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Sample records for human influenza metapneumovirus

  1. Influenza C Virus and Human Metapneumovirus Infections in Hospitalized Children With Lower Respiratory Tract Illness.

    PubMed

    Shimizu, Yukitoshi; Abiko, Chieko; Ikeda, Tatsuya; Mizuta, Katsumi; Matsuzaki, Yoko

    2015-11-01

    A 6-month prospective study in a hospital setting detected influenza C virus and human metapneumovirus in 10.0% (29/289) and 16.6% (48/289), respectively, of children hospitalized with lower respiratory tract illness. Influenza C virus infection had a similar rate of pneumonia (53.3% vs. 57.1%), significantly lower frequency of wheezing (13.3% vs. 68.6%) and higher values of white blood cell and C-reactive protein than human metapneumovirus infection.

  2. Fatal human metapneumovirus and influenza B virus coinfection in an allogeneic hematopoietic stem cell transplant recipient.

    PubMed

    Ghattas, C; Mossad, S B

    2012-10-01

    Human metapneumovirus (hMPV) infection can occur in all age groups with significant morbidity and mortality. Coinfection with influenza virus occurs mainly with influenza type A and all reported cases recovered completely. We report the case of a 61-year-old man who had hematopoietic stem cell transplant for myelodysplastic syndrome. He was admitted to hospital for septic shock and neutropenia, and blood culture was positive for Pseudomonas aeruginosa. He rapidly developed respiratory failure and required ventilator support. His respiratory culture grew P. aeruginosa and hMPV. His course was complicated by persistent shock requiring vasopressor support, and repeat nasopharyngeal swab was positive for influenza type B and hMPV. His condition rapidly deteriorated, his family elected comfort care, and the patient died shortly thereafter. Coinfection with hMPV and influenza virus type B may have a poor outcome and can be fatal, especially in immunocompromised patients.

  3. Human Metapneumovirus.

    PubMed

    Schuster, Jennifer E; Williams, John V

    2014-10-01

    Human metapneumovirus (HMPV), a paramyxovirus identified in 2001, is a leading cause of respiratory tract infections in both children and adults. Seroprevalence studies demonstrate that the primary infection occurs before the age of 5 years, and humans are reinfected throughout life. The four subgroups of HMPV occur with year-to-year variability, and infection with one subgroup confers some serologic cross-protection. Experimental vaccines elicit a humoral response in both animal and human models and have been used to identify antigenic determinants. The main target of protective antibodies is the fusion (F) protein, although many of the remaining eight proteins are immunogenic. Monoclonal antibodies (mAbs) targeting the F protein are both protective and therapeutic in animal models. Most recently, the identification of broadly neutralizing antibodies against HMPV and respiratory syncytial virus demonstrates that common epitopes are present between the two viruses. Broadly neutralizing mAbs have significant clinical implications for prophylaxis and treatment of high-risk hosts as well as vaccine development.

  4. Circulation of human metapneumovirus among children with influenza-like illness in Wuhan, China.

    PubMed

    Kong, Wenhua; Wang, Ying; Zhu, Honghao; Lin, Xinming; Yu, Bin; Hu, Quan; Yang, Xiaobing; Guo, Deyin; Peng, Jinsong; Zhou, Dunjin

    2016-05-01

    Human metapneumovirus (HMPV) is a worldwide distributed pathogen of the respiratory tract. The objectives of this study were to identify HMPV infections among children with influenza-like illness (ILI) in Wuhan and to assess circulation patterns and molecular diversity of HMPV in this area. From July 2008 to December 2013, a total of 3,883 throat swab samples were collected from ILI outpatients under 16 years old. HMPV RNA was detected in 171 samples (4.40%). All the four subtypes of HMPV were identified, among which A2 was the most common subtype (61/145, 42.1%), followed by B1, B2, and A1. During the study period, HMPV circulation presented a biennial alternation between high and low incidence in Wuhan and the seasonal peak also shift between winter and spring in two continuous seasons. Subtype A2, B1, and B2 co-circulated during the study period, with genotype A prevailing in epidemic season 2008-2009 and 2012-2013, and genotype B prevailing during other periods. This large-scale analysis of HMPV prevalence in ILI outpatient children improves the understanding of local HMPV circulation patterns and provides molecular epidemic evidence for comparative analysis of HMPV infection.

  5. Human metapneumovirus in adults.

    PubMed

    Haas, Lenneke E M; Thijsen, Steven F T; van Elden, Leontine; Heemstra, Karen A

    2013-01-08

    Human metapneumovirus (HMPV) is a relative newly described virus. It was first isolated in 2001 and currently appears to be one of the most significant and common human viral infections. Retrospective serologic studies demonstrated the presence of HMPV antibodies in humans more than 50 years earlier. Although the virus was primarily known as causative agent of respiratory tract infections in children, HMPV is an important cause of respiratory infections in adults as well. Almost all children are infected by HMPV below the age of five; the repeated infections throughout life indicate transient immunity. HMPV infections usually are mild and self-limiting, but in the frail elderly and the immunocompromised patients, the clinical course can be complicated. Since culturing the virus is relatively difficult, diagnosis is mostly based on a nucleic acid amplification test, such as reverse transcriptase polymerase chain reaction. To date, no vaccine is available and treatment is supportive. However, ongoing research shows encouraging results. The aim of this paper is to review the current literature concerning HMPV infections in adults, and discuss recent development in treatment and vaccination.

  6. Human Metapneumovirus in Adults

    PubMed Central

    Haas, Lenneke E. M.; Thijsen, Steven F. T.; van Elden, Leontine; Heemstra, Karen A.

    2013-01-01

    Human metapneumovirus (HMPV) is a relative newly described virus. It was first isolated in 2001 and currently appears to be one of the most significant and common human viral infections. Retrospective serologic studies demonstrated the presence of HMPV antibodies in humans more than 50 years earlier. Although the virus was primarily known as causative agent of respiratory tract infections in children, HMPV is an important cause of respiratory infections in adults as well. Almost all children are infected by HMPV below the age of five; the repeated infections throughout life indicate transient immunity. HMPV infections usually are mild and self-limiting, but in the frail elderly and the immunocompromised patients, the clinical course can be complicated. Since culturing the virus is relatively difficult, diagnosis is mostly based on a nucleic acid amplification test, such as reverse transcriptase polymerase chain reaction. To date, no vaccine is available and treatment is supportive. However, ongoing research shows encouraging results. The aim of this paper is to review the current literature concerning HMPV infections in adults, and discuss recent development in treatment and vaccination. PMID:23299785

  7. Long-term impairment of Streptococcus pneumoniae lung clearance is observed after initial infection with influenza A virus but not human metapneumovirus in mice.

    PubMed

    Ludewick, Herbert P; Aerts, Laetitia; Hamelin, Marie-Eve; Boivin, Guy

    2011-07-01

    Human metapneumovirus (hMPV) is a paramyxovirus responsible for respiratory tract infections in humans. Our objective was to investigate whether hMPV could predispose to long-term bacterial susceptibility, such as previously observed with influenza viruses. BALB/c mice were infected with hMPV or influenza A and, 14 days following viral infection, challenged with Streptococcus pneumoniae. Only mice previously infected with influenza A demonstrated an 8% weight loss of their body weight 72 h following S. pneumoniae infection, which correlated with an enhanced lung bacterial replication of >7 log(10) compared with pneumococcus infection alone. This enhanced bacterial replication was not related to altered macrophage or neutrophil recruitment or deficient production of critical cytokines. However, bacterial challenge induced the production of gamma interferon in bronchoalveolar lavages of influenza-infected mice, but not in those of hMPV-infected animals. In conclusion, hMPV does not cause long-term impairment of pneumococcus lung clearance, in contrast to influenza A virus.

  8. Role of Human Metapneumovirus, Influenza A Virus and Respiratory Syncytial Virus in Causing WHO-Defined Severe Pneumonia in Children in a Developing Country

    PubMed Central

    Ali, Asad; Khowaja, Asif Raza; Bashir, Maaman Zahoor; Aziz, Fatima; Mustafa, Sultan; Zaidi, Anita

    2013-01-01

    Objective The role of respiratory viruses in causing severe, life threatening pneumonia in children in developing countries is not well established. Our study aims to determine the role of human metapneumovirus (HMPV), influenza A virus and respiratory syncytial virus (RSV) in children, aged 6 weeks to 2 years, hospitalized with WHO defined severe pneumonia (tachypnea plus any general danger sign or chest in-drawing) at a public sector hospital in Karachi, Pakistan. Methods This study was conducted from November 2010 to September 2011 at Abbassi Shaheed Hospital, a large public tertiary care hospital in Karachi, Pakistan. Children admitted with WHO-defined severe pneumonia were enrolled and throat swabs were obtained to detect respiratory viruses using real time RT-PCR. Chest x-rays of all subjects were obtained and independently interpreted by two radiologists to diagnose radiologic pneumonia. Results 169 children were enrolled. HMPV was detected in 24 (14.2%), influenza A virus in 9 (5.3%) and RSV in 30 (17.8%) children admitted with severe pneumonia. Of 9 patients with influenza A, 8 tested positive for H1N1. Viral etiology was found in 18% of radiologically confirmed pneumonia. HMPV infections peaked in February and April, influenza A was prevalent in January, June and November and RSV infections were most prevalent from June to September. Conclusion HMPV, influenza A and RSV are common causes of WHO-defined severe pneumonia in hospitalized children in Karachi. Knowledge regarding the viral etiology of pediatric pneumonia and individual viral seasonality can help in the recommendation and implementation of appropriate management strategies. PMID:24058625

  9. Human metapneumovirus infection in chimpanzees, United States.

    PubMed

    Slater, Owen M; Terio, Karen A; Zhang, Yange; Erdman, Dean D; Schneider, Eileen; Kuypers, Jane M; Wolinsky, Steven M; Kunstman, Kevin J; Kunstman, Jennifer; Kinsel, Michael J; Gamble, Kathryn C

    2014-12-01

    Zoonotic disease transmission and infections are of particular concern for humans and closely related great apes. In 2009, an outbreak of human metapneumovirus infection was associated with the death of a captive chimpanzee in Chicago, Illinois, USA. Biosecurity and surveillance for this virus in captive great ape populations should be considered.

  10. Human Metapneumovirus, Australia, 2001–2004

    PubMed Central

    Mackay, Ian M.; Bialasiewicz, Seweryn; Jacob, Kevin C.; McQueen, Emily; Harnett, Gerald B.; Siebert, David J.; Masters, I. Brent; Young, Paul R.; Nissen, Michael D.

    2006-01-01

    We examined 10,025 respiratory samples collected for 4 years (2001–2004) and found a 7.1% average annual incidence of human metapneumovirus. The epidemic peak of infection was late winter to spring, and genotyping showed a change in predominant viral genotype in 3 of the 4 years. PMID:16965711

  11. Encephalitis-Associated Human Metapneumovirus Pneumonia in Adult, Australia.

    PubMed

    Fok, Anthony; Mateevici, Cristina; Lin, Belinda; Chandra, Ronil V; Chong, Victor H T

    2015-11-01

    Human metapneumovirus pneumonia, most commonly found in children, was diagnosed in an adult with encephalitis. This case suggests that testing for human metapneumovirus RNA in nasopharyngeal aspirate and cerebrospinal fluid samples should be considered in adults with encephalitis who have a preceding respiratory infection.

  12. Human metapneumovirus infection among outpatient children in Dibrugarh.

    PubMed

    Biswas, Dipankar; Yadav, Kaushal; Borkakoty, Biswajyoti; Mahanta, Jagadish

    2014-11-01

    We describe the prevalence of human metapneumovirus infection in children visiting outpatient department with symptoms of respiratory illness in rural areas of Dibrugarh District of Assam. Human metapneumovirus was observed in 7.2% (20/276) of children aged =5 years with detection of genotypes A2b and B2.

  13. Recent vaccine development for human metapneumovirus

    PubMed Central

    Ren, J.; Phan, T.

    2015-01-01

    Human metapneumovirus (hMPV) and respiratory syncytial virus, its close family member, are two major causes of lower respiratory tract infection in the paediatric population. hMPV is also a common cause of worldwide morbidity and mortality in immunocompromised patients and older adults. Repeated infections occur often, demonstrating a heavy medical burden. However, there is currently no hMPV-specific prevention treatment. This review focuses on the current literature on hMPV vaccine development. We believe that a better understanding of the role(s) of viral proteins in host responses might lead to efficient prophylactic vaccine development. PMID:25667325

  14. Human Metapneumovirus: Lessons Learned over the First Decade †

    PubMed Central

    Schildgen, Verena; van den Hoogen, Bernadette; Fouchier, Ron; Tripp, Ralph A.; Alvarez, Rene; Manoha, Catherine; Williams, John; Schildgen, Oliver

    2011-01-01

    Summary: It has been 10 years since human metapneumovirus (HMPV) was identified as a causative agent of respiratory illness in humans. Since then, numerous studies have contributed to a substantial body of knowledge on many aspects of HMPV. This review summarizes our current knowledge on HMPV, HMPV disease pathogenesis, and disease intervention strategies and identifies a number of areas with key questions to be addressed in the future. PMID:21976607

  15. Structural insights into the human metapneumovirus glycoprotein ectodomain.

    PubMed

    Leyrat, Cedric; Paesen, Guido C; Charleston, James; Renner, Max; Grimes, Jonathan M

    2014-10-01

    Human metapneumovirus is a major cause of respiratory tract infections worldwide. Previous reports have shown that the viral attachment glycoprotein (G) modulates innate and adaptive immune responses, leading to incomplete immunity and promoting reinfection. Using bioinformatics analyses, static light scattering, and small-angle X-ray scattering, we show that the extracellular region of G behaves as a heavily glycosylated, intrinsically disordered polymer. We discuss potential implications of these findings for the modulation of immune responses by G.

  16. Structural Insights into the Human Metapneumovirus Glycoprotein Ectodomain

    PubMed Central

    Leyrat, Cedric; Paesen, Guido C.; Charleston, James; Renner, Max

    2014-01-01

    Human metapneumovirus is a major cause of respiratory tract infections worldwide. Previous reports have shown that the viral attachment glycoprotein (G) modulates innate and adaptive immune responses, leading to incomplete immunity and promoting reinfection. Using bioinformatics analyses, static light scattering, and small-angle X-ray scattering, we show that the extracellular region of G behaves as a heavily glycosylated, intrinsically disordered polymer. We discuss potential implications of these findings for the modulation of immune responses by G. PMID:25031352

  17. [A case of bronchiolitis obliterans secondary to human metapneumovirus bronchiolitis].

    PubMed

    Yeşilbaş, Osman; Şevketoğlu, Esra; Kıhtır, Hasan Serdar; Talip Petmezci, Mey; Bato, Elif; Balkaya, Seda; Hatipoğlu, Nevin; Kuşkucu, Mert Ahmet; Palabıyık, Figen; Çakır, Erkan

    2016-10-01

    Human metapneumovirus (hMPV), formerly classified in Paramyxoviridae family is now moved into Pneumoviridae, which was described as a novel family. It causes upper and lower respiratory tract infections (LRTIs) usually in children younger than five years old. The recent epidemiological studies indicated that hMPV is the second most frequently detected virus in LRTIs of young children, following the respiratory syncytial virus (RSV). Bronchiolitis obliterans (BO) is a chronic obstructive lung disease characterized by fibrosis of the distal respiratory airways. It is usually a result of an inflammatory process triggered by a LRTI related to adenovirus, RSV, Mycoplasma pneumoniae, measles virus, Legionella pneumophila, influenza virus or Bordetella pertussis as a causative agent. In this report, a case of hMPV bronchiolitis complicated with BO has been reported to point out the complications and severity of the clinical progress belongs to this virus. A three-month-old female patient has admitted to our pediatric intensive care unit with the diagnosis of acute bronchiolitis and respiratory failure. She was born at term, weighing 2950 gram and had been hospitalized in newborn intensive care unit for 11 days with the diagnosis of transient tachypnea of the newborn and neonatal sepsis. On auscultation, there were bilateral crepitant rales, wheezing and prolonged expirium. Her oxygen saturation was 97-98% while respiratory support was given with a non-rebreathing reservoir mask. Complete blood count, procalcitonin and C-reactive protein levels were in normal ranges. The chest radiography yielded right middle lobe atalectasia, left paracardiac infiltration and bilateral air trapping. A nasopharyngeal swab sample was analyzed by a commercial multiplex real-time reverse transcriptase-polymerase chain reaction (Thermo Fisher Scientific®, USA) developed for the detection of 15 respiratory viruses. Her sample yielded positive result for only hMPV. On the 4th day of

  18. Live vaccines for human metapneumovirus designed by reverse genetics.

    PubMed

    Buchholz, Ursula J; Nagashima, Kunio; Murphy, Brian R; Collins, Peter L

    2006-10-01

    Human metapneumovirus (HMPV) was first described in 2001 and has quickly become recognized as an important cause of respiratory tract disease worldwide, especially in the pediatric population. A vaccine against HMPV is required to prevent severe disease associated with infection in infancy. The primary strategy is to develop a live-attenuated virus for intranasal immunization, which is particularly well suited against a respiratory virus. Reverse genetics provides a means of developing highly characterized 'designer' attenuated vaccine candidates. To date, several promising vaccine candidates have been developed, each using a different mode of attenuation. One candidate involves deletion of the G glycoprotein, providing attenuation that is probably based on reduced efficiency of attachment. A second candidate involves deletion of the M2-2 protein, which participates in regulating RNA synthesis and whose deletion has the advantageous property of upregulating transcription and increasing antigen synthesis. A third candidate involves replacing the P protein gene of HMPV with its counterpart from the related avian metapneumovirus, thereby introducing attenuation owing to its chimeric nature and host range restriction. Another live vaccine strategy involves using an attenuated parainfluenza virus as a vector to express HMPV protective antigens, providing a bivalent pediatric vaccine. Additional modifications to provide improved vaccines will also be discussed.

  19. Serious outbreak of human metapneumovirus in patients with hematologic malignancies.

    PubMed

    Hoellein, Alexander; Hecker, Judith; Hoffmann, Dieter; Göttle, Franziska; Protzer, Ulrike; Peschel, Christian; Götze, Katharina

    2016-01-01

    Human metapneumovirus (hMPV) is an important cause of lower respiratory tract infection. In healthy subjects infections are usually mild and rarely necessitate hospitalization. However, more serious outcomes have been described for allogeneic stem cell transplant recipients. This study reports an outbreak of hMPV A2 infection in severely immunocompromised adult hematologic cancer patients in a tertiary care unit. HMPV RNA was detected in bronchoalveolar lavage or produced sputum from patients presenting with typical clinical features. A total of 15 patients were diagnosed in a period of 7 weeks. Molecular subtyping revealed infection with genotype A2a virus, implicating nosocomial transmission. Eleven patients (73%) were treated with intravenous immunoglobulins and ribavirin. Ten patients (65%) presented with severe dyspnea, five (33%) required mechanical ventilation. Four patients (26.6%) died from hMPV-associated pneumonia and consequent multi-organ failure. Thus, hMPV is a critical pathogen for patients with hematologic cancers warranting early detection.

  20. Status epilepticus: a possible association with human metapneumovirus infection.

    PubMed

    Webster, Danielle L; Gardner, Aaron H; Dye, Thomas J; Chima, Ranjit S

    2014-03-01

    Human metapneumovirus (hMPV) is a relatively recent addition to the multiplicity of viruses causing respiratory illness in infants and children. Although well described in its ability to cause respiratory illness, there is limited data detailing the association of hMPV with neurologic complications. In this report, we describe 2 toddlers with hMPV infection who presented in status epilepticus and went on to develop respiratory failure. Both patients fully recovered over 2 weeks and were discharged from the hospital with no sequelae. The association between hMPV infection and neurologic complications is increasingly being reported in the literature. Clinicians should be aware of these uncommon manifestations of a common respiratory pathogen and consider testing for hMPV when managing pediatric patients who present with unexplained status epilepticus or encephalitis.

  1. Airway epithelial cell response to human metapneumovirus infection

    SciTech Connect

    Bao, X.; Liu, T.; Spetch, L.; Kolli, D.; Garofalo, R.P.; Casola, A.

    2007-11-10

    Human metapneumovirus (hMPV) is a major cause of lower respiratory tract infections (LRTIs) in infants, elderly and immunocompromised patients. In this study, we show that hMPV can infect in a similar manner epithelial cells representative of different tracts of the airways. hMPV-induced expression of chemokines IL-8 and RANTES in primary small alveolar epithelial cells (SAE) and in a human alveolar type II-like epithelial cell line (A549) was similar, suggesting that A549 cells can be used as a model to study lower airway epithelial cell responses to hMPV infection. A549 secreted a variety of CXC and CC chemokines, cytokines and type I interferons, following hMPV infection. hMPV was also a strong inducer of transcription factors belonging to nuclear factor (NF)-{kappa}B, interferon regulatory factors (IRFs) and signal transducers and activators of transcription (STATs) families, which are known to orchestrate the expression of inflammatory and immunomodulatory mediators.

  2. Human metapneumovirus: review of an important respiratory pathogen.

    PubMed

    Panda, Swagatika; Mohakud, Nirmal Kumar; Pena, Lindomar; Kumar, Subrat

    2014-08-01

    Human metapneumovirus (hMPV), discovered in 2001, most commonly causes upper and lower respiratory tract infections in young children, but is also a concern for elderly subjects and immune-compromised patients. hMPV is the major etiological agent responsible for about 5% to 10% of hospitalizations of children suffering from acute respiratory tract infections. hMPV infection can cause severe bronchiolitis and pneumonia in children, and its symptoms are indistinguishable from those caused by human respiratory syncytial virus. Initial infection with hMPV usually occurs during early childhood, but re-infections are common throughout life. Due to the slow growth of the virus in cell culture, molecular methods (such as reverse transcriptase PCR (RT-PCR)) are the preferred diagnostic modality for detecting hMPV. A few vaccine candidates have been shown to be effective in preventing clinical disease, but none are yet commercially available. Our understanding of hMPV has undergone major changes in recent years and in this article we will review the currently available information on the molecular biology and epidemiology of hMPV. We will also review the current therapeutic interventions and strategies being used to control hMPV infection, with an emphasis on possible approaches that could be used to develop an effective vaccine against hMPV.

  3. Genome-Wide Analysis of Human Metapneumovirus Evolution

    PubMed Central

    Kim, Jin Il; Park, Sehee; Lee, Ilseob; Park, Kwang Sook; Kwak, Eun Jung; Moon, Kwang Mee; Lee, Chang Kyu; Bae, Joon-Yong; Park, Man-Seong; Song, Ki-Joon

    2016-01-01

    Human metapneumovirus (HMPV) has been described as an important etiologic agent of upper and lower respiratory tract infections, especially in young children and the elderly. Most of school-aged children might be introduced to HMPVs, and exacerbation with other viral or bacterial super-infection is common. However, our understanding of the molecular evolution of HMPVs remains limited. To address the comprehensive evolutionary dynamics of HMPVs, we report a genome-wide analysis of the eight genes (N, P, M, F, M2, SH, G, and L) using 103 complete genome sequences. Phylogenetic reconstruction revealed that the eight genes from one HMPV strain grouped into the same genetic group among the five distinct lineages (A1, A2a, A2b, B1, and B2). A few exceptions of phylogenetic incongruence might suggest past recombination events, and we detected possible recombination breakpoints in the F, SH, and G coding regions. The five genetic lineages of HMPVs shared quite remote common ancestors ranging more than 220 to 470 years of age with the most recent origins for the A2b sublineage. Purifying selection was common, but most protein genes except the F and M2-2 coding regions also appeared to experience episodic diversifying selection. Taken together, these suggest that the five lineages of HMPVs maintain their individual evolutionary dynamics and that recombination and selection forces might work on shaping the genetic diversity of HMPVs. PMID:27046055

  4. Paediatric human metapneumovirus infection: epidemiology, prevention and therapy.

    PubMed

    Principi, Nicola; Esposito, Susanna

    2014-03-01

    Since its discovery in 2001, human metapneumovirus (hMPV) has been identified as one of the most frequent causes of upper and lower respiratory tract infections. Although a considerable number of hMPV infections are diagnosed in adults and the elderly, the highest incidence of infection is among children as seropositivity for hMPV approaches 100% by 5-10 years of age. Most of the diseases due to hMPV are mild or moderate, tend to resolve spontaneously, and only require outpatient treatment. However, some may be severe enough to require hospitalisation or, albeit rarely, admission to a paediatric intensive care unit because of acute respiratory failure. Mortality is exceptional, but may occur. The most severe diseases generally affect younger patients, prematurely born children, and children who acquire nosocomial hMPV infection and those with a severe chronic underlying disease. Global hMPV infection has a major impact on national health systems, which is why various attempts have recently been made to introduce effective preventive and therapeutic measures; however, although some are already in the phase of development (including vaccines and monoclonal antibodies), there is currently no substantial possibility of prevention and, despite its limitations, ribavirin is still the only possible treatment. Given the risk of severe disease in various groups of high-risk children and the frequency of infection in the otherwise healthy paediatric population, there is an urgent need for further research aimed at developing effective preventive and therapeutic measures against hMPV.

  5. Role of dietary antioxidants in human metapneumovirus infection.

    PubMed

    Komaravelli, Narayana; Kelley, John P; Garofalo, Matteo P; Wu, Haotian; Casola, Antonella; Kolli, Deepthi

    2015-03-16

    Human metapneumovirus (hMPV) is a major cause of respiratory tract infections in children, elderly and immunocompromised hosts, for which no vaccine or treatment are currently available. Oxidative stress and inflammatory responses represent important pathogenic mechanism(s) of hMPV infection. Here, we explored the potential protective role of dietary antioxidants in hMPV infection. Treatment of airway epithelial cells with resveratrol and quercetin during hMPV infection significantly reduced cellular oxidative damage, inflammatory mediator secretion and viral replication, without affecting viral gene transcription and protein synthesis, indicating that inhibition of viral replication occurred at the level of viral assembly and/or release. Modulation of proinflammatory mediator expression occurred through the inhibition of transcription factor nuclear factor (NF)-κB and interferon regulatory factor (IRF)-3 binding to their cognate site of endogenous gene promoters. Our results indicate the use of dietary antioxidants as an effective treatment approach for modulating hMPV induced lung oxidative damage and inflammation.

  6. Genome-Wide Analysis of Human Metapneumovirus Evolution.

    PubMed

    Kim, Jin Il; Park, Sehee; Lee, Ilseob; Park, Kwang Sook; Kwak, Eun Jung; Moon, Kwang Mee; Lee, Chang Kyu; Bae, Joon-Yong; Park, Man-Seong; Song, Ki-Joon

    2016-01-01

    Human metapneumovirus (HMPV) has been described as an important etiologic agent of upper and lower respiratory tract infections, especially in young children and the elderly. Most of school-aged children might be introduced to HMPVs, and exacerbation with other viral or bacterial super-infection is common. However, our understanding of the molecular evolution of HMPVs remains limited. To address the comprehensive evolutionary dynamics of HMPVs, we report a genome-wide analysis of the eight genes (N, P, M, F, M2, SH, G, and L) using 103 complete genome sequences. Phylogenetic reconstruction revealed that the eight genes from one HMPV strain grouped into the same genetic group among the five distinct lineages (A1, A2a, A2b, B1, and B2). A few exceptions of phylogenetic incongruence might suggest past recombination events, and we detected possible recombination breakpoints in the F, SH, and G coding regions. The five genetic lineages of HMPVs shared quite remote common ancestors ranging more than 220 to 470 years of age with the most recent origins for the A2b sublineage. Purifying selection was common, but most protein genes except the F and M2-2 coding regions also appeared to experience episodic diversifying selection. Taken together, these suggest that the five lineages of HMPVs maintain their individual evolutionary dynamics and that recombination and selection forces might work on shaping the genetic diversity of HMPVs.

  7. Human metapneumovirus in the preterm neonate: current perspectives

    PubMed Central

    Maitre, Nathalie L; Williams, John V

    2016-01-01

    Premature birth (<37 weeks gestation) occurs in ~11% of all births in the US. These infants are at risk of chronic lung disease and respiratory conditions, including bronchopulmonary dysplasia. Respiratory viruses are important causes of acute respiratory illness (ARI) in preterm infants, leading to rehospitalization, increased health care burden, and long-term morbidity. Human metapneumovirus (HMPV) is a paramyxovirus discovered in 2001 that is related to respiratory syncytial virus. Epidemiologic studies show that HMPV is a leading cause of ARI in children and adults worldwide. Prematurity is a major risk factor for severe HMPV disease, requiring hospitalization. Moreover, limited data suggest that HMPV infection during infancy is associated with asthma and recurrent wheezing, which are common long-term pulmonary complication of prematurity. HMPV causes nosocomial outbreaks of ARI in hospitals and long-term care facilities, although there are few studies of the prevalence of HMPV in neonatal intensive care unit populations. HMPV is a common and important virus in premature infants, and caregivers for preterm infants should consider this virus in patients with acute respiratory symptoms. PMID:27891060

  8. Human metapneumovirus in lung transplant recipients: characteristics and outcomes.

    PubMed

    Niggli, Fabian; Huber, Lars C; Benden, Christian; Schuurmans, Macé M

    2016-01-01

    Human metapneumovirus (hMPV) causes serious respiratory tract infections in lung transplant recipients (LTRs). We evaluated the characteristics and adverse drug reactions (ADR) of oral ribavirin therapy for hMPV infections in LTRs. LTRs with respiratory symptoms or suspected infection of unknown origin were routinely sampled with nasopharyngeal swabs (NPS) for virological and bacteriological analysis as part of a diagnostic workup. Medical records of hMPV polymerase chain reaction (PCR)-positive LTRs at the University Hospital of Zurich were reviewed retrospectively. Between January 2012 and June 2014, 12 (80%) of 15 consecutive patients with documented hMPV infection received oral ribavirin therapy (800 mg/d, after 48 h: 400 mg/d). Mean duration of therapy was 28.6 days (range: 11-54). Mean duration of viral shedding was 16.3 days (range: 5-48). In general, oral ribavirin was well tolerated in LTRs. The most common ADR was moderate anaemia. All patients recovered from infection without immediate serious sequelae within 3 months of infection.

  9. [Metapneumovirus infection in an adult].

    PubMed

    Varyasin, V V; Tsinzerling, V A

    2016-01-01

    The paper briefly characterizes human metapneumovirus, a newly discovered pathogen of acute respiratory infections, and gives brief clinical, virological, and pathological data concerning a fatal outcome of a 51-year-old obese woman without severe background pathology. Metapneumovirus infection has been verified by real-time PCR. Morphological examination revealed the signs of subtotal diffuse alveolar damage, ciliary epithelial cell overgrowths, and binucleated macrophages. The changes revealed in the lungs are similar to those as previously described in paramyxovirus infections, but are accompanied by severe nonspecific changes that have been recently observed in swine influenza. Those in the brain meninges, kidneys, pancreas, and intestine may be suggestive of the generalization of the infection. It has been proposed that the properties of the virus may vary.

  10. Human metapneumovirus in Jordan: prevalence and clinical symptoms in hospitalized pediatric patients and molecular virus characterization.

    PubMed

    Qaisy, Lina M; Meqdam, Mamdoh M; Alkhateeb, Asem; Al-Shorman, Abdallah; Al-Rousan, Hiyam O; Al-Mogbel, Mohammed S

    2012-11-01

    Respiratory viral infections account for significant morbidity and mortality especially in young children worldwide. Human metapneumovirus (hMPV) causes illnesses ranging from mild respiratory problems to bronchiolitis and severe pneumonia. From January to December 2007, 220 nasopharyngeal aspirates were collected from children younger ≤ 13 years old hospitalized with lower respiratory tract infection to detect hMPV by revese transcription-polymerase chain reaction and to clone and sequence the hMPV-positive samples. Human metapneumovirus was detected in 28 (12.7%) specimens with a median age of 7 months (range 1.3 to 24 months). Human metapneumovirus type A and type B were detected in 26 (93%) and 8 (28.6%) of specimens, respectively. Coinfection with hMPV type A and type B was detected in 6 (21.4%) specimens positive for hMPV. The major clinical diagnosis of hMPV-positive patients was bronchiolitis (75%). Human metapneumovirus and hMPV type B were found to be significantly associated with bronchiolitis (P = 0.03 and 0.01, respectively). Human metapneumovirus and hMPV type A were found to be significantly associated with pneumonia (P = 0.004 and 0.002, respectively). The main symptoms in patients infected with hMPV were cough (92.9%), fever (82.1%), and wheezing (78.6%), with a significant association of hMPV type A with fever (P = 0.018). Human metapneumovirus was seasonally distributed; most infections with hMPV were reported in the late winter and early spring. The peak of hMPV incidence was in February (10/28; 35.7%). Sequencing of purified plasmid DNA was performed in forward and reverse direction to confirm the results of hMPV-positive samples which scored 97% identity to hMPV type A genome isolate NL/17/00 and showing C-T variation that had no effect on the amino acid sequence F(Phe)-F(Phe).

