is the first report of CE in mountain goat.) Diagnosis was based on clinical signs, histopathology, transmission experiments and the demonstration of a proxvirus with the electron microscope. The infection was transmitted from wild to domestic goat, but not to domestic sheep. Most infections, some of them severe, were found in lambs and kids. Clinical signs of disease were similar to those seen in domestic sheep and goats. General body condition was poor and animals had difficulty feeding normally. All infected herds had prolonged contact with areas where salt was provided artificially (i.e., salt blocks, highways and campgrounds). Fewer infected sheep were observed annually when salt blocks were removed from Jasper National Park. PMID:1113436

Samuel, W M; Chalmers, G A; Stelfox, J G; Loewen, A; Thomsen, J J

1975-01-01

209

Use of penicillin and streptomycin to reduce spread of bacterial coldwater disease I: antibiotics in sperm extenders.  

PubMed

Abstract Bacterial coldwater disease caused by Flavobacterium psychrophilum has led to the loss of significant numbers of hatchery-reared salmonids. The bacteria can be spread from parent to progeny within contaminated sperm and ovarian fluid. Methods for disinfecting ovarian fluid and unfertilized eggs are available, but methods for disinfecting sperm have not been described. In this study we determined whether sperm extenders containing a mixture of penicillin and streptomycin can be used to eliminate F. psychrophilum. In vitro trials demonstrated that when Rainbow Trout Oncorhynchus mykiss sperm is mixed with an extender, a 15-min exposure to 0.197 mg penicillin plus 0.313 mg/mL streptomycin is effective at killing the bacteria and has no effect on sperm motility. Small-scale trials showed that egg fertilization rates were not reduced when sperm held in an extender solution containing the same antibiotic mixture for 15 min was used to fertilize eggs. Production-scale trials, however, showed a roughly 18% decrease in egg fertilization rate when sperm stored in an antibiotic containing extender was used. To determine why a reduction in fertilization capacity was observed, a small-scale experiment testing the fertilization of eggs with larger quantities of sperm was performed and showed that increasing the volume of sperm used did not increase fertilization rates. Our results demonstrate that extenders containing penicillin and streptomycin can be used to disinfect sperm, especially when small quantities of eggs are fertilized, but factors negatively affecting egg fertilization and survival on a production scale still need further investigation. Received May 1, 2014; accepted August 10, 2014. PMID:25581335

Oplinger, Randall W; Wagner, Eric J

2015-03-01

210

Hitting Is Contagious in Baseball: Evidence from Long Hitting Streaks  

PubMed Central

Data analysis is used to test the hypothesis that “hitting is contagious”. A statistical model is described to study the effect of a hot hitter upon his teammates’ batting during a consecutive game hitting streak. Box score data for entire seasons comprising streaks of length games, including a total observations were compiled. Treatment and control sample groups () were constructed from core lineups of players on the streaking batter’s team. The percentile method bootstrap was used to calculate confidence intervals for statistics representing differences in the mean distributions of two batting statistics between groups. Batters in the treatment group (hot streak active) showed statistically significant improvements in hitting performance, as compared against the control. Mean for the treatment group was found to be to percentage points higher during hot streaks (mean difference increased points), while the batting heat index introduced here was observed to increase by points. For each performance statistic, the null hypothesis was rejected at the significance level. We conclude that the evidence suggests the potential existence of a “statistical contagion effect”. Psychological mechanisms essential to the empirical results are suggested, as several studies from the scientific literature lend credence to contagious phenomena in sports. Causal inference from these results is difficult, but we suggest and discuss several latent variables that may contribute to the observed results, and offer possible directions for future research. PMID:23251507

Bock, Joel R.; Maewal, Akhilesh; Gough, David A.

2012-01-01

211

Marek’s disease virus and skin interactions  

PubMed Central

Marek’s disease virus (MDV) is a highly contagious herpesvirus which induces T-cell lymphoma in the chicken. This virus is still spreading in flocks despite forty years of vaccination, with important economical losses worldwide. The feather follicles, which anchor feathers into the skin and allow their morphogenesis, are considered as the unique source of MDV excretion, causing environmental contamination and disease transmission. Epithelial cells from the feather follicles are the only known cells in which high levels of infectious mature virions have been observed by transmission electron microscopy and from which cell-free infectious virions have been purified. Finally, feathers harvested on animals and dust are today considered excellent materials to monitor vaccination, spread of pathogenic viruses, and environmental contamination. This article reviews the current knowledge on MDV-skin interactions and discusses new approaches that could solve important issues in the future. PMID:24694064

2014-01-01

212

INCORPORATION OF DISTANCE-OF-SPREAD CALCULATIONS INTO A WEATHER-BASED MODEL DESCRIBING DISEASE DISTRIBUTION AFTER SEVERE WEATHER EVENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

In Florida, Asiatic citrus canker (Xanthomonas axonopodis pv. citri, XAC) has a long history of multiple introductions followed by eradication campaigns. The latest eradication campaign began in 1995 and continued through 2005 until regulatory agencies concluded that citrus canker had spread to the...

213

A Rational Approach to Estimating the Surgical Demand Elasticity Needed to Guide Manpower Reallocation during Contagious Outbreaks  

PubMed Central

Background Emerging infectious diseases continue to pose serious threats to global public health. So far, however, few published study has addressed the need for manpower reallocation needed in hospitals when such a serious contagious outbreak occurs. Aim To quantify the demand elasticity of the major surgery types in order to guide future manpower reallocation during contagious outbreaks. Materials and Methods Based on a nationwide research database in Taiwan, we extracted the monthly volumes of major surgery types for the period 1998–2003, which covered the SARS period, in order to carry out a time series analysis. The demand elasticity of each surgery type was then estimated by autoregressive integrated moving average (ARIMA) analysis. Results During the study period, the surgical volumes of most selected surgery types either increased or remained steady. We categorized these surgery types into low-, moderate- and high-elastic groups according to their demand elasticity. Appendectomy, ‘open reduction of fracture with internal fixation’ and ‘free skin graft’ were in the low demand elasticity group. Transurethral prostatectomy and extracorporeal shockwave lithotripsy (ESWL) were in the high demand elasticity group. The manpower of the departments carrying out the surgeries with low demand elasticity should be maintained during outbreaks. In contrast, departments in charge of surgeries mainly with high demand elasticity, like urology departments, may be in a position to have part of their staff reallocated. Conclusions Taking advantage of the demand variation during the SARS period in 2003, we adopted the concept of demand elasticity and used a time series approach to figure out an effective index of demand elasticity for various types of surgery that could be used as a rational reference to carry out manpower reallocation during contagious outbreak situations. PMID:25837596

Tsao, Hsiao-Mei; Sun, Ying-Chou; Liou, Der-Ming

2015-01-01

214

Experimental contagious ecthyma in mule deer, white-tailed deer, pronghorn and wapiti.  

PubMed

Hand-reared mule deer fawns (Odocoileus hemionus), white-tailed deer fawns (Odocoileus virginianus), pronghorn fawns (Antilocapra americana) and wapiti calves (Cervus elaphus nelsoni) were exposed to contagious ecthyma lesion material obtained from Rocky Mountain bighorn sheep (Ovis canadensis canadensis) to determine the susceptibility and pathogenesis in these species. All four species developed mucocutaneous proliferative lesions of the oral cavity, grossly and histologically compatible with contagious ecthyma. The limited clinical responses to the virus indicated that contagious ecthyma would not seriously impact free-ranging individuals. PMID:6685778

Lance, W R; Hibler, C P; DeMartini, J

1983-07-01

215

Ebola Virus Disease 2013-2014 Outbreak in West Africa: An Analysis of the Epidemic Spread and Response  

PubMed Central

The Ebola virus epidemic burst in West Africa in late 2013, started in Guinea, reached in a few months an alarming diffusion, actually involving several countries (Liberia, Sierra Leone, Nigeria, Senegal, and Mali). Guinea and Liberia, the first nations affected by the outbreak, have put in place measures to contain the spread, supported by international organizations; then they were followed by the other nations affected. In the present EVD outbreak, the geographical spread of the virus has followed a new route: the achievement of large urban areas at an early stage of the epidemic has led to an unprecedented diffusion, featuring the largest outbreak of EVD of all time. This has caused significant concerns all over the world: the potential reaching of far countries from endemic areas, mainly through fast transports, induced several countries to issue information documents and health supervision for individuals going to or coming from the areas at risk. In this paper the geographical spread of the epidemic was analyzed, assessing the sequential appearance of cases by geographic area, considering the increase in cases and mortality according to affected nations. The measures implemented by each government and international organizations to contain the outbreak, and their effectiveness, were also evaluated. PMID:25852754

Cenciarelli, Orlando; Pietropaoli, Stefano; Carestia, Mariachiara; D'Amico, Fabrizio; Sassolini, Alessandro; Di Giovanni, Daniele; Rea, Silvia; Gabbarini, Valentina; Tamburrini, Annalaura; Palombi, Leonardo; Bellecci, Carlo; Gaudio, Pasquale

2015-01-01

216

Ebola virus disease 2013-2014 outbreak in west Africa: an analysis of the epidemic spread and response.  

PubMed

The Ebola virus epidemic burst in West Africa in late 2013, started in Guinea, reached in a few months an alarming diffusion, actually involving several countries (Liberia, Sierra Leone, Nigeria, Senegal, and Mali). Guinea and Liberia, the first nations affected by the outbreak, have put in place measures to contain the spread, supported by international organizations; then they were followed by the other nations affected. In the present EVD outbreak, the geographical spread of the virus has followed a new route: the achievement of large urban areas at an early stage of the epidemic has led to an unprecedented diffusion, featuring the largest outbreak of EVD of all time. This has caused significant concerns all over the world: the potential reaching of far countries from endemic areas, mainly through fast transports, induced several countries to issue information documents and health supervision for individuals going to or coming from the areas at risk. In this paper the geographical spread of the epidemic was analyzed, assessing the sequential appearance of cases by geographic area, considering the increase in cases and mortality according to affected nations. The measures implemented by each government and international organizations to contain the outbreak, and their effectiveness, were also evaluated. PMID:25852754

Cenciarelli, Orlando; Pietropaoli, Stefano; Malizia, Andrea; Carestia, Mariachiara; D'Amico, Fabrizio; Sassolini, Alessandro; Di Giovanni, Daniele; Rea, Silvia; Gabbarini, Valentina; Tamburrini, Annalaura; Palombi, Leonardo; Bellecci, Carlo; Gaudio, Pasquale

2015-01-01

217

Use of Penicillin and Streptomycin to Reduce Spread of Bacterial Coldwater Disease II: Efficacy of Using Antibiotics in Diluents and During Water Hardening.  

PubMed

Abstract Bacterial coldwater disease, caused by Flavobacterium psychrophilum, has lead to the loss of significant numbers of hatchery-reared salmonids. The bacteria can be spread from parent to progeny within contaminated sperm and ovarian fluid and can enter the egg during fertilization. The addition of antibiotics to diluents and water-hardening solutions could prevent the spread of the disease. In separate trials, a mixture of 0.197 mg/mL penicillin plus 0.313 mg/mL streptomycin was added to both a 0.5% sodium chloride fertilization diluent and hatchery well water during hardening. Tests showed that the addition of the antibiotics to the diluent and during up to 60 min of water hardening had no effect on the eye-up, hatch and deformity rates of Rainbow Trout Oncorhynchus mykiss eggs compared with the nonantibiotic-treated controls. Also, significant reductions in the prevalence of F. psychrophilum on the surface and inside eggs were observed when compared with controls. These results indicate that the addition of penicillin and streptomycin to diluents and during water hardening can prevent the vertical transmission of bacterial coldwater disease. Received May 1, 2014; accepted July 10, 2014. PMID:25581260

Oplinger, Randall W; Wagner, Eric J; Cavender, Wade

2015-03-01

218

Recombinant Newcastle disease vaccines: risk for recombination, reversion to virulence, and spread in non-target species  

Technology Transfer Automated Retrieval System (TEKTRAN)

Newcastle disease (ND), caused by Newcastle disease virus (NDV), is one of the most important diseases of poultry and causes significant economic losses to the poultry industry worldwide. Vaccination is the main form of control of ND and it has been practiced for more than 60 years with billions of...

219

Development of a Discrete Spatial-Temporal SEIR Simulator for Modeling Infectious Diseases  

SciTech Connect

Multiple techniques have been developed to model the temporal evolution of infectious diseases. Some of these techniques have also been adapted to model the spatial evolution of the disease. This report examines the application of one such technique, the SEIR model, to the spatial and temporal evolution of disease. Applications of the SEIR model are reviewed briefly and an adaptation to the traditional SEIR model is presented. This adaptation allows for modeling the spatial evolution of the disease stages at the individual level. The transmission of the disease between individuals is modeled explicitly through the use of exposure likelihood functions rather than the global transmission rate applied to populations in the traditional implementation of the SEIR model. These adaptations allow for the consideration of spatially variable (heterogeneous) susceptibility and immunity within the population. The adaptations also allow for modeling both contagious and non-contagious diseases. The results of a number of numerical experiments to explore the effect of model parameters on the spread of an example disease are presented.

McKenna, S.A.

2000-11-01

220

Investigation of airborne foot-and-mouth disease virus transmission during low-wind conditions in the early phase of the UK 2001 epidemic  

NASA Astrophysics Data System (ADS)

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed domesticated and wild animals. The highly contagious nature of FMD is a reflection of the wide range of host species, the enormous quantities of virus liberated by infected animals, the range of excretions and secretions which can be infectious, the stability of the virus in the environment, the multiplicity of routes of infection and the very small doses of the virus that can initiate infection. One of the mechanisms of spread is the carriage of droplets and droplet nuclei exhaled in the breath of infected animals. Such spread can be rapid and extensive, and it is known in certain circumstances to have transmitted disease over a distance of several hundred kilometres. During the 2001 FMD epidemic in the United Kingdom (UK), atmospheric dispersion models were applied in real time in order to assess the potential for atmospheric dispersion of the disease. The operational value of such modelling is primarily to identify premises which may have been exposed so that the human resources for surveillance and disease control purposes are employed most effectively.

The paper describes the combined modelling techniques and presents the results obtained of detailed analyses performed during the early stages of the UK 2001 epidemic. This paper investigates the potential for disease spread in relation to two outbreaks (Burnside Farm, Heddon-on-the-Wall and Prestwick Hall Farm, Ponteland, Northumberland). A separate paper (Gloster et al., 2002) provides a more detailed analysis of the airborne disease transmission in the vicinity of Burnside Farm.

The combined results are consistent with airborne transmission of disease to livestock in the Heddon-on-the-Wall area. Local topography may have played a significant role in influencing the pattern of disease spread.

Mikkelsen, T.; Alexandersen, S.; Astrup, P.; Champion, H. J.; Donaldson, A. I.; Dunkerley, F. N.; Gloster, J.; Sørensen, J. H.; Thykier-Nielsen, S.

2003-11-01

221

Investigation of airborne foot-and-mouth disease virus transmission during low-wind conditions in the early phase of the UK 2001 epidemic  

NASA Astrophysics Data System (ADS)

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed domesticated and wild animals. The highly contagious nature of FMD is a reflection of the wide range of host species, the enormous quantities of virus liberated by infected animals, the range of excretions and secretions which can be infectious, the stability of the virus in the environment, the multiplicity of routes of infection and the very small doses of the virus that can initiate infection. One of the mechanisms of spread is the carriage of droplets and droplet nuclei exhaled in the breath of infected animals. Such spread can be rapid and extensive, and it is known in certain circumstances to have transmitted disease over a distance of several hundred kilometres. During the 2001 FMD epidemic in the United Kingdom (UK), atmospheric dispersion models were applied in real time in order to assess the potential for atmospheric dispersion of the disease. The operational value of such modelling is primarily to identify premises which may have been exposed so that the human resources for surveillance and disease control purposes are employed most effectively. The paper describes the combined modelling techniques and presents the results obtained of detailed analyses performed during the early stages of the UK 2001 epidemic. This paper investigates the potential for disease spread in relation to two outbreaks (Burnside Farm, Heddon-on-the-Wall and Prestwick Hall Farm, Ponteland, Northumberland). A separate paper (Gloster et al., 2002) provides a more detailed analysis of the airborne disease transmission in the vicinity of Burnside Farm. The combined results are consistent with airborne transmission of disease to livestock in the Heddon-on-the Wall area. Local topography may have played a significant role in influencing the pattern of disease spread.

Mikkelsen, T.; Alexandersen, S.; Astrup, P.; Champion, H. J.; Donaldson, A. I.; Dunkerley, F. N.; Gloster, J.; Sørensen, J. H.; Thykier-Nielsen, S.

2003-02-01

222

Spill Spread  

NSDL National Science Digital Library

In this simulation, learners explore how ocean currents spread all kinds of pollution—including oil spills, sewage, pesticides and factory waste—far beyond where the pollution originates. Learners create an experimental "ocean" (water in a tray) and "continents" (rocks), then add melting ice cubes to create temperature-driven currents in the water. Learners observe how "pollution," represented by food coloring, spreads through the model ocean affected by both "currents" and "continents." This activity can be used with lessons on ocean science or environmental hazards.

2012-11-15

223

Differential induction and spread of tau pathology in young PS19 tau transgenic mice following intracerebral injections of pathological tau from Alzheimer's disease or corticobasal degeneration brains.  

PubMed

Filamentous tau pathologies are hallmark lesions of several neurodegenerative tauopathies including Alzheimer's disease (AD) and corticobasal degeneration (CBD) which show cell type-specific and topographically distinct tau inclusions. Growing evidence supports templated transmission of tauopathies through functionally interconnected neuroanatomical pathways suggesting that different self-propagating strains of pathological tau could account for the diverse manifestations of neurodegenerative tauopathies. Here, we describe the rapid and distinct cell type-specific spread of pathological tau following intracerebral injections of CBD or AD brain extracts enriched in pathological tau (designated CBD-Tau and AD-Tau, respectively) in young human mutant P301S tau transgenic (Tg) mice (line PS19) ~6-9 months before they show onset of mutant tau transgene-induced tau pathology. At 1 month post-injection of CBD-Tau, tau inclusions developed predominantly in oligodendrocytes of the fimbria and white matter near the injection sites with infrequent intraneuronal tau aggregates. In contrast, injections of AD-Tau in young PS19 mice induced tau pathology predominantly in neuronal perikarya with little or no oligodendrocyte involvement 1 month post-injection. With longer post-injection survival intervals of up to 6 months, CBD-Tau- and AD-Tau-induced tau pathology spread to different brain regions distant from the injection sites while maintaining the cell type-specific pattern noted above. Finally, CA3 neuron loss was detected 3 months post-injection of AD-Tau but not CBD-Tau. Thus, AD-Tau and CBD-Tau represent specific pathological tau strains that spread differentially and may underlie distinct clinical and pathological features of these two tauopathies. Hence, these strains could become targets to develop disease-modifying therapies for CBD and AD. PMID:25534024

Boluda, Susana; Iba, Michiyo; Zhang, Bin; Raible, Kevin M; Lee, Virginia M-Y; Trojanowski, John Q

2015-02-01

224

Genetic Control of Contagious Asexuality in the Pea Aphid  

PubMed Central

Although evolutionary transitions from sexual to asexual reproduction are frequent in eukaryotes, the genetic bases of such shifts toward asexuality remain largely unknown. We addressed this issue in an aphid species where both sexual and obligate asexual lineages coexist in natural populations. These sexual and asexual lineages may occasionally interbreed because some asexual lineages maintain a residual production of males potentially able to mate with the females produced by sexual lineages. Hence, this species is an ideal model to study the genetic basis of the loss of sexual reproduction with quantitative genetic and population genomic approaches. Our analysis of the co-segregation of ?300 molecular markers and reproductive phenotype in experimental crosses pinpointed an X-linked region controlling obligate asexuality, this state of character being recessive. A population genetic analysis (>400-marker genome scan) on wild sexual and asexual genotypes from geographically distant populations under divergent selection for reproductive strategies detected a strong signature of divergent selection in the genomic region identified by the experimental crosses. These population genetic data confirm the implication of the candidate region in the control of reproductive mode in wild populations originating from 700 km apart. Patterns of genetic differentiation along chromosomes suggest bidirectional gene flow between populations with distinct reproductive modes, supporting contagious asexuality as a prevailing route to permanent parthenogenesis in pea aphids. This genetic system provides new insights into the mechanisms of coexistence of sexual and asexual aphid lineages. PMID:25473828

Jaquiéry, Julie; Stoeckel, Solenn; Larose, Chloé; Nouhaud, Pierre; Rispe, Claude; Mieuzet, Lucie; Bonhomme, Joël; Mahéo, Frédérique; Legeai, Fabrice; Gauthier, Jean-Pierre; Prunier-Leterme, Nathalie; Tagu, Denis; Simon, Jean-Christophe

2014-01-01

225

Genetic control of contagious asexuality in the pea aphid.  

PubMed

Although evolutionary transitions from sexual to asexual reproduction are frequent in eukaryotes, the genetic bases of such shifts toward asexuality remain largely unknown. We addressed this issue in an aphid species where both sexual and obligate asexual lineages coexist in natural populations. These sexual and asexual lineages may occasionally interbreed because some asexual lineages maintain a residual production of males potentially able to mate with the females produced by sexual lineages. Hence, this species is an ideal model to study the genetic basis of the loss of sexual reproduction with quantitative genetic and population genomic approaches. Our analysis of the co-segregation of ? 300 molecular markers and reproductive phenotype in experimental crosses pinpointed an X-linked region controlling obligate asexuality, this state of character being recessive. A population genetic analysis (>400-marker genome scan) on wild sexual and asexual genotypes from geographically distant populations under divergent selection for reproductive strategies detected a strong signature of divergent selection in the genomic region identified by the experimental crosses. These population genetic data confirm the implication of the candidate region in the control of reproductive mode in wild populations originating from 700 km apart. Patterns of genetic differentiation along chromosomes suggest bidirectional gene flow between populations with distinct reproductive modes, supporting contagious asexuality as a prevailing route to permanent parthenogenesis in pea aphids. This genetic system provides new insights into the mechanisms of coexistence of sexual and asexual aphid lineages. PMID:25473828

Jaquiéry, Julie; Stoeckel, Solenn; Larose, Chloé; Nouhaud, Pierre; Rispe, Claude; Mieuzet, Lucie; Bonhomme, Joël; Mahéo, Frédérique; Legeai, Fabrice; Gauthier, Jean-Pierre; Prunier-Leterme, Nathalie; Tagu, Denis; Simon, Jean-Christophe

2014-12-01

226

Contagious seed dispersal beneath heterospecific fruiting trees and its consequences.  

SciTech Connect

Kwit, Charles, D.J. Levey and Cathryn H. Greenberg. 2004. Contagious seed dispersal beneath heterospecific fruiting trees and its consequences. Oikos. 107:303-308 A n hypothesized advantage of seed dispersal is avoidance of high per capita mortality (i.e. density-dependent mortality) associated with dense populations of seeds and seedlings beneath parent trees. This hypothesis, inherent in nearly all seed dispersal studies, assumes that density effects are species-specific. Yet because many tree species exhibit overlapping fruiting phenologies and share dispersers, seeds may be deposited preferentially under synchronously fruiting heterospecific trees, another location where they may be particularly vulnerable to mortality, in this case by generalist seed predators. We demonstrate that frugivores disperse higher densities of Cornus florida seeds under fruiting (female) I lex opaca trees than under non-fruiting (male) I lex trees in temperate hardwood forest settings in South Carolina, U SA . To determine if density of Cornus and/or I lex seeds influences survivorship of dispersed Cornus seeds, we followed the fates of experimentally dispersed Cornus seeds in neighborhoods of differing, manipulated background densities of Cornus and I lex seeds. We found that the probability of predation on dispersed Cornus seeds was a function of both Cornus and I lex background seed densities. H igher densities of I lex seeds negatively affected Cornus seed survivorship, and this was particularly evident as background densities of dispersed Cornus seeds increased. These results illustrate the importance of viewing seed dispersal and predation in a community context, as the pattern and intensity of density-dependent mortality may not be solely a function of conspecific densities.

Kwit, Charles; Levey, Douglas, J.; Greenberg, Cathyrn, H.

2004-05-03

227

The Science, Spread and Therapy of HIV Disease. Everything You Need To Know, but Had No Idea Who To Ask.  

ERIC Educational Resources Information Center

This book uses a question-and-answer format to provide information on the Human Immunodeficiency Virus (HIV) and the disease caused by infection from the virus, Acquired Immune Deficiency Syndrome (AIDS). Topics covered include: (1) "Outbreak," which discusses the history of the AIDS outbreak including early theories about the causes of AIDS and…

DiSpezio, Michael A.

228

Comparative sequence analysis of a highly oncogenic but horizontal spread-defective clone of Marek's disease virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek’s disease virus (MDV) is a cell-associated alphaherpesvirus that induces rapid-onset T-cell lymphomas in poultry. MDV isolates vary greatly in pathogenicity. While some of the strains such as CVI988 are non-pathogenic and are used as vaccines, others such as RB1B are highly oncogenic. Compa...

229

9 CFR 93.515 - Appearance of disease among swine in quarantine.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Appearance of disease among swine in quarantine. 93.515...CONTAINERS Swine § 93.515 Appearance of disease among swine in quarantine. If any contagious disease appears among swine during the...

2013-01-01

230

9 CFR 93.515 - Appearance of disease among swine in quarantine.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Appearance of disease among swine in quarantine. 93.515...CONTAINERS Swine § 93.515 Appearance of disease among swine in quarantine. If any contagious disease appears among swine during the...

2011-01-01

231

9 CFR 93.213 - Appearance of disease among poultry in quarantine.  

Code of Federal Regulations, 2014 CFR

... 2014-01-01 false Appearance of disease among poultry in quarantine. 93.213... Poultry § 93.213 Appearance of disease among poultry in quarantine. If any contagious disease appears among poultry during the...

2014-01-01

232

9 CFR 93.213 - Appearance of disease among poultry in quarantine.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Appearance of disease among poultry in quarantine. 93.213... Poultry § 93.213 Appearance of disease among poultry in quarantine. If any contagious disease appears among poultry during the...

2011-01-01

233

9 CFR 93.515 - Appearance of disease among swine in quarantine.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 false Appearance of disease among swine in quarantine. 93.515...CONTAINERS Swine § 93.515 Appearance of disease among swine in quarantine. If any contagious disease appears among swine during the...