  11. Human Metapneumovirus: Insights from a Ten-Year Molecular and Epidemiological Analysis in Germany

    PubMed Central

    Reiche, Janine; Jacobsen, Sonja; Neubauer, Katrin; Hafemann, Susi; Nitsche, Andreas; Milde, Jeanette; Wolff, Thorsten; Schweiger, Brunhilde

    2014-01-01

    Human metapneumovirus (HMPV) is a cause of respiratory tract illness at all ages. In this study the epidemiological and molecular diversity among patients of different ages was investigated. Between 2000–2001 and 2009–2010, HMPV was detected in 3% (138/4,549) of samples from outpatients with influenza-like illness with a new, sensitive real-time RT-PCR assay. Several hundred (797) clinical specimens from hospitalized children below the age of 4 years with acute respiratory illness were investigated and HMPV was detected in 11.9% of them. Investigation of outpatients revealed that HMPV infections occurred in individuals of all ages but were most prevalent in children (0–4 years) and the elderly (>60 years). The most present clinical features of HMPV infections were cough, bronchitis, fever/shivers and pneumonia. About two thirds of HMPV-positive samples were detected in February and March throughout the study period. Molecular characterization of HMPV revealed a complex cyclic pattern of group dominance where HMPV subgroup A and B viruses predominated in general for three consecutive seasons. German HMPV represented all genetic lineages including A1, A2, B1, B2, sub-clusters A2a and A2b. For Germany, not only time-dependent circulation of lineages and sub-clusters was observed but also co-circulation of two or three predominant lineages. Two newly emerging amino acid substitutions (positions 223 and 280) of lineage B2 were detected in seven German HMPV sequences. Our study gives new insights into the molecular epidemiology of HMPV in in- and outpatients over a time period of 10 years for the first time. It is one of only few long-term surveillance studies in Europe, and allows comparative molecular analyses of HMPV circulating worldwide. PMID:24505479

  12. Role of human metapneumovirus, human coronavirus NL63 and human bocavirus in infants and young children with acute wheezing.

    PubMed

    Smuts, Heidi; Workman, Lesley; Zar, Heather J

    2008-05-01

    The role of the novel respiratory viruses, human metapneumovirus (hMPV), human coronavirus NL63 (HCoV NL63) and human bocavirus (HBoV), in wheezing illness in children has not been well studied, especially in Africa. The aim of this study was to investigate the prevalence of hMPV, HCoV NL63 and HBoV in South African children with acute wheezing. A prospective study of consecutive children presenting with acute wheezing to a pediatric hospital from May 2004 to November 2005 was undertaken. A nasal swab was taken for reverse transcription-polymerase chain reaction (RT-PCR) and PCR for hMPV, HCoV NL63 and HBoV; when positive, the genes were sequenced. Shell vial culture for RSV, influenza A and B viruses, adenovirus and parainfluenza viruses 1, 2, 3 was performed on every 5th sample. Two hundred and forty two nasal swabs were collected from 238 children (median age 12.4 months). A novel respiratory virus was found in 44/242 (18.2%). hMPV, HBoV, and HCoV NL63 was found in 20 (8.3%), 18 (7.4%), and 6 (2.4%) of samples, respectively. Fifteen of 59 (25%) samples were positive for other respiratory viruses. Viral co-infections, occurred in 6/242 (2.5%). Phylogenetic analysis showed co-circulation of hMPV and HCoV NL63 A and B lineages, although only HBoV genotype st2 was found. Viruses are an important cause of wheezing in preschool children; hMPV, HCoV NL63, and HBoV are less common than the usual respiratory pathogens.

  13. Antiviral Activity of Favipiravir (T-705) against a Broad Range of Paramyxoviruses In Vitro and against Human Metapneumovirus in Hamsters

    PubMed Central

    Jochmans, D.; van Nieuwkoop, S.; Smits, S. L.; Neyts, J.; Fouchier, R. A. M.

    2016-01-01

    The clinical impact of infections with respiratory viruses belonging to the family Paramyxoviridae argues for the development of antiviral therapies with broad-spectrum activity. Favipiravir (T-705) has demonstrated potent antiviral activity against multiple RNA virus families and is presently in clinical evaluation for the treatment of influenza. Here we demonstrate in vitro activity of T-705 against the paramyxoviruses human metapneumovirus (HMPV), respiratory syncytial virus, human parainfluenza virus, measles virus, Newcastle disease virus, and avian metapneumovirus. In addition, we demonstrate activity against HMPV in hamsters. T-705 treatment inhibited replication of all paramyxoviruses tested in vitro, with 90% effective concentration (EC90) values of 8 to 40 μM. Treatment of HMPV-challenged hamsters with T-705 at 200 mg/kg of body weight/day resulted in 100% protection from infection of the lungs. In all treated and challenged animals, viral RNA remained detectable in the respiratory tract. The observation that T-705 treatment had a significant effect on infectious viral titers, with a limited effect on viral genome titers, is in agreement with its proposed mode of action of viral mutagenesis. However, next-generation sequencing of viral genomes isolated from treated and challenged hamsters did not reveal (hyper)mutation. Polymerase activity assays revealed a specific effect of T-705 on the activity of the HMPV polymerase. With the reported antiviral activity of T-705 against a broad range of RNA virus families, this small molecule is a promising broad-range antiviral drug candidate for limiting the viral burden of paramyxoviruses and for evaluation for treatment of infections with (re)emerging viruses, such as the henipaviruses. PMID:27185803

  14. Antiviral Activity of Favipiravir (T-705) against a Broad Range of Paramyxoviruses In Vitro and against Human Metapneumovirus in Hamsters.

    PubMed

    Jochmans, D; van Nieuwkoop, S; Smits, S L; Neyts, J; Fouchier, R A M; van den Hoogen, B G

    2016-08-01

    The clinical impact of infections with respiratory viruses belonging to the family Paramyxoviridae argues for the development of antiviral therapies with broad-spectrum activity. Favipiravir (T-705) has demonstrated potent antiviral activity against multiple RNA virus families and is presently in clinical evaluation for the treatment of influenza. Here we demonstrate in vitro activity of T-705 against the paramyxoviruses human metapneumovirus (HMPV), respiratory syncytial virus, human parainfluenza virus, measles virus, Newcastle disease virus, and avian metapneumovirus. In addition, we demonstrate activity against HMPV in hamsters. T-705 treatment inhibited replication of all paramyxoviruses tested in vitro, with 90% effective concentration (EC90) values of 8 to 40 μM. Treatment of HMPV-challenged hamsters with T-705 at 200 mg/kg of body weight/day resulted in 100% protection from infection of the lungs. In all treated and challenged animals, viral RNA remained detectable in the respiratory tract. The observation that T-705 treatment had a significant effect on infectious viral titers, with a limited effect on viral genome titers, is in agreement with its proposed mode of action of viral mutagenesis. However, next-generation sequencing of viral genomes isolated from treated and challenged hamsters did not reveal (hyper)mutation. Polymerase activity assays revealed a specific effect of T-705 on the activity of the HMPV polymerase. With the reported antiviral activity of T-705 against a broad range of RNA virus families, this small molecule is a promising broad-range antiviral drug candidate for limiting the viral burden of paramyxoviruses and for evaluation for treatment of infections with (re)emerging viruses, such as the henipaviruses.

  15. Identification of human metapneumovirus genotypes A and B from clinical specimens by reverse transcription loop-mediated isothermal amplification.

    PubMed

    Song, Qinwei; Zhu, Runan; Sun, Yu; Zhao, Linqing; Wang, Fang; Deng, Jie; Qian, Yuan

    2014-02-01

    Human metapneumovirus (hMPV) has been recognized as an important pathogen for acute respiratory infections in children worldwide and classified into genotypes A and B. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay is a rapid diagnostic method for detecting nucleic acids with a single step under isothermal conditions in less than 1h. RT-LAMP targeting the M gene of hMPV was developed for detecting and identifying hMPV genotypes A and B. The detection limit of the genotype-specific hMPV RT-LAMP assay was 10 times greater than that of conventional reverse transcription polymerase chain reaction (RT-PCR). No cross-reactivity was found with respiratory syncytial virus, parainfluenza virus 1-3, adenovirus, human bocavirus, human rhinovirus, influenza virus A and B, human coronaviruses and enteroviruses. One hundred and fifteen clinical specimens were detected for hMPV genotypes A and B with RT-LAMP, RT-PCR and real-time SYBR PCR. Kappa coefficients showed that there was a good agreement among these three methods. Compared with RT-PCR and real-time SYBR PCR, the genotype-specific RT-LAMP showed better specificity, sensitivity and is more convenient to perform with reduced turn-around time.

  16. Acute clearance of human metapneumovirus occurs independently of natural killer cells.

    PubMed

    Wen, Sherry C; Tollefson, Sharon J; Johnson, Monika; Gilchuk, Pavlo; Boyd, Kelli L; Shepherd, Bryan; Joyce, Sebastian; Williams, John V

    2014-09-01

    Human metapneumovirus (HMPV) is a major cause of respiratory disease. The role of NK cells in protection against HMPV is unclear. We show that while HMPV-infected C57BL/6 mice had higher numbers of functional lung NK cells than mock-treated mice, comparing NK cell-depleted and control mice did not reveal differences in lung viral titers, histopathology, cytokine levels, or T cell numbers or function. These data indicate that NK cells are not required for host control of HMPV.

  17. [Monoinfection of human Metapneumovirus in Cordoba: first clinical and epidemiological research in children with respiratory infection in 2011].

    PubMed

    Rodriguez, Pamela Elizabeth; Adamo, María Pilar; Paglini, María Gabriela; Moreno, Laura; Camara, Jorge Augusto; Camara, Alicia

    2016-01-01

    Human metapneumovirus (hMPV) RNA virus discovered in 2001, is a pathogen associated with acute respiratory infection (ARI) in children under 5 years; its prevalence ranges from 5-15%. In Córdoba, it is not integrated into the viral research in patients with low IRA (LARI).

  18. Human Influenza Virus Infections.

    PubMed

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

    Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection.

  19. Aberrant T cell immunity triggered by human Respiratory Syncytial Virus and human Metapneumovirus infection.

    PubMed

    González, Andrea E; Lay, Margarita K; Jara, Evelyn L; Espinoza, Janyra A; Gómez, Roberto S; Soto, Jorge; Rivera, Claudia A; Abarca, Katia; Bueno, Susan M; Riedel, Claudia A; Kalergis, Alexis M

    2016-12-02

    Human Respiratory syncytial virus (hRSV) and human metapneumovirus (hMPV) are the two major etiological viral agents of lower respiratory tract diseases, affecting mainly infants, young children and the elderly. Although the infection of both viruses trigger an antiviral immune response that mediate viral clearance and disease resolution in immunocompetent individuals, the promotion of long-term immunity appears to be deficient and reinfection are common throughout life. A possible explanation for this phenomenon is that hRSV and hMPV, can induce aberrant T cell responses, which leads to exacerbated lung inflammation and poor T and B cell memory immunity. The modulation of immune response exerted by both viruses include different strategies such as, impairment of immunological synapse mediated by viral proteins or soluble factors, and the induction of pro-inflammatory cytokines by epithelial cells, among others. All these viral strategies contribute to the alteration of the adaptive immunity in order to increase the susceptibility to reinfections. In this review, we discuss current research related to the mechanisms underlying the impairment of T and B cell immune responses induced by hRSV and hMPV infection. In addition, we described the role each virulence factor involved in immune modulation caused by these viruses.

  20. Serologic Cross-Reactions between Nucleocapsid Proteins of Human Respiratory Syncytial Virus and Human Metapneumovirus

    PubMed Central

    Zhang, Yange; Pohl, Jan; Brooks, W. Abdullah

    2015-01-01

    Human respiratory syncytial virus (hRSV) and human metapneumovirus (hMPV) share virologic and epidemiologic features and cause clinically similar respiratory illness predominantly in young children. In a previous study of acute febrile respiratory illness in Bangladesh, we tested paired serum specimens from 852 children presenting fever and cough for diagnostic increases in titers of antibody to hRSV and hMPV by enzyme immunoassay (EIA). Unexpectedly, of 93 serum pairs that showed a ≥4-fold increase in titers of antibody to hRSV, 24 (25.8%) showed a concurrent increase in titers of antibody to hMPV; of 91 pairs showing an increase to hMPV, 13 (14.3%) showed a concurrent increase to hRSV. We speculated that common antigens shared by these viruses explain this finding. Since the nucleocapsid (N) proteins of these viruses show the greatest sequence homology, we tested hyperimmune antisera prepared for each virus against baculovirus-expressed recombinant N (recN) proteins for potential cross-reactivity. The antisera were reciprocally reactive with both proteins. To localize common antigenic regions, we first expressed the carboxy domain of the hMPV N protein that was the most highly conserved region within the hRSV N protein. Although reciprocally reactive with antisera by Western blotting, this truncated protein did not react with hMPV IgG-positive human sera by EIA. Using 5 synthetic peptides that spanned the amino-terminal portion of the hMPV N protein, we identified a single peptide that was cross-reactive with human sera positive for either virus. Antiserum prepared for this peptide was reactive with recN proteins of both viruses, indicating that a common immunoreactive site exists in this region. PMID:25740767

  1. Immune Response to Human Metapneumovirus Infection: What We Have Learned from the Mouse Model

    PubMed Central

    Cheemarla, Nagarjuna R.; Guerrero-Plata, Antonieta

    2015-01-01

    Human Metapneumovirus (hMPV) is a leading respiratory viral pathogen associated with bronchiolitis, pneumonia, and asthma exacerbation in young children, the elderly and immunocompromised individuals. The development of a potential vaccine against hMPV requires detailed understanding of the host immune system, which plays a significant role in hMPV pathogenesis, susceptibility and vaccine efficacy. As a result, animal models have been developed to better understand the mechanisms by which hMPV causes disease. Several animal models have been evaluated and established so far to study the host immune responses and pathophysiology of hMPV infection. However, inbred laboratory mouse strains have been one of the most used animal species for experimental modeling and therefore used for the studies of immunity and immunopathogenesis to hMPV. This review summarizes the contributions of the mouse model to our understanding of the immune response against hMPV infection. PMID:26393657

  2. Molecular epidemiology of human metapneumovirus from 2005 to 2011 in Fukui, Japan.

    PubMed

    Nakamura, Masako; Hirano, Eiko; Ishiguro, Fubito; Mizuta, Katsumi; Noda, Masahiro; Tanaka, Ryota; Tsukagoshi, Hiroyuki; Kimura, Hirokazu

    2013-01-01

    To investigate the molecular epidemiology of human metapneumovirus (HMPV) infections in acute respiratory infections (ARI), we performed genetic analysis of the F gene in HMPV from patients with ARI in Fukui Prefecture from August 2005 to July 2011. HMPV was detected in 53 of 741 nasopharyngeal swabs (7.2%). Phylogenetic analysis helped us assign 31 strains to subgroup A2, 1 strain to subgroup B1, and 21 strains to subgroup B2. The prevalence of HMPV was peaked between January and June. A high degree of nucleotide identity was seen among subgroup A2 strains (95.6-100%) and subgroup B2 strains (97.5-100%). In addition, no positively selected sites (substitutions) were found in the F gene in these HMPV strains. The results suggest that the prevalent HMPV strains in Fukui were associated with various ARI in Japan during the investigation period.

  3. Human metapneumovirus G protein is highly conserved within but not between genetic lineages.

    PubMed

    Yang, Chin-Fen; Wang, Chiaoyin K; Tollefson, Sharon J; Lintao, Linda D; Liem, Alexis; Chu, Marla; Williams, John V

    2013-06-01

    Human metapneumovirus (HMPV) is an important cause of acute respiratory illnesses in children. HMPV encodes two major surface glycoproteins, fusion (F) and glycoprotein (G). The function of G has not been fully established, though it is dispensable for in vitro and in vivo replication. We analyzed 87 full-length HMPV G sequences from isolates collected over 20 years. The G sequences fell into four subgroups with a mean 63 % amino acid identity (minimum 29 %). The length of G varied from 217 to 241 residues. Structural features such as proline content and N- and O-glycosylation sites were present in all strains but quite variable between subgroups. There was minimal drift within the subgroups over 20 years. The estimated time to the most recent common ancestor was 215 years. HMPV G was conserved within lineages over 20 years, suggesting functional constraints on diversity. However, G was poorly conserved between subgroups, pointing to potentially distinct roles for G among different viral lineages.

  4. Molecular epidemiology of human metapneumovirus from 2009 to 2011 in Okinawa, Japan.

    PubMed

    Nidaira, Minoru; Taira, Katsuya; Hamabata, Hirotsune; Kawaki, Tatsuyoshi; Gushi, Kazuo; Mahoe, Youko; Maeshiro, Noriyuki; Azama, Yasuhito; Okano, Shou; Kyan, Hisako; Kudaka, Jun; Tsukagoshi, Hiroyuki; Noda, Masahiro; Kimura, Hirokazu

    2012-07-01

    To clarify the molecular epidemiology of human metapneumovirus (HMPV) in Okinawa Prefecture, located in a subtropical region of Japan, we performed genetic analysis of the F gene in HMPV from patients with acute respiratory infection from January 2009 to December 2011. HMPV was detected in 18 of 485 throat swabs (3.7%). Phylogenetic analysis showed that 17 strains belonged to subgroup A2 and 1 strain belonged to subgroup B1. We did not observe seasonal prevalence of HMPV during the investigation period. A high level of sequence identity was observed in the strains belonging to subgroup A2 (>95%), and no amino acid substitution was found compared with other strains detected in Japan and other countries. The pairwise distance values among the present strains belonging to subgroup A2 were short. Our results suggest that the predominant HMPV strains belonging to A2 are highly homologous and seasonal epidemics were not seen in Okinawa during the investigation period.

  5. High Prevalence of Human Metapneumovirus Infection in Young Children and Genetic Heterogeneity of the Viral Isolates

    PubMed Central

    Viazov, S.; Ratjen, F.; Scheidhauer, R.; Fiedler, M.; Roggendorf, M.

    2003-01-01

    RNA of the newly identified human metapneumovirus (HMPV) was detected in nasopharyngeal aspirates of 11 of 63 (17.5%) young children with respiratory tract disease. Markers of infection caused by another member of the Pneumovirinae subfamily of the family Paramyxoviridae, respiratory syncytial virus (RSV), were identified in 15 of these patients (23.8%). Three patients were simultaneously infected with HMPV and RSV. Studies of the clinical characteristics of HMPV-infected children did not reveal any difference between HMPV-infected patients and a control population of RSV-infected patients with regard to disease severity, but the duration of symptoms was significantly shorter for HMPV-infected patients. Phylogenetic analysis of the amplified viral genome fragments confirmed the existence and simultaneous circulation within one epidemic season of HMPV isolates belonging to two genetic lineages. PMID:12843040

  6. Suppression of human metapneumovirus (HMPV) infection by the innate sensing gene CEACAM1

    PubMed Central

    Drori, Yaron; Yamin, Rachel; Danziger, Oded; Zamostiano, Rachel; Mandelboim, Michal; Bacharach, Eran; Mandelboim, Ofer

    2016-01-01

    The innate sensing system is equipped with PRRs specialized in recognizing molecular structures (PAMPs) of various pathogens. This leads to the induction of anti-viral genes and inhibition of virus growth. Human Metapneumovirus (HMPV) is a major respiratory virus that causes an upper and lower respiratory tract infection in children. In this study we show that upon HMPV infection, the innate sensing system detects the viral RNA through the RIG-I sensor leading to induction of CEACAM1 expression. We further show that CEACAM1 is induced via binding of IRF3 to the CEACAM1 promoter. We demonstrate that induction of CEACAM1 suppresses the viral loads via inhibition of the translation machinery in the infected cells in an SHP2-dependent manner. In summary, we show here that HMPV-infected cells upregulates CEACAM1 to restrict HMPV infection. PMID:27634893

  7. Phylogenetic analysis of human metapneumovirus among children with acute respiratory infections in Kuala Lumpur, Malaysia.

    PubMed

    Nor'e, S S; Sam, I C; Mohamad Fakri, E F; Hooi, P S; Nathan, A M; de Bruyne, J A; Jafar, F; Hassan, A; AbuBakar, S; Chan, Y F

    2014-09-01

    Human metapneumovirus (HMPV) is a recently discovered cause of viral respiratory infections. We describe clinical and molecular epidemiology of HMPV cases diagnosed in children with respiratory infection at University of Malaya Medical Centre, Kuala Lumpur, Malaysia. The prevalence rate of HMPV between 2010 and 2012 was 1.1%, and HMPV contributed 6.5% of confirmed viral respiratory infections. The HMPV patients had a median age of 1.6 years, and a median hospital admission of 4 days. The most common clinical presentations were fever, rhinitis, pneumonia, vomiting/diarrhoea, and bronchiolitis. Based on the partial sequences of F fusion gene from 26 HMPV strains, 14 (54%) were subgenotype A2b, which was predominant in 2010; 11 (42%) were subgenotype B1, which was predominant in 2012; and 1 (4%) was subgenotype A2a. Knowledge of the circulating subgenotypes in Malaysia, and the displacement of predominant subgenotypes within 3 years, is useful data for future vaccine planning.

  8. Avian Influenza A Virus Infections in Humans

    MedlinePlus

    ... this? Submit Button Past Newsletters Avian Influenza A Virus Infections in Humans Language: English Español Recommend ... with Avian Influenza A Viruses Avian Influenza A Virus Infections in Humans Although avian influenza A viruses ...

  9. Avian Metapneumoviruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian metapneumovirus (aMPV) is an economically important virus that is the primary causal agent of turkey rhinotracheitis (TRT), also known as avian rhinotracheitis (ART). The virus causes an acute highly contagious infection of the upper respiratory tract in turkeys and was first isolated from tur...

  10. NK-cell receptors NKp46 and NCR1 control human metapneumovirus infection.

    PubMed

    Diab, Mohammad; Glasner, Ariella; Isaacson, Batya; Bar-On, Yotam; Drori, Yaron; Yamin, Rachel; Duev-Cohen, Alexandra; Danziger, Oded; Zamostiano, Rachel; Mandelboim, Michal; Jonjic, Stipan; Bacharach, Eran; Mandelboim, Ofer

    2017-02-13

    Natural killer (NK) cells are capable of killing various pathogens upon stimulation of activating receptors. Human metapneumovirus (HMPV) is a respiratory virus, which was discovered in 2001 and is responsible for acute respiratory tract infection in infants and children worldwide. HMPV infection is very common, infecting around 70% of all children under the age of five. Under immune suppressive conditions, HMPV infection can be fatal. Not much is known on how NK cells respond to HMPV. In this study, using reporter assays and NK-cell cytotoxicity assays performed with human and mouse NK cells, we demonstrated that the NKp46-activating receptor and its mouse orthologue Ncr1, both members of the natural cytotoxicity receptor (NCR) family, recognized an unknown ligand expressed by HMPV-infected human cells. We demonstrated that MHC class I is upregulated and MICA is downregulated upon HMPV infection. We also characterized mouse NK-cell phenotype in the blood and the lungs of HMPV-infected mice and found that lung NK cells are more activated and expressing NKG2D, CD43, CD27, KLRG1, and CD69 compared to blood NK cells regardless of HMPV infection. Finally, we demonstrated, using Ncr1-deficient mice, that NCR1 plays a critical role in controlling HMPV infection.

  11. Structural basis for antibody cross-neutralization of respiratory syncytial virus and human metapneumovirus.

    PubMed

    Wen, Xiaolin; Mousa, Jarrod J; Bates, John T; Lamb, Robert A; Crowe, James E; Jardetzky, Theodore S

    2017-01-30

    Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) are two closely related viruses that cause bronchiolitis and pneumonia in infants and the elderly(1), with a significant health burden(2-6). There are no licensed vaccines or small-molecule antiviral treatments specific to these two viruses at present. A humanized murine monoclonal antibody (palivizumab) is approved to treat high-risk infants for RSV infection(7,8), but other treatments, as well as vaccines, for both viruses are still in development. Recent epidemiological modelling suggests that cross-immunity between RSV, HMPV and human parainfluenzaviruses may contribute to their periodic outbreaks(9), suggesting that a deeper understanding of host immunity to these viruses may lead to enhanced strategies for their control. Cross-reactive neutralizing antibodies to the RSV and HMPV fusion (F) proteins have been identified(10,11). Here, we examine the structural basis for cross-reactive antibody binding to RSV and HMPV F protein by two related, independently isolated antibodies, MPE8 and 25P13. We solved the structure of the MPE8 antibody bound to RSV F protein and identified the 25P13 antibody from an independent blood donor. Our results indicate that both antibodies use germline residues to interact with a conserved surface on F protein that could guide the emergence of cross-reactivity. The induction of similar cross-reactive neutralizing antibodies using structural vaccinology approaches could enhance intrinsic cross-immunity to these paramyxoviruses and approaches to controlling recurring outbreaks.

  12. Human metapneumovirus Induces Reorganization of the Actin Cytoskeleton for Direct Cell-to-Cell Spread

    PubMed Central

    El Najjar, Farah; Cifuentes-Muñoz, Nicolás; Zhu, Haining; Buchholz, Ursula J.; Moncman, Carole L.; Dutch, Rebecca Ellis

    2016-01-01

    Paramyxovirus spread generally involves assembly of individual viral particles which then infect target cells. We show that infection of human bronchial airway cells with human metapneumovirus (HMPV), a recently identified paramyxovirus which causes significant respiratory disease, results in formation of intercellular extensions and extensive networks of branched cell-associated filaments. Formation of these structures is dependent on actin, but not microtubule, polymerization. Interestingly, using a co-culture assay we show that conditions which block regular infection by HMPV particles, including addition of neutralizing antibodies or removal of cell surface heparan sulfate, did not prevent viral spread from infected to new target cells. In contrast, inhibition of actin polymerization or alterations to Rho GTPase signaling pathways significantly decreased cell-to-cell spread. Furthermore, viral proteins and viral RNA were detected in intercellular extensions, suggesting direct transfer of viral genetic material to new target cells. While roles for paramyxovirus matrix and fusion proteins in membrane deformation have been previously demonstrated, we show that the HMPV phosphoprotein extensively co-localized with actin and induced formation of cellular extensions when transiently expressed, supporting a new model in which a paramyxovirus phosphoprotein is a key player in assembly and spread. Our results reveal a novel mechanism for HMPV direct cell-to-cell spread and provide insights into dissemination of respiratory viruses. PMID:27683250

  13. Human metapneumovirus inhibits the IL-6-induced JAK/STAT3 signalling cascade in airway epithelium.

    PubMed

    Mitzel, Dana N; Jaramillo, Richard J; Stout-Delgado, Heather; Senft, Albert P; Harrod, Kevin S

    2014-01-01

    The host cytokine IL-6 plays an important role in host defence and prevention of lung injury from various pathogens, making IL-6 an important mediator in the host's susceptibility to respiratory infections. The cellular response to IL-6 is mediated through a Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) signal transduction pathway. Human metapneumovirus (hMPV) is an important causative agent of viral respiratory infections known to inhibit the IFN-mediated activation of STAT1. However, little is known about the interactions between this virus and other STAT signalling cascades. Herein, we showed that hMPV can attenuate the IL-6-mediated JAK/STAT3 signalling cascade in lung epithelial cells. HMPV inhibited a key event in this pathway by impeding the phosphorylation and nuclear translocation of STAT3 in A549 cells and in primary normal human bronchial epithelial cells. Further studies established that hMPV interrupted the IL-6-induced JAK/STAT pathway early in the signal transduction pathway by blocking the phosphorylation of JAK2. By antagonizing the IL-6-mediated JAK/STAT3 pathway, hMPV perturbed the expression of IL-6-inducible genes important for apoptosis, cell differentiation and growth. Infection with hMPV also differentially regulated the effects of IL-6 on apoptosis. Thus, hMPV regulation of these genes could usurp the protective roles of IL-6, and these data provide insight into an important element of viral pathogenesis.

  14. Human metapneumovirus associated with community-acquired pneumonia in children in Beijing, China.

    PubMed

    Lu, Guilan; Li, Jianguo; Xie, Zhengde; Liu, Chunyan; Guo, Li; Vernet, Guy; Shen, Kunling; Wang, Jianwei

    2013-01-01

    Community-acquired pneumonia is a major cause of morbidity and mortality in children worldwide. However, few studies have been conducted on the infection of human metapneumovirus (hMPV) associated with pediatric community-acquired pneumonia in China. Nasopharyngeal aspirates were collected between July 2008 and June 2010 from 1,028 children, aged ≤16.5 years, who were diagnosed with community-acquired pneumonia in Beijing, China. Reverse-transcriptase polymerase chain reaction was used to screen the samples for hMPV and common respiratory viruses. hMPV was detected in 6.3% of the patients with community-acquired pneumonia. This detection rate is the third highest for a respiratory virus in children with community-acquired pneumonia, after that of rhinovirus (30.9%) and respiratory syncytial virus (30.7%). The detection rate of hMPV in 2008/2009 (42/540, 7.8%) was significantly higher than in 2009/2010 (23/488, 4.7%; χ(2)  = 4.065, P = 0.044). The hMPV subtypes A2, B1, and B2 were found to co-circulate, with A2 being most prevalent. These results indicate that hMPV plays a substantial role in pediatric community-acquired pneumonia in China. Overall, these findings provide a better understanding of the epidemiological and clinical features of hMPV infections.

  15. Human metapneumovirus prevalence and molecular epidemiology in respiratory outbreaks in Ontario, Canada.

    PubMed

    Neemuchwala, Alefiya; Duvvuri, Venkata R; Marchand-Austin, Alex; Li, Aimin; Gubbay, Jonathan B

    2015-02-01

    Human metapneumovirus (hMPV) has been identified previously as a cause of respiratory outbreaks in adults, including the elderly. The objective of this study was to document respiratory outbreaks that were caused by hMPV in Ontario, Canada and to identify the various circulating genotypes during April 2009-February 2012. The majority of the outbreaks that were part of this study were in adults (>65 years). Total nucleic acid extraction was done on 123 residual anonymized clinical specimens from 51 different respiratory outbreaks. Specimens were subjected to PCR amplification and Sanger sequencing targeting the F and G genes of hMPV. Phylogenetic analysis was performed to identify genotypes. HMPV accounted for 195 (8.5%) of 2,292 respiratory outbreaks. Genotype A2b was most prevalent, detected in 28 (54.9%) of 51 typed hMPV-positive outbreaks. The genotype A2b2 that was described recently was also identified. In earlier reports, subtype A1 was reported in Canada which was absent in the specimens typed in this study. This shift in genotype may be significant in terms of disease severity, and for any future vaccine considerations. Regular testing for hMPV should be done as part of outbreak investigation.

  16. Mitochondrial antiviral-signalling protein plays an essential role in host immunity against human metapneumovirus.

    PubMed

    Deng, Junfang; Chen, Yu; Liu, Guangliang; Ren, Junping; Go, Caroline; Ivanciuc, Teodora; Deepthi, Kolli; Casola, Antonella; Garofalo, Roberto P; Bao, Xiaoyong

    2015-08-01

    Human metapneumovirus (hMPV) is a common cause of respiratory tract infection in the paediatrics population. Recently, we and others have shown that retinoic acid-inducible gene 1 (RIG-I)-like receptors (RLRs) are essential for hMPV-induced cellular antiviral signalling. However, the contribution of those receptors to host immunity against pulmonary hMPV infection is largely unexplored. In this study, mice deficient in mitochondrial antiviral-signalling protein (MAVS), an adaptor of RLRs, were used to investigate the role(s) of these receptors in pulmonary immune responses to hMPV infection. MAVS deletion significantly impaired the induction of antiviral and pro-inflammatory cytokines and the recruitment of immune cells to the bronchoalveolar lavage fluid by hMPV. Compared with WT mice, mice lacking MAVS demonstrated decreased abilities to activate pulmonary dendritic cells (DCs) and abnormal primary T-cell responses to hMPV infection. In addition, mice deficient in MAVS had a higher peak of viral load at day 5 post-infection (p.i.) than WT mice, but were able to clear hMPV by day 7 p.i. similarly to WT mice. Taken together, our data indicate a role of MAVS-mediated pathways in the pulmonary immune responses to hMPV infection and the early control of hMPV replication.

  17. Structure and self-assembly of the calcium binding matrix protein of human metapneumovirus.

    PubMed

    Leyrat, Cedric; Renner, Max; Harlos, Karl; Huiskonen, Juha T; Grimes, Jonathan M

    2014-01-07

    The matrix protein (M) of paramyxoviruses plays a key role in determining virion morphology by directing viral assembly and budding. Here, we report the crystal structure of the human metapneumovirus M at 2.8 Å resolution in its native dimeric state. The structure reveals the presence of a high-affinity Ca²⁺ binding site. Molecular dynamics simulations (MDS) predict a secondary lower-affinity site that correlates well with data from fluorescence-based thermal shift assays. By combining small-angle X-ray scattering with MDS and ensemble analysis, we captured the structure and dynamics of M in solution. Our analysis reveals a large positively charged patch on the protein surface that is involved in membrane interaction. Structural analysis of DOPC-induced polymerization of M into helical filaments using electron microscopy leads to a model of M self-assembly. The conservation of the Ca²⁺ binding sites suggests a role for calcium in the replication and morphogenesis of pneumoviruses.

  18. Adjuvant effect of the human metapneumovirus (HMPV) matrix protein in HMPV subunit vaccines.

    PubMed

    Aerts, Laetitia; Rhéaume, Chantal; Carbonneau, Julie; Lavigne, Sophie; Couture, Christian; Hamelin, Marie-Ève; Boivin, Guy

    2015-04-01

    The human metapneumovirus (HMPV) fusion (F) protein is the most immunodominant protein, yet subunit vaccines containing only this protein do not confer complete protection. The HMPV matrix (M) protein induces the maturation of antigen-presenting cells in vitro. The inclusion of the M protein into an F protein subunit vaccine might therefore provide an adjuvant effect. We administered the F protein twice intramuscularly, adjuvanted with alum, the M protein or both, to BALB/c mice at 3 week intervals. Three weeks after the boost, mice were infected with HMPV and monitored for 14 days. At day 5 post-challenge, pulmonary viral titres, histopathology and cytokine levels were analysed. Mice immunized with F+alum and F+M+alum generated significantly more neutralizing antibodies than mice immunized with F only [titres of 47 ± 7 (P<0.01) and 147 ± 13 (P<0.001) versus 17 ± 2]. Unlike F only [1.6 ± 0.5 × 10(3) TCID50 (g lung)(-1)], pulmonary viral titres in mice immunized with F+M and F+M+alum were undetectable. Mice immunized with F+M presented the most important reduction in pulmonary inflammation and the lowest T-helper Th2/Th1 cytokine ratio. In conclusion, addition of the HMPV-M protein to an F protein-based vaccine modulated both humoral and cellular immune responses to subsequent infection, thereby increasing the protection conferred by the vaccine.