2012-01-01

234

9 CFR 93.313 - Appearance of disease among horses in quarantine.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 false Appearance of disease among horses in quarantine. 93.313...CONTAINERS Horses § 93.313 Appearance of disease among horses in quarantine. If any contagious disease appears among horses during the...

2012-01-01

235

9 CFR 93.416 - Appearance of disease among ruminants in quarantine.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Appearance of disease among ruminants in quarantine. 93... Ruminants § 93.416 Appearance of disease among ruminants in quarantine. If any contagious disease appears among ruminants during...

2011-01-01

236

9 CFR 93.416 - Appearance of disease among ruminants in quarantine.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 false Appearance of disease among ruminants in quarantine. 93... Ruminants § 93.416 Appearance of disease among ruminants in quarantine. If any contagious disease appears among ruminants during...

2012-01-01

237

9 CFR 93.515 - Appearance of disease among swine in quarantine.  

Code of Federal Regulations, 2014 CFR

... 2014-01-01 false Appearance of disease among swine in quarantine. 93.515...CONTAINERS Swine § 93.515 Appearance of disease among swine in quarantine. If any contagious disease appears among swine during the...

2014-01-01

238

9 CFR 93.313 - Appearance of disease among horses in quarantine.  

Code of Federal Regulations, 2014 CFR

... 2014-01-01 false Appearance of disease among horses in quarantine. 93.313...CONTAINERS Horses § 93.313 Appearance of disease among horses in quarantine. If any contagious disease appears among horses during the...

2014-01-01

239

9 CFR 93.416 - Appearance of disease among ruminants in quarantine.  

Code of Federal Regulations, 2014 CFR

... 2014-01-01 false Appearance of disease among ruminants in quarantine. 93... Ruminants § 93.416 Appearance of disease among ruminants in quarantine. If any contagious disease appears among ruminants during...

2014-01-01

240

9 CFR 93.313 - Appearance of disease among horses in quarantine.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Appearance of disease among horses in quarantine. 93.313...CONTAINERS Horses § 93.313 Appearance of disease among horses in quarantine. If any contagious disease appears among horses during the...

2010-01-01

241

9 CFR 93.313 - Appearance of disease among horses in quarantine.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Appearance of disease among horses in quarantine. 93.313...CONTAINERS Horses § 93.313 Appearance of disease among horses in quarantine. If any contagious disease appears among horses during the...

2011-01-01

242

9 CFR 93.313 - Appearance of disease among horses in quarantine.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Appearance of disease among horses in quarantine. 93.313...CONTAINERS Horses § 93.313 Appearance of disease among horses in quarantine. If any contagious disease appears among horses during the...

2013-01-01

243

9 CFR 93.213 - Appearance of disease among poultry in quarantine.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Appearance of disease among poultry in quarantine. 93.213... Poultry § 93.213 Appearance of disease among poultry in quarantine. If any contagious disease appears among poultry during the...

2013-01-01

244

9 CFR 93.416 - Appearance of disease among ruminants in quarantine.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Appearance of disease among ruminants in quarantine. 93... Ruminants § 93.416 Appearance of disease among ruminants in quarantine. If any contagious disease appears among ruminants during...

2010-01-01

245

Are you protected against Pertussis? Pertussis, or whooping cough, is a highly contagious respiratory infection caused by the bacterium  

E-print Network

Are you protected against Pertussis? Pertussis, or whooping cough, is a highly contagious respiratory infection caused by the bacterium Bordetella pertussis. It causes severe coughing spells, vomiting

246

BBC News In Depth: Foot and Mouth Disease  

NSDL National Science Digital Library

Foot and mouth disease is a highly contagious but not necessarily fatal viral infection that is transmitted through dust particles in the air, infecting the hooves and mouths of pigs, cattle, sheep, and goats. In recent weeks, a string of cases have been reported in England, sparking fears of another repeat of the epidemic of 1967, in which over 400,000 animals were destroyed. Farmers and government officials have so far followed the standard plan for dealing with such outbreaks: isolate affected farms and destroy infected herds. As part of this effort, local authorities have been empowered to prevent all foot traffic in designated areas and there has even been talk of delaying the impending general election in Britain for fear that politicians and staff on the campaign trail might spread the disease. This site, a special report from the BBC, contains breaking news, analysis, background information, and audio and video selections.

2001-01-01

247

Poleward Expansion of the White-Footed Mouse (Peromyscus leucopus) under Climate Change: Implications for the Spread of Lyme Disease  

PubMed Central

The white-footed mouse (Peromyscus leucopus) is an important reservoir host for Borrelia burgdorferi, the pathogen responsible for Lyme disease, and its distribution is expanding northward. We used an Ecological Niche Factor Analysis to identify the climatic factors associated with the distribution shift of the white-footed mouse over the last 30 years at the northern edge of its range, and modeled its current and potential future (2050) distributions using the platform BIOMOD. A mild and shorter winter is favouring the northern expansion of the white-footed mouse in Québec. With more favorable winter conditions projected by 2050, the distribution range of the white-footed mouse is expected to expand further northward by 3° latitude. We also show that today in southern Québec, the occurrence of B. burgdorferi is associated with high probability of presence of the white-footed mouse. Changes in the distribution of the white-footed mouse will likely alter the geographical range of B. burgdorferi and impact the public health in northern regions that have yet to be exposed to Lyme disease. PMID:24260464

Roy-Dufresne, Emilie; Logan, Travis; Simon, Julie A.; Chmura, Gail L.; Millien, Virginie

2013-01-01

248

Contagious yawning in gelada baboons as a possible expression of empathy  

PubMed Central

Yawn contagion in humans has been proposed to be related to our capacity for empathy. It is presently unclear whether this capacity is uniquely human or shared with other primates, especially monkeys. Here, we show that in gelada baboons (Theropithecus gelada) yawning is contagious between individuals, especially those that are socially close, i.e., the contagiousness of yawning correlated with the level of grooming contact between individuals. This correlation persisted after controlling for the effect of spatial association. Thus, emotional proximity rather than spatial proximity best predicts yawn contagion. Adult females showed precise matching of different yawning types, which suggests a mirroring mechanism that activates shared representations. The present study also suggests that females have an enhanced sensitivity and emotional tuning toward companions. These findings are consistent with the view that contagious yawning reveals an emotional connection between individuals. This phenomenon, here demonstrated in monkeys, could be a building block for full-blown empathy. PMID:19889980

Palagi, E.; Leone, A.; Mancini, G.; Ferrari, P. F.

2009-01-01

249

An investigation into the source and spread of foot and mouth disease virus from a wildlife conservancy in Zimbabwe.  

PubMed

African buffalo were introduced into a wildlife conservancy in the southeast of Zimbabwe in an effortto increase the conservancy's economic viability, which is primarily based on eco-tourism. The buffalo were infected with SAT serotypes (SAT-1, SAT-2 and SAT-3) of foot and mouth disease (FMD) virus, and in order to isolate the conservancy and prevent the transmission of FMD to adjacent populations of domestic livestock, the conservancy was surrounded by a double-fence system, 1.8 m in height. The intention was to prevent the movement of both wildlife and domestic animals across the perimeter. However, two years after the buffalo were introduced, FMD occurred in cattle farmed just outside of the conservancy. Using serological and molecular diagnostic tests, epidemiological investigations showed that it was most likely that antelope (impala or kudu), infected through contact with the buffalo herd within the conservancy, had jumped over the fence and transmitted the virus to the cattle. PMID:15861873

Hargreaves, S K; Foggin, C M; Anderson, E C; Bastos, A D S; Thomson, G R; Ferris, N P; Knowles, N J

2004-12-01

250

A Household-Based Study of Contact Networks Relevant for the Spread of Infectious Diseases in the Highlands of Peru  

PubMed Central

Background Few studies have quantified social mixing in remote rural areas of developing countries, where the burden of infectious diseases is usually the highest. Understanding social mixing patterns in those settings is crucial to inform the implementation of strategies for disease prevention and control. We characterized contact and social mixing patterns in rural communities of the Peruvian highlands. Methods and Findings This cross-sectional study was nested in a large prospective household-based study of respiratory infections conducted in the province of San Marcos, Cajamarca-Peru. Members of study households were interviewed using a structured questionnaire of social contacts (conversation or physical interaction) experienced during the last 24 hours. We identified 9015 reported contacts from 588 study household members. The median age of respondents was 17 years (interquartile range [IQR] 4–34 years). The median number of reported contacts was 12 (IQR 8–20) whereas the median number of physical (i.e. skin-to-skin) contacts was 8.5 (IQR 5–14). Study participants had contacts mostly with people of similar age, and with their offspring or parents. The number of reported contacts was mainly determined by the participants’ age, household size and occupation. School-aged children had more contacts than other age groups. Within-household reciprocity of contacts reporting declined with household size (range 70%-100%). Ninety percent of household contact networks were complete, and furthermore, household members' contacts with non-household members showed significant overlap (range 33%-86%), indicating a high degree of contact clustering. A two-level mixing epidemic model was simulated to compare within-household mixing based on observed contact networks and within-household random mixing. No differences in the size or duration of the simulated epidemics were revealed. Conclusion This study of rural low-density communities in the highlands of Peru suggests contact patterns are highly assortative. Study findings support the use of within-household homogenous mixing assumptions for epidemic modeling in this setting. PMID:25734772

Grijalva, Carlos G.; Goeyvaerts, Nele; Verastegui, Hector; Edwards, Kathryn M.; Gil, Ana I.; Lanata, Claudio F.; Hens, Niel

2015-01-01

251

Interspecific competition in honeybee intracellular gut parasites is asymmetric and favours the spread of an emerging infectious disease.  

PubMed

There is increasing appreciation that hosts in natural populations are subject to infection by multiple parasite species. Yet the epidemiological and ecological processes determining the outcome of mixed infections are poorly understood. Here, we use two intracellular gut parasites (Microsporidia), one exotic and one co-evolved in the western honeybee (Apis mellifera), in an experiment in which either one or both parasites were administered either simultaneously or sequentially. We provide clear evidence of within-host competition; order of infection was an important determinant of the competitive outcome between parasites, with the first parasite significantly inhibiting the growth of the second, regardless of species. However, the strength of this 'priority effect' was highly asymmetric, with the exotic Nosema ceranae exhibiting stronger inhibition of Nosema apis than vice versa. Our results reveal an unusual asymmetry in parasite competition that is dependent on order of infection. When incorporated into a mathematical model of disease prevalence, we find asymmetric competition to be an important predictor of the patterns of parasite prevalence found in nature. Our findings demonstrate the wider significance of complex multi-host-multi-parasite interactions as drivers of host-pathogen community structure. PMID:25429014

Natsopoulou, Myrsini E; McMahon, Dino P; Doublet, Vincent; Bryden, John; Paxton, Robert J

2015-01-01

252

Immunoglobulin epitope spreading and autoimmune disease after peptide immunization: Sm B/B'-derived PPPGMRPP and PPPGIRGP induce spliceosome autoimmunity  

PubMed Central

Autoantibodies from many patients with systemic lupus erythematosus bind the Sm autoantigen B/B' polypeptide. The binding of serial serum specimens to the 233 overlapping octapeptides of Sm B/B' have shown that of the B/B'-derived octapeptides, PPPGMRPP and PPPGIRGP are early targets of the autoimmune response in some lupus patients. Rabbits immunized with PPPGMRPP and PPPGIRGP develop antibodies which not only bind these octapeptides, but also subsequently bind many other octapeptides of Sm B/B'. Eventually, the rabbits immunized with one octapeptide develop autoantibodies that bind other spliceosomal proteins including D, 70K, A, and C. Any mechanisms that operate to maintain tolerance or anergy for the spliceosome are thus overcome. Features considered typical of human systemic lupus erythematosus are also found in these peptide-immunized animals, such as antinuclear antibodies, anti-Sm precipitins, anti-double-stranded DNA, thrombocytopenia, seizures, and proteinuria. This disease model provides access to a mechanism for the development of humoral autoimmunity and may provide a basis to explain the immunopathogenesis of lupus in humans. PMID:7530756

1995-01-01

253

VNTR analysis reveals unexpected genetic diversity within Mycoplasma agalactiae, the main causative agent of contagious agalactia  

PubMed Central

Background Mycoplasma agalactiae is the main cause of contagious agalactia, a serious disease of sheep and goats, which has major clinical and economic impacts. Previous studies of M. agalactiae have shown it to be unusually homogeneous and there are currently no available epidemiological techniques which enable a high degree of strain differentiation. Results We have developed variable number tandem repeat (VNTR) analysis using the sequenced genome of the M. agalactiae type strain PG2. The PG2 genome was found to be replete with tandem repeat sequences and 4 were chosen for further analysis. VNTR 5 was located within the hypothetical protein MAG6170 a predicted lipoprotein. VNTR 14 was intergenic between the hypothetical protein MAG3350 and the hypothetical protein MAG3340. VNTR 17 was intergenic between the hypothetical protein MAG4060 and the hypothetical protein MAG4070 and VNTR 19 spanned the 5' end of the pseudogene for a lipoprotein MAG4310 and the 3' end of the hypothetical lipoprotein MAG4320. We have investigated the genetic diversity of 88 M. agalactiae isolates of wide geographic origin using VNTR analysis and compared it with pulsed field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) analysis. Simpson's index of diversity was calculated to be 0.324 for PFGE and 0.574 for VNTR analysis. VNTR analysis revealed unexpected diversity within M. agalactiae with 9 different VNTR types discovered. Some correlation was found between geographical origin and the VNTR type of the isolates. Conclusion VNTR analysis represents a useful, rapid first-line test for use in molecular epidemiological analysis of M. agalactiae for outbreak tracing and control. PMID:18992155

McAuliffe, Laura; Churchward, Colin P; Lawes, Joanna R; Loria, Guido; Ayling, Roger D; Nicholas, Robin AJ

2008-01-01

254

Estimation of impact of contagious bovine pleuropneumonia on pastoralists in Kenya.  

PubMed

Contagious bovine pleuropneumonia (CBPP) is an infectious disease which impacts cattle production in sub-Saharan Africa. To adequately allocate resources for its control, there is a need to assess its impact on cattle producers. The present study estimated the impact of CBPP on pastoralists through analysis of various strategies employed for its control in cattle herds including: preventive vaccination, antimicrobial treatment, slaughter of clinical cases and other combinations of these control strategies. The assessment was based on a loss-expenditure frontier framework to identify a control strategy with minimum cost from both expenditures on control strategies and output losses due to mortalities, reduced milk yield, reduced weight gain and reduced fertility rate. The analysis was undertaken in a stochastic spreadsheet model. The control strategy with minimum cost per herd was preventive vaccination with an estimated cost of US$ 193 (90% CI; 170-215) per 100 cows per year, while slaughter of clinical cases had an estimated cost of US$ 912 (90% CI; 775-1055) per 100 cows per year. The impact of CBPP to the nation was estimated at US$ 7.6 (90% CI; 6.5-8.7) million per year. Yet, if all pastoralists whose cattle are at high risk of infection adopted preventive vaccination, the aggregate national impact would be US$ 3.3 (90% CI; 2.9-3.7) million per year, with savings amounting to US$ 4.3 million through reallocation of control expenditures. The analysis predicted that control of CBPP in Kenya is profitable through preventive vaccination. However, further research is recommended for the technical and financial feasibility of implementing a vaccine delivery system in pastoral areas where CBPP is endemic. PMID:24767814

Onono, J O; Wieland, B; Rushton, J

2014-08-01

255

Characterization of contact structures for the spread of infectious diseases in a pork supply chain in northern Germany by dynamic network analysis of yearly and monthly networks.  

PubMed

A major risk factor in the spread of diseases between holdings is the transport of live animals. This study analysed the animal movements of the pork supply chain of a producer group in Northern Germany. The parameters in-degree and out-degree, ingoing and outgoing infection chain, betweenness and ingoing and outgoing closeness were measured using dynamic network analysis to identify holdings with central positions in the network and to characterize the overall network topology. The potential maximum epidemic size was also estimated. All parameters were calculated for three time periods: the 3-yearly network, the yearly and the monthly networks. The yearly and the monthly networks were more fragmented than the 3-yearly network. On average, one-third of the holdings were isolated in the yearly networks and almost three quarters in the monthly networks. This represented an immense reduction in the number of holdings participating in the trade of the monthly networks. The overall network topology showed right-skewed distributions for all calculated centrality parameters indicating that network resilience was high concerning the random removal of holdings. However, for a targeted removal of holdings according to their centrality, a rapid fragmentation of the trade network could be expected. Furthermore, to capture the real importance of holdings for disease transmission, indirect trade contacts (infection chain) should be considered. In contrast to the parameters regarding direct trade contacts (degree), the infection chain parameter did not underestimate the potential risk of disease transmission. This became more obvious, the longer the observed time period was. For all three time periods, the results for the estimation of the potential maximum epidemic size illustrated that the outgoing infection chain should be chosen. It considers the chronological order and the directed nature of the contacts and has no restrictions such as the strongly connected components of a cyclic network. PMID:23692588

Büttner, K; Krieter, J; Traulsen, I

2015-04-01

256

What is the flu? Influenza, "the flu" is a contagious respiratory infection  

E-print Network

What is the flu? Influenza, "the flu" is a contagious respiratory infection caused by the influenza known as "swine flu") in humans causes similar symptoms to the seasonal flu but may also include. What are the symptoms? Flu symptoms start 1-4 days after exposure. Symptoms usually start suddenly

Virginia Tech

257

A Theory and Dynamic Model of Dyadic Interaction: Concerns, Appraisals, and Contagiousness in a Developmental Context  

ERIC Educational Resources Information Center

A theory of the dynamics of dyadic interaction is presented, based on the concepts of "concern" (i.e., intentions, goals, and interests), "appraisal" and "contagiousness." Differences between children who participate in a specific interaction are linked to differences in social competence and social power. An overview is given of the social…

Steenbeek, Henderien W.; van Geert, Paul L. C.

2007-01-01

258

EXPERIMENTAL CONTAGIOUS ECTHYMA IN MULE DEER, WHITE-TAILED DEER, PRONGHORN AND WAPITI1  

Microsoft Academic Search

Hand-reared mule deer fawns (Odocoileus hemionus), white-tailed deer fawns (Odocoileus virginianus), pronghorn fawns (Antilocapra americana) and wapiti calves (Cervus elaphus nelsoni) were exposed to contagious ecthyma lesion material obtained from Rocky Mountain bighorn sheep (Ocis cana- densis canadensis) to determine the susceptibility and pathogenesis in these species. All four species devel- oped mucocutaneous proliferative lesions of the oral cavity, grossly

William R. Lance; Charles P. Hibler; James DeMartini

259

Contagious itch: what we know and what we would like to know  

PubMed Central

All humans experience itch in the course of their life. Even a discussion on the topic of itch or seeing people scratch can evoke the desire to scratch. These events are coined “contagious itch” and are very common. We and others have shown that videos showing people scratching and pictures of affected skin or insects can induce itch in healthy persons and chronic itch patients. In our studies, patients with atopic dermatitis (AD) were more susceptible to visual itch cues than healthy. Also, personality traits like agreeableness and public self-consciousness were associated with induced scratching in skin patients, while neuroticism correlated with induced itch in healthy subjects. The underlying course of contagious itch is not yet fully understood. It is hypothesized that there are human mirror neurons that are active when we imitate actions and/or negative affect. Until now, there has been only limited data on the mechanisms of brain activation in contagious itch though. We have barely begun to understand the underlying physiological reactions and the triggering factors of this phenomenon. We summarize what we currently know about contagious itch and provide some suggestions what future research should focus on. PMID:25717300

Schut, C.; Grossman, S.; Gieler, U.; Kupfer, J.; Yosipovitch, G.

2015-01-01

260

Male Yawning Is More Contagious than Female Yawning among Chimpanzees (Pan troglodytes)  

PubMed Central

Yawn contagion is not restricted to humans and has also been reported for several non-human animal species, including chimpanzees (Pan troglodytes). Contagious yawning may lead to synchronisation of behaviour. However, the function of contagious yawning is relatively understudied. In this study, we investigated the function of contagious yawning by focusing on two types of signal providers: close social associates and leaders. We provided a captive chimpanzee colony with videos of all individuals of their own group that were either yawning, or at rest. Consistent with other studies, we demonstrated that yawning is contagious for chimpanzees, yet we did not find any effect of relationship quality on yawn contagion. However, we show that yawn contagion is significantly higher when the video model is a yawning male than when the video model was a yawning female, and that this effect is most apparent among males. As males are dominant in chimpanzee societies, male signals may be more relevant to the rest of the group than female signals. Moreover, since chimpanzees form male-bonded societies, male signals are especially relevant for other males. Therefore, we suggest that the sex-differences of yawning contagion among chimpanzees reflect the function of yawning in the synchronisation of behaviour. PMID:22808234

Massen, Jorg J. M.; Vermunt, Dorith A.; Sterck, Elisabeth H. M.

2012-01-01

261

Origin and spread of the 1278insTATC mutation causing Tay-Sachs disease in Ashkenazi Jews: genetic drift as a robust and parsimonious hypothesis.  

PubMed

The 1278insTATC is the most prevalent beta-hexosaminidase A ( HEXA) gene mutation causing Tay-Sachs disease (TSD), one of the four lysosomal storage diseases (LSDs) occurring at elevated frequencies among Ashkenazi Jews (AJs). To investigate the genetic history of this mutation in the AJ population, a conserved haplotype (D15S981:175-D15S131:240-D15S1050:284-D15S197:144-D15S188:418) was identified in 1278insTATC chromosomes from 55 unrelated AJ individuals (15 homozygotes and 40 heterozygotes for the TSD mutation), suggesting the occurrence of a common founder. When two methods were used for analysis of linkage disequilibrium (LD) between flanking polymorphic markers and the disease locus and for the study of the decay of LD over time, the estimated age of the insertion was found to be 40+/-12 generations (95% confidence interval: 30-50 generations), so that the most recent common ancestor of the mutation-bearing chromosomes would date to the 8th-9th century. This corresponds with the demographic expansion of AJs in central Europe, following the founding of the Ashkenaz settlement in the early Middle Ages. The results are consistent with the geographic distribution of the main TSD mutation, 1278insTATC being more common in central Europe, and with the coalescent times of mutations causing two other LSDs, Gaucher disease and mucolipidosis type IV. Evidence for the absence of a determinant positive selection (heterozygote advantage) over the mutation is provided by a comparison between the estimated age of 1278insTATC and the probability of the current AJ frequency of the mutant allele as a function of its age, calculated by use of a branching-process model. Therefore, the founder effect in a rapidly expanding population arising from a bottleneck provides a robust parsimonious hypothesis explaining the spread of 1278insTATC-linked TSD in AJ individuals. PMID:14727180

Frisch, Amos; Colombo, Roberto; Michaelovsky, Elena; Karpati, Mazal; Goldman, Boleslaw; Peleg, Leah

2004-03-01

262

Mathematical Modelling of the Transmission Dynamics of Contagious Bovine Pleuropneumonia Reveals Minimal Target Profiles for Improved Vaccines and Diagnostic Assays  

PubMed Central

Contagious bovine pleuropneumonia (CBPP) is a cattle disease that has hampered the development of the livestock sector in sub-Saharan Africa. Currently, vaccination with a live vaccine strain is its recommended control measure although unofficial antimicrobial use is widely practiced. Here, modelling techniques are used to assess the potential impact of early elimination of infected cattle via accurate diagnosis on CBPP dynamics. A herd-level stochastic epidemiological model explicitly incorporating test sensitivity and specificity is developed. Interventions by annual vaccination, annual testing and elimination and a combination of both are implemented in a stepwise manner and their effectiveness compared by running 1000 simulations per intervention over ten years. The model predicts that among the simulated interventions, the ones likely to eliminate the disease from an isolated herd all involved annual vaccination of more than 75% of the animals with a vaccine that protects for at least 18 months combined with annual testing (and elimination of positive reactors) of 75% of the animals every six months after vaccination. The highest probability of disease elimination was 97.5% and this could occur within a median of 2.3 years. Generally, our model predicts that regular testing and elimination of positive reactors using improved tests will play a significant role in minimizing CBPP burden especially in the current situation where improved vaccines are yet to be developed. PMID:25668725

Ssematimba, Amos; Jores, Joerg; Mariner, Jeffrey C.

2015-01-01

263

Parallelization: Infectious Disease  

NSDL National Science Digital Library

Epidemiology is the study of infectious disease. Infectious diseases are said to be "contagious" among people if they are transmittable from one person to another. Epidemiologists can use models to assist them in predicting the behavior of infectious diseases. This module will develop a simple agent-based infectious disease model, develop a parallel algorithm based on the model, provide a coded implementation for the algorithm, and explore the scaling of the coded implementation on high performance cluster resources.

Aaron Weeden

264

Farmer reported prevalence and factors associated with contagious ovine digital dermatitis in Wales: A questionnaire of 511 sheep farmers.  

PubMed

In 2012, 2000 questionnaires were sent to a random sample of Welsh sheep farmers. The questionnaire investigated farmers' knowledge and views on contagious ovine digital dermatitis (CODD) - an emerging disease of sheep responsible for causing severe lameness, welfare and production problems. The overall response rate was 28.3% with a usable response rate of 25.6%. The between farm prevalence of CODD was 35.0% and the median farmer estimated prevalence of CODD was 2.0%. The disease now appears endemic and widespread in Wales. Furthermore, there has been a rapid increase in reports of CODD arriving on farms since the year 2000. Risk factors for CODD identified in this study include the presence of bovine digital dermatitis (BDD) in cattle on the farm and larger flocks. Farmers also consider concurrent footrot/interdigital dermatitis, buying in sheep, adult sheep, time of year and housing to be associated with CODD. Further experimental research is necessary to establish whether these observations are true associations. PMID:24207114

Angell, J W; Duncan, J S; Carter, S D; Grove-White, D H

2014-01-01

265

What Is Kawasaki Disease?  

MedlinePLUS

... and feet • Redness of the whites of the eyes • Swollen lymph glands in the neck • Irritation and inflammation of the mouth, lips and throat What causes Kawasaki disease? Doctors don’t know what causes it. It doesn’t appear to be hereditary or contagious. It’s very rare for more than ...

266

Infectious Diseases in Day Care.  

ERIC Educational Resources Information Center

Discussed in this publication are infectious illnesses for which children attending day care appear to be at special risk. Also covered are the common cold, some infectious disease problems receiving media attention, and some other annoying but not serious diseases, such as head lice, pinworms, and contagious skin conditions. Causes,…

Sleator, Esther K.

267

Foot-and-mouth disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals. An outbreak of FMD can have a significant economic impact because of the restrictions on international trade of susceptible animals and their products with FMD-free countries. In this chapter we discuss vario...

268

Immunization of Sheep and Goats Against Soremouth (Contagious Ecthyma).  

E-print Network

vaccinated with oremouth scab emulsion were successful in preventing soremouth. re than two and one-half million lambs and kids have been :cinated by Texas sheepmen during the past two gears with ,ellent results. taccination establishes an immunity which... endures for at least mty-ei~ht months and protects the lamb on the range .and in feed lot. The vaccination of lambs and kids infected with emouth is of value in shortening the course and reducing the erity of the disease. Vaccination of lambs and kids...

Boughton, I. B. (Ivan Bertrand); Hardy, W. T. (William Tyree)

1935-01-01

269

Feline parvovirus infection and associated diseases.  

PubMed

Feline panleukopenia, caused by the single-stranded DNA virus feline parvovirus (FPV), is a highly contagious and often lethal disease of cats and other Felidae. FPV, but also canine parvovirus (CPV) can be isolated from both healthy and diseased cats. In Germany, CPV was detected in only approximately 10% of feline samples, but in Southeast Asia, reports estimated that up to approximately 80% of diseased cats were infected with CPV. Infection spreads rapidly, especially in cells with high mitotic activity, such as bone marrow, lymphoid tissue and intestinal crypt cells. Anorexia, vomiting, diarrhoea, neutropenia and lymphopenia are common in clinically affected cases. In utero or neonatal infection can result in cerebellar hypoplasia. Depending on the severity of clinical signs, mortality ranges from 25 to 100%. Effective vaccination and thorough disinfection are of the utmost importance in the prevention of disease transmission in multi-cat households and animal shelters. If clinical signs develop, supportive treatment should be commenced. The efficacy of feline recombinant interferon and FPV antibodies has not been clearly demonstrated. Commercially available vaccines should induce protective immunity when administered according to current guidelines. Recent studies suggest that in some kittens, maternally derived antibodies (MDA) can persist for much longer than has been previously recognised. FPV serum antibody tests are available, but protection status needs to be interpreted with caution in kittens with MDA and a negative titre in adult cats does not necessarily denote lack of protection. PMID:24923754

Stuetzer, Bianca; Hartmann, Katrin

2014-08-01

270

Evolutionary History of Contagious Bovine Pleuropneumonia Using Next Generation Sequencing of Mycoplasma mycoides Subsp. mycoides “Small Colony”  

PubMed Central

Mycoplasma mycoides subsp. mycoides “Small Colony” (MmmSC) is responsible for contagious bovine pleuropneumonia (CBPP) in bovidae, a notifiable disease to the World Organization for Animal Health (OIE). Although its origin is not documented, the disease was known in Europe in 1773. It reached nearly world-wide distribution in the 19th century through the cattle trade and was eradicated from most continents by stamping-out policies. During the 20th century it persisted in Africa, and it reappeared sporadically in Southern Europe. Yet, classical epidemiology studies failed to explain the re-occurrence of the disease in Europe in the 1990s. The objectives of this study were to obtain a precise phylogeny of this pathogen, reconstruct its evolutionary history, estimate the date of its emergence, and determine the origin of the most recent European outbreaks. A large-scale genomic approach based on next-generation sequencing technologies was applied to construct a robust phylogeny of this extremely monomorphic pathogen by using 20 representative strains of various geographical origins. Sixty two polymorphic genes of the MmmSC core genome were selected, representing 83601 bp in total and resulting in 139 SNPs within the 20 strains. A robust phylogeny was obtained that identified a lineage specific to European strains; African strains were scattered in various branches. Bayesian analysis allowed dating the most recent common ancestor for MmmSC around 1700. The strains circulating in Sub-Saharan Africa today, however, were shown to descend from a strain that existed around 1810. MmmSC emerged recently, about 300 years ago, and was most probably exported from Europe to other continents, including Africa, during the 19th century. Its diversity is now greater in Africa, where CBPP is enzootic, than in Europe, where outbreaks occurred sporadically until 1999 and where CBPP may now be considered eradicated unless MmmSC remains undetected. PMID:23071648

Dupuy, Virginie; Manso-Silván, Lucía; Barbe, Valérie; Thebault, Patricia; Dordet-Frisoni, Emilie; Citti, Christine; Poumarat, François; Blanchard, Alain; Breton, Marc; Sirand-Pugnet, Pascal; Thiaucourt, François

2012-01-01

271

Stopping Spread of Apple Scab Fire Blight  

E-print Network

1 Stopping Spread of Apple Scab Fire Blight Stawberry Diseases European Red Mites Rosy Apple Aphid stage of susceptibility from pink until about 3-4 weeks after petal fall. -Pecknold Fire Blight: Even

Ginzel, Matthew

272

Outbreaks where food workers have been implicated in the spread of foodborne disease. Part 11. Use of antiseptics and sanitizers in community settings and issues of hand hygiene compliance in health care and food industries.  

PubMed

Hand washing with soap is a practice that has long been recognized as a major barrier to the spread of disease in food production, preparation, and service and in health care settings, including hospitals, child care centers, and elder care facilities. Many of these settings present multiple opportunities for spread of pathogens within at-risk populations, and extra vigilance must be applied. Unfortunately, hand hygiene is not always carried out effectively, and both enteric and respiratory diseases are easily spread in these environments. Where water is limited or frequent hand hygiene is required on a daily basis, such as for many patients in hospitals and astronauts in space travel, instant sanitizers or sanitary wipes are thought to be an effective way of preventing contamination and spread of organisms among coworkers and others. Most concerns regarding compliance are associated with the health care field, but the food industry also must be considered. Specific reasons for not washing hands at appropriate times are laziness, time pressure, inadequate facilities and supplies, lack of accountability, and lack of involvement by companies, managers, and workers in supporting proper hand washing. To facilitate improvements in hand hygiene, measurement of compliant and noncompliant actions is necessary before implementing any procedural changes. Training alone is not sufficient for long-lasting improvement. Multiactivity strategies also must include modification of the organization culture to encourage safe hygienic practices, motivation of employees willing to use peer pressure on noncompliant coworkers, a reward and/or penalty system, and an operational design that facilitates regular hand hygiene. PMID:21219754

Todd, Ewen C D; Greig, Judy D; Michaels, Barry S; Bartleson, Charles A; Smith, Debra; Holah, John

2010-12-01

273

Quantum Spread Spectrum Communication  

SciTech Connect

We show that communication of single-photon quantum states in a multi-user environment is improved by using spread spectrum communication techniques. We describe a framework for spreading, transmitting, despreading, and detecting single-photon spectral states that mimics conventional spread spectrum techniques. We show in the cases of inadvertent detection, unintentional interference, and multi-user management, that quantum spread spectrum communications may minimize receiver errors by managing quantum channel access.

Humble, Travis S [ORNL

2011-01-01

274

Hierarchical mechanisms of spatially contagious seed dispersal in complex seed-disperser networks.  

PubMed

Intra- and interspecific spatially contagious seed dispersal has far-reaching implications for plant recruitment, distribution, and community assemblage. However, logistical and analytical limitations have curtailed our understanding concerning the mechanisms and resulting spatial patterns of contagious seed dispersal in most systems and, especially, in complex seed-disperser networks. We investigated mechanisms of seed aggregation using techniques of spatial point pattern analysis and extensive data sets on mutispecific endozoochorous seed rain generated by five frugivorous mammals in three Mediterranean shrublands over two seasons. Our novel analytical approach revealed three hierarchical and complementary mechanisms of seed aggregation acting at different levels (fecal samples, seeds, pairs of seed species) and spatial scales. First, the three local guilds of frugivores tended to deliver their feces highly aggregated at small and intermediate spatial scales, and the overall pattern of fecal delivery could be described well by a nested double-cluster Thomas process. Second, once the strong observed fecal aggregation was accounted for, the distribution of mammal feces containing seeds was clustered within the pattern of all feces (i.e., with and without seeds), and the density of fecal samples containing seeds was higher than expected around other feces containing seeds in two out of the three studied seed-disperser networks. Finally, at a finer level, mark correlation analyses revealed that for some plant species pairs, the number of dispersed seeds was positively associated either at small or large spatial scales. Despite the relatively invariant patterning of nested double-clustering, some attributes of endozoochorous seed rain (e.g., intensity, scales of aggregation) were variable among study sites due to changes in the ecological context in which seeds and their dispersers interact. Our investigation disentangles for the first time the hierarchy of synergic mechanisms of spatially contagious seed dispersal at a range of spatial scales in complex seed-disperser networks, thus providing a robust and widely applicable framework for future studies. PMID:24669744

Fedriani, José M; Wiegand, Thorsten

2014-02-01

275

An international collaborative study to determine the prevalence of contagious caprine pleuropneumonia by monoclonal antibody-based cELISA  

PubMed Central

Background Few serological tests are available for detecting antibodies against Mycoplasma capricolum subsp. capripneumoniae, the causal agent of contagious caprine pleuropneumonia (CCPP). The complement fixation test, the test prescribed for international trade purposes, uses a crude antigen that cross-reacts with all the other mycoplasma species of the “mycoides cluster” frequently infecting goat herds. The lack of a more specific test has been a real obstacle to the evaluation of the prevalence and economic impact of CCPP worldwide. A new competitive ELISA kit for CCPP, based on a previous blocking ELISA, was formatted at CIRAD and used to evaluate the prevalence of CCPP in some regions of Kenya, Ethiopia, Mauritius, Tajikistan and Pakistan in an international collaborative study. Results The strict specificity of the test was confirmed in CCPP-free goat herds exposed to other mycoplasma species of the “mycoides cluster”. Prevalence studies were performed across the enzootic range of the disease in Africa and Asia. Seroprevalence was estimated at 14.6% in the Afar region of Ethiopia, whereas all the herds presented for CCPP vaccination in Kenya tested positive (individual seroprevalence varied from 6 to 90% within each herd). In Mauritius, where CCPP emerged in 2009, nine of 62 herds tested positive. In Central Asia, where the disease was confirmed only recently, no positive animals were detected in the Wakhan District of Afghanistan or across the border in neighboring areas of Tajikistan, whereas seroprevalence varied between 2.7% and 44.2% in the other districts investigated and in northern Pakistan. The test was also used to monitor seroconversion in vaccinated animals. Conclusions This newly formatted CCPP cELISA kit has retained the high specificity of the original kit. It can therefore be used to evaluate the prevalence of CCPP in countries or regions without vaccination programs. It could also be used to monitor the efficacy of vaccination campaigns as high-quality vaccines induce high rates of seroconversion. PMID:24565080

2014-01-01

276

Willingness to pay for contagious bovine pleuropneumonia vaccination in Narok South District of Kenya  

PubMed Central

Contagious bovine pleuropneumonia (CBPP) is an economically important trans-boundary cattle disease which affects food security and livelihoods. A conjoint analysis–contingent valuation was carried out on 190 households in Narok South District of Kenya to measure willingness to pay (WTP) and demand for CBPP vaccine and vaccination as well as factors affecting WTP. The mean WTP was calculated at Kenya Shillings (KSh) 212.48 (USD 3.03) for vaccination using a vaccine with the characteristics that were preferred by the farmers (preferred vaccine and vaccination) and KSh ?71.45 (USD ?1.02) for the currently used vaccine and vaccination. The proportion of farmers willing to pay an amount greater than zero was 66.7% and 34.4% for the preferred and current vaccine and vaccination respectively. About one third (33.3%) of farmers would need to be compensated an average amount of KSh 1162.62 (USD 13.68) per animal to allow their cattle to be vaccinated against CBPP using the preferred vaccine and vaccination. About two-thirds (65.6%) of farmers would need to be compensated an average amount of KSh 853.72 (USD 12.20) per animal to allow their cattle to be vaccinated against CBPP using the current vaccine and vaccination. The total amount of compensation would be KSh 61.39 million (USD 0.88 million) for the preferred vaccine and vaccination and KSh 90.15 million (USD 1.29 million) for the current vaccine and vaccination. Demand curves drawn from individual WTP demonstrated that only 59% and 27% of cattle owners with a WTP greater than zero were willing to pay a benchmark cost of KSh 34.60 for the preferred and current vaccine respectively. WTP was negatively influenced by the attitude about household economic situation (p = 0.0078), presence of cross breeds in the herd (p < 0.0001) and years since CBPP had been experienced in the herd (p = 0.0375). It was positively influenced by education (p = 0.0251) and the practice of treating against CBPP (p = 0.0432). The benefit cost ratio (BCR) for CBPP vaccination was 2.9–6.1 depending on the vaccination programme. In conclusion, although a proportion of farmers was willing to pay, participation levels may be lower than those required to interrupt transmission of CBPP. Households with characteristics that influence WTP negatively need persuasion to participate in CBPP vaccination. It is economically worthwhile to vaccinate against CBPP. A benefit cost analysis (BCA) using aggregated WTP as benefits can be used as an alternative method to the traditional BCA which uses avoided production losses (new revenue) and costs saved as benefits. PMID:24774477

Kairu-Wanyoike, Salome W.; Kaitibie, Simeon; Heffernan, Claire; Taylor, Nick M.; Gitau, George K.; Kiara, Henry; McKeever, Declan

2014-01-01

277

Willingness to pay for contagious bovine pleuropneumonia vaccination in Narok South District of Kenya.  

PubMed

Contagious bovine pleuropneumonia (CBPP) is an economically important trans-boundary cattle disease which affects food security and livelihoods. A conjoint analysis-contingent valuation was carried out on 190 households in Narok South District of Kenya to measure willingness to pay (WTP) and demand for CBPP vaccine and vaccination as well as factors affecting WTP. The mean WTP was calculated at Kenya Shillings (KSh) 212.48 (USD 3.03) for vaccination using a vaccine with the characteristics that were preferred by the farmers (preferred vaccine and vaccination) and KSh -71.45 (USD -1.02) for the currently used vaccine and vaccination. The proportion of farmers willing to pay an amount greater than zero was 66.7% and 34.4% for the preferred and current vaccine and vaccination respectively. About one third (33.3%) of farmers would need to be compensated an average amount of KSh 1162.62 (USD 13.68) per animal to allow their cattle to be vaccinated against CBPP using the preferred vaccine and vaccination. About two-thirds (65.6%) of farmers would need to be compensated an average amount of KSh 853.72 (USD 12.20) per animal to allow their cattle to be vaccinated against CBPP using the current vaccine and vaccination. The total amount of compensation would be KSh 61.39 million (USD 0.88 million) for the preferred vaccine and vaccination and KSh 90.15 million (USD 1.29 million) for the current vaccine and vaccination. Demand curves drawn from individual WTP demonstrated that only 59% and 27% of cattle owners with a WTP greater than zero were willing to pay a benchmark cost of KSh 34.60 for the preferred and current vaccine respectively. WTP was negatively influenced by the attitude about household economic situation (p=0.0078), presence of cross breeds in the herd (p<0.0001) and years since CBPP had been experienced in the herd (p=0.0375). It was positively influenced by education (p=0.0251) and the practice of treating against CBPP (p=0.0432). The benefit cost ratio (BCR) for CBPP vaccination was 2.9-6.1 depending on the vaccination programme. In conclusion, although a proportion of farmers was willing to pay, participation levels may be lower than those required to interrupt transmission of CBPP. Households with characteristics that influence WTP negatively need persuasion to participate in CBPP vaccination. It is economically worthwhile to vaccinate against CBPP. A benefit cost analysis (BCA) using aggregated WTP as benefits can be used as an alternative method to the traditional BCA which uses avoided production losses (new revenue) and costs saved as benefits. PMID:24774477

Kairu-Wanyoike, Salome W; Kaitibie, Simeon; Heffernan, Claire; Taylor, Nick M; Gitau, George K; Kiara, Henry; McKeever, Declan

2014-08-01

278

Epidemiology and disease control in everyday beef practice.  

PubMed

It is important for food animal veterinarians to understand the interaction among animals, pathogens, and the environment, in order to implement herd-specific biosecurity plans. Animal factors such as the number of immunologically protected individuals influence the number of individuals that a potential pathogen is able to infect, as well as the speed of spread through a population. Pathogens differ in their virulence and contagiousness. In addition, pathogens have various methods of transmission that impact how they interact with a host population. A cattle population's environment includes its housing type, animal density, air quality, and exposure to mud or dust and other health antagonists such as parasites and stress; these environmental factors influence the innate immunity of a herd by their impact on immunosuppression. In addition, a herd's environment also dictates the "animal flow" or contact and mixing patterns of potentially infectious and susceptible animals. Biosecurity is the attempt to keep infectious agents away from a herd, state, or country, and to control the spread of infectious agents within a herd. Infectious agents (bacteria, viruses, or parasites) alone are seldom able to cause disease in cattle without contributing factors from other infectious agents and/or the cattle's environment. Therefore to develop biosecurity plans for infectious disease in cattle, veterinarians must consider the pathogen, as well as environmental and animal factors. PMID:18501415

Larson, R L

2008-08-01

279

Mirror neuron activity during contagious yawning--an fMRI study.  

PubMed

Yawning is contagious. However, little research has been done to elucidate the neuronal representation of this phenomenon. Our study objective was to test the hypothesis that the human mirror neuron system (MNS) is activated by visually perceived yawning. We used functional magnetic resonance imaging to assess brain activity during contagious yawning (CY). Signal-dependent changes in blood oxygen levels were compared when subjects viewed videotapes of yawning faces as opposed to faces with a neutral expression. In response to yawning, subjects showed unilateral activation of their Brodmann's area 9 (BA 9) portion of the right inferior frontal gyrus, a region of the MNS. In this way, two individuals could share physiological and associated emotional states based on perceived motor patterns. This is one component of empathy (motor empathy) that underlies the development of cognitive empathy. The BA 9 is reportedly active in tasks requiring mentalizing abilities. Our results emphasize the connection between the MNS and higher cognitive empathic functions, including mentalizing. We conclude that CY is based on a functional substrate of empathy. PMID:22772979

Haker, Helene; Kawohl, Wolfram; Herwig, Uwe; Rössler, Wulf

2013-03-01

280

Molecular epidemiology of Rabbit haemorrhagic disease virus  

Microsoft Academic Search

Millions of domestic and wild European rabbits (Oryctolagus cuniculus) have died in Europe, Asia, Australia and New Zealand during the past 17 years following infection by Rabbit haemorrhagic disease virus (RHDV). This highly contagious and deadly disease was first identified in China in 1984. Epidemics of RHDV then radiated across Europe until the virus apparently appeared in Britain in 1992.

S. R. Moss; S. L. Turner; R. C. Trout; P. J. White; P. J. Hudson; A. Desai; M. Armesto; N. L. Forrester; E. A. Gould

2002-01-01

281

Whole Genome Association Study of Johne's Disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bovine Paratuberculosis, commonly referred to as Johne's disease, is a contagious bacterial disease estimated to be present in over 65% of US dairy herds and results in annual losses in the hundreds of millions of US dollars. Mycobacterium avium subspecies paratuberculosis (MAP) is the bacteria resp...

282

Interactions of foot-and-mouth disease virus with cells in organised lymphoid tissue influence innate and adaptive immune responses   

E-print Network

Foot-and-mouth disease virus (FMDV) is one of the most contagious viruses of animals and is recognised as the most important constraint to international trade in animals and animal products. Two fundamental problems remain to be understood before...

Juleff, Nicholas Dylan

2009-01-01

283

Foodborne Diseases  

MedlinePLUS

... JavaScript on. Read more information on enabling JavaScript. Foodborne Diseases Top Banner Content Area Skip Content Marketing Share ... on a clean kitchen countertop. Credit: CDC. Understanding Foodborne Diseases Infectious diseases spread through food or beverages are ...

284

Differential induction and spread of tau pathology in young PS19 tau transgenic mice following intracerebral injections of pathological tau from Alzheimer’s disease or corticobasal degeneration brains  

PubMed Central

Filamentous tau pathologies are hallmark lesions of several neurodegenerative tauopathies including Alzheimer’s disease (AD) and corticobasal degeneration (CBD) which show cell type-specific and topographically distinct tau inclusions. Growing evidence supports templated transmission of tauopathies through functionally interconnected neuroanatomical pathways suggesting that different self-propagating strains of pathological tau could account for the diverse manifestations of neurodegenerative tauopathies. Here, we describe the rapid and distinct cell type-specific spread of pathological tau following intracerebral injections of CBD or AD brain extracts enriched in pathological tau (designated CBD-Tau and AD-Tau, respectively) in young human mutant P301S tau transgenic (Tg) mice (line PS19) ~6–9 months before they show onset of mutant tau transgene-induced tau pathology. At 1 month post-injection of CBD-Tau, tau inclusions developed predominantly in oligodendrocytes of the fimbria and white matter near the injection sites with infrequent intraneuronal tau aggregates. In contrast, injections of AD-Tau in young PS19 mice induced tau pathology predominantly in neuronal perikarya with little or no oligodendrocyte involvement 1 month post-injection. With longer post-injection survival intervals of up to 6 months, CBD-Tau- and AD-Tau-induced tau pathology spread to different brain regions distant from the injection sites while maintaining the cell type-specific pattern noted above. Finally, CA3 neuron loss was detected 3 months post-injection of AD-Tau but not CBD-Tau. Thus, AD-Tau and CBD-Tau represent specific pathological tau strains that spread differentially and may underlie distinct clinical and pathological features of these two tauopathies. Hence, these strains could become targets to develop disease-modifying therapies for CBD and AD. PMID:25534024

Boluda, Susana; Iba, Michiyo; Zhang, Bin; Raible, Kevin M.; Lee, Virginia M-Y.; Trojanowski, John Q.

2015-01-01

285

Contagious Fire? An Empirical Assessment of the Problem of Multi-Shooter, Multi-Shot Deadly Force Incidents in Police Work  

ERIC Educational Resources Information Center

Recent police shootings in which multiple officers fired numerous rounds at suspects have led some observers to assert that such situations involve "contagious fire," where an initial officer's shots launch a cascade of gunfire from other officers present. Although there is anecdotal recognition of the contagious fire phenomenon among police and…

White, Michael D.; Klinger, David

2012-01-01

286

Low major histocompatibility complex diversity in the Tasmanian devil predates European settlement and may explain susceptibility to disease epidemics  

PubMed Central

The Tasmanian devil (Sarcophilus harrisii) is at risk of extinction owing to the emergence of a contagious cancer known as devil facial tumour disease (DFTD). The emergence and spread of DFTD has been linked to low genetic diversity in the major histocompatibility complex (MHC). We examined MHC diversity in historical and ancient devils to determine whether loss of diversity is recent or predates European settlement in Australia. Our results reveal no additional diversity in historical Tasmanian samples. Mainland devils had common modern variants plus six new variants that are highly similar to existing alleles. We conclude that low MHC diversity has been a feature of devil populations since at least the Mid-Holocene and could explain their tumultuous history of population crashes. PMID:23221872

Morris, Katrina; Austin, Jeremy J.; Belov, Katherine

2013-01-01

287

Screwworms, Cochliomyia hominivorax, reared for mass release do not carry and spread foot-and-mouth disease virus and classical swine fever virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Transporting live screwworms Cochliomyia hominivorax Coquerel for developing new strains from countries where foot-and-mouth disease (FMD) and classical swine fever (CSF) are endemic, to the mass rearing facilities in Mexico and Panama may introduce these exotic diseases. This study was conducted to...

288

Maximum linkage space-time permutation scan statistics for disease outbreak detection  

PubMed Central

Background In disease surveillance, the prospective space-time permutation scan statistic is commonly used for the early detection of disease outbreaks. The scanning window that defines potential clusters of diseases is cylindrical in shape, which does not allow incorporating into the cluster shape potential factors that can contribute to the spread of the disease, such as information about roads, landscape, among others. Furthermore, the cylinder scanning window assumes that the spatial extent of the cluster does not change in time. Alternatively, a dynamic space-time cluster may indicate the potential spread of the disease through time. For instance, the cluster may decrease over time indicating that the spread of the disease is vanishing. Methods This paper proposes two irregularly shaped space-time permutation scan statistics. The cluster geometry is dynamically created using a graph structure. The graph can be created to include nearest-neighbor structures, geographical adjacency information or any relevant prior information regarding the contagious behavior of the event under surveillance. Results The new methods are illustrated using influenza cases in three New England states, and compared with the cylindrical version. A simulation study is provided to investigate some properties of the proposed arbitrary cluster detection techniques. Conclusion We have successfully developed two new space-time permutation scan statistics methods with irregular shapes and improved computational performance. The results demonstrate the potential of these methods to quickly detect disease outbreaks with irregular geometries. Future work aims at performing intensive simulation studies to evaluate the proposed methods using different scenarios, number of cases, and graph structures. PMID:24916839

2014-01-01

289

Directional transneuronal spread of ?-herpesvirus infection  

PubMed Central

Most ?-herpesviruses are pantropic, neuroinvasive pathogens that establish a reactivateable, latent infection in the PNS of their natural hosts. Various manifestations of herpes disease rely on extent and direction of the spread of infection between the surface epithelia and the nervous system components that innervate that surface. One aspect of such controlled spread of infection is the capacity for synaptically defined, transneuronal spread, a property that makes ?-herpesviruses useful tools for determining the connectivity of neural circuits. The current understanding of intra-axonal transport and transneuronal spread of ?-herpesviruses is reviewed, focusing on work with herpes simplex virus and pseudorabies virus, the available in vitro technology used to study viral transport and spread is evaluated and how certain viral mutants can be used to examine neural circuit architecture is described in this article. PMID:20161665

Curanovic, D; Enquist, LW

2010-01-01

290

Foot-and-mouth disease: global status and Indian perspective  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease (FMD) is a highly contagious and transboundary viral disease of domesticated and wild cloven-hoofed animals. Wide prevalence of the disease in Asia and Africa associated with huge economic loss to the livestock farming and industry has increased the concern worldwide. The di...

291

Immunological Basis for Resistance and Susceptibility to Marek's Disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek’s disease (MD) is a contagious lymphoproliferative disease of domestic chickens caused by a highly cell-associated alpha-herpesvirus, Marek’s disease virus (MDV). MDV replicates in chicken lymphocytes and establishes a latent infection within CD4+ T cells. Mechanisms of viral pathogenesis, r...