  19. Changing circulation rate of human metapneumovirus strains and types among hospitalized pediatric patients during three consecutive winter-spring seasons. Brief report.

    PubMed

    Gerna, G; Campanini, G; Rovida, F; Sarasini, A; Lilleri, D; Paolucci, S; Marchi, A; Baldanti, F; Revello, M G

    2005-11-01

    From 2001 through 2004, 808 pediatric patients admitted to hospital because of acute respiratory infections were examined for presence of respiratory viruses by either direct fluorescent staining using monoclonal antibodies or RT-PCR during three consecutive winter-spring seasons. On the whole, 336 (42%) patients were detected as positive for one or more respiratory viruses. The most widely circulating virus was human respiratory syncytial virus (hRSV) infecting 50% of positive patients, followed by human metapneumovirus (hMPV) found in 13% of patients, and then by influenza virus type A, human parainfluenzaviruses and coinfections. Significant variations in the circulation rate of hRSV, hMPV and influenzavirus type A were observed during the individual seasons. In addition, the circulation rates of the different types of hMPV changed yearly. In 2001-2002 and 2002-2003 hMPV circulated at a significant lower proportion than hRSV, while in 2003-2004 the circulation rates of the two viruses were closer. In conclusion, the 4 hMPV subtypes circulated yearly in Northern Italy flanking hRSV as major respiratory pathogens in the infantile patient population.

  20. Immunogenicity in mice of human metapneumovirus with a truncated SH glycoprotein.

    PubMed

    Tedcastle, A B; Fenwick, F; Robinson, M J; Toms, G L

    2014-04-01

    The SH glycoprotein of human metapneumovirus (HMPV) is twice the size of that of human respiratory syncytial virus and possesses a large, hydrophilic luminal domain. The glycoprotein is located on the surface of the virion and of virus infected cells and, if immunogenic, might be expected to play a role in anti-viral immunity. Initial attempts to study anti-SH antibody immunogenicity were thwarted by the instability of the SH gene on passage both in human bronchial epithelial cells and in mice. Repeated passage of virus isolates in human bronchial epithelial cells in culture resulted in the appearance and eventual predominance of HMPV mutants lacking all or most of the luminal domain of SH coincidental with the loss of productive infection in mouse lungs. Where infection was established in mice with an early cell culture passage, the virus recovered from mouse lung differed markedly from the inoculum, carrying 19 coding mutations in the SH luminal domain. Immunization of mice with a mutant virus variant expressing only 14 amino acids of the luminal domain of SH induced a cross-reactive antibody response to both the F glycoprotein and the SH glycoprotein but a largely sub-group specific response to the G glycoprotein. Similar patterns of response were achieved by immunization with individual HMPV glycoproteins expressed from recombinant vaccinia viruses. Recombinant truncated SH glycoprotein induced sub-group cross-reactive antibodies capable of neutralizing wild-type virus. Recombinant F glycoprotein also induced cross-reactive neutralizing antibodies whilst recombinant G glycoprotein induced largely strain-specific, non-neutralizing antibodies.

  1. Engineering, Structure and Immunogenicity of the Human Metapneumovirus F Protein in the Postfusion Conformation

    PubMed Central

    Más, Vicente; Rodriguez, Laura; Olmedillas, Eduardo; Cano, Olga; Palomo, Concepción; Terrón, María C.; Luque, Daniel; Melero, José A.; McLellan, Jason S.

    2016-01-01

    Human metapneumovirus (hMPV) is a paramyxovirus that is a common cause of bronchiolitis and pneumonia in children less than five years of age. The hMPV fusion (F) glycoprotein is the primary target of neutralizing antibodies and is thus a critical vaccine antigen. To facilitate structure-based vaccine design, we stabilized the ectodomain of the hMPV F protein in the postfusion conformation and determined its structure to a resolution of 3.3 Å by X-ray crystallography. The structure resembles an elongated cone and is very similar to the postfusion F protein from the related human respiratory syncytial virus (hRSV). In contrast, significant differences were apparent with the postfusion F proteins from other paramyxoviruses, such as human parainfluenza type 3 (hPIV3) and Newcastle disease virus (NDV). The high similarity of hMPV and hRSV postfusion F in two antigenic sites targeted by neutralizing antibodies prompted us to test for antibody cross-reactivity. The widely used monoclonal antibody 101F, which binds to antigenic site IV of hRSV F, was found to cross-react with hMPV postfusion F and neutralize both hRSV and hMPV. Despite the cross-reactivity of 101F and the reported cross-reactivity of two other antibodies, 54G10 and MPE8, we found no detectable cross-reactivity in the polyclonal antibody responses raised in mice against the postfusion forms of either hMPV or hRSV F. The postfusion-stabilized hMPV F protein did, however, elicit high titers of hMPV-neutralizing activity, suggesting that it could serve as an effective subunit vaccine. Structural insights from these studies should be useful for designing novel immunogens able to induce wider cross-reactive antibody responses. PMID:27611367

  2. Identification of human metapneumovirus-induced gene networks in airway epithelial cells by microarray analysis

    SciTech Connect

    Bao, X.; Sinha, M. |; Liu, T.; Hong, C.; Luxon, B.A. |; Garofalo, R.P. ||; Casola, A. ||

    2008-04-25

    Human metapneumovirus (hMPV) is a major cause of lower respiratory tract infections in infants, elderly and immunocompromised patients. Little is known about the response to hMPV infection of airway epithelial cells, which play a pivotal role in initiating and shaping innate and adaptive immune responses. In this study, we analyzed the transcriptional profiles of airway epithelial cells infected with hMPV using high-density oligonucleotide microarrays. Of the 47,400 transcripts and variants represented on the Affimetrix GeneChip Human Genome HG-U133 plus 2 array, 1601 genes were significantly altered following hMPV infection. Altered genes were then assigned to functional categories and mapped to signaling pathways. Many up-regulated genes are involved in the initiation of pro-inflammatory and antiviral immune responses, including chemokines, cytokines, type I interferon and interferon-inducible proteins. Other important functional classes up-regulated by hMPV infection include cellular signaling, gene transcription and apoptosis. Notably, genes associated with antioxidant and membrane transport activity, several metabolic pathways and cell proliferation were down-regulated in response to hMPV infection. Real-time PCR and Western blot assays were used to confirm the expression of genes related to several of these functional groups. The overall result of this study provides novel information on host gene expression upon infection with hMPV and also serves as a foundation for future investigations of genes and pathways involved in the pathogenesis of this important viral infection. Furthermore, it can facilitate a comparative analysis of other paramyxoviral infections to determine the transcriptional changes that are conserved versus the one that are specific to individual pathogens.

  3. Characteristics of human metapneumovirus infection prevailing in hospital wards housing patients with severe disabilities.

    PubMed

    Matsuda, Shunji; Nakamura, Masako; Hirano, Eiko; Kiyota, Naoko; Omura, Tamaki; Suzuki, Yumi; Noda, Masahiro; Kimura, Hirokazu

    2013-01-01

    Epidemics of infectious diseases often occur at long-term inpatient facilities for patients with severe motor and intellectual disabilities. However, the pathogens causing these infections remain unknown in approximately half of such epidemics. Two epidemics of respiratory tract infection occurred in 2 wards in the National Hospital Organization Ehime Hospital (prevalence 1, 34 infected out of 59 inpatients in the A ward in September 2011; prevalence 2, 8 infected out of 58 inpatients in the B ward in June 2012). Human metapneumovirus (HMPV) was detected from the nasal (and some pharyngeal) swabs from 17 patients. Based on phylogenetic analysis of viral genomes, the virus was grouped in subgroup A2 (prevalence 1) and B2 (prevalence 2). We considered that the viruses had spread through the 2 wards. The average duration of high fever in the 42 patients was 6.8 days, with the majority of fevers exceeding 38℃ (79%) and being accompanied by a productive cough. Ten out of 17 patients (59%) in whom HMPV was detected had decreased lymphocyte and increased monocyte counts in the blood. Eleven cases (65%) had elevated-C reactive protein levels and fever protraction as well as images of bronchitis or pneumonia on chest radiographs approximately 1 week after onset. Anti-HMPV antibody in the blood was positive in 95% of patients (151 of 159 inpatients), indicating no relation between HMPV infection and antibody titer but revealing recurrent infections. In view of the fever protraction and frequent co-occurrence of bronchitis and pneumonia at long-term inpatient facilities for immunocompromised patients such as the ones in this study, the prevalence of HMPV must be carefully monitored, and preventive measures and early-stage treatments are required.

  4. Human metapneumovirus glycoprotein G disrupts mitochondrial signaling in airway epithelial cells.

    PubMed

    Bao, Xiaoyong; Kolli, Deepthi; Ren, Junping; Liu, Tianshuang; Garofalo, Roberto P; Casola, Antonella

    2013-01-01

    Human metapneumovirus (hMPV) is a recently identified RNA virus belonging to the Paramyxoviridae family. It is a common cause of respiratory tract infections in children, adults, and immunocompromised patients, for which no specific treatment or vaccine is available. Recent investigations in our lab identified hMPV glycoprotein G as an important virulence factor, as a recombinant virus lacking the G protein (rhMPV-ΔG) exhibited enhanced production of important immune and antiviral mediators, such as cytokines, chemokines and type I interferon (IFN) in airway epithelial cells, and expression of G protein alone inhibits cellular signaling dependent on retinoic induced gene (RIG)-I, a RNA helicase with a fundamental role in initiating hMPV-induced cellular responses. In this study, we have further investigated the mechanism underlying the inhibitory role of hMPV G protein on RIG-I-dependent signaling. We found that the interaction of hMPV G with RIG-I occurs primarily through the CARD domains of RIG-I N-terminus, preventing RIG-I association with the adaptor protein MAVS (mitochondrial antiviral signaling protein), recruitment of RIG-I to mitochondria, as well as the interaction between mitochondria and mitochondria-associated membrane (MAM) component of the endoplasmic reticulum (ER), which contains STINGS, an important part of the viral-induced RIG-I/MAVS signaling pathway, leading in the end to the inhibition of cytokine, chemokine and type I IFN expression. Mutagenesis analysis showed that hMPV G protein cytoplasmic domain played a major role in the observed inhibitory activity, and recombinant viruses expressing a G protein with amino acid substitution in position 2 and 3 recapitulated most of the phenotype observed with rhMPV-ΔG mutant upon infection of airway epithelial cells.

  5. Targeted Proteomics of Human Metapneumovirus in Clinical Samples and Viral Cultures.

    PubMed

    Foster, Matthew W; Gerhardt, Geoff; Robitaille, Lynda; Plante, Pier-Luc; Boivin, Guy; Corbeil, Jacques; Moseley, M Arthur

    2015-10-20

    The rapid, sensitive, and specific identification of infectious pathogens from clinical isolates is a critical need in the hospital setting. Mass spectrometry (MS) has been widely adopted for identification of bacterial pathogens, although polymerase chain reaction remains the mainstay for the identification of viral pathogens. Here, we explored the capability of MS for the detection of human metapneumovirus (HMPV), a common cause of respiratory tract infections in children. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) sequencing of a single HMPV reference strain (CAN97-83) was used to develop a multiple reaction monitoring (MRM) assay that employed stable isotope-labeled peptide internal standards for quantitation of HMPV. Using this assay, we confirmed the presence of HMPV in viral cultures from 10 infected patients and further assigned genetic lineage based on the presence/absence of variant peptides belonging to the viral matrix and nucleoproteins. Similar results were achieved for primary clinical samples (nasopharyngeal aspirates) from the same individuals. As validation, virus lineages, and variant coding sequences, were confirmed by next-generation sequencing of viral RNA obtained from the culture samples. Finally, separate dilution series of HMPV A and B lineages were used to further refine and assess the robustness of the assay and to determine limits of detection in nasopharyngeal aspirates. Our results demonstrate the applicability of MRM for identification of HMPV, and assignment of genetic lineage, from both viral cultures and clinical samples. More generally, this approach should prove tractable as an alternative to nucleic-acid based sequencing for the multiplexed identification of respiratory virus infections.

  6. Prospective evaluation of rapid antigen tests for diagnosis of respiratory syncytial virus and human metapneumovirus infections.

    PubMed

    Aslanzadeh, Jaber; Zheng, Xiaotian; Li, Haijing; Tetreault, Janice; Ratkiewicz, Irene; Meng, Shufang; Hamilton, Pamela; Tang, Yi-Wei

    2008-05-01

    Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two important viral pathogens that cause respiratory tract infections in the pediatric population. The rapid detection of these agents allows the prompt isolation and treatment of infected patients. In the present prospective study, we evaluated the performances of four rapid antigen detection assays, including a rapid chromatographic immunoassay (CIA) for RSV (Directigen EZ RSV; Becton Dickinson, Sparks, MD), a direct fluorescent-antibody assay (DFA) for RSV (Bartels; Trinity Biotech, Carlsbad, CA), and two DFAs for hMPV manufactured by Diagnostic Hybrids Inc. (DHI; Athens, OH) and Imagen (Oxoid Ltd., Basingstoke, Hampshire, United Kingdom). The clinical specimens tested comprised 515 nasopharyngeal aspirates submitted to the Clinical Microbiology Laboratory at Hartford Hospital from 1 November 2006 to 21 April 2007. Compared to the results of real-time reverse transcription-PCR (RT-PCR), the CIA had a sensitivity of 79.8% and a specificity of 89.5%. The RSV DFA with Bartels reagents showed a sensitivity of 94.1% and a specificity of 96.8%. For hMPV, the sensitivity and specificity were 62.5% and 99.8%, respectively, for the DHI DFA and 63.2% and 100%, respectively, for the Imagen DFA. The hands-on and test turnaround times for CIA were 10 and 30 to 60 min, respectively, and the hands-on and test turnaround times for the RSV and hMPV DFAs were 30 and 105 min, respectively. We conclude that while the RSV CIA is user-friendly, it lacks sensitivity and specificity, especially during off-peak months. In contrast, the RSV DFA is more sensitive and specific, but interpretation of its results is subjective and it demands technical time and expertise. Similarly, both hMPV DFAs are highly specific in comparison to the results of RT-PCR, but their sensitivities await further improvements.

  7. Prospective Evaluation of Rapid Antigen Tests for Diagnosis of Respiratory Syncytial Virus and Human Metapneumovirus Infections▿

    PubMed Central

    Aslanzadeh, Jaber; Zheng, Xiaotian; Li, Haijing; Tetreault, Janice; Ratkiewicz, Irene; Meng, Shufang; Hamilton, Pamela; Tang, Yi-Wei

    2008-01-01

    Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two important viral pathogens that cause respiratory tract infections in the pediatric population. The rapid detection of these agents allows the prompt isolation and treatment of infected patients. In the present prospective study, we evaluated the performances of four rapid antigen detection assays, including a rapid chromatographic immunoassay (CIA) for RSV (Directigen EZ RSV; Becton Dickinson, Sparks, MD), a direct fluorescent-antibody assay (DFA) for RSV (Bartels; Trinity Biotech, Carlsbad, CA), and two DFAs for hMPV manufactured by Diagnostic Hybrids Inc. (DHI; Athens, OH) and Imagen (Oxoid Ltd., Basingstoke, Hampshire, United Kingdom). The clinical specimens tested comprised 515 nasopharyngeal aspirates submitted to the Clinical Microbiology Laboratory at Hartford Hospital from 1 November 2006 to 21 April 2007. Compared to the results of real-time reverse transcription-PCR (RT-PCR), the CIA had a sensitivity of 79.8% and a specificity of 89.5%. The RSV DFA with Bartels reagents showed a sensitivity of 94.1% and a specificity of 96.8%. For hMPV, the sensitivity and specificity were 62.5% and 99.8%, respectively, for the DHI DFA and 63.2% and 100%, respectively, for the Imagen DFA. The hands-on and test turnaround times for CIA were 10 and 30 to 60 min, respectively, and the hands-on and test turnaround times for the RSV and hMPV DFAs were 30 and 105 min, respectively. We conclude that while the RSV CIA is user-friendly, it lacks sensitivity and specificity, especially during off-peak months. In contrast, the RSV DFA is more sensitive and specific, but interpretation of its results is subjective and it demands technical time and expertise. Similarly, both hMPV DFAs are highly specific in comparison to the results of RT-PCR, but their sensitivities await further improvements. PMID:18337386

  8. Potential electrostatic interactions in multiple regions affect human metapneumovirus F-mediated membrane fusion.

    PubMed

    Chang, Andres; Hackett, Brent A; Winter, Christine C; Buchholz, Ursula J; Dutch, Rebecca Ellis

    2012-09-01

    The recently identified human metapneumovirus (HMPV) is a worldwide respiratory virus affecting all age groups and causing pneumonia and bronchiolitis in severe cases. Despite its clinical significance, no specific antiviral agents have been approved for treatment of HMPV infection. Unlike the case for most paramyxoviruses, the fusion proteins (F) of a number of strains, including the clinical isolate CAN97-83, can be triggered by low pH. We recently reported that residue H435 in the HRB linker domain acts as a pH sensor for HMPV CAN97-83 F, likely through electrostatic repulsion forces between a protonated H435 and its surrounding basic residues, K295, R396, and K438, at low pH. Through site-directed mutagenesis, we demonstrated that a positive charge at position 435 is required but not sufficient for F-mediated membrane fusion. Arginine or lysine substitution at position 435 resulted in a hyperfusogenic F protein, while replacement with aspartate or glutamate abolished fusion activity. Studies with recombinant viruses carrying mutations in this region confirmed its importance. Furthermore, a second region within the F(2) domain identified as being rich in charged residues was found to modulate fusion activity of HMPV F. Loss of charge at residues E51, D54, and E56 altered local folding and overall stability of the F protein, with dramatic consequences for fusion activity. As a whole, these studies implicate charged residues and potential electrostatic interactions in function, pH sensing, and overall stability of HMPV F.

  9. The Human Metapneumovirus Matrix Protein Stimulates the Inflammatory Immune Response In Vitro

    PubMed Central

    Bagnaud-Baule, Audrey; Reynard, Olivier; Perret, Magali; Berland, Jean-Luc; Maache, Mimoun; Peyrefitte, Christophe; Vernet, Guy; Volchkov, Viktor; Paranhos-Baccalà, Gláucia

    2011-01-01

    Each year, during winter months, human Metapneumovirus (hMPV) is associated with epidemics of bronchiolitis resulting in the hospitalization of many infants. Bronchiolitis is an acute illness of the lower respiratory tract with a consequent inflammation of the bronchioles. The rapid onset of inflammation suggests the innate immune response may have a role to play in the pathogenesis of this hMPV infection. Since, the matrix protein is one of the most abundant proteins in the Paramyxoviridae family virion, we hypothesized that the inflammatory modulation observed in hMPV infected patients may be partly associated with the matrix protein (M-hMPV) response. By western blot analysis, we detected a soluble form of M-hMPV released from hMPV infected cell as well as from M-hMPV transfected HEK 293T cells suggesting that M-hMPV may be directly in contact with antigen presenting cells (APCs) during the course of infection. Moreover, flow cytometry and confocal microscopy allowed determining that M-hMPV was taken up by dendritic cells (moDCs) and macrophages inducing their activation. Furthermore, these moDCs enter into a maturation process inducing the secretion of a broad range of inflammatory cytokines when exposed to M-hMPV. Additionally, M-hMPV activated DCs were shown to stimulate IL-2 and IFN-γ production by allogeneic T lymphocytes. This M-hMPV-mediated activation and antigen presentation of APCs may in part explain the marked inflammatory immune response observed in pathology induced by hMPV in patients. PMID:21412439

  10. Application of RT-PCR for diagnosis of respiratory syncytial virus and human metapneumovirus infections in Bulgaria, 2006-7 and 2007-8.

    PubMed

    Pavlova, S; Hadzhiolova, T; Abadjieva, P; Kotseva, R

    2009-06-11

    We describe here the results of respiratory syncytial virus (RSV) detection by reverse transcription polymerase chain reaction (RT-PCR) during two consecutive seasons, from December 2006 to February 2007 and from October 2007 to March 2008, performed in the National Laboratory of Influenza and Acute Respiratory Diseases, Bulgaria. A total number of 278 nasopharyngeal samples obtained from hospitalised children up to the age of five years were investigated for these two seasons. During the first season, the aetiological role of RSV was confirmed in 56 of 148 samples (37.8%) compared to 11 of 130 samples (8.5%) during the second season. Since the beginning of January 2008, RT-PCR for the detection of the recently identified human metapneumovirus (HMPV) has also been introduced in Bulgaria. This virus has been demonstrated as the aetiological agent in 13 out of 81 samples (16%) from children of the same age group. The use of RT-PCR allows the detection of a broader spectrum of viruses causing respiratory diseases, as well as better discrimination of the aetiological agents in clinically similar cases.

  11. The cellular endosomal sorting complex required for transport pathway is not involved in avian metapneumovirus budding in a virus-like-particle expression system.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian metapneumovirus (AMPV) is a paramyxovirus that principally causes respiratory disease and egg production drops in turkeys and chickens. Together with its closely related human metapneumovirus (HMPV), they comprise the genus metapneumovirus in the Paramyxoviridae family. Little is currently kno...

  12. Clinical and epidemiological comparison of human metapneumovirus and respiratory syncytial virus in seoul, Korea, 2003-2008.

    PubMed

    Kim, Chang Keun; Choi, Jungi; Callaway, Zak; Kim, Hyo Bin; Chung, Ju Young; Koh, Young-Yull; Shin, Bo Moon

    2010-03-01

    Human metapneumovirus (HMPV) shares clinical and epidemiological characteristics with well-known respiratory syncytial virus (RSV). The aim of this study was to investigate the clinical and epidemiological differences between HMPV- and RSV-induced wheezing illnesses. A total of 1,008 nasopharyngeal aspirate specimens was collected from 1,008 pediatric patients hospitalized with acute respiratory tract infection at Inje University Sanggye Paik Hospital from December 2003 to April 2008, and tested for seven common respiratory viruses. Conditions classified as wheezing illness were bronchiolitis, reactive airways disease, and bronchial asthma. HMPV caused a significantly lower proportion of wheezing illness when compared to RSV (48.1% vs. 82.2%, P<0.05). HMPV-induced wheezing illness occurred predominantly in older patients when compared to RSV patients (P<0.001). RSV infections peaked in the fall and winter followed by peaks of HMPV infection in winter and spring. Eosinophil counts were significantly higher (P<0.01) in RSV patients when compared to HMPV patients. These results show that human metapneumovirus patients exhibit several different clinical and epidemiological characteristics, such as higher proportion of wheezing illness, age and seasonal incidence, and eosinophil counts, when compared to RSV patients.

  13. Evolutionary Dynamics Analysis of Human Metapneumovirus Subtype A2: Genetic Evidence for Its Dominant Epidemic

    PubMed Central

    Li, Jianguo; Ren, Lili; Guo, Li; Xiang, Zichun; Paranhos-Baccalà, Gláucia; Vernet, Guy; Wang, Jianwei

    2012-01-01

    Human metapneumovirus (hMPV) is a respiratory viral pathogen in children worldwide. hMPV is divided into four subtypes: hMPV_A1, hMPV_A2, hMPV_B1, and hMPV_B2. hMPV_A2 can be further divided into hMPV_A2a and A2b based on phylogenetic analysis. The typical prevalence pattern of hMPV involves a shift of the predominant subtype within one or two years. However, hMPV_A2, in particular hMPV_A2b, has circulated worldwide with a several years long term high epidemic. To study this distinct epidemic behavior of hMPV_A2, we analyzed 294 sequences of partial G genes of the virus from different countries. Molecular evolutionary data indicates that hMPV_A2 evolved toward heterogeneity faster than the other subtypes. Specifically, a Bayesian skyline plot analysis revealed that hMPV_A2 has undergone a generally upward fluctuation since 1997, whereas the other subtypes experienced only one upward fluctuation. Although hMPV_A2 showed a lower value of mean dN/dS than the other subtypes, it had the largest number of positive selection sites. Meanwhile, various styles of mutation were observed in the mutation hotspots of hMPV_A2b. Bayesian phylogeography analysis also revealed two fusions of diffusion routes of hMPV_A2b in India (June 2006) and Beijing, China (June 2008). Sequences of hMPV_A2b retrieved from GenBank boosted simultaneously with the two fusions respectively, indicating that fusion of genetic transmission routes from different regions improved survival of hMPV_A2. Epidemic and evolutionary dynamics of hMPV_A2b were similar to those of hMPV_A2. Overall, our findings provide important molecular insights into hMPV epidemics and viral variation, and explain the occurrence of an atypical epidemic of hMPV_A2, particularly hMPV_A2b. PMID:22479641

  14. Inhibition of Human Metapneumovirus Binding to Heparan Sulfate Blocks Infection in Human Lung Cells and Airway Tissues

    PubMed Central

    Klimyte, Edita M.; Smith, Stacy E.; Oreste, Pasqua; Lembo, David

    2016-01-01

    ABSTRACT Human metapneumovirus (HMPV), a recently discovered paramyxovirus, infects nearly 100% of the world population and causes severe respiratory disease in infants, the elderly, and immunocompromised patients. We previously showed that HMPV binds heparan sulfate proteoglycans (HSPGs) and that HMPV binding requires only the viral fusion (F) protein. To characterize the features of this interaction critical for HMPV binding and the role of this interaction in infection in relevant models, we utilized sulfated polysaccharides, heparan sulfate mimetics, and occluding compounds. Iota-carrageenan demonstrated potent anti-HMPV activity by inhibiting binding to lung cells mediated by the F protein. Furthermore, analysis of a minilibrary of variably sulfated derivatives of Escherichia coli K5 polysaccharide mimicking the HS structure revealed that the highly O-sulfated K5 polysaccharides inhibited HMPV infection, identifying a potential feature of HS critical for HMPV binding. The peptide dendrimer SB105-A10, which binds HS, reduced binding and infection in an F-dependent manner, suggesting that occlusion of HS at the target cell surface is sufficient to prevent infection. HMPV infection was also inhibited by these compounds during apical infection of polarized airway tissues, suggesting that these interactions take place during HMPV infection in a physiologically relevant model. These results reveal key features of the interaction between HMPV and HS, supporting the hypothesis that apical HS in the airway serves as a binding factor during infection, and HS modulating compounds may serve as a platform for potential antiviral development. IMPORTANCE Human metapneumovirus (HMPV) is a paramyxovirus that causes respiratory disease worldwide. It has been previously shown that HMPV requires binding to heparan sulfate on the surfaces of target cells for attachment and infection. In this study, we characterize the key features of this binding interaction using heparan sulfate

  15. Immunogenicity and efficacy of alphavirus-derived replicon vaccines for respiratory syncytial virus and human metapneumovirus in nonhuman primates.

    PubMed

    Bates, John T; Pickens, Jennifer A; Schuster, Jennifer E; Johnson, Monika; Tollefson, Sharon J; Williams, John V; Davis, Nancy L; Johnston, Robert E; Schultz-Darken, Nancy; Slaughter, James C; Smith-House, Frances; Crowe, James E

    2016-02-10

    Human respiratory syncytial virus (hRSV) and human metapneumovirus (hMPV) are major causes of illness among children, the elderly, and the immunocompromised. No vaccine has been licensed for protection against either of these viruses. We tested the ability of two Venezuelan equine encephalitis virus-based viral replicon particle (VEE-VRP) vaccines that express the hRSV or hMPV fusion (F) protein to confer protection against hRSV or hMPV in African green monkeys. Animals immunized with VEE-VRP vaccines developed RSV or MPV F-specific antibodies and serum neutralizing activity. Compared to control animals, immunized animals were better able to control viral load in the respiratory mucosa following challenge and had lower levels of viral genome in nasopharyngeal and bronchoalveolar lavage fluids. The high level of immunogenicity and protective efficacy induced by these vaccine candidates in nonhuman primates suggest that they hold promise for further development.

  16. Phylogenetic and phylodynamic analyses of human metapneumovirus in Buenos Aires (Argentina) for a three-year period (2009-2011).

    PubMed

    Velez Rueda, Ana Julia; Mistchenko, Alicia Susana; Viegas, Mariana

    2013-01-01

    Human metapneumovirus, which belongs to the Paramyxoviridae family and has been classified as a member of the Pneumovirus genus, is genetically and clinically similar to other family members such as human respiratory syncytial virus. A total of 1146 nasopharyngeal aspirates from pediatric patients with moderate and severe acute lower respiratory tract infections, hospitalized at the Ricardo Gutierrez Childreńs Hospital (Buenos Aires, Argentina), were tested by real time RT-PCR for human metapneumovirus. Results showed that 168 (14.65%) were positive. Thirty-six of these 168 samples were randomly selected to characterize positive cases molecularly. The phylogenetic analysis of the sequences of the G and F genes showed that genotypes A2 and B2 cocirculated during 2009 and 2010 and that only genotype A2 circulated in 2011 in Argentina. Genotype A2 prevailed during the study period, a fact supported by a higher effective population size (Neτ) and higher diversity as compared to that of genotype B2 (10.9% (SE 1.3%) vs. 1.7% (SE 0.4%), respectively). The phylogeographic analysis of the G protein gene sequences showed that this virus has no geographical restrictions and can travel globally harbored in hosts. The selection pressure analysis of the F protein showed that although this protein has regions with polymorphisms, it has vast structural and functional constraints. In addition, the predicted B-linear epitopes and the sites recognized by previously described monoclonal antibodies were conserved in all Argentine sequences. This points out this protein as a potential candidate to be the target of future humanized antibodies or vaccines.

  17. Avian flu to human influenza.

    PubMed

    Lewis, David B

    2006-01-01

    Influenza A viral infection causes substantial annual morbidity and mortality worldwide, particularly for infants, the elderly, and the immunocompromised. The virus mainly replicates in the respiratory tract and is spread by respiratory secretions. A growing concern is the recent identification of H5N1 strains of avian influenza A in Asia that were previously thought to infect only wild birds and poultry, but have now infected humans, cats, pigs, and other mammals, often with fatal results, in an ongoing outbreak. A human pandemic with H5N1 virus could potentially be catastrophic because most human populations have negligible antibody-mediated immunity to the H5 surface protein and this viral subtype is highly virulent. Whether an H5N1 influenza pandemic will occur is likely to hinge on whether the viral strains involved in the current outbreak acquire additional mutations that facilitate efficient human-to-human transfer of infection. Although there is no historical precedent for an H5N1 avian strain causing widespread human-to-human transmission, some type of influenza A pandemic is very likely in the near future. The possibility of an H5N1 influenza pandemic has highlighted the many current limitations of treatment with antiviral agents and of vaccine production and immunogenicity. Future vaccine strategies that may include more robust induction of T-cell responses, such as cytotoxic T lymphocytes, may provide better protection than is offered by current vaccines, which rely solely or mainly on antibody neutralization of infection.

  18. [Phylogenetic variability of human metapneumovirus strains circulating in Turkey during two consecutive epidemic seasons].

    PubMed

    Bayrakdar, Fatma; Altaş, Ayşe Başak; Korukluoğlu, Gülay

    2016-01-01

    Human metapneumovirus (HMPV), classified in Paramyxoviridae family, phylogenetically consists of two major groups namely A and B, with genetic lineages of A1, A2 (comprises of sublineages A2a and A2b) and B1, B2. Although detailed evaluation on phylogenetic analysis of HMPV has been described in other countries, there are no data from Turkey on this subject. The aim of this study was to demonstrate for the first time, the phylogenetic diversity of HMPV strains circulating in Turkey during two consecutive epidemic seasons. A total of 2900 upper respiratory tract samples collected from patients with respiratory illness were evaluated between January 2011 and December 2013, without any special selection criteria. The presence of respiratory viruses in the samples were detected by real-time multiplex polymerase chain reaction (FTD® Respiratory Pathogens 21 Multiplex RT-PCR, Fast Track Diagnostics, Luxemburg), and 76 (2.6%) samples positive for HMPV were included in the study. HPMV nucleocapsid (N) (nt: 454-878) and fusion (F) (nt: 3624-4130) genes were selected for phylogenetic analysis. In sequence analysis, F and N gene sequences could only be obtained successfully from 46 out of 76 HMPV positive samples. According to sequences obtained, 54.3% belonged to B2, 17.4% to B1, 4.3% to A1, 4.3% to A2a, and 20% to A2b. In 2011, the A2b sublineage was predominant, while in 2012 and 2013, B2 lineages were predominant together with the B1 lineage. The A1 lineage was observed only in 2013. For the F gene fragment, nucleotide distance between group A and B was in the range of 0.138-0.168, however aminoacid distance amongst Turkish HMPV sequences were in the range of 0.028-0.042. For the N gene fragment, nucleotide distance between group A and B was in the range of 0.141-0.163, but aminoacid distance between group A and B was in the range of 0.037-0.050. Nucleotide diversity was higher than aminoacid diversity between and within lineages found in this study. This result

  19. Avian-human influenza epidemic model.

    PubMed

    Iwami, Shingo; Takeuchi, Yasuhiro; Liu, Xianning

    2007-05-01

    A mathematical model is proposed to interpret the spread of avian influenza from the bird world to the human world. Our mathematical model warns that two types of the outbreak of avian influenza may occur if the humans do not prevent the spread of avian influenza. Moreover, it suggests that we cannot feel relieved although the total infected humans are kept at low level. In order to prevent spread of avian influenza in the human world, we must take the measures not only for the birds infected with avian influenza to exterminate but also for the humans infected with mutant avian influenza to quarantine when mutant avian influenza has already occurred. In particular, the latter measure is shown to be important to stop the second pandemic of avian influenza.