292

Flame spread across liquids  

NASA Technical Reports Server (NTRS)

Recent reviews of our understanding of flame spread across liquids show that there are many unresolved issues regarding the phenomenology and causal mechanisms affecting ignition susceptibility, flame spread characteristics, and flame spread rates. One area of discrepancy is the effect of buoyancy in both the uniform and pulsating spread regimes. The approach we have taken to resolving the importance of buoyancy for these flames is: (1) normal gravity (1g) and microgravity (micro g) experiments; and (2) numerical modeling at different gravitational levels. Of special interest to this work, as discussed at the previous workshop, is the determination of whether, and under what conditions, pulsating spread occurs in micro g. Microgravity offers a unique ability to modify and control the gas-phase flow pattern by utilizing a forced air flow over the pool surface.

Ross, Howard D.; Miller, Fletcher; Schiller, David; Sirignano, William

1995-01-01

293

Contagious error sources would need time travel to prevent quantum computation  

E-print Network

We consider an error model for quantum computing that consists of "contagious quantum germs" that can infect every output qubit when at least one input qubit is infected. Once a germ actively causes error, it continues to cause error indefinitely for every qubit it infects, with arbitrary quantum entanglement and correlation. Although this error model looks much worse than quasi-independent error, we show that it reduces to quasi-independent error with the technique of quantum teleportation. The construction, which was previously described by Knill, is that every quantum circuit can be converted to a mixed circuit with bounded quantum depth. We also consider the restriction of bounded quantum depth from the point of view of quantum complexity classes.

Gil Kalai; Greg Kuperberg

2014-12-05

294

Prevalence of contagious mastitis pathogens in bulk tank milk in Prince Edward Island.  

PubMed

The purpose of this study was to 1) estimate the herd prevalence of contagious mastitis pathogens in bulk milk from Prince Edward Island (PEI) dairy farms, 2) determine the association between bulk milk culture results and mean bulk milk somatic cell count (BMSCC), and 3) investigate the agreement of repeated bulk milk cultures. Three consecutive bulk milk samples were obtained at weekly intervals from all 258 PEI dairy herds and were cultured using routine laboratory methods. Cumulative prevalence of Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp. (M. bovis and M. alkalescens) was 74%, 1.6%, and 1.9%, respectively. Bulk milk somatic cell count of Staph. aureus-positive herds was higher than that of negative herds. Agreement for Staph. aureus isolation between 3 consecutive tests was moderate (kappa = 0.46). Mycoplasma bovis and M. alkalescens in bulk milk are being reported for the 1st time in PEI ever and in Canada since 1972. PMID:16808229

Olde Riekerink, Richard G M; Barkema, Herman W; Veenstra, Stefan; Poole, Doris E; Dingwell, Randy T; Keefe, Gregory P

2006-06-01

295

Prevalence of contagious mastitis pathogens in bulk tank milk in Prince Edward Island  

PubMed Central

Abstract The purpose of this study was to 1) estimate the herd prevalence of contagious mastitis pathogens in bulk milk from Prince Edward Island (PEI) dairy farms, 2) determine the association between bulk milk culture results and mean bulk milk somatic cell count (BMSCC), and 3) investigate the agreement of repeated bulk milk cultures. Three consecutive bulk milk samples were obtained at weekly intervals from all 258 PEI dairy herds and were cultured using routine laboratory methods. Cumulative prevalence of Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp. (M. bovis and M. alkalescens) was 74%, 1.6%, and 1.9%, respectively. Bulk milk somatic cell count of Staph. aureus-positive herds was higher than that of negative herds. Agreement for Staph. aureus isolation between 3 consecutive tests was moderate (kappa = 0.46). Mycoplasma bovis and M. alkalescens in bulk milk are being reported for the 1st time in PEI ever and in Canada since 1972. PMID:16808229

Barkema, Herman W.; Veenstra, Stefan; Poole, Doris E.; Dingwell, Randy T.; Keefe, Gregory P.

2006-01-01

296

Some evidence on the spread of bacterial wilt  

Microsoft Academic Search

Since the discovery of bacterial wilt and ring rot there has been considerable speculation regarding the amount of spread in the field. Workers, particularly Racicot, Savile and Conners (5) recognized the serious nature of the disease and the fact that it was easily spread, and therefore recommended a zero tolerance for this disease on certification standards. Bonde (I) has shown

C. H. Metzger; A. M. Binkley

1940-01-01

297

Origin and spread of the 1278insTATC mutation causing Tay-Sachs disease in Ashkenazi Jews: genetic drift as a robust and parsimonious hypothesis  

Microsoft Academic Search

The 1278insTATC is the most prevalent ß-hexosaminidase A ( HEXA) gene mutation causing Tay-Sachs disease (TSD), one of the four lysosomal storage diseases (LSDs) occurring at elevated frequencies among Ashkenazi Jews (AJs). To investigate the genetic history of this mutation in the AJ population, a conserved haplotype (D15S981:175–D15S131:240–D15S1050:284–D15S197:144–D15S188:418) was identified in 1278insTATC chromosomes from 55 unrelated AJ individuals (15 homozygotes and

Amos Frisch; Roberto Colombo; Elena Michaelovsky; Mazal Karpati; Boleslaw Goldman; Leah Peleg

2004-01-01

298

Timing of activation of CD4+ memory cells as a possible marker to establish the efficacy of vaccines against contagious agalactia in sheep.  

PubMed

Mycoplasma agalactiae is a major pathogen of sheep and goats in many areas of the world and particularly in Mediterranean countries. It causes contagious agalactia, an infectious disease primarily affecting mammary glands. Many vaccines against the pathogen are currently under development. The aim of the study was to investigate the involvement of T cell-mediated immunity during vaccination and challenge experiments against Mycoplasma agalactiae. A comparison of the antigen-specific expansion of interferon gamma positive T cell memory and naïve subsets was performed between vaccinated and non-vaccinated sheep to identify cellular subsets whose activation was different between protected and non-protected sheep. Data reported in this manuscript demonstrated that two out of the three vaccines used in this study protected sheep from the disease. In the protected groups CD4(+) memory interferon-?(+) T cells underwent an early expansion (p<0.05 when compared to unprotected groups), whilst memory CD8(+) Interferon-?(+) T cells increased in non-protected animals 7 days after infection (p<0.05). ??(+) Interferon-?(+) T cells reached peaks of expansion in infected and in two vaccinated groups thus indicating that these cells are not preferentially involved in protection or pathogenesis (p<0.05). Hereby we propose that the early activation of CD4(+) memory Interferon-?(+) T cells could be considered as a marker of protection from the disease as well as a tool to establish vaccine efficacy. PMID:23333193

Agnone, Annalisa; La Manna, Marco P; Loria, Guido R; Puleio, Roberto; Villari, Sara; Nicholas, Robin A J; Guggino, Giuliana; Sireci, Guido

2013-04-15

299

Targeting juvenile hormone metabolic genes in the Asian citrus psyllid (Diaphorina citri Kuwayama) as a strategy to reduce the spread of citrus greening disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Diaphorina citri Kuwayama, the Asian citrus psyllid (ACP), is a devastating citrus pest due to its transmission of a phloem-limited bacterial pathogen, Candidatus Liberibacter asiaticus, that causes citrus greening. Psyllid control is a major part of effective greening disease management, and our r...

300

One-Health Simulation Modelling: A Case Study of Influenza Spread between Human and Swine Populations using NAADSM.  

PubMed

The circulation of zoonotic influenza A viruses including pH1N1 2009 and H5N1 continue to present a constant threat to animal and human populations. Recently, an H3N2 variant spread from pigs to humans and between humans in limited numbers. Accordingly, this research investigated a range of scenarios of the transmission dynamics of pH1N1 2009 virus at the swine-human interface while accounting for different percentages of swine workers initially immune. Furthermore, the feasibility of using NAADSM (North American Animal Disease Spread Model) applied as a one-health simulation model was assessed. The study population included 488 swine herds and 29, 707 households of people within a county in Ontario, Canada. Households were categorized as follows: (i) rural households with swine workers, (ii) rural households without swine workers, and (iii) urban households without swine workers. Forty-eight scenarios were investigated, based on the combination of six scenarios around the transmissibility of the virus at the interface and four vaccination coverage levels of swine workers (0-60%), all under two settings of either swine or human origin of the virus. Outcomes were assessed in terms of stochastic 'die-out' fraction, size and time to peak epidemic day, overall size and duration of the outbreaks. The modelled outcomes indicated that minimizing influenza transmissibility at the interface and targeted vaccination of swine workers had significant beneficial effects. Our results indicate that NAADSM can be used as a framework to model the spread and control of contagious zoonotic diseases among animal and human populations, under certain simplifying assumptions. Further evaluation of the model is required. In addition to these specific findings, this study serves as a benchmark that can provide useful input to a future one-health influenza modelling studies. Some pertinent information gaps were also identified. Enhanced surveillance and the collection of high-quality information for more accurate parameterization of such models are encouraged. PMID:24661802

Dorjee, S; Revie, C W; Poljak, Z; McNab, W B; Sanchez, J

2014-03-24

301

Lyme Disease Transmission  

MedlinePLUS

... infected ticks. The blacklegged tick (or deer tick, Ixodes scapularis ) spreads the disease in the northeastern, mid- ... central United States, and the western blacklegged tick ( Ixodes pacificus ) spreads the disease on the Pacific Coast. ...

302

Spread like a wildfire--the omnipresence of porcine circovirus type 2 (PCV2) and its ever-expanding association with diseases in pigs.  

PubMed

The discovery of porcine circovirus type 2 (PCV2) in 1998 initiated intensive research on arguably the most economically important pathogen facing the global swine industry today. PCV2 infection is now widespread worldwide, and increasing numbers of disease conditions have been linked to PCV2 infection in pigs. In this special issue of Virus Research, leading experts in the field review the history, epidemiology, transmission, clinical and pathological features, immunology, pathogenesis, molecular biology and vaccine development of PCV2 and porcine circovirus associated disease (PCVAD). In addition, circovirus-like DNA sequences recently identified from humans and other animal species and their biological significances are also reviewed. The articles in this special issue identify gaps in current PCV2 research and offer insights for the direction of future research. PMID:22192532

Meng, Xiang-Jin

2012-03-01

303

The Relationship Between Increasing Sea-surface Temperature and the Northward Spread of Perkinsus marinus(Dermo) Disease Epizootics in Oysters  

NASA Astrophysics Data System (ADS)

From its initial discovery in the Gulf of Mexico in the late 1940s until 1990, Perkinsus marinus, the parasite responsible for Dermo disease in the eastern oyster, Crassostrea virginica, was rarely found north of Chesapeake Bay. In 1990-92, an apparent range extension of the parasite led to epizootic outbreaks of the disease over a 500 km range north of Chesapeake Bay. One of the hypotheses for the range extension argues that small, undetected numbers of parasites were already present in northern oysters as the result of repeated historical introductions, and that a sharp warming trend in 1990-92 stimulated the disease outbreak. This argument was based on trends in air temperature. The present study examined this hypothesis by analysing water temperatures, rather than air temperatures, for five stations located in areas affected by the recent epizootics. At all five stations, there was a strong increasing trend in winter sea-surface temperature (SST) between 1986 and 1991. At four of the five stations, there was a smaller increasing trend in winter temperatures after 1960. There were no consistent or obvious trends in summer (August) temperatures. In Delaware Bay, which has a 40 year history of monitoring for oyster diseases, occasional findings of P. marinusin oysters were correlated with warming episodes that were especially notable in the winter (February) record. Empirical orthogonal function (EOF) analysis showed that winter temperatures varied consistently at the stations examined and were associated with variations in P. marinusprevalence. Associations using EOF analysis with August temperatures were much weaker. The SST record is consistent with the hypothesis that increasing winter water temperatures have been important in the recent outbreak of P. marinusepizootics in the north-eastern U.S.A.

Cook, T.; Folli, M.; Klinck, J.; Ford, S.; Miller, J.

1998-04-01

304

Sea Floor Spreading I  

NSDL National Science Digital Library

In this introductory Excel tutorial (Activity I) students use Excel to explore the geodynamics model equation for ocean depth around a sea-floor spreading center. For students with no prior Excel experience.

Activity and Starting Point page by R.M. MacKay. Clark College, Physics and Meteorology.

305

Tan F. Wong: Spread Spectrum & CDMA 2. Intro. Spread Spectrum Introduction to Spread Spectrum  

E-print Network

Tan F. Wong: Spread Spectrum & CDMA 2. Intro. Spread Spectrum Chapter 2 Introduction to Spread Spectrum Communications As discussed in Chapter 0, a spread spectrum modulation produces a transmitted spectrum much wider than the minimum bandwidth required. There are many ways to generate spread spectrum

Wong, Tan F.

306

The correlation between the spread of metastases by level in the axillary nodes and disease-free survival in breast cancer. A multifactorial analysis.  

PubMed

Axillary lymph nodes were separated from 492 radical or modified radical mastectomies for primary breast cancer and examined according to their anatomical level corresponding to their position along the theoretical pathway of lymph drainage from the breast. The patterns of metastasis and the relationship between metastatized levels and disease-free survival were investigated to see whether complete axillary dissection is necessary for the staging and the planning of adjuvant therapy in breast cancer. Progressive involvement from level I (proximal) to level III (distal) was found in 206 specimens (80.8% of tumors with axillary metastases), while discontinuous or "skip" metastases were present in 49 (19.2%), including 38 (14.9%) with positive nodes at level II or III but not at level I. "Skip" metastasis was more frequent when fewer than four nodes were positive, and not related to either the size of the primary tumor or its location. The effect of age, menopausal status, tumor size, node status, number of positive nodes, anatomic level of axillary node involvement, estrogen and progesterone receptors, and adjuvant therapies on disease-free survival was evaluated using a multivariate proportional hazard model and life table analysis. This showed that disease-free survival was strongly related to the number of positive nodes (P less than 0.001), tumor size (P = 0.001) and level of node involvement (P = 0.01) as independent prognostic factors. Moreover, the subset of patients with four or more positive nodes and involvements of level III had a higher risk of recurrence (25% recurrence-free patients 5 years after mastectomy). The high frequency of "skip" metastases and the prognostic value of both the level of involvement and the number of metastatic nodes suggest that a complete axillary dissection is needed in the surgical management of breast cancer to obtain all the data useful in the planning of adjuvant therapy. PMID:3653201

Gaglia, P; Bussone, R; Caldarola, B; Lai, M; Jayme, A; Caldarola, L

1987-06-01

307

The role of international transport of equine semen on disease transmission.  

PubMed

Despite the numerous benefits of having the capability to transport semen internationally, there are serious potential ramifications if that semen is contaminated with a communicable disease. Bacteria: Many commensal bacteria colonize the exterior of the stallion penis and are not regarded as pathogenic. They may be cultured from an ejaculate. Alterations of the normal bacterial flora on the exterior genitalia may cause the growth of opportunistic bacteria such as Klebsiella pneumonia, Pseudomonas aeruginosa, Streptococcus zooepidemicus, which, if inseminated, may cause infertility in susceptible mares. Contagious equine metritis (CEM), a highly transmissible, true venereal disease of horses, is caused by the gram-negative coccobacillis, Taylorella equigenitalis. Even with the use of rigorous testing protocols, the current techniques used may not ensure accuracy of results. Viruses: Equine coital exanthema (equine herpes virus type 3; EHV-3) is a highly contagious virus that causes painful lesions on the stallion's penis and mare's vulva. Although it is primarily transmitted through coitus, infected fomites have also been implicated in its spread. Therefore, it is possible that the virus can potentially be transmitted to the ejaculate through penile contact with an artificial vagina or sleeve. Equine arteritis virus appears to be becoming more prevalent in recent years. The most common method of transmission is through respiratory disease, but the organism can also be shed in the semen of asymptomatic stallions. Equine infectious anemia virus has also been found to be present in the semen of an infected stallion, although no evidence exists at this time that there is venereal transmission of this disease. Protozoa: Dourine, caused by Trympanosoma equiperidum, is a venereal disease found only in Africa, South and Central America and the Middle East. Serological testing using complement fixation is recommended for diagnosis. Piroplasmosis, a disease caused by Babesia equi or by a less severe strain, Babesia caballi, has received a great deal of attention in recent years due to the increased transfer of horses between countries. It is considered to be enzootic in many areas of the southern US, and is found throughout the world. The protozoal agent is most often spread by ticks, but mechanical transmission has also been documented; therefore, there is concern for venereal transmission if blood from an infected horse contaminates the semen. PMID:11744267

Metcalf, E S

2001-12-01

308

Legionnaires' Disease  

MedlinePLUS

Legionnaires' disease is a type of pneumonia caused by bacteria. You usually get it by breathing in mist from ... spread from person to person. Symptoms of Legionnaires' disease include high fever, chills, a cough, and sometimes ...

309

Chagas Disease  

MedlinePLUS

Chagas disease is caused by a parasite. It is common in Latin America but not in the United States. ... nose, the bite wound or a cut. The disease can also spread through contaminated food, a blood ...

310

Fifth disease  

MedlinePLUS

Parvovirus B19; Erythema infectiosum; Slapped cheek rash ... Fifth disease is caused by human parvovirus B19. It often affects preschoolers or school-age children during the spring. The disease spreads through the fluids in the nose and ...

311

Qualitative assessment of the commodity risk for spread of foot-and-mouth disease associated with international trade in deboned beef.  

PubMed

The risk of importing foot-and-mouth disease virus (FMDV) restricts trade in livestock and their products from parts of the world where the virus is present. This reduces trade opportunities and investment in the livestock sector of many developing countries and constrains global food supply. This review focuses on the risks associated with trade in deboned beef (DB) from foot-and-mouth disease (FMD)-infected cattle, countries or zones. A definition of DB is provided along with a description of the procedures for its preparation within beef slaughtering operations. Evidence is reviewed for circumstances under which DB can be contaminated with FMDV, and a commodity risk factor approach is used to consider the mitigating efficacy of slaughterhouse procedures. A combination of pre-slaughter and slaughterhouse measures has enabled DB to be safely imported into FMD-free countries from countries that were not nationally or zonally FMD-free. Nevertheless, current evidence does not provide absolute assurance that abattoir procedures for producing DB can result, by themselves, in a commodity with a negligible risk of transmitting FMDV without complementary measures to reduce the likelihood of slaughtering infected cattle. The main areas of uncertainty are the amounts of residual FMDV-harbouring tissues within DB, and our understanding of what constitutes a safe level of contamination. More detailed guidance should be developed to specify the mitigating measures needed in support of the export of DB from regions that are not officially FMD-free. This will help to avoid differences in interpretation of what is needed that give rise to obstacles to trade. PMID:20569417

Paton, D J; Sinclair, M; Rodríguez, R

2010-06-01

312

Contagious Comments: What Was the Online Buzz About the 2011 Quebec Measles Outbreak?  

PubMed Central

Background Although interruption of endemic measles was achieved in the Americas in 2002, Quebec experienced an outbreak in 2011 of 776 reported cases; 80% of these individuals had not been fully vaccinated. We analyzed readers’ online responses to Canadian news articles regarding the outbreak to better understand public perceptions of measles and vaccination. Methods We searched Canadian online English and French news sites for articles posted between April 2011 and March 2012 containing the words “measles” and “Quebec”. We included articles that i) concerned the outbreak or related vaccination strategies; and ii) generated at least ten comments. Two English and two bilingual researchers coded the unedited comments, categorizing codes to allow themes to emerge. Results We analyzed 448 comments from 188 individuals, in response to three French articles and six English articles; 112 individuals expressed positive perceptions of measles vaccination (2.2 comments/person), 38 were negative (4.2 comments/person), 11 had mixed feelings (1.5 comments/person), and 27 expressed no opinion (1.1 comments/person). Vaccine-supportive themes involved the success of vaccination in preventing disease spread, societal responsibility to vaccinate for herd immunity, and refutation of the autism link. Those against measles vaccination felt it was a personal rather than societal choice, and conveyed a distrust of vaccine manufacturers, believing that measles infection is not only safe but safer than vaccination. Commenters with mixed feelings expressed uncertainty of the infection’s severity, and varied in support of all vaccines based on perceived risk/benefit ratios. Conclusion The anti-vaccine minority’s volume of comments translates to a disproportionately high representation on online boards. Public health messages should address concerns by emphasizing that immunization is always a personal choice in Canada, and that the pharmaceutical industry is strictly controlled. Illustrating the dangers of measles through personal stories, rather than scientific data only, may also serve to strengthen messaging. PMID:23691152

Pereira, Jennifer A.; Quach, Susan; Dao, Huy Hao; Kwong, Jeffrey C.; Deeks, Shelley L.; Crowcroft, Natasha S.; Quan, Sherman D.; Guay, Maryse

2013-01-01

313

First steps of spreading  

NASA Astrophysics Data System (ADS)

When a spherical liquid droplet is brought in contact with a solid it wets totally, it tends to spread on the solid because of the driving capillary force. On the other hand, inertia and viscosity both resist to the motion. We studied the spreading of spherical millimetric water droplets and we observed that the spreading successively follows two dynamical laws: the solid-liquid contact first increases as t^1/2, and later as t^1/10. We interpreted the first regime as an inertial one and found a quantitative agreement with a recent theory by Eggers, Lister and Stone for a similar problem, namely, the coalescence of drops of low viscosity. The second regime is viscous as shown earlier by Tanner and Cazabat. We therefore measured the duration of the inertial regime, as a function of both the droplet radius and the liquid viscosity.

Biance, Anne-Laure; Clanet, Christophe; Quere, David

2003-11-01

314

Lymphogenous spread of an intravascular bronchioloalveolar tumour  

Microsoft Academic Search

A 56-year-old lady with distinct clinical symptoms was found to have an intravascular bronchioloalveolar tumour. The aetiology and pathogenesis of this disease are unknown; both a bronchoalveolar and a vascular origin of the tumour are discussed in the literature. For the first time, lymphatic spread of tumour to the lymphatic nodes of the hili of the lungs was encountered.

H. J. C. Wenisch; M. Lulay

1980-01-01

315

Asymmetrically interacting spreading dynamics on complex layered networks  

PubMed Central

The spread of disease through a physical-contact network and the spread of information about the disease on a communication network are two intimately related dynamical processes. We investigate the asymmetrical interplay between the two types of spreading dynamics, each occurring on its own layer, by focusing on the two fundamental quantities underlying any spreading process: epidemic threshold and the final infection ratio. We find that an epidemic outbreak on the contact layer can induce an outbreak on the communication layer, and information spreading can effectively raise the epidemic threshold. When structural correlation exists between the two layers, the information threshold remains unchanged but the epidemic threshold can be enhanced, making the contact layer more resilient to epidemic outbreak. We develop a physical theory to understand the intricate interplay between the two types of spreading dynamics. PMID:24872257

Wang, Wei; Tang, Ming; Yang, Hui; Younghae Do; Lai, Ying-Cheng; Lee, GyuWon

2014-01-01

316

Prevalence of contagious mastitis pathogens in bulk tank milk in Québec  

PubMed Central

The objective of this study was to estimate the prevalence of mycoplasma, Staphylococcus aureus, and Streptococcus agalactiae in bulk tank milk (BTM) in Québec dairy herds. BTM was sampled 3 times a month in 117 randomly selected dairy herds. Samples were submitted for S. aureus, S. agalactiae, and mycoplasma and for direct mycoplasma detection by polymerase chain reaction (PCR). Mycoplasma spp. was identified at least once in 3 herds (2.6%) by primary culture and/or PCR and in 4 herds (3.4%) by enrichment culture and/or PCR. Staphylococcus aureus was isolated at least once in 99 (84.6%) and 112 (95.7%) herds in primary culture and after enrichment, respectively. Streptococcus agalactiae was isolated at least once in 9 (7.7%) and 10 (8.6%) herds in primary culture and after enrichment, respectively. Herd prevalence of mycoplasma was similar to that previously reported in Canada. Staphylococcus aureus is still by far the most important contagious mastitis pathogen. PMID:23543925

Francoz, David; Bergeron, Luc; Nadeau, Marie; Beauchamp, Guy

2012-01-01

317

Spread spectrum for commercial communications  

Microsoft Academic Search

The authors describe how spread spectrum operates and explain why the FCC has allocated several spectral bands for spread spectrum. They examine what is wrong with the spectrum allocations the way they are now. They show who is using and will use spread spectrum and why. In particular, they discuss the use of spread spectrum for mobile cellular communications: the

D. L. Schilling; L. B. Milstein; R. L. Pickholtz; M. Kullback; F. Miller

1991-01-01

318

Spatiotemporal Phylogenetic Analysis and Molecular Characterisation of Infectious Bursal Disease Viruses Based on the VP2 Hyper-Variable Region  

PubMed Central

Background Infectious bursal disease is a highly contagious and acute viral disease caused by the infectious bursal disease virus (IBDV); it affects all major poultry producing areas of the world. The current study was designed to rigorously measure the global phylogeographic dynamics of IBDV strains to gain insight into viral population expansion as well as the emergence, spread and pattern of the geographical structure of very virulent IBDV (vvIBDV) strains. Methodology/Principal Findings Sequences of the hyper-variable region of the VP2 (HVR-VP2) gene from IBDV strains isolated from diverse geographic locations were obtained from the GenBank database; Cuban sequences were obtained in the current work. All sequences were analysed by Bayesian phylogeographic analysis, implemented in the Bayesian Evolutionary Analysis Sampling Trees (BEAST), Bayesian Tip-association Significance testing (BaTS) and Spatial Phylogenetic Reconstruction of Evolutionary Dynamics (SPREAD) software packages. Selection pressure on the HVR-VP2 was also assessed. The phylogeographic association-trait analysis showed that viruses sampled from individual countries tend to cluster together, suggesting a geographic pattern for IBDV strains. Spatial analysis from this study revealed that strains carrying sequences that were linked to increased virulence of IBDV appeared in Iran in 1981 and spread to Western Europe (Belgium) in 1987, Africa (Egypt) around 1990, East Asia (China and Japan) in 1993, the Caribbean Region (Cuba) by 1995 and South America (Brazil) around 2000. Selection pressure analysis showed that several codons in the HVR-VP2 region were under purifying selection. Conclusions/Significance To our knowledge, this work is the first study applying the Bayesian phylogeographic reconstruction approach to analyse the emergence and spread of vvIBDV strains worldwide. PMID:23805195

Dolz, Roser; Valle, Rosa; Perera, Carmen L.; Bertran, Kateri; Frías, Maria T.; Majó, Natàlia; Ganges, Llilianne; Pérez, Lester J.