  20. Outbreak of coinfection with human metapneumovirus and measles virus resulting in the death of a child at a hospital in China.

    PubMed

    Kou, Yu; Sun, Zhou; Li, Feng; Yu, Xinfen; Yang, Xuhui; Li, Jun; Pan, Jingcao

    2015-04-01

    Two children with different digestive diseases were admitted to the gastroenterology department of a children's hospital in Hangzhou, Zhejiang Province, China, in May 2010. They manifested successively acute lower respiratory tract infection symptoms during their stay in the hospital. The epidemiologic and experimental evidence supports that one child acquired nosocomial coinfection with measles virus and human metapneumovirus from another child while they shared the same ward.

  1. Variant (Swine Origin) Influenza Viruses in Humans

    MedlinePlus

    ... What's this? Submit Button Past Newsletters Variant Influenza Viruses: Background and CDC Risk Assessment and Reporting Language: ... Background CDC Assessment Reporting Background On Variant Influenza Viruses Swine flu viruses do not normally infect humans. ...

  2. Avian influenza and human health.

    PubMed

    Capua, Ilaria; Alexander, Dennis J

    2002-07-01

    Natural infections with influenza A viruses have been reported in a variety of animal species including humans, pigs, horses, sea mammals, mustelids and birds. Occasionally devastating pandemics occur in humans. Although viruses of relatively few HA and NA subtype combinations have been isolated from mammalian species, all 15 HA subtypes and all 9 NA subtypes, in most combinations, have been isolated from birds. In the 20th century the sudden emergence of antigenically different strains transmissible in humans, termed antigenic shift, has occurred on four occasions, 1918 (H1N1), 1957 (H2N2), 1968 (H3N2) and 1977 (H1N1), each time resulting in a pandemic. Genetic analysis of the isolates demonstrated that 'new' strains most certainly emerged after reassortment of genes of viruses of avian and human origin in a permissive host. The leading theory is that the pig represents the 'mixing vessel' where this genetic reassortment may occur. In 1996, an H7N7 influenza virus of avian origin was isolated from a woman with a self-limiting conjunctivitis. During 1997 in Hong Kong, an H5N1 avian influenza virus was recognised as the cause of death of 6 of 18 infected patients. Genetic analysis revealed these human isolates of H5N1 subtype to be indistinguishable from a highly pathogenic avian influenza virus that was endemic in the local poultry population. More recently, in March 1999, two independent isolations of influenza virus subtype H9N2 were made from girls aged one to four who recovered from flu-like illnesses in Hong Kong. Subsequently, five isolations of H9N2 virus from humans on mainland China in August 1998 were reported. H9N2 viruses were known to be widespread in poultry in China and other Asian countries. In all these cases there was no evidence of human to human spread except with the H5N1 infections where there was evidence of very limited spread. This is in keeping with the finding that all these viruses possessed all eight genes of avian origin. It may well

  3. Large-scale seroprevalence analysis of human metapneumovirus and human respiratory syncytial virus infections in Beijing, China

    PubMed Central

    2011-01-01

    Background Human metapneumovirus (hMPV), a recently identified virus, causes acute respiratory tract infections (ARTIs) in infants and children. However, studies on the seroepidemeology of hMPV are very limited in China. To assess the seroprevalence of hMPV infection in China, we tested a total of 1,156 serum specimens for the presence of anti-hMPV IgG antibody in children and adults free of acute respiratory illness in Beijing, China by using hMPV nucleocapsid (N) protein as an antigen. As a control, we used the human serum antibody against the N protein of human respiratory syncytial virus (hRSV), the most important viral agent responsible for ARIs in children. Results The seropositive rate for hMPV increased steadily with age from 67% at 1-6 mo to 100% at age 20. However, the rate dropped slightly between 6 mo and 1 yr of age. The seropositive rate for hRSV also increased steadily with age from 71% at 1-6 mo to 100% at age 20. In children aged six months to six years, the seropositive rates for the anti-hRSV IgG antibody were significantly higher than those for hMPV. Additionally, IgG antibody titers to hMPV and hRSV were significantly higher in adults than in young children. Consistent with the seropositive rates, the geometric mean titer of anti-hMPV IgG antibody was lower than that of anti-hRSV IgG antibody in children aged six months to six years. Conclusions Our results indicate that similar to hRSV, exposure to hMPV is ubiquitous in the Beijing population. However, the seroprevalence of anti-hMPV IgG antibody is lower than that of hRSV in children between six months and six years old, which suggests a different number of repeat infections or a different response to infections. PMID:21310026

  4. Human metapneumovirus infection activates the TSLP pathway that drives excessive pulmonary inflammation and viral replication in mice.

    PubMed

    Lay, Margarita K; Céspedes, Pablo F; Palavecino, Christian E; León, Miguel A; Díaz, Rodrigo A; Salazar, Francisco J; Méndez, Gonzalo P; Bueno, Susan M; Kalergis, Alexis M

    2015-06-01

    Human metapneumovirus (hMPV) is a leading cause of acute respiratory tract infections in children and the elderly. The mechanism by which this virus triggers an inflammatory response still remains unknown. Here, we evaluated whether the thymic stromal lymphopoietin (TSLP) pathway contributes to lung inflammation upon hMPV infection. We found that hMPV infection promotes TSLP expression both in human airway epithelial cells and in the mouse lung. hMPV infection induced lung infiltration of OX40L(+) CD11b(+) DCs. Mice lacking the TSLP receptor deficient mice (tslpr(-/-) ) showed reduced lung inflammation and hMPV replication. These mice displayed a decreased number of neutrophils as well a reduction in levels of thymus and activation-regulated chemokine/CCL17, IL-5, IL-13, and TNF-α in the airways upon hMPV infection. Furthermore, a higher frequency of CD4(+) and CD8(+) T cells was found in tslpr(-/-) mice compared to WT mice, which could contribute to controlling viral spread. Depletion of neutrophils in WT and tslpr(-/-) mice decreased inflammation and hMPV replication. Remarkably, blockage of TSLP or OX40L with specific Abs reduced lung inflammation and viral replication following hMPV challenge in mice. Altogether, these results suggest that activation of the TSLP pathway is pivotal in the development of pulmonary pathology and pulmonary hMPV replication.

  5. Human metapneumovirus M2-2 protein inhibits innate immune response in monocyte-derived dendritic cells.

    PubMed

    Ren, Junping; Liu, Guangliang; Go, Jonathan; Kolli, Deepthi; Zhang, Guanping; Bao, Xiaoyong

    2014-01-01

    Human metapneumovirus (hMPV) is a leading cause of lower respiratory infection in young children, the elderly and immunocompromised patients. Repeated hMPV infections occur throughout life. However, immune evasion mechanisms of hMPV infection are largely unknown. Recently, our group has demonstrated that hMPV M2-2 protein, an important virulence factor, contributes to immune evasion in airway epithelial cells by targeting the mitochondrial antiviral-signaling protein (MAVS). Whether M2-2 regulates the innate immunity in human dendritic cells (DC), an important family of immune cells controlling antigen presenting, is currently unknown. We found that human DC infected with a virus lacking M2-2 protein expression (rhMPV-ΔM2-2) produced higher levels of cytokines, chemokines and IFNs, compared to cells infected with wild-type virus (rhMPV-WT), suggesting that M2-2 protein inhibits innate immunity in human DC. In parallel, we found that myeloid differentiation primary response gene 88 (MyD88), an essential adaptor for Toll-like receptors (TLRs), plays a critical role in inducing immune response of human DC, as downregulation of MyD88 by siRNA blocked the induction of immune regulatory molecules by hMPV. Since M2-2 is a cytoplasmic protein, we investigated whether M2-2 interferes with MyD88-mediated antiviral signaling. We found that indeed M2-2 protein associated with MyD88 and inhibited MyD88-dependent gene transcription. In this study, we also identified the domains of M2-2 responsible for its immune inhibitory function in human DC. In summary, our results demonstrate that M2-2 contributes to hMPV immune evasion by inhibiting MyD88-dependent cellular responses in human DC.

  6. Excessive production and extreme editing of human metapneumovirus defective interfering RNA is associated with type I IFN induction.

    PubMed

    van den Hoogen, Bernadette G; van Boheemen, Sander; de Rijck, Jonneke; van Nieuwkoop, Stefan; Smith, Derek J; Laksono, Brigitta; Gultyaev, Alexander; Osterhaus, Albert D M E; Fouchier, Ron A M

    2014-08-01

    Type I IFN production is one of the hallmarks of host innate immune responses upon virus infection. Whilst most respiratory viruses carry IFN antagonists, reports on human metapneumovirus (HMPV) have been conflicting. Using deep sequencing, we have demonstrated that HMPV particles accumulate excessive amounts of defective interfering RNA (DIs) rapidly upon in vitro passage, and that these are associated with IFN induction. Importantly, the DIs were edited extensively; up to 70% of the original A and T residues had mutated to G or C, respectively. Such high editing rates of viral RNA have not, to our knowledge, been reported before. Bioinformatics and PCR assays indicated that adenosine deaminase acting on RNA (ADAR) was the most likely editing enzyme. HMPV thus has an unusually high propensity to generate DIs, which are edited at an unprecedented high frequency. The conflicting published data on HMPV IFN induction and antagonism are probably explained by DIs in virus stocks. The interaction of HMPV DIs with the RNA-editing machinery and IFN responses warrants further investigation.

  7. Mortality rates of human metapneumovirus and respiratory syncytial virus lower respiratory tract infections in hematopoietic cell transplantation recipients.

    PubMed

    Renaud, Christian; Xie, Hu; Seo, Sachiko; Kuypers, Jane; Cent, Anne; Corey, Lawrence; Leisenring, Wendy; Boeckh, Michael; Englund, Janet A

    2013-08-01

    Human metapneumovirus (HMPV), a common respiratory virus, can cause severe disease in pre- and post-hematopoietic cell transplantation (HCT) recipients. We conducted a retrospective cohort analysis in HCT patients with HMPV (n = 23) or respiratory syncytial virus (n = 23) detected in bronchoalveolar lavage samples by reverse transcription PCR between 2006 and 2011 to determine disease characteristics and factors associated with outcome. Mortality rates at 100 days were 43% for both HMPV and respiratory syncytial virus lower respiratory tract disease. Steroid therapy, oxygen requirement >2 L or mechanical ventilation, and bone marrow as cell source were significant risk factors for overall and virus-related mortality in multivariable models, whereas the virus type was not. The presence of centrilobular/nodular radiographic infiltrates was a possible protective factor for mechanical ventilation. Thus, HMPV lower respiratory tract disease is associated with high mortality in HCT recipients. Earlier detection in combination with new antiviral therapy is needed to reduce mortality among HCT recipients.

  8. Cytokine Profiles in Human Metapneumovirus Infected Children: Identification of Genes Involved in the Antiviral Response and Pathogenesis

    PubMed Central

    Malmo, Jostein; Moe, Nina; Krokstad, Sidsel; Ryan, Liv; Loevenich, Simon; Johnsen, Ingvild B.; Espevik, Terje; Nordbø, Svein Arne; Døllner, Henrik; Anthonsen, Marit W.

    2016-01-01

    Human metapneumovirus (hMPV) causes severe airway infection in children that may be caused by an unfavorable immune response. The nature of the innate immune response to hMPV in naturally occurring infections in children is largely undescribed, and it is unknown if inflammasome activation is implicated in disease pathogenesis. We examined nasopharynx aspirates and blood samples from hMPV-infected children without detectable co-infections. The expression of inflammatory and antiviral genes were measured in nasal airway secretions by relative mRNA quantification while blood plasma proteins were determined by a multiplex immunoassay. Several genes were significantly up-regulated at mRNA and protein level in the hMPV infected children. Most apparent was the expression of the chemokine IP-10, the pro-inflammatory cytokine IL-18 in addition to the interferon inducible gene ISG54. Interestingly, children experiencing more severe disease, as indicated by a severity index, had significantly more often up-regulation of the inflammasome-associated genes IL-1β and NLRP3. Overall, our data point to cytokines, particularly inflammasome-associated, that might be important in hMPV mediated lung disease and the antiviral response in children with severe infection. Our study is the first to demonstrate that inflammasome components are associated with increased illness severity in hMPV-infected children. PMID:27171557

  9. Infection and maturation of monocyte-derived human dendritic cells by human respiratory syncytial virus, human metapneumovirus, and human parainfluenza virus type 3.

    PubMed

    Le Nouën, Cyril; Munir, Shirin; Losq, Stéphanie; Winter, Christine C; McCarty, Thomas; Stephany, David A; Holmes, Kevin L; Bukreyev, Alexander; Rabin, Ronald L; Collins, Peter L; Buchholz, Ursula J

    2009-03-01

    Human respiratory syncytial virus (HRSV), human metapneumovirus (HMPV), and human parainfluenza virus type 3 (HPIV3) are common, important respiratory pathogens, but HRSV has a substantially greater impact with regard to acute disease, long-term effects on airway function, and frequency of re-infection. It has been reported to strongly interfere with the functioning of dendritic cells (DC). We compared HRSV to HMPV and HPIV3 with regard to their effects on human monocyte-derived immature DC (IDC). Side-by-side analysis distinguished between common effects versus those specific to individual viruses. The use of GFP-expressing viruses yielded clear identification of robustly infected cells and provided the means to distinguish between direct effects of robust viral gene expression versus bystander effects. All three viruses infected inefficiently based on GFP expression, with considerable donor-to donor-variability. The GFP-negative cells exhibited low, abortive levels of viral RNA synthesis. The three viruses induced low-to-moderate levels of DC maturation and cytokine/chemokine responses, increasing slightly in the order HRSV, HMPV, and HPIV3. Infection at the individual cell level was relatively benign, such that in general GFP-positive cells were neither more nor less able to mature compared to GFP-negative bystanders, and cells were responsive to a secondary treatment with lipopolysaccharide, indicating that the ability to mature was not impaired. However, there was a single exception, namely that HPIV3 down-regulated CD38 expression at the RNA level. Maturation by these viruses was anti-apoptotic. Inefficient infection of IDC and sub-optimal maturation might result in reduced immune responses, but these effects would be common to all three viruses rather than specific to HRSV.

  10. Immunization with a recombinant bacillus Calmette-Guerin strain confers protective Th1 immunity against the human metapneumovirus.

    PubMed

    Palavecino, Christian E; Céspedes, Pablo F; Gómez, Roberto S; Kalergis, Alexis M; Bueno, Susan M

    2014-01-01

    Along with the human respiratory syncytial virus (hRSV), the human metapneumovirus (hMPV) is one of the leading causes of childhood hospitalization and a major health burden worldwide. Unfortunately, owing to an inefficient immunological memory, hMPV infection provides limited immune protection against reinfection. Furthermore, hMPV can induce an inadequate Th2 type immune response that causes severe lung inflammation, leading to airway obstruction. Similar to hRSV, it is likely that an effective clearance of hMPV would require a balanced Th1 type immunity by the host, involving the activation of IFN-γ-secreting T cells. A recognized inducer of Th1 immunity is Mycobacterium bovis bacillus Calmette-Guérin (BCG), which has been used in newborns for many decades and in several countries as a tuberculosis vaccine. We have previously shown that immunization with BCG strains expressing hRSV Ags can induce an efficient immune response that protects against this virus. In this study, we show that immunization with rBCG strains expressing the phosphoprotein from hMPV also can induce protective Th1 immunity. Mice immunized with rBCG were protected against weight loss, airway inflammation, and viral replication in the lungs after hMPV infection. Our rBCG vaccine also induced the activation of hMPV-specific T cells producing IFN-γ and IL-2, which could protect from hMPV infection when transferred to recipient mice. These data strongly support the notion that rBCG induces protective Th1 immunity and could be considered as an efficient vaccine against hMPV.

  11. Clinical features of human metapneumovirus genotypes in children with acute lower respiratory tract infection in Changsha, China.

    PubMed

    Zeng, Sai-Zhen; Xiao, Ni-Guang; Zhong, Li-Li; Yu, Tian; Zhang, Bing; Duan, Zhao-Jun

    2015-11-01

    To explore the epidemiological and clinical features of different human metapneumovirus (hMPV) genotypes in hospitalized children. Reverse transcription polymerase chain reaction (RT-PCR) or PCR was employed to screen for both hMPV and other common respiratory viruses in 2613 nasopharyngeal aspirate specimens collected from children with lower respiratory tract infections from September 2007 to February 2011 (a period of 3.5 years). The demographics and clinical presentations of patients infected with different genotypes of hMPV were compared. A total of 135 samples were positive for hMPV (positive detection rate: 5.2%). Co-infection with other viruses was observed in 45.9% (62/135) of cases, and human bocavirus was the most common additional respiratory virus. The most common symptoms included cough, fever, and wheezing. The M gene was sequenced for 135 isolates; of these, genotype A was identified in 72.6% (98/135) of patients, and genotype B was identified in 27.4% (37/135) of patients. The predominant genotype of hMPV changed over the 3.5-year study period from genotype A2b to A2b or B1 and then to predominantly B1. Most of clinical features were similar between patients infected with different hMPV genotypes. These results suggested that hMPV is an important viral pathogen in pediatric patients with acute lower respiratory tract infection in Changsha. The hMPV subtypes A2b and B1 were found to co-circulate. The different hMPV genotypes exhibit similar clinical characteristics.

  12. Alveolar macrophages contribute to the pathogenesis of human metapneumovirus infection while protecting against respiratory syncytial virus infection.

    PubMed

    Kolli, Deepthi; Gupta, Meera R; Sbrana, Elena; Velayutham, Thangam S; Chao, Hong; Casola, Antonella; Garofalo, Roberto P

    2014-10-01

    Human metapneumovirus (hMPV) and respiratory syncytial virus (RSV) are leading causes of upper and lower respiratory tract infections in young children and among elderly and immunocompromised patients. The pathogenesis of hMPV-induced lung disease is poorly understood. The lung macrophage population consists of alveolar macrophages (AMs) residing at the luminal surface of alveoli and interstitial macrophages present within the parenchymal lung interstitium. The involvement of AMs in innate immune responses to virus infections remains elusive. In this study, BALB/c mice depleted of AMs by intranasal instillation of dichloromethylene bisphosphonate (L-CL2MBP) liposomes were examined for disease, lung inflammation, and viral replication after infection with hMPV or RSV. hMPV-infected mice lacking AMs exhibited improved disease in terms of body weight loss, lung inflammation, airway obstruction, and hyperresponsiveness compared with AM-competent mice. AM depletion was associated with significantly reduced hMPV titers in the lungs, suggesting that hMPV required AMs for early entry and replication in the lung. In contrast, AM depletion in the context of RSV infection was characterized by an increase in viral replication, worsened disease, and inflammation, with increased airway neutrophils and inflammatory dendritic cells. Overall, lack of AMs resulted in a broad-spectrum disruption in type I IFN and certain inflammatory cytokine production, including TNF and IL-6, while causing a virus-specific alteration in the profile of several immunomodulatory cytokines, chemokines, and growth factors. Our study demonstrates that AMs have distinct roles in the context of human infections caused by members of the Paramyxoviridae family.

  13. A duplex recombinant viral nucleoprotein microbead immunoassay for simultaneous detection of seroresponses to human respiratory syncytial virus and metapneumovirus infections.

    PubMed

    Zhang, Yange; Brooks, W Abdullah; Goswami, Doli; Rahman, Mustafizur; Luby, Stephen P; Erdman, Dean D

    2014-09-01

    Serologic diagnosis of human respiratory syncytial virus (hRSV) and human metapneumovirus (hMPV) infections has been shown to complement virus detection methods in epidemiologic studies. Enzyme immunoassays (EIAs) using cultured virus lysate antigens are often used to diagnose infection by demonstration of a ≥4-fold rises in antibody titer between acute and convalescent serum pairs. In this study, hRSV and hMPV nucleocapsid (recN) proteins were expressed in a baculovirus system and their performance compared with virus culture lysate antigen in EIAs using paired serum specimens collected from symptomatic children. The recN proteins were also used to develop a duplex assay based on the Luminex microbead-based suspension array technology, where diagnostic rises in antibody levels could be determined simultaneously at a single serum dilution. Antibody levels measured by the recN and viral lysate EIAs correlated moderately (hRSV, r(2)=0.72; hMPV, r(2)=0.76); the recN EIAs identified correctly 35 of 37 (94.6%) and 48 of 50 (96%) serum pairs showing diagnostic antibody rises by viral lysate EIAs. Purified recN proteins were then coupled to microbeads and serum pairs were tested at a single dilution on a Luminex MAGPIX(®) analyzer. The duplex recN assay identified correctly 33 of 39 (85%) and 41 of 47 (86.7%) serum pairs showing diagnostic rises to hRSV and hMPV, respectively. The recN assay permits simultaneous testing for acute hRSV and hMPV infections and offers a platform for expanded multiplexing of other respiratory virus assays.

  14. IRF-3, IRF-7, and IPS-1 promote host defense against acute human metapneumovirus infection in neonatal mice.

    PubMed

    Spann, Kirsten M; Loh, Zhixuan; Lynch, Jason P; Ullah, Ashik; Zhang, Vivian; Baturcam, Engin; Werder, Rhiannon B; Khajornjiraphan, Natthida; Rudd, Penny; Loo, Yeuh-Ming; Suhrbier, Andreas; Gale, Michael; Upham, John W; Phipps, Simon

    2014-06-01

    Human metapneumovirus (hMPV) is a leading cause of respiratory tract disease in children and is associated with acute bronchiolitis, pneumonia, and asthma exacerbations, yet the mechanisms by which the host immune response to hMPV is regulated are poorly understood. By using gene-deleted neonatal mice, we examined the contributions of the innate receptor signaling molecules interferon (IFN)-β promoter stimulator 1 (IPS-1), IFN regulatory factor (IRF) 3, and IRF7. Viral load in the lungs was markedly greater in IPS-1(-/-) > IRF3/7(-/-) > IRF3(-/-), but not IRF7(-/-), mice compared with wild-type mice. IFN-β and IFN-λ2/3 (IL-28A/B) production was attenuated in the bronchoalveolar lavage fluid in all factor-deficient mice compared with wild-type mice at 1 day after infection, although IFN-λ2/3 was greater in IRF3/7(-/-) mice at 5 days after infection. IRF7(-/-) and IRF3/7(-/-) mice presented with airway eosinophilia, whereas only IRF3/7(-/-) mice developed an exaggerated type 1 and 17 helper T-cell response, characterized by natural killer T-cell and neutrophilic inflammation. Despite having the highest viral load, IPS-1(-/-) mice did not develop a proinflammatory cytokine or granulocytic response to hMPV infection. Our findings demonstrate that IFN-β, but not IFN-λ2/3, produced via an IPS-1-IRF3 signaling pathway, is important for hMPV clearance. In the absence of a robust type I IFN-α/β response, targeting the IPS-1 signaling pathway may limit the overexuberant inflammatory response that occurs as a consequence of viral persistence.

  15. Effect of in vitro syncytium formation on the severity of human metapneumovirus disease in a murine model.

    PubMed

    Aerts, Laetitia; Cavanagh, Marie-Hélène; Dubois, Julia; Carbonneau, Julie; Rhéaume, Chantal; Lavigne, Sophie; Couture, Christian; Hamelin, Marie-Ève; Boivin, Guy

    2015-01-01

    Human metapneumovirus (HMPV) is an important cause of acute respiratory tract infections (ARTI) in children, elderly individuals and immunocompromised patients. In vitro, different HMPV strains can induce variable cytopathic effects ranging from large multinucleated syncytia to focal cell rounding. In this study, we investigated the impact of different in vitro phenotypes of two HMPV strains on viral replication and disease severity in a BALB/c mouse model. We first generated two recombinant GFP-expressing HMPV viruses: C-85473, a syncytium-inducing strain (rC-85473) belonging to the A1 subtype and CAN98-75, a focal cell rounding-inducing strain (rCAN98-75) of the B2 subtype. We subsequently exchanged the F genes of both strains to create the chimeric viruses rC-85473_F and rCAN98-75_F. We demonstrated that the F protein was the sole protein responsible for the syncytium phenotype and that viruses carrying a syncytium-inducing F protein replicated to significantly higher titers in vitro. In vivo, however, the virulence and replicative capacity of the different HMPV strains did not appear to be solely dependent on the F gene but also on the viral background, with the strains containing the C-85473 background inducing more weight loss as well as increased lung viral titers, pro-inflammatory cytokines and inflammation than strains containing the CAN98-75 background. In conclusion, the F protein is the main determinant of syncytium formation and replication kinetics in vitro, although it is not the only factor implicated in HMPV disease severity in mice.

  16. A comparison of human metapneumovirus and respiratory syncytial virus WHO-defined severe pneumonia in Moroccan children.

    PubMed

    Jroundi, I; Mahraoui, C; Benmessaoud, R; Moraleda, C; Tligui, H; Seffar, M; El Kettani, S E C; Benjelloun, B S; Chaacho, S; Muñoz-Almagro, C; Ruiz, J; Alonso, P L; Bassat, Q

    2016-02-01

    Acute respiratory infections remain the principal cause of morbidity and mortality in Moroccan children. Besides bacterial infections, respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are prominent among other viruses due to their high prevalence and association with severe clinical episodes. We aimed to describe and compare RSV- and hMPV-associated cases of WHO-defined severe pneumonia in a paediatric population admitted to Morocco's reference hospital. Children aged 2-59 months admitted to the Hôpital d'Enfants de Rabat, Morocco meeting WHO-defined severe pneumonia criteria were recruited during 14 months and thoroughly investigated to ascertain a definitive diagnosis. Viral prevalence of RSV, hMPV and other viruses causing respiratory symptoms was investigated in nasopharyngeal aspirate samples through the use of molecular methods. Of the 683 children recruited and included in the final analysis, 61/683 (8·9%) and 124/683 (18·2%) were infected with hMPV and RSV, respectively. Besides a borderline significant tendency for higher age in hMPV cases, patients infected with either of the viruses behaved similarly in terms of demographics, patient history, past morbidity and comorbidity, vaccination history, socioeconomic background and family environment. Clinical presentation on arrival was also similar for both viruses, but hMPV cases were associated with more severity than RSV cases, had a higher risk of intensive care need, and received antibiotic treatment more frequently. RSV and hMPV are common and potentially life-threatening causes of WHO-defined pneumonia in Moroccan children. Both viruses show indistinctive clinical symptomatology, but in Moroccan children, hMPV was associated with a more severe evolution.

  17. Comparing Human Metapneumovirus and Respiratory Syncytial Virus: Viral Co-Detections, Genotypes and Risk Factors for Severe Disease

    PubMed Central

    Moe, Nina; Krokstad, Sidsel; Stenseng, Inger Heimdal; Christensen, Andreas; Skanke, Lars Høsøien; Risnes, Kari Ravndal; Nordbø, Svein Arne; Døllner, Henrik

    2017-01-01

    Background It is unclarified as to whether viral co-detection and human metapneumovirus (HMPV) genotypes relate to clinical manifestations in children with HMPV and lower respiratory tract infection (LRTI), and if the clinical course and risk factors for severe LRTI differ between HMPV and respiratory syncytial virus (RSV). Methods We prospectively enrolled hospitalized children aged <16 years with LRTI from 2006 to 2015. Children were clinically examined, and nasopharyngeal aspirates were analyzed using semi-quantitative, real-time polymerase chain reaction tests for HMPV, RSV and 17 other pathogens. HMPV-positive samples were genotyped. Results A total of 171 children had HMPV infection. HMPV-infected children with single virus (n = 106) and co-detections (n = 65) had similar clinical manifestations. No clinical differences were found between HMPV genotypes A (n = 67) and B (n = 80). The HMPV-infected children were older (median 17.2 months) than RSV-infected children (median 7.3 months, n = 859). Among single virus-infected children, no differences in age-adjusted LRTI diagnoses were found between HMPV and RSV. Age was an important factor for disease severity among single virus-infected children, where children <6 months old with HMPV had a milder disease than those with RSV, while in children 12–23 months old, the pattern was the opposite. In multivariable logistic regression analysis for each virus type, age ≥12 months (HMPV), and age <6 months (RSV), prematurity, ≥1 chronic disease and high viral loads of RSV, but not high HMPV viral loads, were risk factors for severe disease. Conclusions Among hospitalized children with LRTI, HMPV manifests independently of viral co-detections and HMPV genotypes. Disease severity in HMPV- and RSV-infected children varies in relation to age. A history of prematurity and chronic disease increases the risk of severe LRTI among HMPV- and RSV-infected children. PMID:28095451

  18. Influenza and Other Respiratory Viruses in Three Central American Countries

    DTIC Science & Technology

    2010-01-01

    herpes simplex virus in college students. Pediatr Infect Dis J 1993; 12(4):280–284. Laguna-Torres et al. 12 ª 2010 Blackwell Publishing Ltd, Influenza and Other Respiratory Viruses ...parainfluenza viruses (57; 3.2%), influenza B virus (47; 2.7% of cases), and herpes simplex virus 1 (22; 1.3%). In addition, human metapneumovirus and...the identification of adenovirus- es, influenza A virus, influenza B virus, PIVs (types 1, 2, and 3), and RSV. The D3 DFA Herpes Simplex Virus

  19. Individual contributions of the human metapneumovirus F, G, and SH surface glycoproteins to the induction of neutralizing antibodies and protective immunity

    SciTech Connect

    Skiadopoulos, Mario H. . E-mail: mskiadopoulos@niaid.nih.gov; Biacchesi, Stephane; Buchholz, Ursula J.; Amaro-Carambot, Emerito; Surman, Sonja R.; Collins, Peter L.; Murphy, Brian R.

    2006-02-20

    We evaluated the individual contributions of the three surface glycoproteins of human metapneumovirus (HMPV), namely the fusion F, attachment G, and small hydrophobic SH proteins, to the induction of serum HMPV-binding antibodies, serum HMPV-neutralizing antibodies, and protective immunity. Using reverse genetics, each HMPV protein was expressed individually from an added gene in recombinant human parainfluenza virus type 1 (rHPIV1) and used to infect hamsters once or twice by the intranasal route. The F protein was highly immunogenic and protective, whereas G and SH were only weakly or negligibly immunogenic and protective, respectively. Thus, in contrast to other paramyxoviruses, the HMPV attachment G protein is not a major neutralization or protective antigen. Also, although the SH protein of HMPV is a virion protein that is much larger than its counterparts in previously studied paramyxoviruses, it does not appear to be a significant neutralization or protective antigen.

  20. Pulmonary infection of mice with human metapneumovirus induces local cytotoxic T-cell and immunoregulatory cytokine responses similar to those seen with human respiratory syncytial virus.

    PubMed

    Herd, Karen A; Nelson, Michelle; Mahalingam, Suresh; Tindle, Robert W

    2010-05-01

    Human metapneumovirus (hMPV) is a major cause of upper and lower respiratory-tract infection in infants, the elderly and immunocompromised individuals. Virus-directed cellular immunity elicited by hMPV infection is poorly understood, in contrast to the phylogenetically and clinically related pathogen human respiratory syncytial virus (hRSV). In a murine model of acute lower respiratory-tract infection with hMPV, we demonstrate the accumulation of gamma interferon (IFN-gamma)-producing CD8+ T cells in the airways and lungs at day 7 post-infection (p.i.), associated with cytotoxic T lymphocytes (CTLs) directed to an epitope of the M2-1 protein. This CTL immunity was accompanied by increased pulmonary expression of Th1 cytokines IFN-gamma and interleukin (IL)-12 and antiviral cytokines (IFN-beta), as well as chemokines Mip-1alpha, Mip-1beta, Mig, IP-10 and CX3CL1. There was also a moderate increase in Th2-type cytokines IL-4 and IL-10 compared with uninfected mice. At 21 days p.i., a strong CTL response could be recalled from the spleen. A similar pattern of CTL induction to the homologous M2-1 CTL epitope of hRSV, and of cytokine/chemokine induction, was observed following infection with hRSV, highlighting similarities in the cellular immune response to the two related pathogens.

  1. Development of a multiplex RT-PCR for simultaneous diagnosis of human metapneumovirus (HMPV) and human respiratory syncytial virus (HRSV) from clinical specimens.

    PubMed

    Dayakar, Seetha; Pillai, Heera R; Thulasi, Vineetha P; Nair, Radhakrishnan R

    2016-12-01

    Human metapneumovirus (HMPV) and human respiratory syncytial virus (HRSV) are ubiquitous respiratory viral pathogens. They belong to the family Paramyxoviridae (subfamily Pneumovirinae) and is responsible for acute respiratory tract infections in children, elderly and immunocompromised patients. We designed and tested a multiplex reverse transcriptase polymerase chain reaction (mRT-PCR) as a cost-effective alternative to real-time PCR and cell culture based detection for HMPV and HRSV. The newly developed PCR was used to screen nasal/throat swab samples from 356 patients with suspected acute respiratory infection attending the Government Medical College, Thiruvananthapuram, Kerala, India. The method was compared with a commercially available kit employing real time PCR, for its sensitivity and specificity. 53 (14.9 %) samples were positive for at least one tested pathogen by mRT-PCR. All except one among the positive samples showed similar pathogen profile when tested using real time PCR. 8 (15.1 %) among these 53 were positive for HRSVA, 33 (62.3 %) positive for HRSVB and 12 (22.6 %) were positive for HMPV. 17 (32.7 %) samples showed co-infections in them. Sensitivity and specificity of the mRT-PCR was comparable to that of the commercial kit. Our findings indicate that this newly developed mRT-PCR can be used as a cost-effective alternative for laboratory diagnosis of HMPV/HRSV infection and will significantly reduce diagnostic costs for these viruses in clinical settings.

  2. Methamphetamine Reduces Human Influenza A Virus Replication

    PubMed Central

    Chen, Yun-Hsiang; Wu, Kuang-Lun; Chen, Chia-Hsiang

    2012-01-01

    Methamphetamine (meth) is a highly addictive psychostimulant that is among the most widely abused illicit drugs, with an estimated over 35 million users in the world. Several lines of evidence suggest that chronic meth abuse is a major factor for increased risk of infections with human immunodeficiency virus and possibly other pathogens, due to its immunosuppressive property. Influenza A virus infections frequently cause epidemics and pandemics of respiratory diseases among human populations. However, little is known about whether meth has the ability to enhance influenza A virus replication, thus increasing severity of influenza illness in meth abusers. Herein, we investigated the effects of meth on influenza A virus replication in human lung epithelial A549 cells. The cells were exposed to meth and infected with human influenza A/WSN/33 (H1N1) virus. The viral progenies were titrated by plaque assays, and the expression of viral proteins and cellular proteins involved in interferon responses was examined by Western blotting and immunofluorescence staining. We report the first evidence that meth significantly reduces, rather than increases, virus propagation and the susceptibility to influenza infection in the human lung epithelial cell line, consistent with a decrease in viral protein synthesis. These effects were apparently not caused by meth’s effects on enhancing virus-induced interferon responses in the host cells, reducing viral biological activities, or reducing cell viability. Our results suggest that meth might not be a great risk factor for influenza A virus infection among meth abusers. Although the underlying mechanism responsible for the action of meth on attenuating virus replication requires further investigation, these findings prompt the study to examine whether other structurally similar compounds could be used as anti-influenza agents. PMID:23139774

  3. Novel human H7N9 influenza virus in China.

    PubMed

    Wang, Chengmin; Luo, Jing; Wang, Jing; Su, Wen; Gao, Shanshan; Zhang, Min; Xie, Li; Ding, Hua; Liu, Shelan; Liu, Xiaodong; Chen, Yu; Jia, Yaxiong; He, Hongxuan

    2014-06-01

    Outbreaks of H7N9 avian influenza in humans in 5 provinces and 2 municipalities of China have reawakened concern that avian influenza viruses may again cross species barriers to infect the human population and thereby initiate a new influenza pandemic. Evolutionary analysis shows that human H7N9 influenza viruses originated from the H9N2, H7N3 and H11N9 avian viruses, and that it is as a novel reassortment influenza virus. This article reviews current knowledge on 11 subtypes of influenza A virus from human which can cause human infections.

  4. Detection of human coronavirus NL63, human metapneumovirus and respiratory syncytial virus in children with respiratory tract infections in south-west Sweden.

    PubMed

    Koetz, A; Nilsson, P; Lindén, M; van der Hoek, L; Ripa, T

    2006-11-01

    Two recently detected viruses, human metapneumovirus (hMPV) and coronavirus NL63 (HCoV-NL63), have been associated with acute respiratory tract infections, particularly in young children. This study investigated the frequency of hMPV and HCoV-NL63 infections in Swedish children by screening 221 nasopharyngeal aspirates, collected between November 2003 and May 2005, from 212 children attending the paediatric department of a county hospital in Sweden or submitted from local general practitioners. The samples were originally submitted to be tested for respiratory syncytial virus (RSV), and were examined retrospectively for hMPV and HCoV-NL63 by RT-PCR. Of the 212 patients, 101 were positive for RSV (48%), 22 (10%) were positive for hMPV, and 12 (6%) were positive for HCoV-NL63. The frequency of HCoV-NL63 infection increased from 1% in 2003-2004 to 10% in 2004-2005. Sequence analysis of parts of the coronavirus genomes showed considerable similarity to the HCoV-NL63 prototype sequence. The study demonstrated that HCoV-NL63 and hMPV occur in south-west Sweden with essentially the same frequency, seasonal distribution and clinical characteristics as have been reported in other countries.

  5. Avian influenza viruses and human health.

    PubMed

    Alexander, D J

    2006-01-01

    Influenza A viruses cause natural infections of humans, some other mammals and birds. Few of the 16 haemagglutinin and nine neuraminidase subtype combinations have been isolated from mammals, but all subtypes have been isolated from birds. In the 20th century, there were four pandemics of influenza as a result of the emergence of antigenically different strains in humans: 1918 (H1N1), 1957 (H2N2), 1968 (H3N2) and 1977 (H1N1). Influenza A viruses contain eight distinct RNA genes and reassortment of these can occur in mixed infections with different viruses. The 1957 and 1968 pandemic viruses differed from the preceding viruses in humans by the substitution of genes that came from avian viruses, suggesting they arose by genetic reassortment of viruses of human and avian origin. Up to 1995, there had been only three reports of avian influenza viruses infecting humans, in 1959, 1977 and 1981 (all H7N7), but, since 1996, there have been regular reports of natural infections of humans with avian influenza viruses: in England in 1996 (H7N7), Hong Kong 1997 (H5N1), 1999 (H9N2), and 2003 (H5N1), in The Netherlands 2003 (H7N7), Canada 2004 (H7N3), Vietnam 2004 (H5N1) and Thailand 2004 (H5N1). The H5N1 virus is alarming because 51 (64 %) of the 80 people confirmed as infected since 1997 have died.

  6. Influenza A(H3N2) outbreak at Transit Center at Manas, Kyrgyzstan, 2014.

    PubMed

    Parms, Tiffany A; Zorich, Shauna C; Kramer, Karen P

    2015-01-01

    In February 2014, the U.S. Air Force School of Aerospace Medicine Epidemiology Consult Service provided support in response to a moderate outbreak of influenza at the Transit Center at Manas (Kyrgyzstan). A total of 215 individuals presented with influenza-like illness symptoms from 3 December 2013 through 28 February 2014. There were 85 specimens positive for influenza (18 influenza A(H1N1)pdm09, 65 influenza A(H3N2), one influenza A/not subtyped, and one influenza B); six specimens were positive for other respiratory viruses (one human metapneumovirus, two parainfluenza, and three rhinovirus/enterovirus) and eight specimens were negative. Twenty-two of the specimens that were positive for influenza were sequenced and were not remarkably different from the strains seen during routine surveillance for the 2013-2014 season or from specimens collected at other deployed sites.

  7. A host-range restricted parainfluenza virus type 3 (PIV3) expressing the human metapneumovirus (hMPV) fusion protein elicits protective immunity in African green monkeys.

    PubMed

    Tang, Roderick S; Mahmood, Kutubuddin; Macphail, Mia; Guzzetta, Jeanne M; Haller, Aurelia A; Liu, Hui; Kaur, Jasmine; Lawlor, Heather A; Stillman, Elizabeth A; Schickli, Jeanne H; Fouchier, Ron A M; Osterhaus, Albert D M E; Spaete, Richard R

    2005-02-25

    Human metapneumovirus (hMPV) infection causes respiratory tract disease similar to that observed during human respiratory syncytial virus infection (hRSV). hMPV infections have been reported across the entire age spectrum although the most severe disease occurs in young children. No vaccines, chemotherapeutics or antibodies are presently available for preventing or treating hMPV infections. In this study, a bovine/human chimeric parainfluenza virus type 3 (b/h PIV3) expressing the human parainfluenza type 3 (hPIV3) fusion (F) and hemagglutinin-neuraminidase (HN) proteins was engineered to express hMPV fusion (F) protein from the second genome position (b/h PIV3/hMPV F2) with the goal of generating a novel hMPV vaccine. b/h PIV3/hMPV F2 was previously shown to protect hamsters from challenge with wt hMPV (Tang RS, Schickli JH, Macphail M, Fernandes F, Bicha L, Spaete J, et al. Effects of human metapneumovirus and respiratory syncytial virus antigen insertion in two 3' proximal genome positions of bovine/human parainfluenza virus type 3 on virus replication and immunogenicity. J Virol 2003;77:10819-28) and is here further evaluated for efficacy and immunogenicity in African green monkeys (AGMs). AGMs immunized intranasally and intratracheally with b/h PIV3/hMPV F2 generated hMPV- and hPIV3-specific humoral and cellular immune responses and were protected from wt hMPV infection. In a separate study, the host-range restriction of b/h PIV3/hMPV F2 replication relative to wt hPIV3 was performed in rhesus monkeys to demonstrate attenuation. These studies showed that b/h PIV3/hMPV F2 was immunogenic, protective and attenuated in non-human primates and warrants further evaluation in humans as a vaccine candidate for prevention of hMPV-associated respiratory tract diseases.

  8. Sialic acid content in human saliva and anti-influenza activity against human and avian influenza viruses.

    PubMed

    Limsuwat, Nattavatchara; Suptawiwat, Ornpreya; Boonarkart, Chompunuch; Puthavathana, Pilaipan; Wiriyarat, Witthawat; Auewarakul, Prasert

    2016-03-01

    It was shown previously that human saliva has higher antiviral activity against human influenza viruses than against H5N1 highly pathogenic avian influenza viruses, and that the major anti-influenza activity was associated with sialic-acid-containing molecules. To further characterize the differential susceptibility to saliva among influenza viruses, seasonal influenza A and B virus, pandemic H1N1 virus, and 15 subtypes of avian influenza virus were tested for their susceptibility to human and chicken saliva. Human saliva showed higher hemagglutination inhibition (HI) and neutralization (NT) titers against seasonal influenza A virus and the pandemic H1N1 viruses than against influenza B virus and most avian influenza viruses, except for H9N2 and H12N9 avian influenza viruses, which showed high HI and NT titers. To understand the nature of sialic-acid-containing anti-influenza factors in human saliva, α2,3- and α2,6-linked sialic acid was measured in human saliva samples using a lectin binding and dot blot assay. α2,6-linked sialic acid was found to be more abundant than α2,3-linked sialic acid, and a seasonal H1N1 influenza virus bound more efficiently to human saliva than an H5N1 virus in a dot blot analysis. These data indicated that human saliva contains the sialic acid type corresponding to the binding preference of seasonal influenza viruses.

  9. Avian influenza virus infections in humans.

    PubMed

    Wong, Samson S Y; Yuen, Kwok-Yung

    2006-01-01

    Seroepidemiologic and virologic studies since 1889 suggested that human influenza pandemics were caused by H1, H2, and H3 subtypes of influenza A viruses. If not for the 1997 avian A/H5N1 outbreak in Hong Kong of China, subtype H2 is the likely candidate for the next pandemic. However, unlike previous poultry outbreaks of highly pathogenic avian influenza due to H5 that were controlled by depopulation with or without vaccination, the presently circulating A/H5N1 genotype Z virus has since been spreading from Southern China to other parts of the world. Migratory birds and, less likely, bird trafficking are believed to be globalizing the avian influenza A/H5N1 epidemic in poultry. More than 200 human cases of avian influenza virus infection due to A/H5, A/H7, and A/H9 subtypes mainly as a result of poultry-to-human transmission have been reported with a > 50% case fatality rate for A/H5N1 infections. A mutant or reassortant virus capable of efficient human-to-human transmission could trigger another influenza pandemic. The recent isolation of this virus in extrapulmonary sites of human diseases suggests that the high fatality of this infection may be more than just the result of a cytokine storm triggered by the pulmonary disease. The emergence of resistance to adamantanes (amantadine and rimantadine) and recently oseltamivir while H5N1 vaccines are still at the developmental stage of phase I clinical trial are causes for grave concern. Moreover, the to-be pandemic strain may have little cross immunogenicity to the presently tested vaccine strain. The relative importance and usefulness of airborne, droplet, or contact precautions in infection control are still uncertain. Laboratory-acquired avian influenza H7N7 has been reported, and the laboratory strains of human influenza H2N2 could also be the cause of another pandemic. The control of this impending disaster requires more research in addition to national and international preparedness at various levels. The

  10. DC-SIGN and L-SIGN Are Attachment Factors That Promote Infection of Target Cells by Human Metapneumovirus in the Presence or Absence of Cellular Glycosaminoglycans

    PubMed Central

    Gillespie, Leah; Gerstenberg, Kathleen; Ana-Sosa-Batiz, Fernanda; Parsons, Matthew S.; Farrukee, Rubaiyea; Krabbe, Mark; Spann, Kirsten; Brooks, Andrew G.; Londrigan, Sarah L.

    2016-01-01

    ABSTRACT It is well established that glycosaminoglycans (GAGs) function as attachment factors for human metapneumovirus (HMPV), concentrating virions at the cell surface to promote interaction with other receptors for virus entry and infection. There is increasing evidence to suggest that multiple receptors may exhibit the capacity to promote infectious entry of HMPV into host cells; however, definitive identification of specific transmembrane receptors for HMPV attachment and entry is complicated by the widespread expression of cell surface GAGs. pgsA745 Chinese hamster ovary (CHO) cells are deficient in the expression of cell surface GAGs and resistant to HMPV infection. Here, we demonstrate that the expression of the Ca2+-dependent C-type lectin receptor (CLR) DC-SIGN (CD209L) or L-SIGN (CD209L) rendered pgsA745 cells permissive to HMPV infection. Unlike infection of parental CHO cells, HMPV infection of pgsA745 cells expressing DC-SIGN or L-SIGN was dynamin dependent and inhibited by mannan but not by pretreatment with bacterial heparinase. Parental CHO cells expressing DC-SIGN/L-SIGN also showed enhanced susceptibility to dynamin-dependent HMPV infection, confirming that CLRs can promote HMPV infection in the presence or absence of GAGs. Comparison of pgsA745 cells expressing wild-type and endocytosis-defective mutants of DC-SIGN/L-SIGN indicated that the endocytic function of CLRs was not essential but could contribute to HMPV infection of GAG-deficient cells. Together, these studies confirm a role for CLRs as attachment factors and entry receptors for HMPV infection. Moreover, they define an experimental system that can be exploited to identify transmembrane receptors and entry pathways where permissivity to HMPV infection can be rescued following the expression of a single cell surface receptor. IMPORTANCE On the surface of CHO cells, glycosaminoglycans (GAGs) function as the major attachment factor for human metapneumoviruses (HMPV), promoting dynamin

  11. Genetic diversity, seasonality and transmission network of human metapneumovirus: identification of a unique sub-lineage of the fusion and attachment genes

    PubMed Central

    Chow, Wei Zhen; Chan, Yoke Fun; Oong, Xiang Yong; Ng, Liang Jie; Nor’E, Siti Sarah; Ng, Kim Tien; Chan, Kok Gan; Hanafi, Nik Sherina; Pang, Yong Kek; Kamarulzaman, Adeeba; Tee, Kok Keng

    2016-01-01

    Human metapneumovirus (HMPV) is an important viral respiratory pathogen worldwide. Current knowledge regarding the genetic diversity, seasonality and transmission dynamics of HMPV among adults and children living in tropical climate remains limited. HMPV prevailed at 2.2% (n = 86/3,935) among individuals presented with acute respiratory tract infections in Kuala Lumpur, Malaysia between 2012 and 2014. Seasonal peaks were observed during the northeast monsoon season (November–April) and correlated with higher relative humidity and number of rainy days (P < 0.05). Phylogenetic analysis of the fusion and attachment genes identified the co-circulation of three known HMPV sub-lineages, A2b and B1 (30.2% each, 26/86) and B2 (20.9%, 18/86), with genotype shift from sub-lineage B1 to A2b observed in 2013. Interestingly, a previously unrecognized sub-lineage of A2 was identified in 18.6% (16/86) of the population. Using a custom script for network construction based on the TN93 pairwise genetic distance, we identified up to nine HMPV transmission clusters circulating as multiple sub-epidemics. Although no apparent major outbreak was observed, the increased frequency of transmission clusters (dyads) during seasonal peaks suggests the potential roles of transmission clusters in driving the spread of HMPV. Our findings provide essential information for therapeutic research, prevention strategies, and disease outbreak monitoring of HMPV. PMID:27279080

  12. A live attenuated human metapneumovirus vaccine strain provides complete protection against homologous viral infection and cross-protection against heterologous viral infection in BALB/c mice.

    PubMed

    Liu, Ping; Shu, Zhou; Qin, Xian; Dou, Ying; Zhao, Yao; Zhao, Xiaodong

    2013-08-01

    A live attenuated vaccine candidate strain (M2) of human metapneumovirus (hMPV) was generated by removing the N-linked carbohydrate at amino acid 172 in the fusion (F) protein. Previously, replication of M2 in mouse lungs could be detected by molecular assays but not by viral titration. In the present study, the protective effects of M2 against infection by homologous or heterologous viruses were evaluated in BALB/c mice. Immunization with M2 produced a high titer of serum virus-neutralizing antibodies in BALB/c mice at 4 and 8 weeks postimmunization, with the titers against the homologous virus being higher than those against the heterologous virus. Challenges at 4 and 8 weeks postinoculation with M2 or wild-type virus led to no replication when mice were challenged with a homologous virus and extremely reduced replication when mice were challenged with a heterologous virus, as determined by the detection of viral genomic RNA copies in the lungs, as well as significantly milder pulmonary pathology. Thus, M2, with only one N-linked carbohydrate removed in the F protein, provides complete protection from homologous virus infection and substantial cross-protection from heterologous virus infection for at least 56 days after inoculation. This vaccine strain may therefore be a candidate for further preclinical study. Furthermore, this attenuating strategy (changing the glycosylation of a major viral protein) may be useful in the development of other viral vaccines.

  13. Development of real-time RT-PCR for detection of human metapneumovirus and genetic analysis of circulating strains (2009-2011) in Pune, India.

    PubMed

    Choudhary, Manohar Lal; Anand, Siddharth P; Sonawane, Nupoor S; Chadha, Mandeep S

    2014-02-01

    Human metapneumovirus (HMPV) is an important respiratory virus implicated in respiratory infections. The purpose of this study was to develop a one-step real-time RT-PCR assay that can detect all four lineages of HMPV and to identify the HMPV lineages circulating in Pune, India. Conserved regions of the nucleoprotein gene were used to design real-time primers and a probe. A total of 224 clinical samples that were positive for different respiratory viruses (including 51 samples that were positive for HMPV) were tested using the real time RT-PCR assay, and the specificity of the assay was observed to be 100 %. Using in vitro-synthesized RNA, the sensitivity of the assay was ascertained to be 100 copies of the target gene per reaction. Phylogenetic analysis of the nucleoprotein (N) and attachment glycoprotein (G) genes confirmed that this assay detected all lineages of HMPV. A2, B1 and B2 strains were observed during the study period. Our assay is highly sensitive and specific for all known lineages of HMPV, making it a valuable tool for rapid detection of the virus. A2 and B2 were the predominant subtypes circulating in Pune, Western India.

  14. Cross talk between animal and human influenza viruses.

    PubMed

    Ozawa, Makoto; Kawaoka, Yoshihiro

    2013-01-01

    Although outbreaks of highly pathogenic avian influenza in wild and domestic birds have been posing the threat of a new influenza pandemic for the past decade, the first pandemic of the twenty-first century came from swine viruses. This fact emphasizes the complexity of influenza viral ecology and the difficulty of predicting influenza viral dynamics. Complete control of influenza viruses seems impossible. However, we must minimize the impact of animal and human influenza outbreaks by learning lessons from past experiences and recognizing the current status. Here, we review the most recent influenza virology data in the veterinary field, including aspects of zoonotic agents and recent studies that assess the pandemic potential of H5N1 highly pathogenic avian influenza viruses.

  15. Seasonal and pandemic human influenza viruses attach better to human upper respiratory tract epithelium than avian influenza viruses.

    PubMed

    van Riel, Debby; den Bakker, Michael A; Leijten, Lonneke M E; Chutinimitkul, Salin; Munster, Vincent J; de Wit, Emmie; Rimmelzwaan, Guus F; Fouchier, Ron A M; Osterhaus, Albert D M E; Kuiken, Thijs

    2010-04-01

    Influenza viruses vary markedly in their efficiency of human-to-human transmission. This variation has been speculated to be determined in part by the tropism of influenza virus for the human upper respiratory tract. To study this tropism, we determined the pattern of virus attachment by virus histochemistry of three human and three avian influenza viruses in human nasal septum, conchae, nasopharynx, paranasal sinuses, and larynx. We found that the human influenza viruses-two seasonal influenza viruses and pandemic H1N1 virus-attached abundantly to ciliated epithelial cells and goblet cells throughout the upper respiratory tract. In contrast, the avian influenza viruses, including the highly pathogenic H5N1 virus, attached only rarely to epithelial cells or goblet cells. Both human and avian viruses attached occasionally to cells of the submucosal glands. The pattern of virus attachment was similar among the different sites of the human upper respiratory tract for each virus tested. We conclude that influenza viruses that are transmitted efficiently among humans attach abundantly to human upper respiratory tract, whereas inefficiently transmitted influenza viruses attach rarely. These results suggest that the ability of an influenza virus to attach to human upper respiratory tract is a critical factor for efficient transmission in the human population.

  16. Evidence of avian metapneumovirus subtype C infection of wild birds in Georgia, South Carolina, Arkansas and Ohio,USA.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metapneumoviruses were first reported in humans in 2001 and avian species in the late 1970s. Although avian metapneumoviruses (aMPV) have been reported in Europe and Asia for over 20 years, the virus first appeared in the United States in 1996, leaving many to question the origin of the virus. To ex...

  17. A Defective Interfering Influenza RNA Inhibits Infectious Influenza Virus Replication in Human Respiratory Tract Cells: A Potential New Human Antiviral

    PubMed Central

    Smith, Claire M.; Scott, Paul D.; O’Callaghan, Christopher; Easton, Andrew J.; Dimmock, Nigel J.

    2016-01-01

    Defective interfering (DI) viruses arise during the replication of influenza A virus and contain a non-infective version of the genome that is able to interfere with the production of infectious virus. In this study we hypothesise that a cloned DI influenza A virus RNA may prevent infection of human respiratory epithelial cells with infection by influenza A. The DI RNA (244/PR8) was derived by a natural deletion process from segment 1 of influenza A/PR/8/34 (H1N1); it comprises 395 nucleotides and is packaged in the DI virion in place of a full-length genome segment 1. Given intranasally, 244/PR8 DI virus protects mice and ferrets from clinical influenza caused by a number of different influenza A subtypes and interferes with production of infectious influenza A virus in cells in culture. However, evidence that DI influenza viruses are active in cells of the human respiratory tract is lacking. Here we show that 244/PR8 DI RNA is replicated by an influenza A challenge virus in human lung diploid fibroblasts, bronchial epithelial cells, and primary nasal basal cells, and that the yield of challenge virus is significantly reduced in a dose-dependent manner indicating that DI influenza virus has potential as a human antiviral. PMID:27556481

  18. A Defective Interfering Influenza RNA Inhibits Infectious Influenza Virus Replication in Human Respiratory Tract Cells: A Potential New Human Antiviral.

    PubMed

    Smith, Claire M; Scott, Paul D; O'Callaghan, Christopher; Easton, Andrew J; Dimmock, Nigel J

    2016-08-22

    Defective interfering (DI) viruses arise during the replication of influenza A virus and contain a non-infective version of the genome that is able to interfere with the production of infectious virus. In this study we hypothesise that a cloned DI influenza A virus RNA may prevent infection of human respiratory epithelial cells with infection by influenza A. The DI RNA (244/PR8) was derived by a natural deletion process from segment 1 of influenza A/PR/8/34 (H1N1); it comprises 395 nucleotides and is packaged in the DI virion in place of a full-length genome segment 1. Given intranasally, 244/PR8 DI virus protects mice and ferrets from clinical influenza caused by a number of different influenza A subtypes and interferes with production of infectious influenza A virus in cells in culture. However, evidence that DI influenza viruses are active in cells of the human respiratory tract is lacking. Here we show that 244/PR8 DI RNA is replicated by an influenza A challenge virus in human lung diploid fibroblasts, bronchial epithelial cells, and primary nasal basal cells, and that the yield of challenge virus is significantly reduced in a dose-dependent manner indicating that DI influenza virus has potential as a human antiviral.

  19. Influenza infection in humans and pigs in southeastern China.

    PubMed

    Zhou, N; He, S; Zhang, T; Zou, W; Shu, L; Sharp, G B; Webster, R G

    1996-01-01

    The three last pandemic strains of influenza A virus-Asian/57, Hong Kong/68 and Russian/77-are believed to have originated in China. The strains responsible for the 1957 and 1968 human pandemics were reassortants incorporating both human and avian influenza viruses, which may have arisen in pigs. We therefore undertook a population-based study in the Nanchang region of Central China to establish the prevalence, types and seasonal pattern of human influenza infection and to screen serum samples from animals and humans for evidence of interspecies transmission of influenza viruses. Two definite influenza seasons were demonstrated, one extending from November to March and the other July to September. The profile of antibodies to commonly circulating human influenza viruses was no different in Nanchang and neighboring rural communities than in Memphis, Tennessee, USA. In particular, Chinese women who raised pigs in their homes were no more likely to have been exposed to influenza virus than were subjects who seldom or never had contact with pigs. However, we did obtain evidence using isolated H7 protein in an enzyme-linked immunoabsorbent assay for infection of pig farmers by an avian H7 influenza virus suggesting that influenza. A viruses may have been transmitted directly from ducks to humans. The results of the serological survey also indicated that pigs in or near Nanchang were infected by human H1N1 and H3N2 influenza viruses, but not with typical swine viruses. We found no serological evidence for H2 influenza viruses in humans after 1968.

  20. Current Approaches for Diagnosis of Influenza Virus Infections in Humans

    PubMed Central

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-01-01

    Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000–50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans. PMID:27077877

  1. Avian metapneumovirus in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the United States of America (USA), avian metapneumovirus (aMPV) causes an upper respiratory tract infection in turkeys; no outbreaks have been reported in commercial chicken flocks. Typical clinical signs of the disease in turkey poults include coughing, sneezing, nasal discharge, tracheal rale...

  2. Reverse genetics of avian metapneumoviruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An overview of avian metapneumovirus (aMPV) infection in turkeys and development of a reverse genetics system for aMPV subgroup C (aMPV-C) virus will be presented. By using reverse genetics technology, we generated recombinant aMPV-C viruses containing a different length of glycoprotein (G) gene or...

  3. Detection of novel respiratory viruses from influenza-like illness in the Philippines.

    PubMed

    Furuse, Yuki; Suzuki, Akira; Kishi, Makiko; Galang, Hazel O; Lupisan, Socorro P; Olveda, Remigio M; Oshitani, Hitoshi

    2010-05-01

    Several novel viruses have been recently identified in respiratory samples. However, the epidemiology of these viruses in tropical countries remains unclear. The aim of the present study was to provide an overview of the epidemiology of novel respiratory viruses, including human metapneumovirus, human bocavirus, new subtypes of human coronavirus (NL63 and HKU1), KI virus, WU virus, and Melaka virus in the Philippines, a tropical country. Nasopharyngeal aspirates from 465 patients with influenza-like illness were collected in 2006 and 2007. Reverse transcription polymerase chain reaction (RT-PCR) and PCR were performed to detect viruses from culture-negative specimens. Human metapneumovirus, human bocavirus, human coronavirus HKU1, KI virus, and WU virus were detected for the first time in the Philippines; Melaka virus was not found.

  4. Zoonotic diseases and human health: the human influenza example.

    PubMed

    Schoub, Barry D

    2012-06-20

    Over the past few decades a large number of new and emerging infectious diseases have been recognised in humans, partly because of improved diagnostic technologies and increased awareness and also, partly because of dynamic ecological changes between human hosts and their exposure to animals and the environment (Coker et al. 2011). Some 177 new pathogenic organisms have been recognised to be 'emerging', that is, have newly arisen or been newly introduced into human populations; almost three quarters of these, 130 (73%), have come from zoonotic origins (Cascio et al. 2011; Cutler, Fooks & Van Der Poel 2010; Taylor, Latham & Woolhouse 2001; Woolhouse & Gowtage-Sequeria 2005). One of the most prevalent and important human infectious disease is influenza, a disease responsible globally for a quarter million deaths annually. In the USA alone the toll from influenza is estimated at 36 000 deaths and 226 000 hospitalisations, and it ranks as the most important cause of vaccine preventable mortality in that country (CDC 2010). The epidemiological behaviour of human influenza clearly defines it as an emerging infectious disease and the recent understanding of its zoonotic origins has contributed much to the understanding of its behaviour in humans (Fauci 2006).

  5. Diversity of influenza viruses in swine and the emergence of a novel human pandemic influenza A (H1N1).

    PubMed

    Brockwell-Staats, Christy; Webster, Robert G; Webby, Richard J

    2009-09-01

    The novel H1N1 influenza virus that emerged in humans in Mexico in early 2009 and transmitted efficiently in the human population with global spread has been declared a pandemic strain. Here we review influenza infections in swine since 1918 and the introduction of different avian and human influenza virus genes into swine influenza viruses of North America and Eurasia. These introductions often result in viruses of increased fitness for pigs that occasionally transmit to humans. The novel virus affecting humans is derived from a North American swine influenza virus that has acquired two gene segments [Neuraminidase (NA) and Matrix (M)] from the European swine lineages. This reassortant appears to have increased fitness in humans. The potential for increased virulence in humans and of further reassortment between the novel H1N1 influenza virus and oseltamivir resistant seasonal H1N1 or with highly pathogenic H5N1 influenza stresses the need for urgent pandemic planning.

  6. Etiology of Influenza-Like Illnesses from Sentinel Network Practitioners in Réunion Island, 2011-2012

    PubMed Central

    Brottet, Elise; Jaffar-Bandjee, Marie-Christine; Li-Pat-Yuen, Ghislaine; Filleul, Laurent

    2016-01-01

    In Réunion Island, despite an influenza surveillance established since 1996 by the sentinel general practitioner’s network, little is known about the etiology of Influenza like-illness (ILI) that differs from influenza viruses in a tropical area. We set up a retrospective study using nasal swabs collected by sentinel GPs from ILI patients in 2011 and 2012. A total of 250 swabs were randomly selected and analyzed by multiplex reverse transcriptase polymerase chain reaction (RT-PCR) including research of 18 viruses and 4 bacteria. We detected respiratory viruses in 169/222 (76.1%) samples, mostly rhinovirus (23.4%), influenza A virus (21.2%), influenza B virus (12.6%), coronavirus (4.9%) and Human metapneumovirus (3.6%). Nine swabs (5.3% of positive swabs) revealed co-infections with two viruses identified, among which six concerned co-infections with influenza viruses. We observed important seasonal differences, with circulation of Human Metapneumoviruses, RSV A and B and coronavirus only during summer; whereas parainfluenza viruses were identified only during winter. In conclusion, this study highlights a substantial circulation of multiple respiratory pathogens in Réunion Island throughout the year. It shows that ILI are not only attributable to influenza and underlines the need for biological surveillance. As the use of multiplex RT-PCR showed its efficacy, it is now used routinely in the surveillance of ILI. PMID:27654509

  7. Human influenza is more effective than avian influenza at antiviral suppression in airway cells.

    PubMed

    Hsu, Alan Chen-Yu; Barr, Ian; Hansbro, Philip M; Wark, Peter A

    2011-06-01

    Airway epithelial cells are the initial site of infection with influenza viruses. The innate immune responses of airway epithelial cells to infection are important in limiting virus replication and spread. However, relatively little is known about the importance of this innate antiviral response to infection. Avian influenza viruses are a potential source of future pandemics; therefore, it is critical to examine the effectiveness of the host antiviral system to different influenza viruses. We used a human influenza (H3N2) and a low-pathogenic avian influenza (H11N9) to assess and compare the antiviral responses of Calu-3 cells. After infection, H3N2 replicated more effectively than the H11N9 in Calu-3 cells. This was not due to differential expression of sialic acid residues on Calu-3 cells, but was attributed to the interference of host antiviral responses by H3N2. H3N2 induced a delayed antiviral signaling and impaired type I and type III IFN induction compared with the H11N9. The gene encoding for nonstructural (NS) 1 protein was transfected into the bronchial epithelial cells (BECs), and the H3N2 NS1 induced a greater inhibition of antiviral responses compared with the H11N9 NS1. Although the low-pathogenic avian influenza virus was capable of infecting BECs, the human influenza virus replicated more effectively than avian influenza virus in BECs, and this was due to a differential ability of the two NS1 proteins to inhibit antiviral responses. This suggests that the subversion of human antiviral responses may be an important requirement for influenza viruses to adapt to the human host and cause disease.