2013-01-01

319

Emergence of blind areas in information spreading.  

PubMed

Recently, contagion-based (disease, information, etc.) spreading on social networks has been extensively studied. In this paper, other than traditional full interaction, we propose a partial interaction based spreading model, considering that the informed individuals would transmit information to only a certain fraction of their neighbors due to the transmission ability in real-world social networks. Simulation results on three representative networks (BA, ER, WS) indicate that the spreading efficiency is highly correlated with the network heterogeneity. In addition, a special phenomenon, namely Information Blind Areas where the network is separated by several information-unreachable clusters, will emerge from the spreading process. Furthermore, we also find that the size distribution of such information blind areas obeys power-law-like distribution, which has very similar exponent with that of site percolation. Detailed analyses show that the critical value is decreasing along with the network heterogeneity for the spreading process, which is complete the contrary to that of random selection. Moreover, the critical value in the latter process is also larger than that of the former for the same network. Those findings might shed some lights in in-depth understanding the effect of network properties on information spreading. PMID:24763456

Zhang, Zi-Ke; Zhang, Chu-Xu; Han, Xiao-Pu; Liu, Chuang

2014-01-01

320

Molecular Analysis of Spring Viraemia of Carp Virus in China: A Fatal Aquatic Viral Disease that Might Spread in East Asian  

PubMed Central

Spring viraemia of carp (SVC) is a fatal viral disease for cyprinid fish, which is caused by spring viraemia of carp virus (SVCV). To date, no SVC outbreak has been reported in China. Between 1998 and 2002, outbreaks of SVC were reported in ornamental and wild fish in Europe and America, imported from multiple sources including China. Based on phylogenetic analysis, the viral strain isolated from America was shown to be originated from Asia. These outbreaks not only resulted in huge economic losses, but also raise an interesting question as to whether SVCV really exists in China and if so, is it responsible for SVC outbreaks? From 2002 to 2006, we screened 6700 samples from ornamental fish farms using the cell culture method of the Office International des Epizooties (OIE), and further verified the presence of SVCV by ELISA and real-time quantitative RT-PCR. Two infected samples were found and the complete genome of SVCV was sequenced from one of the isolates, termed SVCV-C1. Several unique hallmarks of SVCV-C1 were identified, including six amino acid (KSLANA) insertion in the viral RNA-dependent RNA polymerase (L) protein and ten nucleotide insertion in the region between glycoprotein (G) and L genes in European SVCV strains. Phylogenetic tree analysis of the full-length G protein of selected SVCV isolates from the United Kingdom and United States revealed that G proteins could be classified into Ia and Id sub genogroups. The Ia sub genogroup can be further divided into newly defined sub genogroups Ia-A and Ia-B. The isolates derived from the United States and China including the SVCV-C1 belongs to in the Ia-A sub genogroup. The SVCV-C1 G protein shares more than 99% homology with the G proteins of the SVCV strains from England and the United States, making it difficult to compare their pathogenicity. Comparison of the predicted three-dimensional structure based on the published G protein sequences from five SVCV strains revealed that the main differences were in the loops of the pleckstrin homology domains. Since SVCV is highly pathogenic, we speculate that SVC may therefore pose a serious threat to farmed cyprinid fish in China. PMID:19623265

Jiang, Yi Nan; Zhang, Ting; Xia, Chun

2009-01-01

321

25 CFR 168.15 - Control of livestock diseases and parasites.  

Code of Federal Regulations, 2011 CFR

...false Control of livestock diseases and parasites. 168.15 Section 168.15 Indians...15 Control of livestock diseases and parasites. Whenever livestock within the Hopi...with contagious or infectious diseases or parasites or have been exposed thereto, such...

2011-04-01

322

25 CFR 700.723 - Control of livestock disease and parasites.  

Code of Federal Regulations, 2012 CFR

...false Control of livestock disease and parasites. 700.723 Section 700.723 Indians...723 Control of livestock disease and parasites. Whenever livestock within the New...with contagious or infectious disease or parasites or have been exposed thereto, such...

2012-04-01

323

25 CFR 168.15 - Control of livestock diseases and parasites.  

Code of Federal Regulations, 2014 CFR

...false Control of livestock diseases and parasites. 168.15 Section 168.15 Indians...15 Control of livestock diseases and parasites. Whenever livestock within the Hopi...with contagious or infectious diseases or parasites or have been exposed thereto, such...

2014-04-01

324

25 CFR 168.15 - Control of livestock diseases and parasites.  

Code of Federal Regulations, 2010 CFR

...false Control of livestock diseases and parasites. 168.15 Section 168.15 Indians...15 Control of livestock diseases and parasites. Whenever livestock within the Hopi...with contagious or infectious diseases or parasites or have been exposed thereto, such...

2010-04-01

325

25 CFR 700.723 - Control of livestock disease and parasites.  

Code of Federal Regulations, 2014 CFR

...false Control of livestock disease and parasites. 700.723 Section 700.723 Indians...723 Control of livestock disease and parasites. Whenever livestock within the New...with contagious or infectious disease or parasites or have been exposed thereto, such...

2014-04-01

326

25 CFR 700.723 - Control of livestock disease and parasites.  

Code of Federal Regulations, 2013 CFR

...false Control of livestock disease and parasites. 700.723 Section 700.723 Indians...723 Control of livestock disease and parasites. Whenever livestock within the New...with contagious or infectious disease or parasites or have been exposed thereto, such...

2013-04-01

327

25 CFR 168.15 - Control of livestock diseases and parasites.  

Code of Federal Regulations, 2012 CFR

...true Control of livestock diseases and parasites. 168.15 Section 168.15 Indians...15 Control of livestock diseases and parasites. Whenever livestock within the Hopi...with contagious or infectious diseases or parasites or have been exposed thereto, such...

2012-04-01

328

25 CFR 168.15 - Control of livestock diseases and parasites.  

Code of Federal Regulations, 2013 CFR

...false Control of livestock diseases and parasites. 168.15 Section 168.15 Indians...15 Control of livestock diseases and parasites. Whenever livestock within the Hopi...with contagious or infectious diseases or parasites or have been exposed thereto, such...

2013-04-01

329

25 CFR 700.723 - Control of livestock disease and parasites.  

Code of Federal Regulations, 2011 CFR

...false Control of livestock disease and parasites. 700.723 Section 700.723 Indians...723 Control of livestock disease and parasites. Whenever livestock within the New...with contagious or infectious disease or parasites or have been exposed thereto, such...

2011-04-01

330

25 CFR 700.723 - Control of livestock disease and parasites.  

Code of Federal Regulations, 2010 CFR

...false Control of livestock disease and parasites. 700.723 Section 700.723 Indians...723 Control of livestock disease and parasites. Whenever livestock within the New...with contagious or infectious disease or parasites or have been exposed thereto, such...

2010-04-01

331

Genetics and Vaccine Efficacy: Host Genetic Variation Affecting Marek's Disease Vaccine Efficacy in White Leghorn Chickens  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek’s disease (MD) is a T cell lymphoma disease of domestic chickens induced by Marek’s disease viruses (MDV), a naturally oncogenic and highly contagious cell-associated alpha-herpesvirus. Earlier reports have shown that the major histocompatibility complex (MHC) haplotype as well as non-MHC gene...

332

Newcastle Disease: Progress and gaps in the development of vaccines and diagnostic tools  

Technology Transfer Automated Retrieval System (TEKTRAN)

Newcastle disease (ND) is a contagious disease of birds that can have severe economic consequences for any poultry producer, including a serious impact on the international trade of poultry and eggs. Newcastle disease virus (NDV) isolates are also called avian paramyxovirus serotype-1 isolates, but ...

333

Effectively controlling infectious diseases requires quantitative comparisons of quarantine, infection control  

E-print Network

disease, such as severe acute respira- tory syndrome, and a moderately contagious disease syndrome (SARS) (1), avian influenza (2), monkeypox infection (3), West Nile virus disease (4), mad cow in a community, be it a hospital, school, or city (12­21). This approach differs from fully mixed compart- mental

Myers, Lauren Ancel

334

LincRNAs in CD4+ T cells and Marek’s disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek’s disease (MD) is a T cell lymphoma of domestic chickens induced by Marek’s disease virus (MDV) and causes severe economic loss. The MDV is a naturally oncogenic, highly contagious, and cell associated alpha-herpesvirus. For a long time, resistance to MD and disease risk have long been thought...

335

NEW APPROACHES TO CONTROL FOOT-AND-MOUTH DISEASE: ANTIVIRALS AND NOVEL VACCINES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-Mouth Disease (FMD) is a highly contagious viral-induced disease of cloven-hoofed animals that results in serious economic consequences in affected countries that have a significant international livestock trade. Currently, disease control measures include inhibition of susceptible animal ...

336

Foot-and-mouth disease in Asiatic black bears (Ursus thibetanus).  

PubMed

Foot-and-mouth disease (FMD) is a highly contagious, debilitating, and globally significant viral disease typically affecting cloven-hoofed hosts. The diagnosis of FMD in bears in Vietnam is described. The current study describes a confirmed case of FMD in a bear species, and the clinical signs compatible with FMD in a Malayan sun bear. Thirteen Asiatic black bears (Ursus thibetanus) and 1 Malayan sun bear (Helarctos malayanus) were apparently affected. In August 2011, an adult bear became lethargic, and developed footpad vesicles. Over 15 days, 14 out of 17 bears developed similar signs; the remaining 3 co-housed bears and another 57 resident bears did not. All affected bears developed vesicles on all footpads, and most were lethargic for 24-48 hr. Nasal and oral lesions were noted in 6 and 3 cases, respectively. Within 1 month, all looked normal. Foot-and-mouth disease virus (FMDV) was detected by reverse transcription polymerase chain reaction, classified as serotype O, and isolated by virus isolation techniques. Phylogenetic analysis demonstrated clustering of 3 bear isolates, in a branch distinct from other FMDV type O isolates. The outbreak likely occurred due to indirect contact with livestock, and was facilitated by the high density of captive bears. It showed that Asiatic black bears are capable of contracting FMDV and developing clinical disease, and that the virus spreads easily between bears in close contact. PMID:25135011

Officer, Kirsty; Lan, Nguyen Thi; Wicker, Leanne; Hoa, Nguyen Thi; Weegenaar, Annemarie; Robinson, Jill; Ryoji, Yamaguchi; Loukopoulos, Panayiotis

2014-09-01

337

Transgenic banana expressing Pflp gene confers enhanced resistance to Xanthomonas wilt disease.  

PubMed

Banana Xanthomonas wilt (BXW), caused by Xanthomonas campestris pv. musacearum, is one of the most important diseases of banana (Musa sp.) and currently considered as the biggest threat to banana production in Great Lakes region of East and Central Africa. The pathogen is highly contagious and its spread has endangered the livelihood of millions of farmers who rely on banana for food and income. The development of disease resistant banana cultivars remains a high priority since farmers are reluctant to employ labor-intensive disease control measures and there is no host plant resistance among banana cultivars. In this study, we demonstrate that BXW can be efficiently controlled using transgenic technology. Transgenic bananas expressing the plant ferredoxin-like protein (Pflp) gene under the regulation of the constitutive CaMV35S promoter were generated using embryogenic cell suspensions of banana. These transgenic lines were characterized by molecular analysis. After challenge with X. campestris pv. musacearum transgenic lines showed high resistance. About 67% of transgenic lines evaluated were completely resistant to BXW. These transgenic lines did not show any disease symptoms after artificial inoculation of in vitro plants under laboratory conditions as well as potted plants in the screen-house, whereas non-transgenic control plants showed severe symptoms resulting in complete wilting. This study confirms that expression of the Pflp gene in banana results in enhanced resistance to BXW. This transgenic technology can provide a timely solution to the BXW pandemic. PMID:22101927

Namukwaya, B; Tripathi, L; Tripathi, J N; Arinaitwe, G; Mukasa, S B; Tushemereirwe, W K

2012-08-01

338

Alone in the Crowd: The Structure and Spread of Loneliness in a Large Social Network  

PubMed Central

The discrepancy between an individual’s loneliness and the number of connections in a social network is well documented, yet little is known about the placement of loneliness within, or the spread of loneliness through, social networks. We use network linkage data from the population-based Framingham Heart Study to trace the topography of loneliness in people’s social networks and the path through which loneliness spreads through these networks. Results indicated that loneliness occurs in clusters, extends up to three degrees of separation, is disproportionately represented at the periphery of social networks, and spreads through a contagious process. The spread of loneliness was found to be stronger than the spread of perceived social connections, stronger for friends than family members, and stronger for women than for men. The results advance our understanding of the broad social forces that drive loneliness and suggest that efforts to reduce loneliness in our society may benefit by aggressively targeting the people in the periphery to help repair their social networks and to create a protective barrier against loneliness that can keep the whole network from unraveling. PMID:19968414

Cacioppo, John T.; Fowler, James H.; Christakis, Nicholas A.

2009-01-01

339

Spread of an SIS epidemic in a network $ A. Shausana,  

E-print Network

Spread of an SIS epidemic in a network $ A. Shausana, , R. McVinisha , P.K. Polletta a School a Markov chain model for the spread of a disease with Suscep- tible­Infective­Susceptible (SIS) dynamics to the Markov chain model. Keywords: Density­dependent Markov process, metapopulation network, mobility, SIS

Pollett, Phil

340

Analyzing the spread of active worms over VANET  

Microsoft Academic Search

This paper investigates the parameters governing the spread of active worms over VANET. To this end, we first define the average degree of a VANET node using freeway traffic parameters. The spread of a worm in congested and low-density traffic scenarios is modeled using a stochastic model of infectious disease. Analysis is provided for preemptive and interactive patching scenarios.

Syed A. Khayam; Hayder Radha

2004-01-01

341

Response Strategies in Deterministic Models of Spread: Vaccination and Firefighting  

E-print Network

38 Chapter 3 Response Strategies in Deterministic Models of Spread: Vaccination and Firefighting 3 are occurring. This is particularly relevant in disease spread processes, where vaccinations and quarantines. The response allowed is only a limited number of vaccinations of non-infected vertices. Specifically, let G

Hartke, Stephen

342

High-Level Association of Bovine Digital Dermatitis Treponema spp. with Contagious Ovine Digital Dermatitis Lesions and Presence of Fusobacterium necrophorum and Dichelobacter nodosus.  

PubMed

Contagious ovine digital dermatitis (CODD) is an important foot disease in sheep, with significant animal welfare and economic implications. It is thought that CODD emerged from bovine digital dermatitis (BDD) via treponemal bacteria. With wildlife species such as elk now suffering a CODD-like disease, it is imperative to clarify these disease etiologies. A large investigation into treponemal association with CODD is warranted. CODD lesions (n = 58) and healthy sheep foot tissues (n = 56) were analyzed by PCR for the three BDD-associated Treponema phylogroups and two other lameness-associated bacteria, Dichelobacter nodosus and Fusobacterium necrophorum. Spirochete culture was also attempted on CODD lesions. "Treponema medium/Treponema vincentii-like," "Treponema phagedenis-like," and Treponema pedis spirochetes were identified in 39/58 (67%), 49/58 (85%), and 41/58 (71%) of CODD lesions, respectively. One or more BDD-associated Treponema phylogroups were detected in 100% of CODD lesions. Healthy foot tissues did not amplify BDD-associated Treponema phylogroup DNA. D. nodosus and F. necrophorum were present in 34/58 (59%) and 41/58 (71%) of CODD lesions and 22/56 (39%) and 5/56 (9%) of healthy foot tissues, respectively. Thirty-two spirochetes were isolated from CODD lesions, with representatives clustering with, and indistinguishable from, each of the three BDD-associated Treponema phylogroups based on 16S rRNA gene comparisons. This study for the first time demonstrates a high-level association for BDD treponeme phylogroups in CODD and their absence from healthy tissues, supporting the hypothesis that BDD treponemes play a primary causative role in CODD and confirming that the specific PCR assays are an effective differential diagnostic tool for CODD. PMID:25740778

Sullivan, L E; Clegg, S R; Angell, J W; Newbrook, K; Blowey, R W; Carter, S D; Bell, J; Duncan, J S; Grove-White, D H; Murray, R D; Evans, N J

2015-05-01

343

The role of transnational mobility in the local spread of mosquito-borne disease: Measuring the determinants of spatial-temporal lags of imported dengue cases initiating indigenous epidemics in Taiwan  

NASA Astrophysics Data System (ADS)

Dengue fever is one of the world's most widely spread mosquito-borne diseases. International travelers who acquire dengue infection are important routes for virus transmission from one country to another one. Previous studies have shown that imported dengue cases are able to initiate indigenous epidemics when appropriate weather conditions are present. However, the spatial-temporal associations between imported cases and indigenous epidemics in areas with different social-economic conditions are still unclear. This study investigated determinants of spatial-temporal lags of imported dengue cases who initiated indigenous epidemics from 2003 to 2012 in Taiwan. The quantile regression is used to explore the associations between spatial-temporal lags of imported cases and social-economic indicators with geographic heterogeneity. Our results indicated that imported cases in April and May have statistically significant contribution to initiate indigenous epidemics. Areas with high population density and low average income have significant risk of being imported virus from other areas. However, the areas with imported cases are not significant transmission risk. The results imply that imported cases reported in early summer may be an early-warning indicator of indigenous epidemics. Local demographic and economic conditions, rather than imported cases, may determine the areas with the risk of indigenous epidemics.

Wen, Tzai-Hung

2014-05-01

344

Chimpanzees show a developmental increase in susceptibility to contagious yawning: a test of the effect of ontogeny and emotional closeness on yawn contagion.  

PubMed

Contagious yawning has been reported for humans, dogs and several non-human primate species, and associated with empathy in humans and other primates. Still, the function, development and underlying mechanisms of contagious yawning remain unclear. Humans and dogs show a developmental increase in susceptibility to yawn contagion, with children showing an increase around the age of four, when also empathy-related behaviours and accurate identification of others' emotions begin to clearly evince. Explicit tests of yawn contagion in non-human apes have only involved adult individuals and examined the existence of conspecific yawn contagion. Here we report the first study of heterospecific contagious yawning in primates, and the ontogeny of susceptibility thereto in chimpanzees, Pan troglodytes verus. We examined whether emotional closeness, defined as attachment history with the yawning model, affected the strength of contagion, and compared the contagiousness of yawning to nose-wiping. Thirty-three orphaned chimpanzees observed an unfamiliar and familiar human (their surrogate human mother) yawn, gape and nose-wipe. Yawning, but not nose-wiping, was contagious for juvenile chimpanzees, while infants were immune to contagion. Like humans and dogs, chimpanzees are subject to a developmental trend in susceptibility to contagious yawning, and respond to heterospecific yawn stimuli. Emotional closeness with the model did not affect contagion. The familiarity-biased social modulatory effect on yawn contagion previously found among some adult primates, seem to only emerge later in development, or be limited to interactions with conspecifics. The influence of the 'chameleon effect', targeted vs. generalised empathy, perspective-taking and visual attention on contagious yawning is discussed. PMID:24146848

Madsen, Elainie Alenkær; Persson, Tomas; Sayehli, Susan; Lenninger, Sara; Sonesson, Göran

2013-01-01

345

Bird Flu Spreads Across China, Posing Threat to People  

MedlinePLUS

... sharing features on this page, please enable JavaScript. Bird Flu Spreads Across China, Posing Threat to People: ... Related MedlinePlus Pages Animal Diseases and Your Health Bird Flu International Health WEDNESDAY, March 11, 2015 (HealthDay ...

346

Foot-and-mouth disease: susceptibility of domestic poultry and free-living birds to infection and to disease--a review of the historical and current literature concerning the role of birds in spread of foot-and-mouth disease viruses.  

PubMed

Ruminants and pigs are the dominant natural hosts of food-and-mouth disease (FMD) viruses. Approximately 70 additional mammalian species are found to be susceptible under natural or experimental conditions. Reptilia, amphibia, and fish are probably naturally resistant to infection. According to the reviewed literature, domestic birds (chickens, turkeys, guinea fowl, ducks and geese) have been experimentally infected with some strains of FMD viruses and may develop lesions suggestive of FMD such as vesicular lesions on the comb, wattles, eye lids, and feet. Since chickens are to some extent coprophagous, chickens get infected by ingestion of virus under conditions of natural exposure or their plumage gets contaminated in an infectious environment. Thus, domestic birds kept in free-run systems may serve as virus vectors for short distances. Free-living birds, especially starlings (Sturnus vulgaris), sea gulls (Larus canus), house-sparrows (Passer domesticus) have been successfully experimentally infected and developed vesicular lesions on the skin and mucosal membranes of the mouth. During epizootics of FMD the plumage of these free-living birds can be contaminated with FMD viruses and the virus is spread over long distances during migration periods in spring and autumn. Thus migrating birds may assume an active role in long distance dissemination of FMD viruses. PMID:12395578

Kaleta, E F

2002-09-01

347

Prevent the Spread of Zoonotic Diseases (Spanish)  

E-print Network

Tome precauciones al manejar o cuidar de los animales Al dar cuidado rutinario a los animales observe las siguientes precauciones para evitar la transmisi?n de g?rmenes que causan enfermedad. Use ropa y equipo de protecci?n personal La ropa, las... botas y el equipo de protecci?n personal pueden reducir el riesgo de transmitir enfermedades contagiosas a otros animales o personas. Use botas y un conjunto de ropa protectora que usa ?nicamente ? cuando maneja o cuida de los animales. Ejemplos...

Pena, Josefa

2008-11-10

348

Prevent the Spread of Zoonotic Diseases  

E-print Network

, and under ? jewelry. Wash for at least 15 seconds to remove germs.? When warm water is not available, wash for a longer time.? When soap and water are not available, use an alcohol-based hand ? sanitizer. Practice Food Safety Do not consume unpasteurized...

Pena, Josefa

2008-11-10

349

Hybrid spread spectrum radio system  

DOEpatents

Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

Smith, Stephen F. (London, TN) [London, TN; Dress, William B. (Camas, WA) [Camas, WA

2010-02-09

350

ANALYSIS OF FOOT-AND MOUTH DISEASE VIRUS RECEPTOR EXPRESSION IN TISSUES FROM NORMAL AND INFECTED CATTLE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals principally affecting cattle, pigs, sheep and goats. One of the prominent characteristics of the disease are the lesions that form in the keratinocyte-containing stratum spinosum layer of the epithelium. It ...

351

25 CFR 161.206 - What must a permittee do to protect livestock from exposure to disease?  

Code of Federal Regulations, 2014 CFR

...do to protect livestock from exposure to disease? 161.206 Section 161.206 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

2014-04-01

352

25 CFR 166.310 - What must a permittee do to protect livestock from exposure to disease?  

Code of Federal Regulations, 2010 CFR

...do to protect livestock from exposure to disease? 166.310 Section 166.310 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

2010-04-01

353

25 CFR 161.206 - What must a permittee do to protect livestock from exposure to disease?  

Code of Federal Regulations, 2013 CFR

...do to protect livestock from exposure to disease? 161.206 Section 161.206 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

2013-04-01

354

25 CFR 166.310 - What must a permittee do to protect livestock from exposure to disease?  

Code of Federal Regulations, 2012 CFR

...do to protect livestock from exposure to disease? 166.310 Section 166.310 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

2012-04-01

355

25 CFR 166.310 - What must a permittee do to protect livestock from exposure to disease?  

Code of Federal Regulations, 2013 CFR

...do to protect livestock from exposure to disease? 166.310 Section 166.310 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

2013-04-01

356

25 CFR 161.206 - What must a permittee do to protect livestock from exposure to disease?  

Code of Federal Regulations, 2011 CFR

...do to protect livestock from exposure to disease? 161.206 Section 161.206 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

2011-04-01

357

25 CFR 161.206 - What must a permittee do to protect livestock from exposure to disease?  

Code of Federal Regulations, 2010 CFR

...do to protect livestock from exposure to disease? 161.206 Section 161.206 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

2010-04-01

358

25 CFR 166.310 - What must a permittee do to protect livestock from exposure to disease?  

Code of Federal Regulations, 2011 CFR

...do to protect livestock from exposure to disease? 166.310 Section 166.310 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

2011-04-01

359

25 CFR 166.310 - What must a permittee do to protect livestock from exposure to disease?  

Code of Federal Regulations, 2014 CFR

...do to protect livestock from exposure to disease? 166.310 Section 166.310 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

2014-04-01

360

25 CFR 161.206 - What must a permittee do to protect livestock from exposure to disease?  

Code of Federal Regulations, 2012 CFR

...do to protect livestock from exposure to disease? 161.206 Section 161.206 Indians...do to protect livestock from exposure to disease? In accordance with applicable law...infected with contagious or infectious diseases; and (c) Restrict the movement...

2012-04-01

361

Evolved Disease-Avoidance Processes and Contemporary Anti-Social Behavior: Prejudicial Attitudes and Avoidance of People with Physical Disabilities  

Microsoft Academic Search

Drawing on evolutionary psychological logic, we describe a model that links evolved mechanisms of disease-avoidance to contemporary prejudices against individuals with physical disabilities. Because contagious diseases were often accompanied by anomalous physical features, humans plausibly evolved psychological mechanisms that respond heuristically to the perception of these features, triggering specific emotions (disgust, anxiety), cognitions (negative attitudes), and behaviors (avoidance). This disease-avoidance

Justin H. Park; Jason Faulkner; Mark Schaller

2003-01-01

362

Characterization of Newcastle disease virus isolated from cormorant and gull species in the United States in 2010  

Technology Transfer Automated Retrieval System (TEKTRAN)

Newcastle disease virus (NDV), a member of the genus Avulavirus of the family Paramyxoviridae, is the causative agent of Newcastle disease (ND) a highly contagious disease that affects many species of birds and which frequently causes significant economic losses to the poultry industry worldwide. V...