  8. 180-Nucleotide Duplication in the G Gene of Human metapneumovirus A2b Subgroup Strains Circulating in Yokohama City, Japan, since 2014

    PubMed Central

    Saikusa, Miwako; Kawakami, Chiharu; Nao, Naganori; Takeda, Makoto; Usuku, Shuzo; Sasao, Tadayoshi; Nishimoto, Kimiko; Toyozawa, Takahiro

    2017-01-01

    Human metapneumovirus (HMPV), a member of the family Paramyxoviridae, was first isolated in 2001. Seroepidemiological studies have shown that HMPV has been a major etiological agent of acute respiratory infections in humans for more than 50 years. Molecular epidemiological, genetic, and antigenetic evolutionary studies of HMPV will strengthen our understanding of the epidemic behavior of the virus and provide valuable insight for the control of HMPV and the development of vaccines and antiviral drugs against HMPV infection. In this study, the nucleotide sequence of and genetic variations in the G gene were analyzed in HMPV strains prevalent in Yokohama City, in the Kanto area, Japan, between January 2013 and June 2016. As a part of the National Epidemiological Surveillance of Infectious Diseases, Japan, 1308 clinical specimens (throat swabs, nasal swabs, nasal secretions, and nasal aspirate fluids) collected at 24 hospitals or clinics in Yokohama City were screened for 15 major respiratory viruses with a multiplex reverse transcription–PCR assay. HMPV was detected in 91 specimens, accounting for 7.0% of the total specimens, and the nucleotide sequences of the G genes of 84 HMPV strains were determined. Among these 84 strains, 6, 43, 10, and 25 strains were classified into subgroups A2a, A2b, B1, and B2, respectively. Approximately half the HMPV A2b subgroup strains detected since 2014 had a 180-nucleotide duplication (180nt-dup) in the G gene and clustered on a phylogenic tree with four classical 180nt-dup-lacking HMPV A2b strains prevalent between 2014 and 2015. The 180nt-dup causes a 60-amino-acid duplication (60aa-dup) in the G protein, creating 23–25 additional potential acceptor sites for O-linked sugars. Our data suggest that 180nt-dup occurred between 2011 and 2013 and that HMPV A2b strains with 180nt-dup (A2b180nt-dup HMPV) became major epidemic strains within 3 years. The detailed mechanism by which the A2b180nt-dup HMPV strains gained an advantage

  9. Emerging, novel, and known influenza virus infections in humans.

    PubMed

    Tang, Julian W; Shetty, Nandini; Lam, Tommy T Y; Hon, K L Ellis

    2010-09-01

    Influenza viruses continue to cause yearly epidemics and occasional pandemics in humans. In recent years, the threat of a possible influenza pandemic arising from the avian influenza A(H5N1) virus has prompted the development of comprehensive pandemic preparedness programs in many countries. The recent emergence of the pandemic influenza A(H1N1) 2009 virus from the Americas in early 2009, although surprising in its geographic and zoonotic origins, has tested these preparedness programs and revealed areas in which further work is necessary. Nevertheless, the plethora of epidemiologic, diagnostic, mathematical and phylogenetic modeling, and investigative methodologies developed since the severe acute respiratory syndrome outbreak of 2003 and the subsequent sporadic human cases of avian influenza have been applied effectively and rapidly to the emergence of this novel pandemic virus. This article summarizes some of the findings from such investigations, including recommendations for the management of patients infected with this newly emerged pathogen.

  10. Influenza virus resistance to human neutralizing antibodies.

    PubMed

    Crowe, James E

    2012-01-01

    The human antibody repertoire has an exceptionally large capacity to recognize new or changing antigens through combinatorial and junctional diversity established at the time of V(D)J recombination and through somatic hypermutation. Influenza viruses exhibit a relentless capacity to escape the human antibody response by altering the amino acids of their surface proteins in hypervariable domains that exhibit a high level of structural plasticity. Both parties in this high-stakes game of shape shifting drive structural evolution of their functional proteins (the B cell receptor/antibody on one side and the viral hemagglutinin and neuraminidase proteins on the other) using error-prone polymerase systems. It is likely that most of the genetic mutations that occur in these systems are deleterious, resulting in the failure of the B cell or virus with mutations to propagate in the immune repertoire or viral quasispecies. A subset of mutations is tolerated in functional surface proteins that enter the B cell or virus progeny pool. In both cases, selection occurs in the population of mutated and unmutated species. In cases where the functional avidity of the B cell receptor is increased significantly, that clone may be selected for preferential expansion. In contrast, an influenza virus that "escapes" the inhibitory effect of secreted antibodies may represent a high proportion of the progeny virus in that host. The recent paper by O'Donnell et al. [C. D. O'Donnell et al., mBio 3(3):e00120-12, 2012] identifies a mechanism for antibody resistance that does not require escape from binding but rather achieves a greater efficiency in replication.

  11. [Comparative study of the differential susceptibility of different cell lines to pandemic H1N1v influenza viruses and avian influenza, swine influenza, and human influenza viruses].

    PubMed

    Danilenko, D M; Smirnova, T D; Gudkova, T M; Eropkin, M Iu; Kiselev, O I

    2011-01-01

    The proliferation characteristics of influenza viruses of different origin were tested in various human and animal cell cultures. Pandemic H1N1v influenza and swine influenza viruses were shown to have a low infectious activity in virtually all the test lines. In spite of this, the replication of this group of viruses may be detected by de novo NP synthesis. These viruses are able to activate programmed cell death. Moreover, a low inoculative virus dose exerts a stimulating effect on cell proliferation in both suspension and monolayer cell lines.

  12. The contrasting phylodynamics of human influenza B viruses.

    PubMed

    Vijaykrishna, Dhanasekaran; Holmes, Edward C; Joseph, Udayan; Fourment, Mathieu; Su, Yvonne C F; Halpin, Rebecca; Lee, Raphael T C; Deng, Yi-Mo; Gunalan, Vithiagaran; Lin, Xudong; Stockwell, Timothy B; Fedorova, Nadia B; Zhou, Bin; Spirason, Natalie; Kühnert, Denise; Bošková, Veronika; Stadler, Tanja; Costa, Anna-Maria; Dwyer, Dominic E; Huang, Q Sue; Jennings, Lance C; Rawlinson, William; Sullivan, Sheena G; Hurt, Aeron C; Maurer-Stroh, Sebastian; Wentworth, David E; Smith, Gavin J D; Barr, Ian G

    2015-01-16

    A complex interplay of viral, host, and ecological factors shapes the spatio-temporal incidence and evolution of human influenza viruses. Although considerable attention has been paid to influenza A viruses, a lack of equivalent data means that an integrated evolutionary and epidemiological framework has until now not been available for influenza B viruses, despite their significant disease burden. Through the analysis of over 900 full genomes from an epidemiological collection of more than 26,000 strains from Australia and New Zealand, we reveal fundamental differences in the phylodynamics of the two co-circulating lineages of influenza B virus (Victoria and Yamagata), showing that their individual dynamics are determined by a complex relationship between virus transmission, age of infection, and receptor binding preference. In sum, this work identifies new factors that are important determinants of influenza B evolution and epidemiology.

  13. Canalization of the evolutionary trajectory of the human influenza virus

    PubMed Central

    2012-01-01

    Background Since its emergence in 1968, influenza A (H3N2) has evolved extensively in genotype and antigenic phenotype. However, despite strong pressure to evolve away from human immunity and to diversify in antigenic phenotype, H3N2 influenza shows paradoxically limited genetic and antigenic diversity present at any one time. Here, we propose a simple model of antigenic evolution in the influenza virus that accounts for this apparent discrepancy. Results In this model, antigenic phenotype is represented by a N-dimensional vector, and virus mutations perturb phenotype within this continuous Euclidean space. We implement this model in a large-scale individual-based simulation, and in doing so, we find a remarkable correspondence between model behavior and observed influenza dynamics. This model displays rapid evolution but low standing diversity and simultaneously accounts for the epidemiological, genetic, antigenic, and geographical patterns displayed by the virus. We find that evolution away from existing human immunity results in rapid population turnover in the influenza virus and that this population turnover occurs primarily along a single antigenic axis. Conclusions Selective dynamics induce a canalized evolutionary trajectory, in which the evolutionary fate of the influenza population is surprisingly repeatable. In the model, the influenza population shows a 1- to 2-year timescale of repeatability, suggesting a window in which evolutionary dynamics could be, in theory, predictable. PMID:22546494

  14. Clinical review: Update of avian influenza A infections in humans

    PubMed Central

    Sandrock, Christian; Kelly, Terra

    2007-01-01

    Influenza A viruses have a wide host range for infection, from wild waterfowl to poultry to humans. Recently, the cross-species transmission of avian influenza A, particularly subtype H5N1, has highlighted the importance of the non-human subtypes and their incidence in the human population has increased over the past decade. During cross-species transmission, human disease can range from the asymptomatic to mild conjunctivitis to fulminant pneumonia and death. With these cases, however, the risk for genetic change and development of a novel virus increases, heightening the need for public health and hospital measures. This review discusses the epidemiology, host range, human disease, outcome, treatment, and prevention of cross-transmission of avian influenza A into humans. PMID:17419881

  15. SnapShot: Evolution of human influenza A viruses.

    PubMed

    Wendel, Isabel; Matrosovich, Mikhail; Klenk, Hans Dieter

    2015-03-11

    The major natural hosts of influenza A viruses are wild aquatic birds. Occasionally, viruses are transmitted to mammalian and other avian species, including humans. Due to the high mutation rate and reassortment of the viral genome, the viruses may undergo adaptation to humans and then give rise to a pandemic.

  16. Dynamically correlated mutations drive human Influenza A evolution.

    PubMed

    Tria, F; Pompei, S; Loreto, V

    2013-01-01

    Human Influenza A virus undergoes recurrent changes in the hemagglutinin (HA) surface protein, primarily involved in the human antibody recognition. Relevant antigenic changes, enabling the virus to evade host immune response, have been recognized to occur in parallel to multiple mutations at antigenic sites in HA. Yet, the role of correlated mutations (epistasis) in driving the molecular evolution of the virus still represents a challenging puzzle. Further, though circulation at a global geographic level is key for the survival of Influenza A, its role in shaping the viral phylodynamics remains largely unexplored. Here we show, through a sequence based epidemiological model, that epistatic effects between amino acids substitutions, coupled with a reservoir that mimics worldwide circulating viruses, are key determinants that drive human Influenza A evolution. Our approach explains all the up-to-date observations characterizing the evolution of H3N2 subtype, including phylogenetic properties, nucleotide fixation patterns, and composition of antigenic clusters.

  17. Respiratory Mucosal Proteome Quantification in Human Influenza Infections.

    PubMed

    Marion, Tony; Elbahesh, Husni; Thomas, Paul G; DeVincenzo, John P; Webby, Richard; Schughart, Klaus

    2016-01-01

    Respiratory influenza virus infections represent a serious threat to human health. Underlying medical conditions and genetic make-up predispose some influenza patients to more severe forms of disease. To date, only a few studies have been performed in patients to correlate a selected group of cytokines and chemokines with influenza infection. Therefore, we evaluated the potential of a novel multiplex micro-proteomics technology, SOMAscan, to quantify proteins in the respiratory mucosa of influenza A and B infected individuals. The analysis included but was not limited to quantification of cytokines and chemokines detected in previous studies. SOMAscan quantified more than 1,000 secreted proteins in small nasal wash volumes from infected and healthy individuals. Our results illustrate the utility of micro-proteomic technology for analysis of proteins in small volumes of respiratory mucosal samples. Furthermore, when we compared nasal wash samples from influenza-infected patients with viral load ≥ 2(8) and increased IL-6 and CXCL10 to healthy controls, we identified 162 differentially-expressed proteins between the two groups. This number greatly exceeds the number of DEPs identified in previous studies in human influenza patients. Most of the identified proteins were associated with the host immune response to infection, and changes in protein levels of 151 of the DEPs were significantly correlated with viral load. Most important, SOMAscan identified differentially expressed proteins heretofore not associated with respiratory influenza infection in humans. Our study is the first report for the use of SOMAscan to screen nasal secretions. It establishes a precedent for micro-proteomic quantification of proteins that reflect ongoing response to respiratory infection.

  18. Respiratory Mucosal Proteome Quantification in Human Influenza Infections

    PubMed Central

    Marion, Tony; Elbahesh, Husni; Thomas, Paul G.; DeVincenzo, John P.; Webby, Richard; Schughart, Klaus

    2016-01-01

    Respiratory influenza virus infections represent a serious threat to human health. Underlying medical conditions and genetic make-up predispose some influenza patients to more severe forms of disease. To date, only a few studies have been performed in patients to correlate a selected group of cytokines and chemokines with influenza infection. Therefore, we evaluated the potential of a novel multiplex micro-proteomics technology, SOMAscan, to quantify proteins in the respiratory mucosa of influenza A and B infected individuals. The analysis included but was not limited to quantification of cytokines and chemokines detected in previous studies. SOMAscan quantified more than 1,000 secreted proteins in small nasal wash volumes from infected and healthy individuals. Our results illustrate the utility of micro-proteomic technology for analysis of proteins in small volumes of respiratory mucosal samples. Furthermore, when we compared nasal wash samples from influenza-infected patients with viral load ≥ 28 and increased IL-6 and CXCL10 to healthy controls, we identified 162 differentially-expressed proteins between the two groups. This number greatly exceeds the number of DEPs identified in previous studies in human influenza patients. Most of the identified proteins were associated with the host immune response to infection, and changes in protein levels of 151 of the DEPs were significantly correlated with viral load. Most important, SOMAscan identified differentially expressed proteins heretofore not associated with respiratory influenza infection in humans. Our study is the first report for the use of SOMAscan to screen nasal secretions. It establishes a precedent for micro-proteomic quantification of proteins that reflect ongoing response to respiratory infection. PMID:27088501

  19. Human influenza viruses and CD8(+) T cell responses.

    PubMed

    Grant, Emma J; Quiñones-Parra, Sergio M; Clemens, E Bridie; Kedzierska, Katherine

    2016-02-01

    Influenza A viruses (IAVs) cause significant morbidity and mortality worldwide, despite new strain-specific vaccines being available annually. As IAV-specific CD8(+) T cells promote viral control in the absence of neutralizing antibodies, and can mediate cross-reactive immunity toward distinct IAVs to drive rapid recovery from both mild and severe influenza disease, there is great interest in developing a universal T cell vaccine. However, despite detailed studies in mouse models of influenza virus infection, there is still a paucity of data on human epitope-specific CD8(+) T cell responses to IAVs. This review focuses on our current understanding of human CD8(+) T cell immunity against distinct IAVs and discusses the possibility of achieving a CD8(+) T cell mediated-vaccine that protects against multiple, distinct IAV strains across diverse human populations. We also review the importance of CD8(+) T cell immunity in individuals highly susceptible to severe influenza infection, including those hospitalised with influenza, the elderly and Indigenous populations.

  20. Isolation of a novel swine influenza virus from Oklahoma in 2011 which is distantly related to human influenza C viruses.

    PubMed

    Hause, Ben M; Ducatez, Mariette; Collin, Emily A; Ran, Zhiguang; Liu, Runxia; Sheng, Zizhang; Armien, Anibal; Kaplan, Bryan; Chakravarty, Suvobrata; Hoppe, Adam D; Webby, Richard J; Simonson, Randy R; Li, Feng

    2013-02-01

    Of the Orthomyxoviridae family of viruses, only influenza A viruses are thought to exist as multiple subtypes and has non-human maintenance hosts. In April 2011, nasal swabs were collected for virus isolation from pigs exhibiting influenza-like illness. Subsequent electron microscopic, biochemical, and genetic studies identified an orthomyxovirus with seven RNA segments exhibiting approximately 50% overall amino acid identity to human influenza C virus. Based on its genetic organizational similarities to influenza C viruses this virus has been provisionally designated C/Oklahoma/1334/2011 (C/OK). Phylogenetic analysis of the predicted viral proteins found that the divergence between C/OK and human influenza C viruses was similar to that observed between influenza A and B viruses. No cross reactivity was observed between C/OK and human influenza C viruses using hemagglutination inhibition (HI) assays. Additionally, screening of pig and human serum samples found that 9.5% and 1.3%, respectively, of individuals had measurable HI antibody titers to C/OK virus. C/OK virus was able to infect both ferrets and pigs and transmit to naive animals by direct contact. Cell culture studies showed that C/OK virus displayed a broader cellular tropism than a human influenza C virus. The observed difference in cellular tropism was further supported by structural analysis showing that hemagglutinin esterase (HE) proteins between two viruses have conserved enzymatic but divergent receptor-binding sites. These results suggest that C/OK virus represents a new subtype of influenza C viruses that currently circulates in pigs that has not been recognized previously. The presence of multiple subtypes of co-circulating influenza C viruses raises the possibility of reassortment and antigenic shift as mechanisms of influenza C virus evolution.

  1. Topology and cellular localization of the small hydrophobic protein of avian metapneumovirus.

    PubMed

    Deng, Qiji; Weng, Yuejin; Lu, Wuxun; Demers, Andrew; Song, Minxun; Wang, Dan; Yu, Qingzhong; Li, Feng

    2011-09-01

    The small hydrophobic protein (SH) is a type II integral membrane protein that is packaged into virions and is only present in certain paramyxoviruses including metapneumovirus. In addition to a highly divergent primary sequence, SH proteins vary significantly in size amongst the different viruses. Human respiratory syncytial virus (HRSV) encodes the smallest SH protein consisting of only 64 amino acids, while metapneumoviruses have the longest SH protein ranging from 174 to 179 amino acids in length. Little is currently known about the cellular localization and topology of the metapneumovirus SH protein. Here we characterize for the first time metapneumovirus SH protein with respect to topology, subcellular localization, and transport using avian metapneumovirus subgroup C (AMPV-C) as a model system. We show that AMPV-C SH is an integral membrane protein with N(in)C(out) orientation located in both the plasma membrane as well as within intracellular compartments, which is similar to what has been described previously for SH proteins of other paramyxoviruses. Furthermore, we demonstrate that AMPV-C SH protein localizes in the endoplasmic reticulum (ER), Golgi, and cell surface, and is transported through ER-Golgi secretory pathway.

  2. Pandemic influenza: human rights, ethics and duty to treat.

    PubMed

    Pahlman, I; Tohmo, H; Gylling, H

    2010-01-01

    The 2009 influenza A/H1N1 pandemic seems to be only moderately severe. In the future, a pandemic influenza with high lethality, such as the Spanish influenza in 1918-1919 or even worse, may emerge. In this kind of scenario, lethality rates ranging roughly from 2% to 30% have been proposed. Legal and ethical issues should be discussed before the incident. This article aims to highlight the legal, ethical and professional aspects that might be relevant to anaesthesiologists in the case of a high-lethality infectious disease such as a severe pandemic influenza. The epidemiology, the role of anaesthesiologists and possible threats to the profession and colleagueship within medical specialties relevant to anaesthesiologists are reviewed. During historical plague epidemics, some doctors have behaved like 'deserters'. However, during the Spanish influenza, physicians remained at their jobs, although many perished. In surveys, more than half of the health-care workers have reported their willingness to work in the case of severe pandemics. Physicians have the same human rights as all citizens: they have to be effectively protected against infectious disease. However, they have a duty to treat. Fair and responsible colleagueship among the diverse medical specialties should be promoted. Until disaster threatens humanity, volunteering to work during a pandemic might be the best way to ensure that physicians and other health-care workers stay at their workplace. Broad discussion in society is needed.

  3. Use of a multiplex real-time PCR to study the incidence of human metapneumovirus and human respiratory syncytial virus infections during two winter seasons in a Belgian paediatric hospital.

    PubMed

    Bonroy, C; Vankeerberghen, A; Boel, A; De Beenhouwer, H

    2007-05-01

    Viruses are an important cause of acute respiratory tract infection (ARTI) in children. This study aimed to develop and evaluate a rapid molecular diagnostic test (duplex real-time PCR) for human respiratory syncytial virus (hRSV) and human metapneumovirus (hMPV), and to determine the frequency of these two viruses as causative agents of ARTI in Belgium. Nasopharyngeal aspirates were collected over two winter and spring seasons (November 2003 to May 2004 and November 2004 to May 2005) from children aged <5 years with ARTI (n = 778). The duplex real-time PCR showed a linear range of 10(4)-10(10) copies/mL for both hMPV and hRSV. Analysis of the stability of the hRSV and hMPV genomes revealed that nasopharyngeal aspirates could be stored at room temperature for up to 1 month without significant loss of detection. hRSV was detected by antigen testing and by real-time PCR; hMPV was detected by real-time PCR only. The hRSV antigen test was less sensitive than PCR, and failed to detect one-third of the hRSV infections. Overall, 54 (6.9%) and 306 (39.3%) of the 778 samples were positive for hMPV and hRSV, respectively. Both viruses infected young infants, but the mean age of infants infected by hRSV was lower than that of infants infected by hMPV (12 months vs. 17 months, respectively).

  4. Contrasting substitution patterns between HA proteins of avian and human influenza viruses: Implication for monitoring human influenza epidemics.

    PubMed

    Liao, Yu-Chieh; Chen, Feng-Chi; Hsiung, Chao A

    2010-11-23

    The HA1 domain of influenza A viruses is critical for immune escape and host receptor recognition. However, the association between HA1 evolution and host species-specific adaptations remains unclear. We have identified the amino acid sites that are related to the host species-specific adaptations by systematically comparing the evolutionary dynamics of HA1 between human and avian hosts for both H1N1 and H3N2 viruses. We can thus refine the "positively selected sites" in the HA1 domain of these two virus subtypes to those that occur only in humans. We further demonstrate that the refined sets can accurately reflect influenza epidemics. Our retrospective study shows that when substitutions occur at more than three out of these identified sites in the same year, an epidemic is very likely to occur. Therefore, our approach could potentially be used in determining whether new influenza vaccines are needed.

  5. Serologic Evidence of Human and Swine Influenza in Mayan Persons

    PubMed Central

    Cadavieco-Burgos, Juan Manuel; Canul-Armas, Alejandro Bernardino

    2005-01-01

    Antibodies against influenza viruses were detected in 115 serum samples from indigenous Mayan persons from Kochol, Yucatán. Seropositivity rates were 26.9% to A/Bayern/7/95, 40.8% to A/Sydney/5/97, 1.7% to A/Swine/Wisconsin/238/97, and 79.1% to A/Swine/Minnesota/593/99. This report is the first in Mexico of the prevalence of antibodies to swine influenza virus in humans. PMID:15705345

  6. Influenza A Viruses of Human Origin in Swine, Brazil.

    PubMed

    Nelson, Martha I; Schaefer, Rejane; Gava, Danielle; Cantão, Maurício Egídio; Ciacci-Zanella, Janice Reis

    2015-08-01

    The evolutionary origins of the influenza A(H1N1)pdm09 virus that caused the first outbreak of the 2009 pandemic in Mexico remain unclear, highlighting the lack of swine surveillance in Latin American countries. Although Brazil has one of the largest swine populations in the world, influenza was not thought to be endemic in Brazil's swine until the major outbreaks of influenza A(H1N1)pdm09 in 2009. Through phylogenetic analysis of whole-genome sequences of influenza viruses of the H1N1, H1N2, and H3N2 subtypes collected in swine in Brazil during 2009-2012, we identified multiple previously uncharacterized influenza viruses of human seasonal H1N2 and H3N2 virus origin that have circulated undetected in swine for more than a decade. Viral diversity has further increased in Brazil through reassortment between co-circulating viruses, including A(H1N1)pdm09. The circulation of multiple divergent hemagglutinin lineages challenges the design of effective cross-protective vaccines and highlights the need for additional surveillance.

  7. Systems Biology of Seasonal Influenza Vaccination in Humans

    PubMed Central

    Nakaya, Helder I; Wrammert, Jens; Lee, Eva K; Racioppi, Luigi; Marie-Kunze, Stephanie; Haining, W. Nicholas; Means, Anthony R; Kasturi, Sudhir P; Khan, Nooruddin; Li, Gui-Mei; McCausland, Megan; Kanchan, Vibhu; Kokko, Kenneth E; Li, Shuzhao; Elbein, Rivka; Mehta, Aneesh K; Aderem, Alan; Subbarao, Kanta; Ahmed, Rafi; Pulendran, Bali

    2011-01-01

    We used a systems biological approach to study innate and adaptive responses to influenza vaccination in humans, during 3 consecutive influenza seasons. Healthy adults were vaccinated with inactivated (TIV) or live attenuated (LAIV) influenza vaccines. TIV induced greater antibody titers and enhanced numbers of plasmablasts than LAIV. In TIV vaccinees, early molecular signatures correlated with, and accurately predicted, later antibody titers in two independent trials. Interestingly, the expression of Calcium/calmodulin-dependent kinase IV (CamkIV) at day 3 was inversely correlated with later antibody titers. Vaccination of CamkIV −/− mice with TIV induced enhanced antigen-specific antibody titers, demonstrating an unappreciated role for CaMKIV in the regulation of antibody responses. Thus systems approaches can predict immunogenicity, and reveal new mechanistic insights about vaccines. PMID:21743478

  8. Severe metapneumovirus infections among immunocompetent and immunocompromised patients admitted to hospital with respiratory infection.

    PubMed

    Souza, Juliana Sinohara; Watanabe, Aripuana; Carraro, Emerson; Granato, Celso; Bellei, Nancy

    2013-03-01

    Human metapneumovirus (hMPV) is considered an important cause of acute respiratory infections. hMPV can cause morbidity in hematopoietic stem cell transplant recipients and recent research has demonstrated that it is an important virus in patients admitted to hospital with respiratory infections and suspected of having pandemic 2009 influenza A (H1N1pdm09) virus. The purpose of this study was to investigate infections caused by hMPV in two groups of patients admitted to hospital: Immunocompromized patients with a potential risk of severe outcomes and immunocompetent patients with severe acute respiratory syndrome. A total of 288 samples were tested: 165 samples were collected from patients with suspected influenza A (H1N1) pdm09 infection during the first pandemic wave in 2009; and 123 samples were collected from patients of a hematopoietic stem cell transplantation program in 2008-2009. Amplification of the hMPV genes was performed by polymerase chain reaction. This was followed by sequencing and phylogenetic analysis. hMPV was detected in 14.2% (41/288) of all samples: 17% (28/165) of immunocompetent patients with suspected H1N1 infection and 10.6% (13/123) among hematopoietic stem cell transplant recipients. hMPV accounted for 12.1% (8/66) of immunocompetent adults patients with severe respiratory infections (median age, 55.9 years). Two hMPV subtypes were identified, A2 (26.9%; 7/26) and B2 (73.1%; 19/26) but no difference was observed between the patient groups in terms of age or immunosuppression level. This study highlights the significance of hMPV in immunocompetent adult patients with severe infections and further investigations are recommended for understanding the impact of this virus.

  9. The cellular endosomal sorting complex required for transport pathway is not involved in avian metapneumovirus budding in a virus-like-particle expression system.

    PubMed

    Weng, Yuejin; Lu, Wuxun; Harmon, Aaron; Xiang, Xiaoxiao; Deng, Qiji; Song, Minxun; Wang, Dan; Yu, Qingzhong; Li, Feng

    2011-05-01

    Avian metapneumovirus (AMPV) is a paramyxovirus that principally causes respiratory disease and egg production drops in turkeys and chickens. Together with its closely related human metapneumovirus (HMPV), they comprise the genus Metapneumovirus in the family Paramyxoviridae. Little is currently known about the mechanisms involved in the budding of metapneumovirus. By using AMPV as a model system, we showed that the matrix (M) protein by itself was insufficient to form virus-like-particles (VLPs). The incorporation of M into VLPs was shown to occur only when both the viral nucleoprotein (N) and the fusion (F) proteins were co-expressed. Furthermore, we provided evidence indicating that two YSKL and YAGL segments encoded within the M protein were not a functional late domain, and the endosomal sorting complex required for transport (ESCRT) machinery was not involved in metapneumovirus budding, consistent with a recent observation that human respiratory syncytial virus, closely related to HMPV, uses an ESCRT-independent budding mechanism. Taken together, these results suggest that metapneumovirus budding is independent of the ESCRT pathway and the minimal budding machinery described here will aid our future understanding of metapneumovirus assembly and egress.

  10. Susceptibility of human and avian influenza viruses to human and chicken saliva.

    PubMed

    Limsuwat, Nattavatchara; Suptawiwat, Ornpreya; Boonarkart, Chompunuch; Puthavathana, Pilaipan; Auewarakul, Prasert; Wiriyarat, Witthawat

    2014-05-01

    Oral cavity can be an entry site of influenza virus and saliva is known to contain innate soluble anti-influenza factors. Influenza strains were shown to vary in their susceptibility to those antiviral factors. Whether the susceptibility to the saliva antiviral factors plays any role in the host species specificity of influenza viruses is not known. In this study, the antiviral activity of human and chicken saliva against human and the H5N1 avian influenza viruses were investigated by hemagglutination inhibition (HI) and neutralization (NT) assays. In comparison to human influenza viruses, H5N1 isolates showed reduced susceptibility to human saliva as measured by HI and NT assays. Interestingly, an H5N1 isolate that bind to both α2,3- and α2,6-linked sialic acid showed much higher HI titers with human saliva, suggesting that the susceptibility profile was linked to the receptor-binding preference and the presence of α2,6-linked sialic in human saliva. On the other hand, the H5N1 isolates showed increased HI titers but reduced NT titers to chicken saliva as compared to human influenza isolates. The human salivary antiviral components were characterized by testing the sensitivity to heat, receptor destroying enzyme (RDE), CaCl₂/EDTA dependence, and inhibition by mannan, and shown to be α- and γ-inhibitors. These data suggest that the H5N1 HPAI influenza virus had distinctive susceptibility patterns to human and chicken saliva, which may play some roles in its infectivity and transmissibility in these hosts.

  11. Human and Avian Influenza Viruses Target Different Cells in the Lower Respiratory Tract of Humans and Other Mammals

    PubMed Central

    van Riel, Debby; Munster, Vincent J.; de Wit, Emmie; Rimmelzwaan, Guus F.; Fouchier, Ron A.M.; Osterhaus, Albert D.M.E.; Kuiken, Thijs

    2007-01-01

    Viral attachment to the host cell is critical for tissue and species specificity of virus infections. Recently, pattern of viral attachment (PVA) in human respiratory tract was determined for highly pathogenic avian influenza virus of subtype H5N1. However, PVA of human influenza viruses and other avian influenza viruses in either humans or experimental animals is unknown. Therefore, we compared PVA of two human influenza viruses (H1N1 and H3N2) and two low pathogenic avian influenza viruses (H5N9 and H6N1) with that of H5N1 virus in respiratory tract tissues of humans, mice, ferrets, cynomolgus macaques, cats, and pigs by virus histochemistry. We found that human influenza viruses attached more strongly to human trachea and bronchi than H5N1 virus and attached to different cell types than H5N1 virus. These differences correspond to primary diagnoses of tracheobronchitis for human influenza viruses and diffuse alveolar damage for H5N1 virus. The PVA of low pathogenic avian influenza viruses in human respiratory tract resembled that of H5N1 virus, demonstrating that other properties determine its pathogenicity for humans. The PVA in human respiratory tract most closely mirrored that in ferrets and pigs for human influenza viruses and that in ferrets, pigs, and cats for avian influenza viruses. PMID:17717141

  12. Heterosubtypic T-Cell Immunity to Influenza in Humans: Challenges for Universal T-Cell Influenza Vaccines

    PubMed Central

    Sridhar, Saranya

    2016-01-01

    Influenza A virus (IAV) remains a significant global health issue causing annual epidemics, pandemics, and sporadic human infections with highly pathogenic avian or swine influenza viruses. Current inactivated and live vaccines are the mainstay of the public health response to influenza, although vaccine efficacy is lower against antigenically distinct viral strains. The first pandemic of the twenty-first century underlined the urgent need to develop new vaccines capable of protecting against a broad range of influenza strains. Such “universal” influenza vaccines are based on the idea of heterosubtypic immunity, wherein immune responses to epitopes conserved across IAV strains can confer protection against subsequent infection and disease. T-cells recognizing conserved antigens are a key contributor in reducing viral load and limiting disease severity during heterosubtypic infection in animal models. Recent studies undertaken during the 2009 H1N1 pandemic provided key insights into the role of cross-reactive T-cells in mediating heterosubtypic protection in humans. This review focuses on human influenza to discuss the epidemiological observations that underpin cross-protective immunity, the role of T-cells as key players in mediating heterosubtypic immunity including recent data from natural history cohort studies and the ongoing clinical development of T-cell-inducing universal influenza vaccines. The challenges and knowledge gaps for developing vaccines to generate long-lived protective T-cell responses is discussed. PMID:27242800

  13. Fourth European Conference on Infections in Leukaemia (ECIL-4): guidelines for diagnosis and treatment of human respiratory syncytial virus, parainfluenza virus, metapneumovirus, rhinovirus, and coronavirus.

    PubMed

    Hirsch, Hans H; Martino, Rodrigo; Ward, Katherine N; Boeckh, Michael; Einsele, Hermann; Ljungman, Per

    2013-01-01

    Community-acquired respiratory virus (CARV) infections have been recognized as a significant cause of morbidity and mortality in patients with leukemia and those undergoing hematopoietic stem cell transplantation (HSCT). Progression to lower respiratory tract infection with clinical and radiological signs of pneumonia and respiratory failure appears to depend on the intrinsic virulence of the specific CARV as well as factors specific to the patient, the underlying disease, and its treatment. To better define the current state of knowledge of CARVs in leukemia and HSCT patients, and to improve CARV diagnosis and management, a working group of the Fourth European Conference on Infections in Leukaemia (ECIL-4) 2011 reviewed the literature on CARVs, graded the available quality of evidence, and made recommendations according to the Infectious Diseases Society of America grading system. Owing to differences in screening, clinical presentation, and therapy for influenza and adenovirus, ECIL-4 recommendations are summarized for CARVs other than influenza and adenovirus.