363

Differentially Expressed Genes in Bordetella pertussis Strains Belonging to a Lineage Which Recently Spread Globally  

PubMed Central

Pertussis is a highly contagious, acute respiratory disease in humans caused by the Gram-negative pathogen Bordetella pertussis. Pertussis has resurged in the face of intensive vaccination and this has coincided with the emergence of strains carrying a particular allele for the pertussis toxin promoter, ptxP3, which is associated with higher levels of pertussis toxin (Ptx) production. Within 10 to 20 years, ptxP3 strains have nearly completely replaced the previously dominant ptxP1 strains resulting in a worldwide selective sweep. In order to identify B. pertussis genes associated with the selective sweep, we compared the expression of genes in ptxP1 and ptxP3 strains that are under control of the Bordetella master virulence regulatory locus (bvgASR). The BvgAS proteins comprise a two component sensory transduction system which is regulated by temperature, nicotinic acid and sulfate. By increasing the sulfate concentration, it is possible to change the phase of B. pertussis from virulent to avirulent. Until recently, the only distinctive phenotype of ptxP3 strains was a higher Ptx production. Here we identify additional phenotypic differences between ptxP1 and ptxP3 strains which may have contributed to its global spread by comparing global transcriptional responses under sulfate-modulating conditions. We show that ptxP3 strains are less sensitive to sulfate-mediated gene suppression, resulting in an increased production of the vaccine antigens pertactin (Prn) and Ptx and a number of other virulence genes, including a type III secretion toxin, Vag8, a protein involved in complement resistance, and lpxE involved in lipid A modification. Furthermore, enhanced expression of the vaccine antigens Ptx and Prn by ptxP3 strains was confirmed at the protein level. Identification of genes differentially expressed between ptxP1 and ptxP3 strains may elucidate how B. pertussis has adapted to vaccination and allow the improvement of pertussis vaccines by identifying novel vaccine candidates. PMID:24416242

de Gouw, Daan; Hermans, Peter W. M.; Bootsma, Hester J.; Zomer, Aldert; Heuvelman, Kees; Diavatopoulos, Dimitri A.; Mooi, Frits R.

2014-01-01

364

How the devil facial tumor disease escapes host immune responses  

PubMed Central

The devil facial tumor disease (DFTD) is a contagious cancer that has recently emerged among Tasmanian devils, rapidly decimating the population. We have recently discovered that DFTD cells lose the expression MHC molecules on the cell surface, explaining how this tumor avoids recognition by host CD8+ T cells. PMID:24083079

Siddle, Hannah V; Kaufman, Jim

2013-01-01

365

Illusory spreading of watercolor  

PubMed Central

The watercolor effect (WCE) is a phenomenon of long-range color assimilation occurring when a dark chromatic contour delineating a figure is flanked on the inside by a brighter chromatic contour; the brighter color spreads into the entire enclosed area. Here, we determined the optimal chromatic parameters and the cone signals supporting the WCE. To that end, we quantified the effect of color assimilation using hue cancellation as a function of hue, colorimetric purity, and cone modulation of inducing contours. When the inner and outer contours had chromaticities that were in opposite directions in color space, a stronger WCE was obtained as compared with other color directions. Additionally, equal colorimetric purity between the outer and inner contours was necessary to obtain a large effect compared with conditions in which the contours differed in colorimetric purity. However, there was no further increase in the magnitude of the effect when the colorimetric purity increased beyond a value corresponding to an equal vector length between the inner and outer contours. Finally, L–M-cone-modulated WCE was perceptually stronger than S-cone-modulated WCE for our conditions. This last result demonstrates that both L–M-cone and S-cone pathways are important for watercolor spreading. Our data suggest that the WCE depends critically upon the particular spatiochromatic arrangement in the display, with the relative chromatic contrast between the inducing contours being particularly important. PMID:16881793

Devinck, Frédéric; Hardy, Joseph L.; Delahunt, Peter B.; Spillmann, Lothar; Werner, John S.

2008-01-01

366

The Spread of Inequality  

PubMed Central

The causes of socioeconomic inequality have been debated since the time of Plato. Many reasons for the development of stratification have been proposed, from the need for hierarchical control over large-scale irrigation systems to the accumulation of small differences in wealth over time via inheritance processes. However, none of these explains how unequal societies came to completely displace egalitarian cultural norms over time. Our study models demographic consequences associated with the unequal distribution of resources in stratified societies. Agent-based simulation results show that in constant environments, unequal access to resources can be demographically destabilizing, resulting in the outward migration and spread of such societies even when population size is relatively small. In variable environments, stratified societies spread more and are also better able to survive resource shortages by sequestering mortality in the lower classes. The predictions of our simulation are provided modest support by a range of existing empirical studies. In short, the fact that stratified societies today vastly outnumber egalitarian societies may not be due to the transformation of egalitarian norms and structures, but may instead reflect the more rapid migration of stratified societies and consequent conquest or displacement of egalitarian societies over time. PMID:21957457

Rogers, Deborah S.; Deshpande, Omkar; Feldman, Marcus W.

2011-01-01

367

Tumor-activated protein promotes cancer spread  

Cancer.gov

Researchers at the University of California, San Diego School of Medicine and UC San Diego Moores Cancer Center report that cancers physically alter cells in the lymphatic system – a network of vessels that transports and stores immune cells throughout the body – to promote the spread of disease, a process called metastasis. The findings are published in this week’s online Early Edition of the Proceedings of the National Academy of Sciences.

368

Smallpox  

MedlinePLUS

Smallpox is a serious disease that is easily passed from person to person (contagious). It is caused ... Smallpox spreads from one person to another from saliva droplets. It may also be spread from bed ...

369

Tan F. Wong: Spread Spectrum & CDMA 3. Spreading Sequences Spreading Sequences  

E-print Network

of the spread spectrum signal in Chapter 2, we model the sequence elements as iid random variables. Based to approximate random sequences so that we are actually spreading the spectrum of the data signal. This explains # ; (3.3) where T = NT c 1 is the common period of the spreading signals and #28; 2 [0; T ) 2 . We

Wong, Tan F.

370

Did ice-age bovids spread tuberculosis?  

NASA Astrophysics Data System (ADS)

Pathognomonic metacarpal undermining is a skeletal pathology that has been associated with Mycobacterium tuberculosis in bovids. Postcranial artiodactyl, perissodactyl, and carnivore skeletons were examined in major university and museum collections of North America and Europe for evidence of this and other pathology potentially attributable to tuberculosis. Among nonproboscidean mammals from pre-Holocene North America, bone lesions indicative of tuberculosis were restricted to immigrant bovids from Eurasia. No bone lesions compatible with diagnosis of tuberculosis were found in large samples of other pre-Holocene (164 Oligocene, 397 Miocene, and 1,041 Plio Pleistocene) North American mammals, including 114 antilocaprids. Given the unchanged frequency of bovid tubercular disease during the Pleistocene, it appears that most did not die from the disease but actually reached an accommodation with it (as did the mastodon) (Rothschild and Laub 2006). Thus, they were sufficiently long-lived to assure greater spread of the disease. The relationships of the proboscidean examples need further study, but present evidence suggests a Holarctic spread of tuberculosis during the Pleistocene, with bovids acting as vectors. While the role of other animals in the transmission of tuberculosis could be considered, the unique accommodation achieved by bovids and mastodons makes them the likely “culprits” in its spread.

Rothschild, Bruce M.; Martin, Larry D.

2006-11-01

371

Genome-Wide SNP Association Analysis for Loci Conferring Marek's Disease  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marek’s disease (MD) is a T cell lymphoma of domestic chickens caused by Marek’s disease virus (MDV), a highly oncogenic and contagious cell-associated alpha-herpesvirus. Since the 1970s, MD has been controlled by vaccination. However, due to continuous viral evolution with increasing virulence, and...

372

The threat of peste des petits ruminants: progress in vaccine development for disease control  

Microsoft Academic Search

Peste des petits ruminants (PPR) is a highly contagious animal disease caused by a virus in the genus Morbillivirus, family Paramyxoviridae. This infection is responsible for high morbidity and mortality in sheep and goats and in some small wild ruminant species. The huge number of small ruminants, which are reared in the endemic areas makes PPR a serious disease threatening

A. Diallo; C. Minet; C. Le Goff; G. Berhe; E. Albina; G. Libeau; T. Barrett

2007-01-01

373

SNP discovery and marker development for disease resistance candidate genes in common carp (Cyprinus carpio)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Single nucleotide polymorphisms (SNPs) in immune response genes have been reported as markers of susceptibility to infectious diseases in human and livestock. A disease caused by cyprinid herpes virus 3 (CyHV-3) is highly contagious and virulent in common carp. With the aim to investigate the gene...

374

Description of an as Yet Unclassified DNA Virus from Diseased Cyprinus carpio Species  

Microsoft Academic Search

Numerous deaths of koi and common carp (Cyprinus carpio) were observed on many farms throughout Israel, resulting in severe financial losses. The lethal viral disease observed is highly contagious and extremely virulent, but morbidity and mortality are restricted to koi and common carp populations. Diseased fish exhibit fatigue and gasping movements in shallow water. Infected fish had interstitial nephritis and

Marina Hutoran; Ariel Ronen; Ayana Perelberg; Maya Ilouze; Arnon Dishon; Izhak Bejerano; Nissim Chen; Moshe Kotler

2005-01-01

375

Natural Killer Cells in Foot-and-Mouth Disease Virus Infection  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. Immunological knowledge required to design a rational vaccine against FMDV is presently limited. We examined the reactivity of swine and cattle NK cells following infection for their capability to express intracell...

376

Chagas disease  

MedlinePLUS

... help control the spread of the disease. Blood banks in Central and South America screen donors for ... discarded if the donor tests positive. Most blood banks in the United States began screening for Chagas ...

377

How Is Mono Spread?  

MedlinePLUS

TeensHealth from Nemours for Parents for Kids for Teens Teens Home Body Mind Sexual Health Food & Fitness Diseases & Conditions Infections Q&A School & Jobs Drugs & Alcohol Staying Safe Recipes En Español Making a change - Use this tool ...

378

Did Vaccination Slow the Spread of Bluetongue in France?  

PubMed Central

Vaccination is one of the most efficient ways to control the spread of infectious diseases. Simulations are now widely used to assess how vaccination can limit disease spread as well as mitigate morbidity or mortality in susceptible populations. However, field studies investigating how much vaccines decrease the velocity of epizootic wave-fronts during outbreaks are rare. This study aimed at investigating the effect of vaccination on the propagation of bluetongue, a vector-borne disease of ruminants. We used data from the 2008 bluetongue virus serotype 1 (BTV-1) epizootic of southwest France. As the virus was newly introduced in this area, natural immunity of livestock was absent. This allowed determination of the role of vaccination in changing the velocity of bluetongue spread while accounting for environmental factors that possibly influenced it. The average estimated velocity across the country despite restriction on animal movements was 5.4 km/day, which is very similar to the velocity of spread of the bluetongue virus serotype 8 epizootic in France also estimated in a context of restrictions on animal movements. Vaccination significantly reduced the propagation velocity of BTV-1. In comparison to municipalities with no vaccine coverage, the velocity of BTV-1 spread decreased by 1.7 km/day in municipalities with immunized animals. For the first time, the effect of vaccination has been quantified using data from a real epizootic whilst accounting for environmental factors known to modify the velocity of bluetongue spread. Our findings emphasize the importance of vaccination in limiting disease spread across natural landscape. Finally, environmental factors, specifically those related to vector abundance and activity, were found to be good predictors of the velocity of BTV-1 spread, indicating that these variables need to be adequately accounted for when evaluating the role of vaccination on bluetongue spread. PMID:24465562

Pioz, Maryline; Guis, Hélène; Pleydell, David; Gay, Emilie; Calavas, Didier; Durand, Benoît; Ducrot, Christian; Lancelot, Renaud

2014-01-01

379

A new kinetic model to discuss the control of panic spreading in emergency  

NASA Astrophysics Data System (ADS)

Individual panic behavior during an emergency is contagious. It often leads to collective panic behavior, which can be disruptive and even disastrous if handled incorrectly. In this paper, a novel kinetic model is developed to describe the dynamics of panic spreading in a real emergency. The global dynamics of the proposed model are analyzed by using the method of Lyapunov function and the Poincarè-Bendixson property, and the obtained theoretical results are numerically validated. The Runge-Kutta method is used for numerical simulations, and these simulations are used to investigate the impact of corresponding management strategies on the containment of individual panic behavior. Meanwhile, the implications of these simulation results are discussed with the "2011 Xiangshui chemical explosion rumor" event. Finally, some recommendations for emergency management agencies are put forward by us to reduce individual panic behavior.

Chen, Guanghua; Shen, Huizhang; Chen, Guangming; Ye, Teng; Tang, Xiangbin; Kerr, Naphtali

2015-01-01

380

Axonal and Transynaptic Spread of Prions  

PubMed Central

ABSTRACT Natural transmission of prion diseases depends upon the spread of prions from the nervous system to excretory or secretory tissues, but the mechanism of prion transport in axons and into peripheral tissue is unresolved. Here, we examined the temporal and spatial movement of prions from the brain stem along cranial nerves into skeletal muscle as a model of axonal transport and transynaptic spread. The disease-specific isoform of the prion protein, PrPSc, was observed in nerve fibers of the tongue approximately 2 weeks prior to PrPSc deposition in skeletal muscle. Initially, PrPSc deposits had a small punctate pattern on the edge of muscle cells that colocalized with synaptophysin, a marker for the neuromuscular junction (NMJ), in >50% of the cells. At later time points PrPSc was widely distributed in muscle cells, but <10% of prion-infected cells exhibited PrPSc deposition at the NMJ, suggesting additional prion replication and dissemination within muscle cells. In contrast to the NMJ, PrPSc was not associated with synaptophysin in nerve fibers but was found to colocalize with LAMP-1 and cathepsin D during early stages of axonal spread. We propose that PrPSc-bound endosomes can lead to membrane recycling in which PrPSc is directed to the synapse, where it either moves across the NMJ into the postsynaptic muscle cell or induces PrPSc formation on muscle cells across the NMJ. IMPORTANCE Prion diseases are transmissible and fatal neurodegenerative diseases in which prion dissemination to excretory or secretory tissues is necessary for natural disease transmission. Despite the importance of this pathway, the cellular mechanism of prion transport in axons and into peripheral tissue is unresolved. This study demonstrates anterograde spread of prions within nerve fibers prior to infection of peripheral synapses (i.e., neuromuscular junction) and infection of peripheral tissues (i.e., muscle cells). Within nerve fibers prions were associated with the endosomal-lysosomal pathway prior to entry into muscle cells. Since early prion spread is anterograde and endosome-lysosomal movement within axons is primarily retrograde, these findings suggest that endosome-bound prions may have an alternate fate that directs prions to the peripheral synapse. PMID:24850738

Shearin, Harold

2014-01-01

381

Spreading convulsions, spreading depolarization and epileptogenesis in human cerebral cortex  

PubMed Central

Spreading depolarization of cells in cerebral grey matter is characterized by massive ion translocation, neuronal swelling and large changes in direct current-coupled voltage recording. The near-complete sustained depolarization above the inactivation threshold for action potential generating channels initiates spreading depression of brain activity. In contrast, epileptic seizures show modest ion translocation and sustained depolarization below the inactivation threshold for action potential generating channels. Such modest sustained depolarization allows synchronous, highly frequent neuronal firing; ictal epileptic field potentials being its electrocorticographic and epileptic seizure its clinical correlate. Nevertheless, Leão in 1944 and Van Harreveld and Stamm in 1953 described in animals that silencing of brain activity induced by spreading depolarization changed during minimal electrical stimulations. Eventually, epileptic field potentials were recorded during the period that had originally seen spreading depression of activity. Such spreading convulsions are characterized by epileptic field potentials on the final shoulder of the large slow potential change of spreading depolarization. We here report on such spreading convulsions in monopolar subdural recordings in 2 of 25 consecutive aneurismal subarachnoid haemorrhage patients in vivo and neocortical slices from 12 patients with intractable temporal lobe epilepsy in vitro. The in vitro results suggest that ?-aminobutyric acid-mediated inhibition protects from spreading convulsions. Moreover, we describe arterial pulse artefacts mimicking epileptic field potentials in three patients with subarachnoid haemorrhage that ride on the slow potential peak. Twenty-one of the 25 subarachnoid haemorrhage patients (84%) had 656 spreading depolarizations in contrast to only three patients (12%) with 55 ictal epileptic events isolated from spreading depolarizations. Spreading depolarization frequency and depression periods per 24?h recording episodes showed an early and a delayed peak on Day 7. Patients surviving subarachnoid haemorrhage with poor outcome at 6 months showed significantly higher total and peak numbers of spreading depolarizations and significantly longer total and peak depression periods during the electrocorticographic monitoring than patients with good outcome. In a semi-structured telephone interview 3 years after the initial haemorrhage, 44% of the subarachnoid haemorrhage survivors had developed late post-haemorrhagic seizures requiring anti-convulsant medication. In those patients, peak spreading depolarization number had been significantly higher [15.1 (11.4–30.8) versus 7.0 (0.8–11.2) events per day, P?=?0.045]. In summary, monopolar recordings here provided unequivocal evidence of spreading convulsions in patients. Hence, practically all major pathological cortical network events in animals have now been observed in people. Early spreading depolarizations may indicate a risk for late post-haemorrhagic seizures. PMID:22120143

Major, Sebastian; Pannek, Heinz-Wolfgang; Woitzik, Johannes; Scheel, Michael; Wiesenthal, Dirk; Martus, Peter; Winkler, Maren K.L.; Hartings, Jed A.; Fabricius, Martin; Speckmann, Erwin-Josef; Gorji, Ali

2012-01-01

382

Cortical Spreading Depression and Migraine  

Microsoft Academic Search

Cortical spreading depression, a slowly propagating wave of transient neuronal and glial depolarization, is widely accepted\\u000a as the electrophysiologic substrate of migraine aura and a trigger for headache. Recent clinical and experimental evidence\\u000a reinforces the putative role of cortical spreading depression in migraine pathophysiology. Imaging studies in migraineurs\\u000a demonstrated hemodynamic changes consistent with cortical spreading depression during aura, whereas recent

Katharina Eikermann-Haerter; Cenk Ayata

2010-01-01

383

The Geomorphology of Spread F  

Microsoft Academic Search

An analysis has been made of reliable spread-F data obtained from IGY f plots for ionosonde stations grouped about longitudes 75øW and 120øE. The temporal variations of occurrence of the frequency-spreading component of spread F are found to change with lati- tude, these changes having a certain symmetry about the geomagnetic equator rather than about the geographic or dip equators.

D. G. Singleton

1960-01-01

384

Liquid spreading ASTP Science Demonstration  

NASA Technical Reports Server (NTRS)

Wetting and spreading phenomena are significant in a wide variety of processes. This report discusses the results of an ASTP Science Demonstration, 'Liquid Spreading', and compares these results to theoretical predictions. On earth the initial spreading of large liquid drops on solid surfaces is always dominated by gravity; in this demonstration the effect of gravity is greatly reduced so that surface energy forces are the controlling factor.

Bourgeois, S. V.; Facemire, B. R.

1978-01-01

385

Lesion of the Olfactory Epithelium Accelerates Prion Neuroinvasion and Disease Onset when Prion Replication Is Restricted to Neurons  

PubMed Central

Natural prion diseases of ruminants are moderately contagious and while the gastrointestinal tract is the primary site of prion agent entry, other mucosae may be entry sites in a subset of infections. In the current study we examined prion neuroinvasion and disease induction following disruption of the olfactory epithelium in the nasal mucosa since this site contains environmentally exposed olfactory sensory neurons that project directly into the central nervous system. Here we provide evidence for accelerated prion neuroinvasion and clinical onset from the olfactory mucosa after disruption and regeneration of the olfactory epithelium and when prion replication is restricted to neurons. In transgenic mice with neuron restricted replication of prions, there was a reduction in survival when the olfactory epithelium was disrupted prior to intranasal inoculation and there was >25% decrease in the prion incubation period. In a second model, the neurotropic DY strain of transmissible mink encephalopathy was not pathogenic in hamsters by the nasal route, but 50% of animals exhibited brain infection and/or disease when the olfactory epithelium was disrupted prior to intranasal inoculation. A time course analysis of prion deposition in the brain following loss of the olfactory epithelium in models of neuron-restricted prion replication suggests that neuroinvasion from the olfactory mucosa is via the olfactory nerve or brain stem associated cranial nerves. We propose that induction of neurogenesis after damage to the olfactory epithelium can lead to prion infection of immature olfactory sensory neurons and accelerate prion spread to the brain. PMID:25822718

Crowell, Jenna; Wiley, James A.; Bessen, Richard A.

2015-01-01

386

New Insights into the Role of MHC Diversity in Devil Facial Tumour Disease  

PubMed Central

Background Devil facial tumour disease (DFTD) is a fatal contagious cancer that has decimated Tasmanian devil populations. The tumour has spread without invoking immune responses, possibly due to low levels of Major Histocompatibility Complex (MHC) diversity in Tasmanian devils. Animals from a region in north-western Tasmania have lower infection rates than those in the east of the state. This area is a genetic transition zone between sub-populations, with individuals from north-western Tasmania displaying greater diversity than eastern devils at MHC genes, primarily through MHC class I gene copy number variation. Here we test the hypothesis that animals that remain healthy and tumour free show predictable differences at MHC loci compared to animals that develop the disease. Methodology/Principal Findings We compared MHC class I sequences in 29 healthy and 22 diseased Tasmanian devils from West Pencil Pine, a population in north-western Tasmania exhibiting reduced disease impacts of DFTD. Amplified alleles were assigned to four loci, Saha-UA, Saha-UB, Saha-UC and Saha-UD based on recently obtained genomic sequence data. Copy number variation (caused by a deletion) at Saha-UA was confirmed using a PCR assay. No association between the frequency of this deletion and disease status was identified. All individuals had alleles at Saha-UD, disproving theories of disease susceptibility relating to copy number variation at this locus. Genetic variation between the two sub-groups (healthy and diseased) was also compared using eight MHC-linked microsatellite markers. No significant differences were identified in allele frequency, however differences were noted in the genotype frequencies of two microsatellites located near non-antigen presenting genes within the MHC. Conclusions/Significance We did not find predictable differences in MHC class I copy number variation to account for differences in susceptibility to DFTD. Genotypic data was equivocal but indentified genomic areas for further study. PMID:22701561

Wright, Belinda; Hamede, Rodrigo; Levan, Laura; Jones, Menna; Ujvari, Beata; Belov, Katherine

2012-01-01

387

9 CFR 319.762 - Ham spread, tongue spread, and similar products.  

Code of Federal Regulations, 2010 CFR

... 2 2010-01-01 2010-01-01 false Ham spread, tongue spread, and similar products. 319.762 Section 319...OF IDENTITY OR COMPOSITION Meat Salads and Meat Spreads § 319.762 Ham spread, tongue spread, and...

2010-01-01

388

9 CFR 319.762 - Ham spread, tongue spread, and similar products.  

Code of Federal Regulations, 2011 CFR

... 2 2011-01-01 2011-01-01 false Ham spread, tongue spread, and similar products. 319.762 Section 319...OF IDENTITY OR COMPOSITION Meat Salads and Meat Spreads § 319.762 Ham spread, tongue spread, and...

2011-01-01

389

Using a Bear Put Spread  

E-print Network

might be used when the marketer is bearish on a market to a point (i.e., the marketer believes the market has limited downside risk). An attractive feature of the bear put spread is that once the strike prices are selected and the premiums are known..., the maximum loss and net potential gain from the spread are also known. When to Use a Bear Put Spread A producer can use a bear put spread to hedge against a falling market. However, if the market falls below the strike price of the sold put op- tion...

Bevers, Stan; Amosson, Stephen H.; Waller, Mark L.; Dhuyvetter, Kevin C.

2008-10-07

390

Synchrony, Waves, and Spatial Hierarchies in the Spread of Influenza  

NASA Astrophysics Data System (ADS)

Quantifying long-range dissemination of infectious diseases is a key issue in their dynamics and control. Here, we use influenza-related mortality data to analyze the between-state progression of interpandemic influenza in the United States over the past 30 years. Outbreaks show hierarchical spatial spread evidenced by higher pairwise synchrony between more populous states. Seasons with higher influenza mortality are associated with higher disease transmission and more rapid spread than are mild ones. The regional spread of infection correlates more closely with rates of movement of people to and from their workplaces (workflows) than with geographical distance. Workflows are described in turn by a gravity model, with a rapid decay of commuting up to around 100 km and a long tail of rare longer range flow. A simple epidemiological model, based on the gravity formulation, captures the observed increase of influenza spatial synchrony with transmissibility; high transmission allows influenza to spread rapidly beyond local spatial constraints.

Viboud, Cécile; Bjørnstad, Ottar N.; Smith, David L.; Simonsen, Lone; Miller, Mark A.; Grenfell, Bryan T.

2006-04-01

391

Whole-Genome Sequencing of Mycoplasma mycoides subsp. mycoides Italian Strain 57/13, the Causative Agent of Contagious Bovine Pleuropneumonia  

PubMed Central

Mycoplasma mycoides subsp. mycoides is generally considered one of most pathogenic Mycoplasma species, and it is the etiological agent of contagious bovine pleuropneumonia (CBPP). Here, we present the annotated genome sequence of M. mycoides subsp. mycoides Italian strain 57/13, isolated in 1992 during CBPP outbreaks in Italy. PMID:25814605

Orsini, M.; Krasteva, I.; Marcacci, M.; Ancora, M.; Ciammaruconi, A.; Gentile, B.; Lista, F.; Pini, A.; Scacchia, M.; Sacchini, F.

2015-01-01

392

Agent-based modeling to simulate the dengue spread  

NASA Astrophysics Data System (ADS)

In this paper, we introduce a novel method ABM in simulating the unique process for the dengue spread. Dengue is an acute infectious disease with a long history of over 200 years. Unlike the diseases that can be transmitted directly from person to person, dengue spreads through a must vector of mosquitoes. There is still no any special effective medicine and vaccine for dengue up till now. The best way to prevent dengue spread is to take precautions beforehand. Thus, it is crucial to detect and study the dynamic process of dengue spread that closely relates to human-environment interactions where Agent-Based Modeling (ABM) effectively works. The model attempts to simulate the dengue spread in a more realistic way in the bottom-up way, and to overcome the limitation of ABM, namely overlooking the influence of geographic and environmental factors. Considering the influence of environment, Aedes aegypti ecology and other epidemiological characteristics of dengue spread, ABM can be regarded as a useful way to simulate the whole process so as to disclose the essence of the evolution of dengue spread.

Deng, Chengbin; Tao, Haiyan; Ye, Zhiwei

2008-10-01

393

Cryptographic Spread Spectrum Relay Communication  

Microsoft Academic Search

Spread spectrum (SS) is a technique of secure communication, which increases resistance to natural interference and jamming, and prevents detection. If a cryptographically secure pseudo random sequence is used, the communication becomes more secure. Generally some short pseudo-random sequences are used in Spread spectrum. In this paper we present comparatively a different technique of signal hiding where we use a

Zahoor Ahmed; J. P. Cances; V. Meghdadi

2008-01-01

394

Western blot analysis of virus-specific antibody responses for capripox and contagious pustular dermatitis viral infections in sheep.  

PubMed Central

This paper reports the development and evaluation of serological tests for the differentiation of antibodies in animals infected with capripox and parapox viruses. Agar-gel immunodiffusion tests using sera from sheep with naturally-acquired infections and from sheep experimentally inoculated with orf or capripox viruses showed cross reactions. Virus-specific antibody responses to structural proteins of the viruses were analysed by Western-blot analysis. This analysis readily differentiated the infections as either capripox or contagious pustular dermatitis. The antibody responses to the 32 kDa and 26 kDa proteins of capripoxvirus provided a firm basis for differentiation. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7925674

Chand, P.; Kitching, R. P.; Black, D. N.

1994-01-01

395

Analysis of foot-and-mouth disease virus integrin receptor expression in tissues from naive and infected cattle  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals principally affecting cattle, pigs and sheep. FMD virus (FMDV) uses the alphaVbeta1, alphaVbeta3, alphaVbeta6 and alphaVbeta8 integrins as receptors in vitro via a highly conserved arginine-glycine-aspartic ac...

396

Loss of plasmacytoid dendritic cell function coincides with lymphopenia and viremia during foot-and-mouth disease infection  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot and mouth disease virus (FMDV) causes an acute, highly contagious disease of livestock. Though FMDV is very sensitive to interferon (IFN) alpha, beta, and gamma, the virus has evolved mechanisms to evade such innate responses. For instance, during acute infection, FMDV suppresses IFNa productio...

397

Poly ICLC increases the potency of a replication-defective human adenovirus vectored foot-and-mouth disease vaccine  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hoofed animals. We have previously demonstrated that a replication-defective human adenovirus 5 vector carrying the FMDV capsid coding region of serotype A24 Cruzeiro (Ad5-CI-A24-2B) protects swine and cattle against FM...

398

A survey of Newcastle disease in Swiss laying-hen flocks using serological testing and simulation modelling  

Microsoft Academic Search

Newcastle disease (ND) is a highly contagious viral disease of birds particularly domestic poultry. Switzerland is currently declared free from ND; since vaccination is prohibited, the detection of antibodies against ND virus (NDV) results in the destruction of the respective flock (stamping-out policy). However, in 1995 and 1996, antibody-positive flocks were detected and sporadic ND outbreaks even occurred in Switzerland.

Daniela S Gohm; Barbara Thür; Laurent Audigé; Martin A Hofmann

1999-01-01

399

POTENTIAL ROLE OF FLIES IN THE PERSISTENCE AND DISPERSAL OF EXOTIC NEWCASTLE DISEASE VIRUS IN SOUTHERN CALIFORNIA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Exotic Newcastle Disease (END) is a highly virulent and contagious disease affecting poultry and other birds with the potential of causing 100% mortality in unvaccinated poultry. Transmission of END virus to susceptible birds is primarily thought to occur via direct contact with infected birds or in...

400

PATHOGENIC CHARACTERISTICS OF THE KOREAN 2002 ISOLATE OF FOOT-AND-MOUTH DISEASE VIRUS SEROTYPE O IN PIGS AND CATTLE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Experimental infection of susceptible cattle and pigs with foot-and-mouth disease virus (FMDV) O/SKN/AS/2002 pig strain indicates that this virus causes a disease that is highly virulent and contagious in swine, but causes a very limited infection in bovine. Pigs directly inoculated with, or expose...

401

Gasping for truth : tracking the spread of SARS around the world  

NSDL National Science Digital Library

This is a lesson plan in which students investigate global responses to fighting the spread of severe acute respiratory syndrome. Students will read a newspaper article to discover what is being done to curb the spread of the deadly disease. Then, students will use a variety of different media to track the spread and other statistics related to the disease. Students will write news reports advising citizens of what to do in affected areas.

Clayton DeKorne

2003-01-01

402

Disease transmission in horses.  

PubMed

Bacterial, viral and protozoal infections may cause severe reproductive losses. The present paper reviews the risk factors, clinical signs and preventive measures for the most important venereal or potential sexually transmitted diseases in horses. The stallion and use of semen for artificial insemination represent major risk factors for the transmission of bacterial contaminants of the penis, including Streptococcus equi subspecies zooepidemicus, Pseudomonas aeruginosa and Klebsiella pneumoniae, known to cause endometritis and infertility in the mare. The role of the stallion in disease transmission is also due to the non-clinical manifestation of diseases such as contagious equine metritis and equine viral arteritis. Dourine has been eradicated from many countries, but continues to be a problem in other areas of the globe. Strategies for the prevention of introduction and transmission of diseases in breeding operation are discussed. PMID:16837034

Samper, Juan C; Tibary, Ahmed

2006-08-01

403

Disease control during the colonial period in Australia.  

PubMed

The first permanent European settlers of Australia arrived in 1788 to establish a penal colony at Sydney, New South Wales (NSW). As the colony grew and wool production increased, more free settlers and emancipists developed farming in inland Australia. During the 1840s veterinarians commenced arriving in small numbers but they were not closely associated with the development and execution of disease control programs, which was left to lay inspectors of stock. The arrival of William Tyson Kendall and coordinated action with Graham Mitchell led to the establishment of a private veterinary college following the passage of veterinary surgeons legislation in Victoria. From this time, veterinarians came to be appointed to positions formerly occupied by lay inspectors and the veterinary profession was able to take up the role of planning and executing government-led disease control programs. From a colony relying on wool for export to the UK, technical advancements in meat freezing and pasture improvement widened the range and increased the quantity of exported products. Before the advent of veterinary advances, sheep scab was eradicated, a vaccine was developed for anthrax and glanders infection of horses was prevented entry to Australia. Graduates from the Melbourne Veterinary College spread across Australia and in this period a conservative quarantine policy was developed following inaction to control an outbreak of contagious bovine pleuropneumonia (CBPP) and the escape of rabbits to form a plague across the continent. Coordinated control of CBPP had to await the next century and advancement of technology increased our understanding of bacteriology and immunity of infectious diseases. Veterinary services were provided to the militia sent by the colonies to the Boer Wars in South Africa 1987-1901 and the veterinarians from Victoria were led by an Australian trained veterinarian. PMID:21696369

Turner, A J

2011-07-01

404

Comparative assessment of two commonly used commercial ELISA tests for the serological diagnosis of contagious agalactia of small ruminants caused by Mycoplasma agalactiae  

PubMed Central

Background Contagious agalactia (CA) of sheep and goats caused by Mycoplasma agalactiae is a widely occurring economically important disease that is difficult to control. The ELISA is commonly used for the serological detection of CA but it has some limitations and the performance of the available tests have not been properly evaluated. Two commercial ELISA kits are widely used, one involving a fusion protein as target antigen and the other a total antigen. The objectives were to compare these tests by evaluating: i. Their diagnostic sensitivity and specificity, the relevance of the recommended cut-off points, the correlation between the two tests, and, the correlation between serology data and the milk shedding of M. agalatiae; ii. The influence of extrinsic factors such as the targeted animal species, geographical origin of the samples, intra-specific variability of M. agalactiae and concurrent mycoplasma infections. A sample of 5900 animals from 211 farms with continuous CA monitoring for 20?years and no prior vaccination history was used. The infection status was known from prior bacteriological, epidemiological and serological monitoring with a complementary immunoblotting test. Results The average diagnostic sensitivity was 56% [51.8–59.8] for the fusion protein ELISA and 84% [81.3–87.2] for the total antigen ELISA, with noteworthy flock-related variations. The average diagnostic specificity for the fusion protein ELISA was 100% [99.9–100], and for the total antigen ELISA differed significantly between goats and sheep: 99.3% [97.4–99.9] and 95.7% [93.8–97.2] respectively. Experimental inoculations with different M. agalactiae strains revealed that the ELISA kits poorly detected the antibody response to certain strains. Furthermore, test performances varied according to the host species or geographical origin of the samples. Finally, the correlation between milk shedding of M. agalactiae and the presence of detectable antibodies in the blood was poor. Conclusions These serological tests are not interchangeable. The choice of a test will depend on the objectives (early detection of infection or disease control program), on the prevalence of infection and the control protocol used. Given the variety of factors that may influence performance, a preliminary assessment of the test in a given situation is recommended prior to widespread use. PMID:22776779

2012-01-01

405

The contagious nature of imprisonment: an agent-based model to explain racial disparities in incarceration rates.  

PubMed

We build an agent-based model of incarceration based on the susceptible-infected-suspectible (SIS) model of infectious disease propagation. Our central hypothesis is that the observed racial disparities in incarceration rates between Black and White Americans can be explained as the result of differential sentencing between the two demographic groups. We demonstrate that if incarceration can be spread through a social influence network, then even relatively small differences in sentencing can result in large disparities in incarceration rates. Controlling for effects of transmissibility, susceptibility and influence network structure, our model reproduces the observed large disparities in incarceration rates given the differences in sentence lengths for White and Black drug offenders in the USA without extensive parameter tuning. We further establish the suitability of the SIS model as applied to incarceration by demonstrating that the observed structural patterns of recidivism are an emergent property of the model. In fact, our model shows a remarkably close correspondence with California incarceration data. This work advances efforts to combine the theories and methods of epidemiology and criminology. PMID:24966237

Lum, Kristian; Swarup, Samarth; Eubank, Stephen; Hawdon, James

2014-09-01

406

The contagious nature of imprisonment: an agent-based model to explain racial disparities in incarceration rates  

PubMed Central

We build an agent-based model of incarceration based on the susceptible–infected–suspectible (SIS) model of infectious disease propagation. Our central hypothesis is that the observed racial disparities in incarceration rates between Black and White Americans can be explained as the result of differential sentencing between the two demographic groups. We demonstrate that if incarceration can be spread through a social influence network, then even relatively small differences in sentencing can result in large disparities in incarceration rates. Controlling for effects of transmissibility, susceptibility and influence network structure, our model reproduces the observed large disparities in incarceration rates given the differences in sentence lengths for White and Black drug offenders in the USA without extensive parameter tuning. We further establish the suitability of the SIS model as applied to incarceration by demonstrating that the observed structural patterns of recidivism are an emergent property of the model. In fact, our model shows a remarkably close correspondence with California incarceration data. This work advances efforts to combine the theories and methods of epidemiology and criminology. PMID:24966237

Lum, Kristian; Swarup, Samarth; Eubank, Stephen; Hawdon, James

2014-01-01

407

Antibody inhibition of human cytomegalovirus spread in epithelial cell cultures  

PubMed Central

Anti-cytomegalovirus (CMV) antibodies reduce the incidence of CMV transmission and ameliorate the severity of CMV-associated disease. Neutralizing activity, measured as the ability of antibodies to prevent entry of cell-free virus, is an important component of natural immunity. However, in vivo CMV amplification may occur mainly via spread between adjacent cells within tissues. Thus, inhibition of cell-to-cell spread may be important when evaluating therapeutic antibodies or humoral responses to infection or immunization. In vitro CMV cell-to-cell spread is largely resistant to antibodies in fibroblast cultures but sensitive in endothelial cell cultures. In the present study antibodies in CMV hyperimmuneglobulin or seropositive human sera inhibited CMV cell-to-cell spread in epithelial cell cultures. Spread inhibition activity was quantitated with a GFP reporter assay employing GFP-tagged epithelialtropic variants of CMV strains Towne or AD169. Measurement of spread inhibition provides an additional parameter for the evaluation of candidate vaccines or immunotherapeutics and to further characterize the role of antibodies in controlling CMV transmission and disease. PMID:23669101

Cui, Xiaohong; Lee, Ronzo; Adler, Stuart P.; McVoy, Michael A.

2013-01-01

408

Immune Evasion During Foot-and-Mouth Disease Virus (FMDV) Infection of Swine  

Technology Transfer Automated Retrieval System (TEKTRAN)

The interface between successful pathogens and their hosts is often a tenuous balance. In acute viral infections, this involves induction and inhibition of innate responses. Foot-and-mouth disease virus (FMDV) is considered one of the most contagious viruses known and is characterized by rapid induc...

409

Epidemic spreading in time-varying community networks  

SciTech Connect

The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q{sub c}. The epidemic will survive when q?>?q{sub c} and die when q?spreading in complex networks with community structure.

Ren, Guangming, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [School of Electronic and Information, Guangdong Polytechnic Normal University, Guangzhou 510665 (China) [School of Electronic and Information, Guangdong Polytechnic Normal University, Guangzhou 510665 (China); Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Xingyuan, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China)] [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China)

2014-06-15

410

Infection as cause of stroke: a contagious idea that may explain racial disparity.  

PubMed

In the aftermath of an acute cardiovascular event such as stroke, patients and families frequently ask whether preceding circumstances such as viral illnesses, stress, and other medical or surgical events brought on the disease. Although it seems intuitive to patients and families that acute precipitants or disease triggers play a substantial role, the evidence to support this concept has accumulated slowly.(1,2) Support for acute systemic infection as a trigger of stroke, a particularly interesting hypothesis, continues to grow.(3) The potential mechanisms underlying such a relationship include systemic inflammation, endothelial dysfunction, and activation of the clotting system by infectious organisms or the systemic response to them.(4,5). PMID:24532270

Jeerakathil, Thomas; Lo, Warren

2014-03-18

411

PREVENTING DISEASES AND INFECTIONS  

NSDL National Science Digital Library

DESK Standard: Determine how communicable diseases are spread. . DATES: You can begin this activity on January 8. You should complete it by January 12. OBJECTIVE: Everyone wants to feel healthy because being sick is a drag! We have been discussing ways to prevent the spread of infections and diseases during class. There are many ...

Mr. Hughes

2006-02-19

412

Newcastle disease virus (NDV) recombinants expressing infectious laryngotracheitis virus (ILTV) glycoproteins gB and gD protect chickens against ILTV and NDV challenges  

Technology Transfer Automated Retrieval System (TEKTRAN)

Infectious laryngotracheitis (ILT) is a highly contagious acute respiratory disease of chickens caused by infectious laryngotracheitis virus (ILTV). The disease is mainly controlled through biosecurity and vaccination with live-attenuated strains of the virus and vectored vaccines based on turkey he...

413

THE LEADER PROTEINASE OF FOOT-AND-MOUTH DISEASE VIRUS INHIBITS THE INDUCTION OF INTERFERON BETA MRNA AND BLOCKS THE HOST INNATE IMMUNE RESPONSE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth disease virus (FMDV) is a highly contagious pathogen of cloven hoofed animals that causes an economically devastating disease. We have previously shown that the virulence of FMDV correlates with the presence of the viral gene product Lpro (leader), a papain-like proteinase responsible...

414

The 2.6Angstrom Structure of Infectious Bursal Disease Virus-Derived T=1 Particles Reveals New Stabilizing Elements of the Virus Capsid  

Microsoft Academic Search

Infectious bursal disease virus (IBDV), a member of the Birnaviridae family, is a double-stranded RNA virus that causes a highly contagious disease in young chickens leading to significant economic losses in the poultry industry. The VP2 protein, the only structural component of the IBDV icosahedral capsid, spontaneously assembles into T1 subviral particles (SVP) when individually expressed as a chimeric gene.

D. Garriga; J. Querol-Audi; F. Abaitua; I. Saugar; J. Pous; N. Verdaguer; J. R. Caston; J. F. Rodriguez

2006-01-01

415

RECOMBINANT ENGINEERED SAT1 FOOT-AND-MOUTH DISEASE VIRUS AS AN APPROACH TO INVESTIGATE RECEPTOR USAGE AND GROWTH DETERMINANTS OF OUTBREAK STRAINS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foot-and-mouth desease (FMD), a highly contagious viral disease of cattle, sheep, pigs and other cloven-hoofed animals has recently caused devastating epidemics world-wide. In the three South African Territories (SAT) types of foot-and-mouth disease virus (FMDV), the aetiological agent display grea...

416

Worldwide Spread of Dengue Virus Type 1  

PubMed Central

Background DENV-1 is one of the four viral serotypes that causes Dengue, the most common mosquito-borne viral disease of humans. The prevalence of these viruses has grown in recent decades and is now present in more than 100 countries. Limited studies document the spread of DENV-1 over the world despite its importance for human health. Methodology/Principal Findings We used representative DENV-1 envelope gene sequences to unravel the dynamics of viral diffusion under a Bayesian phylogeographic approach. Data included strains from 45 distinct geographic locations isolated from 1944 to 2009. The estimated mean rate of nucleotide substitution was 6.56×10?4 substitutions/site/year. The larger genotypes (I, IV and V) had a distinctive phylogenetic structure and since 1990 they experienced effective population size oscillations. Thailand and Indonesia represented the main sources of strains for neighboring countries. Besides, Asia broadcast lineages into the Americas and the Pacific region that diverged in isolation. Also, a transmission network analysis revealed the pivotal role of Indochina in the global diffusion of DENV-1 and of the Caribbean in the diffusion over the Americas. Conclusions/Significance The study summarizes the spatiotemporal DENV-1 worldwide spread that may help disease control. PMID:23675416

Villabona-Arenas, Christian Julián; Zanotto, Paolo Marinho de Andrade

2013-01-01

417

Animals: Disease Risks for People  

MedlinePLUS

... Care Animal Welfare Veterinary Careers Public Health Disease Risks for People at Dog Social Events People attending dog social events can be at risk of zoonotic diseases, which are diseases that spread ...

418

Fifth Disease (Parvovirus B19)  

MedlinePLUS

... Disease (Parvovirus B19) Health Issues Listen Fifth Disease (Parvovirus B19) Article Body Fifth disease, also called erythema ... cheeks. It is caused by a virus called parvovirus B19 and can be spread from one person ...

419

The role of hybridization in the origin and spread of asexuality in Daphnia.  

PubMed

The molecular mechanisms leading to asexuality remain little understood despite their substantial bearing on why sexual reproduction is dominant in nature. Here, we examine the role of hybridization in the origin and spread of obligate asexuality in Daphnia pulex, arguably the best-documented case of contagious asexuality. Obligately parthenogenetic (OP) clones of D. pulex have traditionally been separated into 'hybrid' (Ldh SF) and 'nonhybrid' (Ldh SS) forms because the lactase dehydrogenase (Ldh) locus distinguishes the cyclically parthenogenetic (CP) lake dwelling Daphnia pulicaria (Ldh FF) from its ephemeral pond dwelling sister species D. pulex (Ldh SS). The results of our population genetic analyses based on microsatellite loci suggest that both Ldh SS and SF OP individuals can originate from the crossing of CP female F1 (D. pulex × D. pulicaria) and backcross with males from OP lineages carrying genes that suppress meiosis specifically in female offspring. In previous studies, a suite of diagnostic markers was found to be associated with OP in Ldh SS D. pulex lineages. Our association mapping supports a similar genetic mechanism for the spread of obligate parthenogenesis in Ldh SF OP individuals. Interestingly, our study shows that CP D. pulicaria carry many of the diagnostic microsatellite alleles associated with obligate parthenogenesis. We argue that the assemblage of mutations that suppress meiosis and underlie obligate parthenogenesis in D. pulex originated due to a unique historical hybridization and introgression event between D. pulex and D. pulicaria. PMID:23879327

Xu, Sen; Innes, David J; Lynch, Michael; Cristescu, Melania E

2013-09-01

420

The role of hybridization in the origin and spread of asexuality in Daphnia  

PubMed Central

The molecular mechanisms leading to asexuality remain little understood despite their substantial bearing on why sexual reproduction is dominant in nature. Here we examine the role of hybridization in the origin and spread of obligate asexuality in Daphnia pulex, arguably the best-documented case of contagious asexuality. Obligately parthenogenetic (OP) clones of D. pulex have traditionally been separated into “hybrid” (Ldh SF) and “non-hybrid” (Ldh SS) forms because the lactase dehydrogenase (Ldh) locus distinguishes the cyclically parthenogenetic (CP) lake dwelling Daphnia pulicaria (Ldh FF) from its ephemeral pond dwelling sister species D. pulex (Ldh SS). The results of our population genetic analyses based on microsatellite loci suggest that both Ldh SS and SF OP individuals can originate from the crossing of CP female F1 (D. pulex × D. pulicaria) and backcrosses with males from OP lineages carrying genes that suppress meiosis specifically in female offspring. In previous studies, a suite of diagnostic markers was found to be associated with OP in Ldh SS D. pulex lineages. Our association mapping supports a similar genetic mechanism for the spread of obligate parthenogenesis in Ldh SF OP individuals. Interestingly, our study shows that CP D. pulicaria carry many of the diagnostic microsatellite alleles associated with obligate parthenogenesis. We argue that the assemblage of mutations that suppress meiosis and underlie obligate parthenogenesis in D. pulex originated due to a unique historical hybridization and introgression event between D. pulex and D. pulicaria. PMID:23879327

Xu, Sen; Innes, David J.; Lynch, Michael; Cristescu, Melania E.

2014-01-01

421

Synchrony, Waves, and Spatial Hierarchies in the Spread of Influenza  

E-print Network

Synchrony, Waves, and Spatial Hierarchies in the Spread of Influenza Ce´cile Viboud,1 * Ottar N-range dissemination of infectious diseases is a key issue in their dynamics and control. Here, we use influenza-related mortality data to analyze the between-state progression of interpandemic influenza in the United States over

422

Detonation spreading in fine TATBs  

SciTech Connect

A test has been devised that permits rapid evaluation of the detonation-spreading (or corner-turning) properties of detonations in insensitive high explosives. The test utilizes a copper witness plate as the medium to capture performance data. Dent depth and shape in the copper are used as quantitative measures of the detonation output and spreading behavior. The merits of the test are that it is easy to perform with no dynamic instrumentation, and the test requires only a few grams of experimental explosive materials.

Kennedy, J.E.; Lee, K.Y.; Spontarelli, T.; Stine, J.R.

1998-12-31

423

Detection of African swine fever, classical swine fever, and foot-and-mouth disease viruses in swine oral fluids by multiplex reverse transcription real-time polymerase chain reaction.  

PubMed

African swine fever (ASF), classical swine fever (CSF), and foot-and-mouth disease (FMD) are highly contagious animal diseases of significant economic importance. Pigs infected with ASF and CSF viruses (ASFV and CSFV) develop clinical signs that may be indistinguishable from other diseases. Likewise, various causes of vesicular disease can mimic clinical signs caused by the FMD virus (FMDV). Early detection is critical to limiting the impact and spread of these disease outbreaks, and the ability to perform herd-level surveillance for all 3 diseases rapidly and cost effectively using a single diagnostic sample and test is highly desirable. This study assessed the feasibility of simultaneous ASFV, CSFV, and FMDV detection by multiplex reverse transcription real-time polymerase chain reaction (mRT-qPCR) in swine oral fluids collected through the use of chewing ropes. Animal groups were experimentally infected independently with each virus, observed for clinical signs, and oral fluids collected and tested throughout the course of infection. All animal groups chewed on the ropes readily before and after onset of clinical signs and before onset of lameness or serious clinical signs. ASFV was detected as early as 3 days postinoculation (dpi), 2-3 days before onset of clinical disease; CSFV was detected at 5 dpi, coincident with onset of clinical disease; and FMDV was detected as early as 1 dpi, 1 day before the onset of clinical disease. Equivalent results were observed in 4 independent studies and demonstrate the feasibility of oral fluids and mRT-qPCR for surveillance of ASF, CSF, and FMD in swine populations. PMID:25776540

Grau, Frederic R; Schroeder, Megan E; Mulhern, Erin L; McIntosh, Michael T; Bounpheng, Mangkey A

2015-03-01

424

Spreading of persistent infections in heterogeneous populations  

NASA Astrophysics Data System (ADS)

Up to now, the effects of having heterogeneous networks of contacts have been studied mostly for diseases which are not persistent in time, i.e., for diseases where the infectious period can be considered very small compared to the lifetime of an individual. Moreover, all these previous results have been obtained for closed populations, where the number of individuals does not change during the whole duration of the epidemics. Here, we go one step further and analyze, both analytically and numerically, a radically different kind of diseases: those that are persistent and can last for an individual’s lifetime. To be more specific, we particularize to the case of tuberculosis’ (TB) infection dynamics, where the infection remains latent for a period of time before showing up and spreading to other individuals. We introduce an epidemiological model for TB-like persistent infections taking into account the heterogeneity inherent to the population structure. This sort of dynamics introduces new analytical and numerical challenges that we are able to sort out. Our results show that also for persistent diseases the epidemic threshold depends on the ratio of the first two moments of the degree distribution so that it goes to zero in a class of scale-free networks when the system approaches the thermodynamic limit.

Sanz, J.; Floría, L. M.; Moreno, Y.

2010-05-01

425

Control of contagious bovine pleuropneumonia: knowledge, attitudes, perceptions and practices in Narok district of Kenya.  