  14. Mapping influenza transmission in the ferret model to transmission in humans.

    PubMed

    Buhnerkempe, Michael G; Gostic, Katelyn; Park, Miran; Ahsan, Prianna; Belser, Jessica A; Lloyd-Smith, James O

    2015-09-02

    The controversy surrounding 'gain-of-function' experiments on high-consequence avian influenza viruses has highlighted the role of ferret transmission experiments in studying the transmission potential of novel influenza strains. However, the mapping between influenza transmission in ferrets and in humans is unsubstantiated. We address this gap by compiling and analyzing 240 estimates of influenza transmission in ferrets and humans. We demonstrate that estimates of ferret secondary attack rate (SAR) explain 66% of the variation in human SAR estimates at the subtype level. Further analysis shows that ferret transmission experiments have potential to identify influenza viruses of concern for epidemic spread in humans, though small sample sizes and biological uncertainties prevent definitive classification of human transmissibility. Thus, ferret transmission experiments provide valid predictions of pandemic potential of novel influenza strains, though results should continue to be corroborated by targeted virological and epidemiological research.

  15. Mapping influenza transmission in the ferret model to transmission in humans

    PubMed Central

    Buhnerkempe, Michael G; Gostic, Katelyn; Park, Miran; Ahsan, Prianna; Belser, Jessica A; Lloyd-Smith, James O

    2015-01-01

    The controversy surrounding 'gain-of-function' experiments on high-consequence avian influenza viruses has highlighted the role of ferret transmission experiments in studying the transmission potential of novel influenza strains. However, the mapping between influenza transmission in ferrets and in humans is unsubstantiated. We address this gap by compiling and analyzing 240 estimates of influenza transmission in ferrets and humans. We demonstrate that estimates of ferret secondary attack rate (SAR) explain 66% of the variation in human SAR estimates at the subtype level. Further analysis shows that ferret transmission experiments have potential to identify influenza viruses of concern for epidemic spread in humans, though small sample sizes and biological uncertainties prevent definitive classification of human transmissibility. Thus, ferret transmission experiments provide valid predictions of pandemic potential of novel influenza strains, though results should continue to be corroborated by targeted virological and epidemiological research. DOI: http://dx.doi.org/10.7554/eLife.07969.001 PMID:26329460

  16. Influenza virus reservoirs and intermediate hosts: dogs, horses, and new possibilities for influenza virus exposure of humans.

    PubMed

    Parrish, Colin R; Murcia, Pablo R; Holmes, Edward C

    2015-03-01

    Influenza A virus (IAV) infections in hosts outside the main aquatic bird reservoirs occur periodically. Although most such cross-species transmission events result in limited onward transmission in the new host, sustained influenza outbreaks have occurred in poultry and in a number of mammalian species, including humans, pigs, horses, seals, and mink. Recently, two distinct strains of IAV have emerged in domestic dogs, with each circulating widely for several years. Here, we briefly outline what is known about the role of intermediate hosts in influenza emergence, summarize our knowledge of the new canine influenza viruses (CIVs) and how they provide key new information on the process of host adaptation, and assess the risk these viruses pose to human populations.

  17. Human Coronavirus-Associated Influenza-Like Illness in the Community Setting in Peru.

    PubMed

    Razuri, Hugo; Malecki, Monika; Tinoco, Yeny; Ortiz, Ernesto; Guezala, M Claudia; Romero, Candice; Estela, Abel; Breña, Patricia; Morales, Maria-Luisa; Reaves, Erik J; Gomez, Jorge; Uyeki, Timothy M; Widdowson, Marc-Alain; Azziz-Baumgartner, Eduardo; Bausch, Daniel G; Schildgen, Verena; Schildgen, Oliver; Montgomery, Joel M

    2015-11-01

    We present findings describing the epidemiology of non-severe acute respiratory syndrome human coronavirus-associated influenza-like illness from a population-based active follow-up study in four different regions of Peru. In 2010, the prevalence of infections by human coronaviruses 229E, OC43, NL63, or HKU1 was 6.4% in participants with influenza-like illness who tested negative for influenza viruses. Ten of 11 human coronavirus infections were identified in the fall-winter season. Human coronaviruses are present in different regions of Peru and are relatively frequently associated with influenza-like illness in Peru.

  18. Human Coronavirus-Associated Influenza-Like Illness in the Community Setting in Peru

    PubMed Central

    Razuri, Hugo; Malecki, Monika; Tinoco, Yeny; Ortiz, Ernesto; Guezala, M. Claudia; Romero, Candice; Estela, Abel; Breña, Patricia; Morales, Maria-Luisa; Reaves, Erik J.; Gomez, Jorge; Uyeki, Timothy M.; Widdowson, Marc-Alain; Azziz-Baumgartner, Eduardo; Bausch, Daniel G.; Schildgen, Verena; Schildgen, Oliver; Montgomery, Joel M.

    2015-01-01

    We present findings describing the epidemiology of non-severe acute respiratory syndrome human coronavirus-associated influenza-like illness from a population-based active follow-up study in four different regions of Peru. In 2010, the prevalence of infections by human coronaviruses 229E, OC43, NL63, or HKU1 was 6.4% in participants with influenza-like illness who tested negative for influenza viruses. Ten of 11 human coronavirus infections were identified in the fall–winter season. Human coronaviruses are present in different regions of Peru and are relatively frequently associated with influenza-like illness in Peru. PMID:26324726

  19. Human Infections with Novel Reassortant Influenza A(H3N2)v Viruses, United States, 2011

    PubMed Central

    Lindstrom, Stephen; Garten, Rebecca; Balish, Amanda; Shu, Bo; Emery, Shannon; Berman, LaShondra; Barnes, Nathelia; Sleeman, Katrina; Gubareva, Larisa; Villanueva, Julie

    2012-01-01

    During July–December 2011, a variant virus, influenza A(H3N2)v, caused 12 human cases of influenza. The virus contained genes originating from swine, avian, and human viruses, including the M gene from influenza A(H1N1)pdm09 virus. Influenza A(H3N2)v viruses were antigenically distinct from seasonal influenza viruses and similar to proposed vaccine virus A/Minnesota/11/2010. PMID:22516540

  20. Challenges of selecting seasonal influenza vaccine strains for humans with diverse pre-exposure histories

    PubMed Central

    Hensley, Scott E.

    2014-01-01

    Seasonal influenza vaccine strains are routinely updated when influenza viruses acquire mutations in exposed regions of the hemagglutinin and neuraminidase glycoproteins. Ironically, although thousands of viral isolates are sequenced each year, today's influenza surveillance community places less emphasis on viral genetic information and more emphasis on classical serological assays when choosing vaccine strains. Here, I argue that these classical serological assays are oversimplified and that they fail to detect influenza mutations that facilitate escape of particular types of human antibodies. I propose that influenza vaccine strains should be updated more frequently even when classical serological assays fail to detect significant antigenic alterations. PMID:25108824

  1. An overview of the epidemiology and emergence of influenza A infection in humans over time.

    PubMed

    Bui, Chau Minh; Chughtai, Abrar Ahmad; Adam, Dillon Charles; MacIntyre, C Raina

    2017-01-01

    In recent years multiple novel influenza A strains have emerged in humans. We reviewed publically available data to summarise epidemiological characteristics of distinct avian influenza viruses known to cause human infection and describe changes over time. Most recently identified zoonotic strains have emerged in China (H7N9, H5N6, H10N8) - these strains have occurred mostly in association with visiting a live bird market. Most zoonotic AIVs and swine influenza variants typically cause mild infections in humans however severe illness and fatalities are associated with zoonotic H5N6, H10N8, H7N9 and H5N1 serotypes, and the H1N1 1918 Spanish Influenza. The changing landscape of avian influenza globally indicates a need to reassess the risk of a pandemic influenza outbreak of zoonotic origin.

  2. Influenza Forecasting in Human Populations: A Scoping Review

    PubMed Central

    Chretien, Jean-Paul; George, Dylan; Shaman, Jeffrey; Chitale, Rohit A.; McKenzie, F. Ellis

    2014-01-01

    Forecasts of influenza activity in human populations could help guide key preparedness tasks. We conducted a scoping review to characterize these methodological approaches and identify research gaps. Adapting the PRISMA methodology for systematic reviews, we searched PubMed, CINAHL, Project Euclid, and Cochrane Database of Systematic Reviews for publications in English since January 1, 2000 using the terms “influenza AND (forecast* OR predict*)”, excluding studies that did not validate forecasts against independent data or incorporate influenza-related surveillance data from the season or pandemic for which the forecasts were applied. We included 35 publications describing population-based (N = 27), medical facility-based (N = 4), and regional or global pandemic spread (N = 4) forecasts. They included areas of North America (N = 15), Europe (N = 14), and/or Asia-Pacific region (N = 4), or had global scope (N = 3). Forecasting models were statistical (N = 18) or epidemiological (N = 17). Five studies used data assimilation methods to update forecasts with new surveillance data. Models used virological (N = 14), syndromic (N = 13), meteorological (N = 6), internet search query (N = 4), and/or other surveillance data as inputs. Forecasting outcomes and validation metrics varied widely. Two studies compared distinct modeling approaches using common data, 2 assessed model calibration, and 1 systematically incorporated expert input. Of the 17 studies using epidemiological models, 8 included sensitivity analysis. This review suggests need for use of good practices in influenza forecasting (e.g., sensitivity analysis); direct comparisons of diverse approaches; assessment of model calibration; integration of subjective expert input; operational research in pilot, real-world applications; and improved mutual understanding among modelers and public health officials. PMID:24714027

  3. Influenza forecasting in human populations: a scoping review.

    PubMed

    Chretien, Jean-Paul; George, Dylan; Shaman, Jeffrey; Chitale, Rohit A; McKenzie, F Ellis

    2014-01-01

    Forecasts of influenza activity in human populations could help guide key preparedness tasks. We conducted a scoping review to characterize these methodological approaches and identify research gaps. Adapting the PRISMA methodology for systematic reviews, we searched PubMed, CINAHL, Project Euclid, and Cochrane Database of Systematic Reviews for publications in English since January 1, 2000 using the terms "influenza AND (forecast* OR predict*)", excluding studies that did not validate forecasts against independent data or incorporate influenza-related surveillance data from the season or pandemic for which the forecasts were applied. We included 35 publications describing population-based (N = 27), medical facility-based (N = 4), and regional or global pandemic spread (N = 4) forecasts. They included areas of North America (N = 15), Europe (N = 14), and/or Asia-Pacific region (N = 4), or had global scope (N = 3). Forecasting models were statistical (N = 18) or epidemiological (N = 17). Five studies used data assimilation methods to update forecasts with new surveillance data. Models used virological (N = 14), syndromic (N = 13), meteorological (N = 6), internet search query (N = 4), and/or other surveillance data as inputs. Forecasting outcomes and validation metrics varied widely. Two studies compared distinct modeling approaches using common data, 2 assessed model calibration, and 1 systematically incorporated expert input. Of the 17 studies using epidemiological models, 8 included sensitivity analysis. This review suggests need for use of good practices in influenza forecasting (e.g., sensitivity analysis); direct comparisons of diverse approaches; assessment of model calibration; integration of subjective expert input; operational research in pilot, real-world applications; and improved mutual understanding among modelers and public health officials.

  4. Human Infection with Avian Influenza A(H7N9) Virus - China

    MedlinePlus

    ... reduction Human infection with avian influenza A(H7N9) virus – China Disease outbreak news 18 January 2017 On ... confirmed human infection with avian influenza A(H7N9) virus and on 12 January 2017, the Health Bureau, ...

  5. Reverse zoonosis of influenza to swine: new perspectives on the human-animal interface.

    PubMed

    Nelson, Martha I; Vincent, Amy L

    2015-03-01

    The origins of the 2009 influenza A (H1N1) pandemic in swine are unknown, highlighting gaps in our understanding of influenza A virus (IAV) ecology and evolution. We review how recently strengthened influenza virus surveillance in pigs has revealed that influenza virus transmission from humans to swine is far more frequent than swine-to-human zoonosis, and is central in seeding swine globally with new viral diversity. The scale of global human-to-swine transmission represents the largest 'reverse zoonosis' of a pathogen documented to date. Overcoming the bias towards perceiving swine as sources of human viruses, rather than recipients, is key to understanding how the bidirectional nature of the human-animal interface produces influenza threats to both hosts.

  6. Avian metapneumovirus subgroup C infection in chickens, China.

    PubMed

    Wei, Li; Zhu, Shanshan; Yan, Xv; Wang, Jing; Zhang, Chunyan; Liu, Shuhang; She, Ruiping; Hu, Fengjiao; Quan, Rong; Liu, Jue

    2013-07-01

    Avian metapneumovirus causes acute respiratory tract infection and reductions in egg production in various avian species. We isolated and characterized an increasingly prevalent avian metapneumovirus subgroup C strain from meat-type commercial chickens with severe respiratory signs in China. Culling of infected flocks could lead to economic consequences.

  7. Avian Metapneumovirus Molecular Biology and Development of Genetically Engineered Vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian metapneumovirus (aMPV) is an economically important pathogen of turkeys with a worldwide distribution. aMPV is a member of the genus Metapneumovirus within the subfamily Pneumovirinae of the family Paramyxoviridae. The genome of aMPV is a non-segmented, single-stranded, negative-sense RNA of 1...

  8. Weighing serological evidence of human exposure to animal influenza viruses − a literature review

    PubMed Central

    Sikkema, Reina Saapke; Freidl, Gudrun Stephanie; de Bruin, Erwin; Koopmans, Marion

    2016-01-01

    Assessing influenza A virus strains circulating in animals and their potential to cross the species barrier and cause human infections is important to improve human influenza surveillance and preparedness. We reviewed studies describing serological evidence of human exposure to animal influenza viruses. Comparing serological data is difficult due to a lack of standardisation in study designs and in laboratory methods used in published reports. Therefore, we designed a scoring system to assess and weigh specificity of obtained serology results in the selected articles. Many studies report reliable evidence of antibodies to swine influenza viruses among persons occupationally exposed to pigs. Most avian influenza studies target H5, H7 and H9 subtypes and most serological evidence of human exposure to avian influenza viruses is reported for these subtypes. Avian influenza studies receiving a low grade in this review often reported higher seroprevalences in humans compared with studies with a high grade. Official surveillance systems mainly focus on avian H5 and H7 viruses. Swine influenza viruses and avian subtypes other than H5 and H7 (emphasising H9) should be additionally included in official surveillance systems. Surveillance efforts should also be directed towards understudied geographical areas, such as Africa and South America. PMID:27874827

  9. Weighing serological evidence of human exposure to animal influenza viruses - a literature review.

    PubMed

    Sikkema, Reina Saapke; Freidl, Gudrun Stephanie; de Bruin, Erwin; Koopmans, Marion

    2016-11-03

    Assessing influenza A virus strains circulating in animals and their potential to cross the species barrier and cause human infections is important to improve human influenza surveillance and preparedness. We reviewed studies describing serological evidence of human exposure to animal influenza viruses. Comparing serological data is difficult due to a lack of standardisation in study designs and in laboratory methods used in published reports. Therefore, we designed a scoring system to assess and weigh specificity of obtained serology results in the selected articles. Many studies report reliable evidence of antibodies to swine influenza viruses among persons occupationally exposed to pigs. Most avian influenza studies target H5, H7 and H9 subtypes and most serological evidence of human exposure to avian influenza viruses is reported for these subtypes. Avian influenza studies receiving a low grade in this review often reported higher seroprevalences in humans compared with studies with a high grade. Official surveillance systems mainly focus on avian H5 and H7 viruses. Swine influenza viruses and avian subtypes other than H5 and H7 (emphasising H9) should be additionally included in official surveillance systems. Surveillance efforts should also be directed towards understudied geographical areas, such as Africa and South America.

  10. Pandemic and Avian Influenza A Viruses in Humans: Epidemiology, Virology, Clinical Characteristics, and Treatment Strategy.

    PubMed

    Li, Hui; Cao, Bin

    2017-03-01

    The intermittent outbreak of pandemic influenza and emergence of novel avian influenza A virus is worldwide threat. Although most patients present with mild symptoms, some deteriorate to severe pneumonia and even death. Great progress in the understanding of the mechanism of disease pathogenesis and a series of vaccines has been promoted worldwide; however, incidence, morbidity, and mortality remains high. To step up vigilance and improve pandemic preparedness, this article elucidates the virology, epidemiology, pathogenesis, clinical characteristics, and treatment of human infections by influenza A viruses, with an emphasis on the influenza A(H1N1)pdm09, H5N1, and H7N9 subtypes.

  11. Subclinical avian influenza A(H5N1) virus infection in human, Vietnam.

    PubMed

    Le, Mai Quynh; Horby, Peter; Fox, Annette; Nguyen, Hien Tran; Le Nguyen, Hang Khanh; Hoang, Phuong Mai Vu; Nguyen, Khanh Cong; de Jong, Menno D; Jeeninga, Rienk E; Rogier van Doorn, H; Farrar, Jeremy; Wertheim, Heiman F L

    2013-10-01

    Laboratory-confirmed cases of subclinical infection with avian influenza A(H5N1) virus in humans are rare, and the true number of these cases is unknown. We describe the identification of a laboratory-confirmed subclinical case in a woman during an influenza A(H5N1) contact investigation in northern Vietnam.

  12. Programme of the Community Network of Reference Laboratories for Human Influenza to improve Influenza Surveillance in Europe.

    PubMed

    Meijer, Adam; Brown, Caroline; Hungnes, Olav; Schweiger, Brunhilde; Valette, Martine; van der Werf, Sylvie; Zambon, Maria

    2006-11-10

    All laboratories participating in the Community Network of Reference Laboratories for Human Influenza in Europe (CNRL) co-ordinated by the European Influenza Surveillance Scheme (EISS) should be able to perform a range of influenza diagnostics. This includes direct detection, culture, typing, subtyping and strain characterisation of influenza viruses, diagnostic serology and the creation of archives for clinical specimens and virus isolates. To improve the capacity and quality of the laboratories of the CNRL and to increase the consistency in performance among all 25 European Union countries plus Norway, Romania, and Switzerland, five task groups were set up in February 2005. These task groups developed work programmes in the areas of virus isolation, antibodies, molecular virology, quality control assessment and antiviral susceptibility testing. This report outlines the programmes and the results achieved in the first half-year of operation of the task groups. The action plans are challenging and it is expected that these efforts will lead to considerable improvements in the performance of the laboratories and in the standardisation of methods employed in Europe with regard to routine influenza surveillance and early warning for emerging viruses.

  13. Pilus-Mediated Adherence of Haemophilus influenzae to Human Respiratory Mucins

    PubMed Central

    Kubiet, Martin; Ramphal, Reuben; Weber, Allan; Smith, Arnold

    2000-01-01

    Haemophilus influenzae, especially the nontypeable strains, are among the most common pathogens encountered in patients with chronic lung disease and otitis media. We and others have demonstrated that respiratory isolates of nontypeable H. influenzae bind to human mucins, but the mechanism of binding is not entirely clear. We have therefore examined the role of pili in the adherence of both type b and nontypeable H. influenzae to human respiratory mucins. We used isogenic H. influenzae strains with a mutation in the structural gene for pilin (hifA), a laboratory H. influenzae strain transformed with a type b pilus gene cluster (from strain C54), antibodies raised against H. influenzae HifA, and Escherichia coli strains carrying a cloned type b pilus gene cluster (from strain AM30) in these studies. All bacteria lacking HifA or the pilus gene cluster had decreased adherence of piliated H. influenzae to mucins, and Fab fragments of anti-HifA antibodies inhibited the adherence. E. coli strains carrying the cloned type b pilus gene cluster were six to seven times more adhesive than strains carrying the vector. The role of other putative adhesins was not examined and thus cannot be excluded, but these studies support a role for pili in the binding of H. influenzae to human respiratory mucins. PMID:10816486

  14. H7N9 avian influenza A virus and the perpetual challenge of potential human pandemicity.

    PubMed

    Morens, David M; Taubenberger, Jeffery K; Fauci, Anthony S

    2013-07-09

    ABSTRACT The ongoing H7N9 influenza epizootic in China once again presents us questions about the origin of pandemics and how to recognize them in early stages of development. Over the past ~135 years, H7 influenza viruses have neither caused pandemics nor been recognized as having undergone human adaptation. Yet several unusual properties of these viruses, including their poultry epizootic potential, mammalian adaptation, and atypical clinical syndromes in rarely infected humans, suggest that they may be different from other avian influenza viruses, thus questioning any assurance that the likelihood of human adaptation is low. At the same time, the H7N9 epizootic provides an opportunity to learn more about the mammalian/human adaptational capabilities of avian influenza viruses and challenges us to integrate virologic and public health research and surveillance at the animal-human interface.

  15. Spatial dynamics of human-origin H1 influenza A virus in North American swine.

    PubMed

    Nelson, Martha I; Lemey, Philippe; Tan, Yi; Vincent, Amy; Lam, Tommy Tsan-Yuk; Detmer, Susan; Viboud, Cécile; Suchard, Marc A; Rambaut, Andrew; Holmes, Edward C; Gramer, Marie

    2011-06-01

    The emergence and rapid global spread of the swine-origin H1N1/09 pandemic influenza A virus in humans underscores the importance of swine populations as reservoirs for genetically diverse influenza viruses with the potential to infect humans. However, despite their significance for animal and human health, relatively little is known about the phylogeography of swine influenza viruses in the United States. This study utilizes an expansive data set of hemagglutinin (HA1) sequences (n = 1516) from swine influenza viruses collected in North America during the period 2003-2010. With these data we investigate the spatial dissemination of a novel influenza virus of the H1 subtype that was introduced into the North American swine population via two separate human-to-swine transmission events around 2003. Bayesian phylogeographic analysis reveals that the spatial dissemination of this influenza virus in the US swine population follows long-distance swine movements from the Southern US to the Midwest, a corn-rich commercial center that imports millions of swine annually. Hence, multiple genetically diverse influenza viruses are introduced and co-circulate in the Midwest, providing the opportunity for genomic reassortment. Overall, the Midwest serves primarily as an ecological sink for swine influenza in the US, with sources of virus genetic diversity instead located in the Southeast (mainly North Carolina) and South-central (mainly Oklahoma) regions. Understanding the importance of long-distance pig transportation in the evolution and spatial dissemination of the influenza virus in swine may inform future strategies for the surveillance and control of influenza, and perhaps other swine pathogens.

  16. Serological report of pandemic and seasonal human influenza virus infection in dogs in southern China.

    PubMed

    Yin, Xin; Zhao, Fu-Rong; Zhou, Dong-Hui; Wei, Ping; Chang, Hui-Yun

    2014-11-01

    From January to July 2012, we looked for evidence of subclinical A (H1N1) pdm09 and seasonal human influenza viruses infections in healthy dogs in China. Sera from a total of 1920 dogs were collected from Guangdong, Guangxi, Fujian and Jiangxi provinces. We also examined archived sera from 66 dogs and cats that were collected during 2008 from these provinces. Using hemagglutination inhibition (HI) and microneutralization (MN) assays, we found that only the dogs sampled in 2012 had elevated antibodies (≥ 1:32) against A(H1N1)pdm09 virus and seasonal human influenza viruses: Of the 1920 dog sera, 20.5 % (n = 393) had elevated antibodies against influenza A(H1N1) pdm09 by the HI assay, 1.1 % (n = 22), and 4.7 % (n = 91) of the 1920 dogs sera had elevated antibodies against human seasonal H1N1 influenza virus and human seasonal H3N2 influenza virus by the HI assay. Compared with dogs that were raised on farms, dogs that were raised as pets were more likely to have elevated antibodies against A(H1N1)pdm09 and seasonal human influenza viruses. Seropositivity was highest among pet dogs, which likely had more diverse and frequent exposures to humans than farm dogs. These findings will help us better understand which influenza A viruses are present in dogs and will contribute to the prevention and control of influenza A virus. Moreover, further in-depth study is necessary for us to understand what roles dogs play in the ecology of influenza A.

  17. Human infections with influenza A(H3N2) variant virus in the United States, 2011-2012

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND. During August 2011-April 2012, 13 human infections with influenza A(H3N2) variant (H3N2v) virus were identified in the United States; 8 occurred in the prior 2 years. This virus differs from previous variant influenza viruses in that it contains the matrix (M) gene from the Influenza A(H...

  18. Integrating Decision Tree and Hidden Markov Model (HMM) for Subtype Prediction of Human Influenza A Virus

    NASA Astrophysics Data System (ADS)

    Attaluri, Pavan K.; Chen, Zhengxin; Weerakoon, Aruna M.; Lu, Guoqing

    Multiple criteria decision making (MCDM) has significant impact in bioinformatics. In the research reported here, we explore the integration of decision tree (DT) and Hidden Markov Model (HMM) for subtype prediction of human influenza A virus. Infection with influenza viruses continues to be an important public health problem. Viral strains of subtype H3N2 and H1N1 circulates in humans at least twice annually. The subtype detection depends mainly on the antigenic assay, which is time-consuming and not fully accurate. We have developed a Web system for accurate subtype detection of human influenza virus sequences. The preliminary experiment showed that this system is easy-to-use and powerful in identifying human influenza subtypes. Our next step is to examine the informative positions at the protein level and extend its current functionality to detect more subtypes. The web functions can be accessed at http://glee.ist.unomaha.edu/.

  19. A humanized anti-M2 scFv shows protective in vitro activity against influenza

    SciTech Connect

    Bradbury, Andrew M; Velappan, Nileena; Schmidt, Jurgen G

    2008-01-01

    M2 is one of the most conserved influenza proteins, and has been widely prospected as a potential universal vaccine target, with protection predominantly mediated by antibodies. In this paper we describe the creation of a humanized single chain Fv from 14C2, a potent monoclonal antibody against M2. We show that the humanized scFv demonstrates similar activity to the parental mAb: it is able to recognize M2 in its native context on cell surfaces and is able to show protective in vitro activity against influenza, and so represents a potential lead antibody candidate for universal prophylactic or therapeutic intervention in influenza.

  20. Replication of swine and human influenza viruses in juvenile and layer turkey hens.

    PubMed

    Ali, Ahmed; Yassine, Hadi; Awe, Olusegun O; Ibrahim, Mahmoud; Saif, Yehia M; Lee, Chang-Won

    2013-04-12

    Since the first reported isolation of swine influenza viruses (SIVs) in turkeys in the 1980s, transmission of SIVs to turkeys was frequently documented. Recently, the 2009 pandemic H1N1 virus, that was thought to be of swine origin, was detected in turkeys with a severe drop in egg production. In this study, we assessed the infectivity of different mammalian influenza viruses including swine, pandemic H1N1 and seasonal human influenza viruses in both juvenile and layer turkeys. In addition, we investigated the potential influenza virus dissemination in the semen of experimentally infected turkey toms. Results showed that all mammalian origin influenza viruses tested can infect turkeys. SIVs were detected in respiratory and digestive tracts of both juvenile and layer turkeys. Variations in replication efficiencies among SIVs were observed especially in the reproductive tract of layer turkeys. Compared to SIVs, limited replication of seasonal human H1N1 and no detectable replication of recent human-like swine H1N2, pandemic H1N1 and seasonal human H3N2 viruses was noticed. All birds seroconverted to all tested viruses regardless of their replication level. In turkey toms, we were able to detect swine H3N2 virus in semen and reproductive tract of infected toms by real-time RT-PCR although virus isolation was not successful. These data suggest that turkey hens could be affected by diverse influenza strains especially SIVs. Moreover, the differences in the replication efficiency we demonstrated among SIVs and between SIV and human influenza viruses in layer turkeys suggest a possible use of turkeys as an animal model to study host tropism and pathogenesis of influenza viruses. Our results also indicate a potential risk of venereal transmission of influenza viruses in turkeys.

  1. Unifying viral genetics and human transportation data to predict the global transmission dynamics of human influenza H3N2.

    PubMed

    Lemey, Philippe; Rambaut, Andrew; Bedford, Trevor; Faria, Nuno; Bielejec, Filip; Baele, Guy; Russell, Colin A; Smith, Derek J; Pybus, Oliver G; Brockmann, Dirk; Suchard, Marc A

    2014-02-01

    Information on global human movement patterns is central to spatial epidemiological models used to predict the behavior of influenza and other infectious diseases. Yet it remains difficult to test which modes of dispersal drive pathogen spread at various geographic scales using standard epidemiological data alone. Evolutionary analyses of pathogen genome sequences increasingly provide insights into the spatial dynamics of influenza viruses, but to date they have largely neglected the wealth of information on human mobility, mainly because no statistical framework exists within which viral gene sequences and empirical data on host movement can be combined. Here, we address this problem by applying a phylogeographic approach to elucidate the global spread of human influenza subtype H3N2 and assess its ability to predict the spatial spread of human influenza A viruses worldwide. Using a framework that estimates the migration history of human influenza while simultaneously testing and quantifying a range of potential predictive variables of spatial spread, we show that the global dynamics of influenza H3N2 are driven by air passenger flows, whereas at more local scales spread is also determined by processes that correlate with geographic distance. Our analyses further confirm a central role for mainland China and Southeast Asia in maintaining a source population for global influenza diversity. By comparing model output with the known pandemic expansion of H1N1 during 2009, we demonstrate that predictions of influenza spatial spread are most accurate when data on human mobility and viral evolution are integrated. In conclusion, the global dynamics of influenza viruses are best explained by combining human mobility data with the spatial information inherent in sampled viral genomes. The integrated approach introduced here offers great potential for epidemiological surveillance through phylogeographic reconstructions and for improving predictive models of disease control.

  2. Isolation of influenza viruses in MDCK 33016PF cells and clearance of contaminating respiratory viruses.

    PubMed

    Roth, Bernhard; Mohr, Hannah; Enders, Martin; Garten, Wolfgang; Gregersen, Jens-Peter

    2012-01-11

    This paper summarizes results obtained by multiplex PCR screening of human clinical samples for respiratory viruses and corresponding data obtained after passaging of virus-positive samples in MDCK 33016PF cells. Using the ResPlexII v2.0 (Qiagen) multiplex PCR, 393 positive results were obtained in 468 clinical samples collected during an influenza season in Germany. The overall distribution of positive results was influenza A 42.0%, influenza B 38.7%, adenovirus 1.5%, bocavirus 0.5%, coronavirus 3.3%, enterovirus 5.6%, metapneumovirus 1.0%, parainfluenza virus 0.8%, rhinovirus 4.1%, and respiratory syncytial virus (RSV) 2.5%. Double infections of influenza virus together with another virus were found for adenovirus B and E, bocavirus, coronavirus, enterovirus and for rhinovirus. These other viruses were rapidly lost upon passages in MDCK 33016PF cells and under conditions as applied to influenza virus passaging. Clinical samples, in which no influenza virus but other viruses were found, were also subject to passages in MDCK 33016PF cells. Using lower inoculum dilutions than those normally applied for preparations containing influenza virus (total dilution of the original sample of ∼10(4)), the positive results for the different viruses turned negative already after 2 or 3 passages in MDCK 33016PF cells. These results demonstrate that, under practical conditions as applied to grow influenza viruses, contaminating viruses can be effectively removed by passages in MDCK cells. In combination with their superior isolation efficiency, MDCK cells appear highly suitable to be used as an alternative to embryonated eggs to isolate and propagate influenza vaccine candidate viruses.

  3. [Equine influenza in Chile (1963-1992): a possible human case].

    PubMed

    Berríos, Patricio

    2005-03-01

    In Chile equine influenza has been strongly related to continental epizootics. First outbreak was described in 1963; main outbreaks were reported in 1977, 1985 and 1992. Equine influenza virus was isolated in three opportunities: H7N7 (A/equi/1/Santiago, Chile/1977); H3N8 (A/equi/2/Santiago, Chile/1985) and H3N8 (A/equi/2/Quillota, Chile/1992). The most serious outbreak was caused by strain H7N7 in 1977. Since 1992 equine influenza has not been reported in our country. In 1973 was described a case of influenza and seroconversion in a human being related with horses suffering a respiratory distress diagnosed as equine influenza; unfortunately the isolated virus was not typed.

  4. Adaptation of pandemic H2N2 influenza A viruses in humans.

    PubMed

    Joseph, Udayan; Linster, Martin; Suzuki, Yuka; Krauss, Scott; Halpin, Rebecca A; Vijaykrishna, Dhanasekaran; Fabrizio, Thomas P; Bestebroer, Theo M; Maurer-Stroh, Sebastian; Webby, Richard J; Wentworth, David E; Fouchier, Ron A M; Bahl, Justin; Smith, Gavin J D

    2015-02-01

    The 1957 A/H2N2 influenza virus caused an estimated 2 million fatalities during the pandemic. Since viruses of the H2 subtype continue to infect avian species and pigs, the threat of reintroduction into humans remains. To determine factors involved in the zoonotic origin of the 1957 pandemic, we performed analyses on genetic sequences of 175 newly sequenced human and avian H2N2 virus isolates and all publicly available influenza virus genomes.

  5. Novel swine-origin influenza A virus in humans: another pandemic knocking at the door.

    PubMed

    Michaelis, Martin; Doerr, Hans Wilhem; Cinatl, Jindrich

    2009-08-01

    Influenza A viruses represent a continuous pandemic threat. In April 2009, a novel influenza A virus, the so-called swine-origin influenza A (H1N1) virus (S-OIV), was identified in Mexico. Although S-OIV originates from triple-reassortant swine influenza A (H1) that has been circulating in North American pig herds since the end of the 1990s, S-OIV is readily transmitted between humans but is not epidemic in pigs. After its discovery, S-OIV rapidly spread throughout the world within few weeks. In this review, we sum up the current situation and put it into the context of the current state of knowledge of influenza and influenza pandemics. Some indications suggest that a pandemic may be mild but even "mild" pandemics can result in millions of deaths. However, no reasonable forecasts how this pandemic may develop can be made at this time. Despite stockpiling by many countries and WHO, antiviral drugs will be limited in case of pandemic and resistances may emerge. Effective vaccines are regarded to be crucial for the control of influenza pandemics. However, production capacities are restricted and development/production of a S-OIV vaccine will interfere with manufacturing of seasonal influenza vaccines. The authors are convinced that S-OIV should be taken seriously as pandemic threat and underestimation of the menace by S-OIV to be by far more dangerous than its overestimation.