PubMed

CBPP is an important transboundary disease in sub-Saharan Africa whose control is urgent. Participatory data collection involving 52 focus group discussions in 37 village clusters and key informant interviews, a cross-sectional study involving 232 households and a post-vaccination follow up involving 203 households was carried out in 2006-2007 in Narok South district of Kenya. This was to investigate knowledge, attitudes, perceptions and practices (KAPP) associated with control of CBPP as well as the adverse post-vaccination reactions in animals in order to advice the control policy. The community perceived trans-boundary CBPP threat to their cattle. They had traditional disease coping mechanisms and were conversant with CBPP prevention and control with 49.8% (95%CI: 42.8-56.7%) giving priority to CBPP control. However, 12.9% (95%CI: 9.0-18.1%) of pastoralists had no knowledge of any prevention method and 10.0% (95%CI: 6.5-14.7%) would not know what to do or would do nothing in the event of an outbreak. Although 43.5% (95%CI: 37.1-50.2%) of pastoralists were treating CBPP cases with antimicrobials, 62.5% (95%CI: 52.1-71.7%) of them doubted the effectiveness of the treatments. Pastoralists perceived vaccination to be the solution to CBPP but vaccination was irregular due to unavailability of the vaccine. Vaccination was mainly to control outbreaks rather than preventive and exhibited adverse post-vaccination reactions among 70.4% (95%CI: 63.6-76.5%) of herds and 3.8% (95%CI: 3.5-4.2%) of animals. Consequently, nearly 25.2% (95%CI: 18.5-33.2%) of pastoralists may resist subsequent vaccinations against CBPP. Pastoralists preferred CBPP vaccination at certain times of the year and that it is combined with other vaccinations. In conclusion, pastoralists were not fully aware of the preventive measures and interventions and post-vaccination reactions may discourage subsequent CBPP vaccinations. Consequently there is need for monitoring and management of post vaccination reactions and awareness creation on CBPP prevention and interventions and their merits and demerits. CBPP vaccine was largely unavailable to the pastoralists and the preference of the pastoralists was for vaccination at specified times and vaccine combinations which makes it necessary to avail the vaccine in conformity with the pastoralists preferences. In addition, planning vaccinations should involve pastoralists and neighbouring countries. As the results cannot be generalized, further studies on CBPP control methods and their effectiveness are recommended. PMID:24768437

Kairu-Wanyoike, S W; Kiara, H; Heffernan, C; Kaitibie, S; Gitau, G K; McKeever, D; Taylor, N M

2014-08-01

426

Control of contagious bovine pleuropneumonia: Knowledge, attitudes, perceptions and practices in Narok district of Kenya  

PubMed Central

CBPP is an important transboundary disease in sub-Saharan Africa whose control is urgent. Participatory data collection involving 52 focus group discussions in 37 village clusters and key informant interviews, a cross-sectional study involving 232 households and a post-vaccination follow up involving 203 households was carried out in 2006–2007 in Narok South district of Kenya. This was to investigate knowledge, attitudes, perceptions and practices (KAPP) associated with control of CBPP as well as the adverse post-vaccination reactions in animals in order to advice the control policy. The community perceived trans-boundary CBPP threat to their cattle. They had traditional disease coping mechanisms and were conversant with CBPP prevention and control with 49.8% (95%CI: 42.8–56.7%) giving priority to CBPP control. However, 12.9% (95%CI: 9.0–18.1%) of pastoralists had no knowledge of any prevention method and 10.0% (95%CI: 6.5–14.7%) would not know what to do or would do nothing in the event of an outbreak. Although 43.5% (95%CI: 37.1–50.2%) of pastoralists were treating CBPP cases with antimicrobials, 62.5% (95%CI: 52.1–71.7%) of them doubted the effectiveness of the treatments. Pastoralists perceived vaccination to be the solution to CBPP but vaccination was irregular due to unavailability of the vaccine. Vaccination was mainly to control outbreaks rather than preventive and exhibited adverse post-vaccination reactions among 70.4% (95%CI: 63.6–76.5%) of herds and 3.8% (95%CI: 3.5–4.2%) of animals. Consequently, nearly 25.2% (95%CI: 18.5–33.2%) of pastoralists may resist subsequent vaccinations against CBPP. Pastoralists preferred CBPP vaccination at certain times of the year and that it is combined with other vaccinations. In conclusion, pastoralists were not fully aware of the preventive measures and interventions and post-vaccination reactions may discourage subsequent CBPP vaccinations. Consequently there is need for monitoring and management of post vaccination reactions and awareness creation on CBPP prevention and interventions and their merits and demerits. CBPP vaccine was largely unavailable to the pastoralists and the preference of the pastoralists was for vaccination at specified times and vaccine combinations which makes it necessary to avail the vaccine in conformity with the pastoralists preferences. In addition, planning vaccinations should involve pastoralists and neighbouring countries. As the results cannot be generalized, further studies on CBPP control methods and their effectiveness are recommended. PMID:24768437

Kairu-Wanyoike, S.W.; Kiara, H.; Heffernan, C.; Kaitibie, S.; Gitau, G.K.; McKeever, D.; Taylor, N.M.

2014-01-01

427

Spreading rate, spreading obliquity, and melt supply at the ultraslow spreading Southwest Indian Ridge  

NASA Astrophysics Data System (ADS)

We use bathymetry, gravimetry, and basalt composition to examine the relationship between spreading rate, spreading obliquity, and the melt supply at the ultraslow spreading Southwest Indian Ridge (SWIR). We find that at regional scales (more than 200 km), melt supply reflects variations in mantle melting that are primarily controlled by large-scale heterogeneities in mantle temperature and/or composition. Focusing on adjacent SWIR regions with contrasted obliquity, we find that the effect of obliquity on melt production is significant (about 1.5 km less melt produced for a decrease of 7 mm/a to 4 mm/a in effective spreading rates, ESR) but not enough to produce near-amagmatic spreading in the most oblique regions of the ridge, unless associated with an anomalously cold and/or depleted mantle source. Our observations lead us to support models in which mantle upwelling beneath slow and ultraslow ridges is somewhat focused and accelerated, thereby reducing the effect of spreading rate and obliquity on upper mantle cooling and melt supply. To explain why very oblique SWIR regions nonetheless have large outcrops of mantle-derived ultramafic rocks and, in many cases, no evidence for axial volcanism (Cannat et al., 2006; Dick et al., 2003), we develop a model which combines melt migration along axis to more volcanically robust areas, melt trapping in the lithospheric mantle, and melt transport in dikes that may only form where enough melt has gathered to build sufficient overpressure. These dikes would open perpendicularly to the direction of the least compressive stress and favor the formation of orthogonal ridge sections. The resulting segmentation pattern, with prominent orthogonal volcanic centers and long intervening avolcanic or nearly avolcanic ridge sections, is not specific to oblique ridge regions. It is also observed along the SWIR and the arctic Gakkel Ridge in orthogonal regions underlain by cold and/or depleted mantle.

Cannat, Mathilde; Sauter, Daniel; Bezos, Antoine; Meyzen, Christine; Humler, Eric; Le Rigoleur, Marion

2008-04-01

428

Droplet spreading: Theory and experiments  

NASA Astrophysics Data System (ADS)

A hypothesis is presented that distinguishes the characteristics of spreading by hydrodynamic forces from those driven by molecular/kinetic effects, demarking the regimes by contact-line speeds and contact angles. Several applications of the criterion to experiments are discussed.

Davis, Michael J.; Davis, Stephen H.

2013-08-01

429

Dual polarized, heat spreading rectenna  

NASA Technical Reports Server (NTRS)

An aperture coupled patch splits energy from two different polarization components to different locations to spread heat. In addition, there is no physical electrical connection between the slot, patch and circuitry. The circuitry is located under a ground plane which shields against harmonic radiation back to the RF source.

Epp, Larry W. (Inventor); Khan, Abdur R. (Inventor); Smith, R. Peter (Inventor); Smith, Hugh K. (Inventor)

1999-01-01

430

Mid-Ocean Ridge Spreading  

NSDL National Science Digital Library

In this earth science activity (page 14 of the PDF), learners use layers of closed-cell foam to create their own model of the mid-ocean ridge in order to simulate seafloor spreading. Although this was created as a post-visit activity for a workshop about earth processes, it also makes an excellent stand alone activity.

COSI

2009-01-01

431

3D Fire Spread Animations  

NSDL National Science Digital Library

These excellent animations overlay animations of fire spread on 3D terrain that incorporates satellite imagery. A timeline shows the animation's current time relative to the fire occurrence, and an inset map provides an overhead view of the fire on a map that shows fuels by location. Animations are available for several wildfires that occurred in California.

Harry D. Johson

432

Using a Bull Call Spread  

E-print Network

The Bull Call Spread can be used to hedge against or to benefit from a rising market. The user buys a call option at a particular strike price and sells a call option at a higher strike price. Margin requirements, advantages and disadvantages...

Bevers, Stan; Amosson, Stephen H.; Waller, Mark L.; Dhuyvetter, Kevin C.

2008-10-07

433

Is participation contagious? Evidence from a household vector control campaign in urban Peru  

PubMed Central

Objectives High rates of household participation are critical to the success of door-to-door vector control campaigns. We used the Health Belief Model to assess determinants of participation, including neighbor participation as a cue to action, in a Chagas disease vector control campaign in Peru. Methods We evaluated clustering of participation among neighbors; estimated participation as a function of household infestation status, neighborhood type, and number of participating neighbors; and described reported reasons for refusal to participate in a district of 2911 households. Results We observed significant clustering of participation along city blocks (p< .0001). Participation was significantly higher for households in new vs. established neighborhoods, for infested households, and for households with more participating neighbors. The effect of neighbor participation was greater in new neighborhoods. Conclusions Results support a “contagion” model of participation, highlighting the possibility that one or two participating households can tip a block towards full participation. Future campaigns can leverage these findings by making participation more visible, by addressing stigma associated with spraying, and by employing group incentives to spray. PMID:24062411

Buttenheim, Alison M.; Paz-Soldan, Valerie; Barbu, Corentin; Skovira, Christine; Calderón, Javier Quintanilla; Riveros, Lina Margot Mollesaca; Cornejo, Juan Oswaldo; Small, Dylan S.; Bicchieri, Christina; Naquira, Cesar; Levy, Michael Z.

2013-01-01

434

Predictive Validation of an Influenza Spread Model  

PubMed Central

Background Modeling plays a critical role in mitigating impacts of seasonal influenza epidemics. Complex simulation models are currently at the forefront of evaluating optimal mitigation strategies at multiple scales and levels of organization. Given their evaluative role, these models remain limited in their ability to predict and forecast future epidemics leading some researchers and public-health practitioners to question their usefulness. The objective of this study is to evaluate the predictive ability of an existing complex simulation model of influenza spread. Methods and Findings We used extensive data on past epidemics to demonstrate the process of predictive validation. This involved generalizing an individual-based model for influenza spread and fitting it to laboratory-confirmed influenza infection data from a single observed epidemic (1998–1999). Next, we used the fitted model and modified two of its parameters based on data on real-world perturbations (vaccination coverage by age group and strain type). Simulating epidemics under these changes allowed us to estimate the deviation/error between the expected epidemic curve under perturbation and observed epidemics taking place from 1999 to 2006. Our model was able to forecast absolute intensity and epidemic peak week several weeks earlier with reasonable reliability and depended on the method of forecasting-static or dynamic. Conclusions Good predictive ability of influenza epidemics is critical for implementing mitigation strategies in an effective and timely manner. Through the process of predictive validation applied to a current complex simulation model of influenza spread, we provided users of the model (e.g. public-health officials and policy-makers) with quantitative metrics and practical recommendations on mitigating impacts of seasonal influenza epidemics. This methodology may be applied to other models of communicable infectious diseases to test and potentially improve their predictive ability. PMID:23755236

Hyder, Ayaz; Buckeridge, David L.; Leung, Brian

2013-01-01

435

THE SURVIVAL OF FOOT-AND-MOUTH DISEASE VIRUS IN RAW AND PASTEURIZED MILK AND MILK PRODUCTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The foot-and-mouth disease (FMD) virus is not a threat to public health, but is highly contagious to cloven-footed animals. The literature reports that FMD virus has a higher thermal resistance in milk than other viruses. The purpose of this paper is to review experiments that were performed to dete...

436

Mothers produce less aggressive sons with altered immunity when there is a threat of disease during pregnancy  

Microsoft Academic Search

Maternal experience before and during pregnancy is known to play a key role in offspring development. However, the influence of social cues about disease in the maternal environment has not been explored. We indirectly exposed pregnant mice to infected neighbours by housing them next to non-contagious conspecifics infected with Babesia microti. We examined the effect of this indirect immunological exposure

Olivia Curno; Jerzy M. Behnke; Alan G. McElligott; Tom Reader

2008-01-01

437

A Lattice Model for Influenza Spreading  

PubMed Central

We construct a stochastic SIR model for influenza spreading on a D-dimensional lattice, which represents the dynamic contact network of individuals. An age distributed population is placed on the lattice and moves on it. The displacement from a site to a nearest neighbor empty site, allows individuals to change the number and identities of their contacts. The dynamics on the lattice is governed by an attractive interaction between individuals belonging to the same age-class. The parameters, which regulate the pattern dynamics, are fixed fitting the data on the age-dependent daily contact numbers, furnished by the Polymod survey. A simple SIR transmission model with a nearest neighbors interaction and some very basic adaptive mobility restrictions complete the model. The model is validated against the age-distributed Italian epidemiological data for the influenza A(H1N1) during the season, with sensible predictions for the epidemiological parameters. For an appropriate topology of the lattice, we find that, whenever the accordance between the contact patterns of the model and the Polymod data is satisfactory, there is a good agreement between the numerical and the experimental epidemiological data. This result shows how rich is the information encoded in the average contact patterns of individuals, with respect to the analysis of the epidemic spreading of an infectious disease. PMID:23717512

Liccardo, Antonella; Fierro, Annalisa

2013-01-01

438

Sero-prevalence and associated risk factors of peste des petits ruminants and contagious caprine pleuro-pneumonia in goats and sheep in the Southern Zone of Tanzania.  

PubMed

A retrospective Sero-prevalence analysis was conducted in 2012 in order to find out whether contagious caprine pleuro-pneumonia (CCPP) and peste des petits ruminants (PPR) had already been introduced in Mtwara and Lindi regions of Southern Tanzania by 2007 and 2009. A total of 477 randomly selected sera from a bank of 3500 small ruminant samples that were collected as part of Rift Valley Fever surveillance of 2007 in Mtwara and Lindi regions were used in this study. Seroconversion was also evaluated in the 504 sera that were collected in 2009 as part of disease outbreak investigations in Tandahimba and Newala districts of Mtwara region. Seroconversions to CCPP and PPR were tested using competitive ELISA. In addition, information on different variables available in the existing surveillance forms gathered during sampling was used in the analysis of risk factors associated with seropositivity to the two diseases. The overall seroprevalence of CCPP for the sera of 2007 and 2009 in goats was 52.1% (n=447) and 35.5% (n=434) respectively; while in sheep the seroprevalence was 36.7% (n=30) and 22.9% (n=70) respectively. Seroconversion to PPR in goats and sheep was 28.7% (n=434) and 35.7% (n=70) respectively based on the sera of 2009. However, no antibodies were detected in the 2007 sera. Mixed infections were detected in 7.4% (n=434) of the goat and 12.9% (n=70) of sheep samples. Significant risk factors associated with seropositivity to CCPP in 2007 included introduction of new animals in flocks (OR=3.94; 95% CI 1.86-8.36; p<0.001) and raising animals in government farms (OR=4.92; 95% CI 1.57-15.76; p=0.02); whereas, seropositivity to CCPP in 2009 increased with introduction of new animals in flocks (OR=18.82; 95% CI 8.06-43.96; p<0.001), raising animals in government farms (OR=4.04; 95% CI 2.69-6.42; p<0.001) and raising animals in Newala district (OR=2.35; 95% CI 1.53-3.62; p<0.001). On the other hand, predictors for seropositivity to PPR in 2009 were introduction of new animals in flocks (OR=2.83; 95% CI 1.73-4.62; p<0.001) and communal grazing of animals (OR=7.60; 95% CI 1.77-32.58; p=0.01). Therefore, these results show that CCPP was already circulating in goats in the southern zone by 2007 and that PPR was probably introduced thereafter. Their presence in this emerging animal keeping area in Tanzania calls for improved surveillance and control systems. PMID:25022914

Mbyuzi, Albano O; Komba, Erick V G; Kimera, Sharadhuli I; Kambarage, Dominic M

2014-09-01

439

A model for multiseasonal spread of verticillium wilt of lettuce.  

PubMed

Verticillium wilt, caused by Verticillium dahliae, is a destructive disease in lettuce, and the pathogen is seedborne. Even though maximum seed infestation rates of <5% have been detected in commercial lettuce seed lots, it is necessary to establish acceptable contamination thresholds to prevent introduction and establishment of the pathogen in lettuce production fields. However, introduction of inoculum into lettuce fields for experimental purposes to determine its long term effects is undesirable. Therefore, we constructed a simulation model to study the spread of Verticillium wilt following pathogen introduction from seed. The model consists of four components: the first for simulating infection of host plants, the second for simulating reproduction of microsclerotia on diseased plants, the third for simulating the survival of microsclerotia, and the fourth for simulating the dispersal of microsclerotia. The simulation results demonstrated that the inoculum density-disease incidence curve parameters and the dispersal gradients affect disease spread in the field. Although a steep dispersal gradient facilitated the establishment of the disease in a new field with a low inoculum density, a long-tail gradient allowed microsclerotia to be dispersed over greater distances, promoting the disease spread in fields with high inoculum density. The simulation results also revealed the importance of avoiding successive lettuce crops in the same field, reducing survival rate of microsclerotia between crops, and the need for breeding resistance against V. dahliae in lettuce cultivars to lower the number of microsclerotia formed on each diseased plant. The simulation results, however, suggested that, even with a low seed infestation rate, the pathogen would eventually become established if susceptible lettuce cultivars were grown consecutively in the same field for many years. A threshold for seed infestation can be established only when two of the three drivers of the disease-(i) low microsclerotia production per diseased plant, (ii) long-tail dispersal gradient, and (iii) low microsclerotia survival between lettuce crops-are present. PMID:24624952

Wu, B M; Subbarao, K V

2014-09-01

440

Potential corridors and barriers for plague spread in central Asia  

PubMed Central

Background Plague (Yersinia pestis infection) is a vector-borne disease which caused millions of human deaths in the Middle Ages. The hosts of plague are mostly rodents, and the disease is spread by the fleas that feed on them. Currently, the disease still circulates amongst sylvatic rodent populations all over the world, including great gerbil (Rhombomys opimus) populations in Central Asia. Great gerbils are social desert rodents that live in family groups in burrows, which are visible on satellite images. In great gerbil populations an abundance threshold exists, above which plague can spread causing epizootics. The spatial distribution of the host species is thought to influence the plague dynamics, such as the direction of plague spread, however no detailed analysis exists on the possible functional or structural corridors and barriers that are present in this population and landscape. This study aims to fill that gap. Methods Three 20 by 20 km areas with known great gerbil burrow distributions were used to analyse the spatial distribution of the burrows. Object-based image analysis was used to map the landscape at several scales, and was linked to the burrow maps. A novel object-based method was developed – the mean neighbour absolute burrow density difference (MNABDD) – to identify the optimal scale and evaluate the efficacy of using landscape objects as opposed to square cells. Multiple regression using raster maps was used to identify the landscape-ecological variables that explain burrow density best. Functional corridors and barriers were mapped using burrow density thresholds. Cumulative resistance of the burrow distribution to potential disease spread was evaluated using cost distance analysis. A 46-year plague surveillance dataset was used to evaluate whether plague spread was radially symmetric. Results The burrow distribution was found to be non-random and negatively correlated with Greenness, especially in the floodplain areas. Corridors and barriers showed a mostly NWSE alignment, suggesting easier spreading along this axis. This was confirmed by the analysis of the plague data. Conclusions Plague spread had a predominantly NWSE direction, which is likely due to the NWSE alignment of corridors and barriers in the burrow distribution and the landscape. This finding may improve predictions of plague in the future and emphasizes the importance of including landscape analysis in wildlife disease studies. PMID:24171709

2013-01-01

441

77 FR 30293 - Recommendations for the Identification of Hepatitis C Virus (HCV) Chronic Infection  

Federal Register 2010, 2011, 2012, 2013, 2014

...Recommendations for the Identification of Hepatitis C Virus (HCV) Chronic Infection AGENCY: Centers...SUPPLEMENTARY INFORMATION: Hepatitis C virus infection is a contagious liver disease...results from infection with the hepatitis C virus (HCV), which is spread primarily...

2012-05-22

442

Quantum spread spectrum multiple access  

E-print Network

We describe a quantum multiple access scheme that can take separate single photon channels and combine them in the same path. We propose an add-drop multiplexer that can insert or extract a single photon into an optical fibre carrying the qubits of all the other users. The system follows the principle of code division multiple access, a spread spectrum technique widely used in cellular networks.

Juan Carlos Garcia-Escartin; Pedro Chamorro-Posada

2014-11-27

443

Spreading dynamics of water droplets  

NASA Astrophysics Data System (ADS)

The spreading dynamics of water droplets on flat silicon surfaces is investigated. It is shown that, for situations close to complete wetting, the radius evolution with time can be described using a power law with a nonstandard exponent of 1/7. This dynamics is interpreted using a hydrodynamic model with an invariant dissipation profile. Such a description is also consistent with the slow dynamics observed for larger contact angles.

Rieutord, F.; Rayssac, O.; Moriceau, H.

2000-11-01

444

Fractal dimensions of wildfire spreading  

NASA Astrophysics Data System (ADS)

The time series data of 31 wildfires in 2012 in the US were analyzed. The fractal dimensions (FD) of the wildfires during spreading were studied and their geological features were identified. A growth model based on the cellular automata method is proposed here. Numerical study was performed and is shown to give good agreement with the fractal dimensions and scaling behaviors of the corresponding empirical data.

Wang, S.-L.; Lee, H.-I.; Li, S.-P.

2014-08-01

445

Neoplastic lumbosacral radiculoplexopathy in prostate cancer by direct perineural spread: an unusual entity.  

PubMed

Neoplastic lumbosacral plexopathy occurs with some abdominal and pelvic malignancies. Patients present with severe pain radiating from the low back down to the lower extremities, and this progresses to weakness. Neoplastic lumbosacral plexopathy is virtually always associated with known malignancy or obvious pelvic metastatic disease. Uncommonly, prostate cancer can present as a lumbosacral plexopathy occurring through direct pelvic spread. We describe two cases of lumbosacral radiculoplexopathy from infiltrative prostate cancer without evidence of other pelvic or extraprostatic spread. The probable etiology of tumor spreading along prostatic nerves into the lumbosacral plexus (i.e., perineural spread) is discussed as are the potential mechanisms for this unusual mode of cancer dissemination. PMID:16810682

Ladha, Shafeeq S; Spinner, Robert J; Suarez, Guillermo A; Amrami, Kimberly K; Dyck, P James B

2006-11-01

446

Epidemic spread in coupled populations with seasonally varying migration rates  

NASA Astrophysics Data System (ADS)

The H5N1 strain of avian influenza has spread worldwide, and this spread may be due to seasonal migration of birds and mixing of birds from different regions in the wintering grounds. We studied a multipatch model for avian influenza with seasonally varying migration rates. The bird population was divided into two spatially distinct patches, or subpopulations. Within each patch, the disease followed the SIR (susceptible-infected-recovered) model for epidemic spread. Migration rates were varied periodically, with a net flux toward the breeding grounds during the spring and towards the wintering grounds during the fall. The case of two symmetric patches reduced to single-patch SIR dynamics. However, asymmetry in the birth and contact rates in the breeding grounds and wintering grounds led to bifurcations to longer period orbits and chaotic dynamics. We studied the bifurcation structure of the model and the phase relationships between outbreaks in the two patches.

Muzyczyn, Adam; Shaw, Leah B.

2009-03-01

447

Measuring node spreading power by expected cluster degree  

E-print Network

Traditional metrics of node influence such as degree or betweenness identify highly influential nodes, but are rarely usefully accurate in quantifying the spreading power of nodes which are not. Such nodes are the vast majority of the network, and the most likely entry points for novel influences, be they pandemic disease or new ideas. Several recent works have suggested metrics based on path counting. The current work proposes instead using the expected number of infected-susceptible edges, and shows that this measure predicts spreading power in discrete time, continuous time, and competitive spreading processes simulated on large random networks and on real world networks. Applied to the Ugandan road network, it predicts that Ebola is unlikely to pose a pandemic threat.

Lawyer, Glenn

2012-01-01

448

The nationalization of a disease: a paradigm?  

PubMed Central

The early history of the Federal involvement in Hansen's Disease reflects the history of the Public Health Service itself. As a young and aggressive institution, the Public Health Service sought out contagious, infectious diseases that threatened the public health. National resources and national coordination were needed to fight the likes of malaria, hookworm, or smallpox. The customary attack would consist of a field study, determination of the etiology, the method of transmission, and, then, perhaps, preventive measures. An eradication campaign would follow. Leprosy fit perfectly into the model--a disease of unknown etiology, an unknown method of transmission, thought to be highly contagious, and no known cure. The United States launched a major investigation in Hawaii, where the disease was prevalent and its victims conveniently segregated. The investigation failed. The Public Health Service then turned toward segregation and isolation as a way to fulfill its public health role. A bureaucracy was established around the idea that victims of leprosy must be incarcerated for the good of the public. The institutionalization of the Public Health Service and the philosophy upon which its treatment of leprosy was based proved difficult to change when researchers in the field made major scientific breakthroughs in the 1940s. The realization that the disease was only feebly contagious, activities of patient organizations, and pressure from the media and the Congress did not achieve as dramatic results as the sulfone drugs did. The Public Health Service moved, but slowly. What are the lessons in all of this?. Images p401-a p402-a p403-a PMID:3090606

Soviero, D J

1986-01-01

449

Epidemics of emerging animal diseases and food-borne infection problems over the last 5 years in Japan.  

PubMed

There have been several emerging animal diseases and food-borne infection problems occurring in Japan over the last 5 years. We describe brief pictures of these epidemics and our control activities. As acute contagious and/or emerging animal diseases, the foot and mouth disease (FMD) outbreak caused by the Pan-Asian topotype of the type O virus occurred in March 2000 after 92 years of FMD-free status. In 2004, four cases of the highly pathogenic avian influenza (HPAI), which was the first outbreak after 79 years, and caused by the H5N1 subtype, were identified. As part of the responses against these outbreaks, all the animals in the affected farms were destroyed, and movement control areas were established around the infected premises, and a nation-wide intensive survey for FMD and HPAI was performed. As for food-borne or feed-borne infections, the first bovine spongiform encephalopathy (BSE) was identified in September 2001 and 19 more cases have been reported until June 2005. A large outbreak of food-borne infection caused by low-fat milk contaminated with enterotoxin A produced by Staphylococcus aureus, involving more than 13,000 patients, occurred in 2000. In 2003, people who consumed uncooked liver and meat from wild boar and deer developed clinical signs of hepatitis caused by the hepatitis E virus. Pork is also suspected as natural source of virus transmission. Early detection of the first cases and rapid action in preventing and controlling the spread of infections are very important combined with proper risk communication about correct information of the diseases. PMID:17135492

Yamane, Itsuro

2006-10-01

450

Impact of changing societal trends on the spread of infections in American and Canadian homes  

Microsoft Academic Search

Infectious diseases continue to exert a heavy toll on human health even in industrialized countries. Recent data from the World Health Organization suggests that infectious diseases are the leading cause of death in the world. Many changing trends in our society have a known or potential impact on infectious disease spread and may have an impact on the normal routine

Syed A. Sattar; Jason Tetro; V. Susan Springthorpe

1999-01-01

451