  6. Deep Sequencing Reveals Potential Antigenic Variants at Low Frequencies in Influenza A Virus-Infected Humans

    PubMed Central

    Dinis, Jorge M.; Florek, Nicholas W.; Fatola, Omolayo O.; Moncla, Louise H.; Mutschler, James P.; Charlier, Olivia K.; Meece, Jennifer K.; Belongia, Edward A.

    2016-01-01

    ABSTRACT Influenza vaccines must be frequently reformulated to account for antigenic changes in the viral envelope protein, hemagglutinin (HA). The rapid evolution of influenza virus under immune pressure is likely enhanced by the virus's genetic diversity within a host, although antigenic change has rarely been investigated on the level of individual infected humans. We used deep sequencing to characterize the between- and within-host genetic diversity of influenza viruses in a cohort of patients that included individuals who were vaccinated and then infected in the same season. We characterized influenza HA segments from the predominant circulating influenza A subtypes during the 2012-2013 (H3N2) and 2013-2014 (pandemic H1N1; H1N1pdm) flu seasons. We found that HA consensus sequences were similar in nonvaccinated and vaccinated subjects. In both groups, purifying selection was the dominant force shaping HA genetic diversity. Interestingly, viruses from multiple individuals harbored low-frequency mutations encoding amino acid substitutions in HA antigenic sites at or near the receptor-binding domain. These mutations included two substitutions in H1N1pdm viruses, G158K and N159K, which were recently found to confer escape from virus-specific antibodies. These findings raise the possibility that influenza antigenic diversity can be generated within individual human hosts but may not become fixed in the viral population even when they would be expected to have a strong fitness advantage. Understanding constraints on influenza antigenic evolution within individual hosts may elucidate potential future pathways of antigenic evolution at the population level. IMPORTANCE Influenza vaccines must be frequently reformulated due to the virus's rapid evolution rate. We know that influenza viruses exist within each infected host as a “swarm” of genetically distinct viruses, but the role of this within-host diversity in the antigenic evolution of influenza has been unclear

  7. A systems approach to understanding human rhinovirus and influenza virus infection.

    PubMed

    Kim, Taek-Kyun; Bheda-Malge, Anjali; Lin, Yakang; Sreekrishna, Koti; Adams, Rachel; Robinson, Michael K; Bascom, Charles C; Tiesman, Jay P; Isfort, Robert J; Gelinas, Richard

    2015-12-01

    Human rhinovirus and influenza virus infections of the upper airway lead to colds and the flu and can trigger exacerbations of lower airway diseases including asthma and chronic obstructive pulmonary disease. Novel diagnostic and therapeutic targets are still needed to differentiate between the cold and the flu, since the clinical course of influenza can be severe while that of rhinovirus is usually more mild. In our investigation of influenza and rhinovirus infection of human respiratory epithelial cells, we used a systems approach to identify the temporally changing patterns of host gene expression from these viruses. After infection of human bronchial epithelial cells (BEAS-2B) with rhinovirus, influenza virus or co-infection with both viruses, we studied the time-course of host gene expression changes over three days. We modeled host responses to these viral infections with time and documented the qualitative and quantitative differences in innate immune activation and regulation.

  8. Constitutively Expressed IFITM3 Protein in Human Endothelial Cells Poses an Early Infection Block to Human Influenza Viruses.

    PubMed

    Sun, Xiangjie; Zeng, Hui; Kumar, Amrita; Belser, Jessica A; Maines, Taronna R; Tumpey, Terrence M

    2016-12-15

    A role for pulmonary endothelial cells in the orchestration of cytokine production and leukocyte recruitment during influenza virus infection, leading to severe lung damage, has been recently identified. As the mechanistic pathway for this ability is not fully known, we extended previous studies on influenza virus tropism in cultured human pulmonary endothelial cells. We found that a subset of avian influenza viruses, including potentially pandemic H5N1, H7N9, and H9N2 viruses, could infect human pulmonary endothelial cells (HULEC) with high efficiency compared to human H1N1 or H3N2 viruses. In HULEC, human influenza viruses were capable of binding to host cellular receptors, becoming internalized and initiating hemifusion but failing to uncoat the viral nucleocapsid and to replicate in host nuclei. Unlike numerous cell types, including epithelial cells, we found that pulmonary endothelial cells constitutively express a high level of the restriction protein IFITM3 in endosomal compartments. IFITM3 knockdown by small interfering RNA (siRNA) could partially rescue H1N1 virus infection in HULEC, suggesting IFITM3 proteins were involved in blocking human influenza virus infection in endothelial cells. In contrast, selected avian influenza viruses were able to escape IFITM3 restriction in endothelial cells, possibly by fusing in early endosomes at higher pH or by other, unknown mechanisms. Collectively, our study demonstrates that the human pulmonary endothelium possesses intrinsic immunity to human influenza viruses, in part due to the constitutive expression of IFITM3 proteins. Notably, certain avian influenza viruses have evolved to escape this restriction, possibly contributing to virus-induced pneumonia and severe lung disease in humans.

  9. Reassortment ability of the 2009 pandemic H1N1 influenza virus with circulating human and avian influenza viruses: public health risk implications.

    PubMed

    Stincarelli, Maria; Arvia, Rosaria; De Marco, Maria Alessandra; Clausi, Valeria; Corcioli, Fabiana; Cotti, Claudia; Delogu, Mauro; Donatelli, Isabella; Azzi, Alberta; Giannecchini, Simone

    2013-08-01

    Exploring the reassortment ability of the 2009 pandemic H1N1 (A/H1N1pdm09) influenza virus with other circulating human or avian influenza viruses is the main concern related to the generation of more virulent or new variants having implications for public health. After different coinfection experiments in human A549 cells, by using the A/H1N1pdm09 virus plus one of human seasonal influenza viruses of H1N1 and H3N2 subtype or one of H11, H10, H9, H7 and H1 avian influenza viruses, several reassortant viruses were obtained. Among these, the HA of H1N1 was the main segment of human seasonal influenza virus reassorted in the A/H1N1pdm09 virus backbone. Conversely, HA and each of the three polymerase segments, alone or in combination, of the avian influenza viruses mainly reassorted in the A/H1N1pdm09 virus backbone. Of note, A/H1N1pdm09 viruses that reassorted with HA of H1N1 seasonal human or H11N6 avian viruses or carried different combination of avian origin polymerase segments, exerted a higher replication effectiveness than that of the parental viruses. These results confirm that reassortment of the A/H1N1pdm09 with circulating low pathogenic avian influenza viruses should not be misjudged in the prediction of the next pandemic.

  10. High permissivity of human HepG2 hepatoma cells for influenza viruses.

    PubMed

    Ollier, Laurence; Caramella, Anne; Giordanengo, Valérie; Lefebvre, Jean-Claude

    2004-12-01

    Human HepG2 hepatoma cells are highly permissive for influenza virus type A and type B, even without the addition of trypsin, and they exhibit a marked cytopathic effect. This property greatly facilitates the primary isolation of influenza viruses. Virus replication was significantly reduced by the plasmin(ogen)-specific inhibitor tranexamic acid, and this suggests a potential role played by the plasminogen/tissue plasminogen activator complex at the surface of HepG2 cells. This might represent a new approach for study of the interrelations of this complex with influenza viruses.

  11. High Permissivity of Human HepG2 Hepatoma Cells for Influenza Viruses

    PubMed Central

    Ollier, Laurence; Caramella, Anne; Giordanengo, Valérie; Lefebvre, Jean-Claude

    2004-01-01

    Human HepG2 hepatoma cells are highly permissive for influenza virus type A and type B, even without the addition of trypsin, and they exhibit a marked cytopathic effect. This property greatly facilitates the primary isolation of influenza viruses. Virus replication was significantly reduced by the plasmin(ogen)-specific inhibitor tranexamic acid, and this suggests a potential role played by the plasminogen/tissue plasminogen activator complex at the surface of HepG2 cells. This might represent a new approach for study of the interrelations of this complex with influenza viruses. PMID:15583326

  12. Large-scale sequencing of human influenza reveals the dynamic nature of viral genome evolution.

    PubMed

    Ghedin, Elodie; Sengamalay, Naomi A; Shumway, Martin; Zaborsky, Jennifer; Feldblyum, Tamara; Subbu, Vik; Spiro, David J; Sitz, Jeff; Koo, Hean; Bolotov, Pavel; Dernovoy, Dmitry; Tatusova, Tatiana; Bao, Yiming; St George, Kirsten; Taylor, Jill; Lipman, David J; Fraser, Claire M; Taubenberger, Jeffery K; Salzberg, Steven L

    2005-10-20

    Influenza viruses are remarkably adept at surviving in the human population over a long timescale. The human influenza A virus continues to thrive even among populations with widespread access to vaccines, and continues to be a major cause of morbidity and mortality. The virus mutates from year to year, making the existing vaccines ineffective on a regular basis, and requiring that new strains be chosen for a new vaccine. Less-frequent major changes, known as antigenic shift, create new strains against which the human population has little protective immunity, thereby causing worldwide pandemics. The most recent pandemics include the 1918 'Spanish' flu, one of the most deadly outbreaks in recorded history, which killed 30-50 million people worldwide, the 1957 'Asian' flu, and the 1968 'Hong Kong' flu. Motivated by the need for a better understanding of influenza evolution, we have developed flexible protocols that make it possible to apply large-scale sequencing techniques to the highly variable influenza genome. Here we report the results of sequencing 209 complete genomes of the human influenza A virus, encompassing a total of 2,821,103 nucleotides. In addition to increasing markedly the number of publicly available, complete influenza virus genomes, we have discovered several anomalies in these first 209 genomes that demonstrate the dynamic nature of influenza transmission and evolution. This new, large-scale sequencing effort promises to provide a more comprehensive picture of the evolution of influenza viruses and of their pattern of transmission through human and animal populations. All data from this project are being deposited, without delay, in public archives.

  13. Haemophilus influenzae can use human transferrin as a sole source for required iron.

    PubMed Central

    Herrington, D A; Sparling, P F

    1985-01-01

    Haemophilus influenzae grown on enriched medium containing protoporphyrin IX rather than hemin was iron starved by the addition of the chelator ethylenediamine di-o-hydroxyphenylacetic acid. Iron starvation could be overcome in each of 33 H. influenzae type b isolates by 30% Fe-saturated human transferrin but not by human lactoferrin. Among nontypeable H. influenzae, 28 of 35 isolates, including 2 of 3 systemic isolates, were able to utilize Fe-transferrin. None of 18 H. parainfluenzae isolates was able to use Fe-transferrin. Iron starvation of H. influenzae type b resulted in increased amounts of three membrane proteins of 94,000 to 98,000 daltons. Images PMID:3872264

  14. Molecular comparisons of full length metapneumovirus (MPV) genomes, including newly determined French AMPV-C and -D isolates, further supports possible subclassification within the MPV Genus.

    PubMed

    Brown, Paul A; Lemaitre, Evelyne; Briand, François-Xavier; Courtillon, Céline; Guionie, Olivier; Allée, Chantal; Toquin, Didier; Bayon-Auboyer, Marie-Hélène; Jestin, Véronique; Eterradossi, Nicolas

    2014-01-01

    Four avian metapneumovirus (AMPV) subgroups (A-D) have been reported previously based on genetic and antigenic differences. However, until now full length sequences of the only known isolates of European subgroup C and subgroup D viruses (duck and turkey origin, respectively) have been unavailable. These full length sequences were determined and compared with other full length AMPV and human metapneumoviruses (HMPV) sequences reported previously, using phylogenetics, comparisons of nucleic and amino acid sequences and study of codon usage bias. Results confirmed that subgroup C viruses were more closely related to HMPV than they were to the other AMPV subgroups in the study. This was consistent with previous findings using partial genome sequences. Closer relationships between AMPV-A, B and D were also evident throughout the majority of results. Three metapneumovirus "clusters" HMPV, AMPV-C and AMPV-A, B and D were further supported by codon bias and phylogenetics. The data presented here together with those of previous studies describing antigenic relationships also between AMPV-A, B and D and between AMPV-C and HMPV may call for a subclassification of metapneumoviruses similar to that used for avian paramyxoviruses, grouping AMPV-A, B and D as type I metapneumoviruses and AMPV-C and HMPV as type II.

  15. The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.

    PubMed

    Memish, Ziad A; Assiri, Abdullah M; Alshehri, Mohammed; Hussain, Raheela; Alomar, Ibrahim

    2012-01-01

    Despite the high risk of acquiring respiratory infections, healthcare workers who treat pilgrims at Hajj have not been studied in previous research on respiratory diseases during Hajj. The objective of this study was to determine the prevalence of different respiratory viruses among healthcare workers who treated pilgrims during Hajj 2009, the year of the influenza A H1N1 pandemic. A cross-sectional study was performed just before and after Hajj (25-29 November, 2009). Nasal and throat swabs were tested for 18 respiratory virus types and subtypes. A total of 184 healthcare workers were examined. Most were men (85%) with an average age of 41 years. Before the Hajj, rates of seasonal influenza vaccination were higher (51%) than rates of pandemic influenza A H1N1 vaccination (22%). After the Hajj, participants reported high rates of maintaining hand hygiene (98%), cough etiquette (89%), and wearing a face mask (90%). Among all the viruses tested, only two were detected: rhinovirus was detected in 12.6% and Coronavirus 229E in 0.6%. Rhinovirus was detected in 21% of those who had respiratory symptoms during Hajj. Influenza A (including H1N1), influenza B. respiratory syncytial virus, other coronaviruses, parainfluenza viruses, human metapneumovirus, adenovirus, and human bocavirus were not detected. The finding of high rates of rhinovirus infection corresponds to their frequent occurrence in adults. None of the participants had influenza A H1N1 2009, possibly because it was also infrequent among the 2009 pilgrims.

  16. Influenza infection in human host: challenges in making a better influenza vaccine.

    PubMed

    Virk, Ramandeep Kaur; Gunalan, Vithiagaran; Tambyah, Paul Anantharajah

    2016-01-01

    Influenza is a ubiquitous infection with a spectrum ranging from mild to severe. The mystery regarding such variability in the clinical spectrum has not been fully unravelled, although a role for the complex interplay among virus characteristics, host immune response and environmental factors has been suggested. Antivirals and current vaccines have a limited role in prophylaxis and treatment because they primarily target surface glycoproteins which undergo antigenic/genetic changes under host immune pressure. Targeting conserved internal proteins could lead the way to a universal vaccine which can be used against various types/subtypes. However, this is on the distant horizon, so in the meantime, developing improved vaccines should be given high priority. In this review, we discuss where the current influenza research stands in terms of vaccines, adjuvants, and how we can better predict the vaccine strains for upcoming influenza seasons by understanding complex phenomena which drive the continuous antigenic evolution.

  17. Neutralizing activities against seasonal influenza viruses in human intravenous immunoglobulin

    PubMed Central

    Onodera, Hiroyuki; Urayama, Takeru; Hirota, Kazue; Maeda, Kazuhiro; Kubota-Koketsu, Ritsuko; Takahashi, Kazuo; Hagiwara, Katsuro; Okuno, Yoshinobu; Ikuta, Kazuyoshi; Yunoki, Mikihiro

    2017-01-01

    Influenza viruses A/H1N1, A/H3N2, and B are known seasonal viruses that undergo annual mutation. Intravenous immunoglobulin (IVIG) contains anti-seasonal influenza virus globulins. Although the virus-neutralizing (VN) titer is an indicator of protective antibodies, changes in this titer over extended time periods have yet to be examined. In this study, variations in hemagglutination inhibition (HI) and VN titers against seasonal influenza viruses in IVIG lots over extended time periods were examined. In addition, the importance of monitoring the reactivity of IVIG against seasonal influenza viruses with varying antigenicity was evaluated. A/H1N1, A/H3N2, and B influenza virus strains and IVIG lots manufactured from 1999 to 2014 were examined. The HI titer was measured by standard methods. The VN titer was measured using a micro-focus method. IVIG exhibited significant HI and VN titers against all investigated strains. Our results suggest that the donor population maintains both specific and cross-reactive antibodies against seasonal influenza viruses, except in cases of pandemic viruses, despite major antigen changes. The titers against seasonal influenza vaccine strains, including past strains, were stable over short time periods but increased slowly over time. PMID:28331286

  18. Antiviral Responses by Swine Primary Bronchoepithelial Cells Are Limited Compared to Human Bronchoepithelial Cells Following Influenza Virus Infection

    PubMed Central

    Hauser, Mary J.; Dlugolenski, Daniel; Culhane, Marie R.; Wentworth, David E.; Tompkins, S. Mark; Tripp, Ralph A.

    2013-01-01

    Swine generate reassortant influenza viruses because they can be simultaneously infected with avian and human influenza; however, the features that restrict influenza reassortment in swine and human hosts are not fully understood. Type I and III interferons (IFNs) act as the first line of defense against influenza virus infection of respiratory epithelium. To determine if human and swine have different capacities to mount an antiviral response the expression of IFN and IFN-stimulated genes (ISG) in normal human bronchial epithelial (NHBE) cells and normal swine bronchial epithelial (NSBE) cells was evaluated following infection with human (H3N2), swine (H1N1), and avian (H5N3, H5N2, H5N1) influenza A viruses. Expression of IFNλ and ISGs were substantially higher in NHBE cells compared to NSBE cells following H5 avian influenza virus infection compared to human or swine influenza virus infection. This effect was associated with reduced H5 avian influenza virus replication in human cells at late times post infection. Further, RIG-I expression was lower in NSBE cells compared to NHBE cells suggesting reduced virus sensing. Together, these studies identify key differences in the antiviral response between human and swine respiratory epithelium alluding to differences that may govern influenza reassortment. PMID:23875024

  19. Antiviral activity and increased host defense against influenza infection elicited by the human cathelicidin LL-37.

    PubMed

    Barlow, Peter G; Svoboda, Pavel; Mackellar, Annie; Nash, Anthony A; York, Ian A; Pohl, Jan; Davidson, Donald J; Donis, Ruben O

    2011-01-01

    The extensive world-wide morbidity and mortality caused by influenza A viruses highlights the need for new insights into the host immune response and novel treatment approaches. Cationic Host Defense Peptides (CHDP, also known as antimicrobial peptides), which include cathelicidins and defensins, are key components of the innate immune system that are upregulated during infection and inflammation. Cathelicidins have immunomodulatory and anti-viral effects, but their impact on influenza virus infection has not been previously assessed. We therefore evaluated the effect of cathelicidin peptides on disease caused by influenza A virus in mice. The human cathelicidin, LL-37, and the murine cathelicidin, mCRAMP, demonstrated significant anti-viral activity in vivo, reducing disease severity and viral replication in infected mice to a similar extent as the well-characterized influenza virus-specific antiviral drug zanamivir. In vitro and in vivo experiments suggested that the peptides may act directly on the influenza virion rather than via receptor-based mechanisms. Influenza virus-infected mice treated with LL-37 had lower concentrations of pro-inflammatory cytokines in the lung than did infected animals that had not been treated with cathelicidin peptides. These data suggest that treatment of influenza-infected individuals with cathelicidin-derived therapeutics, or modulation of endogenous cathelicidin production may provide significant protection against disease.

  20. A Review of the Antiviral Susceptibility of Human and Avian Influenza Viruses over the Last Decade

    PubMed Central

    Oh, Ding Yuan; Hurt, Aeron C.

    2014-01-01

    Antivirals play an important role in the prevention and treatment of influenza infections, particularly in high-risk or severely ill patients. Two classes of influenza antivirals have been available in many countries over the last decade (2004–2013), the adamantanes and the neuraminidase inhibitors (NAIs). During this period, widespread adamantane resistance has developed in circulating influenza viruses rendering these drugs useless, resulting in the reliance on the most widely available NAI, oseltamivir. However, the emergence of oseltamivir-resistant seasonal A(H1N1) viruses in 2008 demonstrated that NAI-resistant viruses could also emerge and spread globally in a similar manner to that seen for adamantane-resistant viruses. Previously, it was believed that NAI-resistant viruses had compromised replication and/or transmission. Fortunately, in 2013, the majority of circulating human influenza viruses remain sensitive to all of the NAIs, but significant work by our laboratory and others is now underway to understand what enables NAI-resistant viruses to retain the capacity to replicate and transmit. In this review, we describe how the susceptibility of circulating human and avian influenza viruses has changed over the last ten years and describe some research studies that aim to understand how NAI-resistant human and avian influenza viruses may emerge in the future. PMID:24800107

  1. Phylogenetic evolution of swine-origin human influenza virus: a pandemic H1N1 2009.

    PubMed

    Kowalczyk, A; Markowska-Daniel, I

    2010-01-01

    The knowledge of the genome constellation in pandemic influenza A virus H1N1 2009 from different countries and different hosts is valuable for monitoring and understanding of the evolution and migration of these strains. The complete genome sequences of selected worldwide distributed influenza A viruses are publicly available and there have been few longitudinal genome studies of human, avian and swine influenza A viruses. All possible to download SIV sequences of influenza A viruses available at GISAID Platform (Global Initiative on Sharing Avian Influenza Data) were analyzed firstly through the web servers of the Influenza Virus Resource in NCBI. Phylogenetic study of circulating human pandemic H1N1 virus indicated that the new variant possesses a distinctive evolutionary trait. There is no one way the pandemic H1N1 have acquired new genes from other distinguishable viruses circulating recently in local human, pig or domestic poultry populations from various geographic regions. The extensive genetic diversity among whole segments present in pandemic H1N1 genome suggests that multiple introduction of virus have taken place during the period 1999-2009. The initial interspecies transmission could have occurred in the long-range past and after it the reassortants steps lead to three lineages: classical SIV prevalent in the North America, avian-like SIV in Europe and avian-like related SIV in Asia. This analysis contributes to the evidence that pigs are not the only hosts playing the role of "mixing vessel", as it was suggested for many years.

  2. [Interspecies transmission, adaptation to humans and pathogenicity of animal influenza viruses].

    PubMed

    Munier, S; Moisy, D; Marc, D; Naffakh, N

    2010-04-01

    The emergence in 2009 of a novel A(H1N1)v influenza virus of swine origin and the regular occurrence since 2003 of human cases of infection with A(H5N1) avian influenza viruses underline the zoonotic and pandemic potential of type A influenza viruses. Influenza viruses from the wild aquatic birds reservoir usually do not replicate efficiently in humans. Domestic poultry and swine can act as intermediate hosts for the acquisition of determinants that increase the potential of transmission and adaptation to humans, through the accumulation of mutations or by genetic reassortment. The rapid evolution of influenza viruses following interspecies transmission probably results from the selection of genetic variations that favor optimal interactions between viral proteins and cellular factors, leading to an increased multiplication potential and a better escape to the host antiviral response. Whereas influenza viruses usually cause asymptomatic infections in wild aquatic birds, they may be highly pathogenic in other species. Molecular determinants of host-specificity and pathogenesis have been identified in most viral genes, notably in genes that encode viral surface glycoproteins, proteins involved in the viral genome replication, and proteins that counteract the host immune response. However, our knowledge of these numerous and interdependant determinants remains incomplete, and the molecular mechanisms involved are still to be understood.

  3. A Novel H1N2 Influenza Virus Related to the Classical and Human Influenza Viruses from Pigs in Southern China

    PubMed Central

    Song, Yafen; Wu, Xiaowei; Wang, Nianchen; Ouyang, Guowen; Qu, Nannan; Cui, Jin; Qi, Yan; Liao, Ming; Jiao, Peirong

    2016-01-01

    Southern China has long been considered to be an epicenter of pandemic influenza viruses. The special environment, breeding mode, and lifestyle in southern China provides more chances for wild aquatic birds, domestic poultry, pigs, and humans to be in contact. This creates the opportunity for interspecies transmission and generation of new influenza viruses. In this study, we reported a novel reassortant H1N2 influenza virus from pigs in southern China. According to the phylogenetic trees and homology of the nucleotide sequence, the virus was confirmed to be a novel triple-reassortant H1N2 virus containing genes from classical swine (PB2, PB1, HA, NP, and NS genes), triple-reassortant swine (PA and M genes), and recent human (NA gene) lineages. It indicated that the novel reassortment virus among human and swine influenza viruses occurred in pigs in southern China. The isolation of the novel reassortant H1N2 influenza viruses provides further evidence that pigs are “mixing vessels,” and swine influenza virus surveillance in southern China will provide important information about genetic evaluation and antigenic variation of swine influenza virus to formulate the prevention and control measures for the viruses. PMID:27458456

  4. A Novel H1N2 Influenza Virus Related to the Classical and Human Influenza Viruses from Pigs in Southern China.

    PubMed

    Song, Yafen; Wu, Xiaowei; Wang, Nianchen; Ouyang, Guowen; Qu, Nannan; Cui, Jin; Qi, Yan; Liao, Ming; Jiao, Peirong

    2016-01-01

    Southern China has long been considered to be an epicenter of pandemic influenza viruses. The special environment, breeding mode, and lifestyle in southern China provides more chances for wild aquatic birds, domestic poultry, pigs, and humans to be in contact. This creates the opportunity for interspecies transmission and generation of new influenza viruses. In this study, we reported a novel reassortant H1N2 influenza virus from pigs in southern China. According to the phylogenetic trees and homology of the nucleotide sequence, the virus was confirmed to be a novel triple-reassortant H1N2 virus containing genes from classical swine (PB2, PB1, HA, NP, and NS genes), triple-reassortant swine (PA and M genes), and recent human (NA gene) lineages. It indicated that the novel reassortment virus among human and swine influenza viruses occurred in pigs in southern China. The isolation of the novel reassortant H1N2 influenza viruses provides further evidence that pigs are "mixing vessels," and swine influenza virus surveillance in southern China will provide important information about genetic evaluation and antigenic variation of swine influenza virus to formulate the prevention and control measures for the viruses.

  5. Multiple Natural Substitutions in Avian Influenza A Virus PB2 Facilitate Efficient Replication in Human Cells

    PubMed Central

    Mänz, Benjamin; de Graaf, Miranda; Mögling, Ramona; Richard, Mathilde; Bestebroer, Theo M.; Rimmelzwaan, Guus F.

    2016-01-01

    ABSTRACT A strong restriction of the avian influenza A virus polymerase in mammalian cells generally limits viral host-range switching. Although substitutions like E627K in the PB2 polymerase subunit can facilitate polymerase activity to allow replication in mammals, many human H5N1 and H7N9 viruses lack this adaptive substitution. Here, several previously unknown, naturally occurring, adaptive substitutions in PB2 were identified by bioinformatics, and their enhancing activity was verified using in vitro assays. Adaptive substitutions enhanced polymerase activity and virus replication in mammalian cells for avian H5N1 and H7N9 viruses but not for a partially human-adapted H5N1 virus. Adaptive substitutions toward basic amino acids were frequent and were mostly clustered in a putative RNA exit channel in a polymerase crystal structure. Phylogenetic analysis demonstrated divergent dependency of influenza viruses on adaptive substitutions. The novel adaptive substitutions found in this study increase basic understanding of influenza virus host adaptation and will help in surveillance efforts. IMPORTANCE Influenza viruses from birds jump the species barrier into humans relatively frequently. Such influenza virus zoonoses may pose public health risks if the virus adapts to humans and becomes a pandemic threat. Relatively few amino acid substitutions—most notably in the receptor binding site of hemagglutinin and at positions 591 and 627 in the polymerase protein PB2—have been identified in pandemic influenza virus strains as determinants of host adaptation, to facilitate efficient virus replication and transmission in humans. Here, we show that substantial numbers of amino acid substitutions are functionally compensating for the lack of the above-mentioned mutations in PB2 and could facilitate influenza virus emergence in humans. PMID:27076644

  6. Human antibodies reveal a protective epitope that is highly conserved among human and nonhuman influenza A viruses.

    PubMed

    Grandea, Andres G; Olsen, Ole A; Cox, Thomas C; Renshaw, Mark; Hammond, Philip W; Chan-Hui, Po-Ying; Mitcham, Jennifer L; Cieplak, Witold; Stewart, Shaun M; Grantham, Michael L; Pekosz, Andrew; Kiso, Maki; Shinya, Kyoko; Hatta, Masato; Kawaoka, Yoshihiro; Moyle, Matthew

    2010-07-13

    Influenza remains a serious public health threat throughout the world. Vaccines and antivirals are available that can provide protection from infection. However, new viral strains emerge continuously because of the plasticity of the influenza genome, which necessitates annual reformulation of vaccine antigens, and resistance to antivirals can appear rapidly and become entrenched in circulating virus populations. In addition, the spread of new pandemic strains is difficult to contain because of the time required to engineer and manufacture effective vaccines. Monoclonal antibodies that target highly conserved viral epitopes might offer an alternative protection paradigm. Herein we describe the isolation of a panel of monoclonal antibodies derived from the IgG(+) memory B cells of healthy, human subjects that recognize a previously unknown conformational epitope within the ectodomain of the influenza matrix 2 protein, M2e. This antibody binding region is highly conserved in influenza A viruses, being present in nearly all strains detected to date, including highly pathogenic viruses that infect primarily birds and swine, and the current 2009 swine-origin H1N1 pandemic strain (S-OIV). Furthermore, these human anti-M2e monoclonal antibodies protect mice from lethal challenges with either H5N1 or H1N1 influenza viruses. These results suggest that viral M2e can elicit broadly cross-reactive and protective antibodies in humans. Accordingly, recombinant forms of these human antibodies may provide useful therapeutic agents to protect against infection from a broad spectrum of influenza A strains.

  7. Adaptive strategies of the influenza virus polymerase for replication in humans.

    PubMed

    Mehle, Andrew; Doudna, Jennifer A

    2009-12-15

    Transmission of influenza viruses into the human population requires surmounting barriers to cross-species infection. Changes in the influenza polymerase overcome one such barrier. Viruses isolated from birds generally contain polymerases with the avian-signature glutamic acid at amino acid 627 in the PB2 subunit. These polymerases display restricted activity in human cells. An adaptive change in this residue from glutamic acid to the human-signature lysine confers high levels of polymerase activity in human cells. This mutation permits escape from a species-specific restriction factor that targets polymerases from avian viruses. A 2009 swine-origin H1N1 influenza A virus recently established a pandemic infection in humans, even though the virus encodes a PB2 with the restrictive glutamic acid at amino acid 627. We show here that the 2009 H1N1 virus has acquired second-site suppressor mutations in its PB2 polymerase subunit that convey enhanced polymerase activity in human cells. Introduction of this polymorphism into the PB2 subunit of a primary avian isolate also increased polymerase activity and viral replication in human and porcine cells. An alternate adaptive strategy has also been identified, whereby introduction of a human PA subunit into an avian polymerase overcomes restriction in human cells. These data reveal a strategy used by the 2009 H1N1 influenza A virus and identify other pathways by which avian and swine-origin viruses may evolve to enhance replication, and potentially pathogenesis, in humans.

  8. Broad-range neutralizing anti-influenza A human monoclonal antibodies: new perspectives in therapy and prophylaxis.

    PubMed

    Clementi, Nicola; Criscuolo, Elena; Castelli, Matteo; Clementi, Massimo

    2012-10-01

    Broadly neutralizing monoclonal antibodies (mAbs) directed against different subtypes of influenza A viruses are novel tools for the potential development of effective anti-influenza prophylactic and therapeutic strategies. In both cases, the main candidates for passive transfer and new vaccine development are represented by protective mAbs directed against influenza hemagglutinin (HA). A large number of mAbs directed against influenza HA has been developed to date. However, even if they can be useful and contribute to develop new vaccinal strategies, only few of them can be a good candidate for human administration. In this review, we will describe the most relevant human mAb directed against influenza HA able to recognize highly divergent influenza isolates and possibly useful for human therapy and prophylaxis.

  9. Modelling the species jump: towards assessing the risk of human infection from novel avian influenzas.

    PubMed

    Hill, A A; Dewé, T; Kosmider, R; Von Dobschuetz, S; Munoz, O; Hanna, A; Fusaro, A; De Nardi, M; Howard, W; Stevens, K; Kelly, L; Havelaar, A; Stärk, K

    2015-09-01

    The scientific understanding of the driving factors behind zoonotic and pandemic influenzas is hampered by complex interactions between viruses, animal hosts and humans. This complexity makes identifying influenza viruses of high zoonotic or pandemic risk, before they emerge from animal populations, extremely difficult and uncertain. As a first step towards assessing zoonotic risk of influenza, we demonstrate a risk assessment framework to assess the relative likelihood of influenza A viruses, circulating in animal populations, making the species jump into humans. The intention is that such a risk assessment framework could assist decision-makers to compare multiple influenza viruses for zoonotic potential and hence to develop appropriate strain-specific control measures. It also provides a first step towards showing proof of principle for an eventual pandemic risk model. We show that the spatial and temporal epidemiology is as important in assessing the risk of an influenza A species jump as understanding the innate molecular capability of the virus. We also demonstrate data deficiencies that need to be addressed in order to consistently combine both epidemiological and molecular virology data into a risk assessment framework.

  10. Human infection with highly pathogenic H5N1 influenza virus.

    PubMed

    Gambotto, Andrea; Barratt-Boyes, Simon M; de Jong, Menno D; Neumann, Gabriele; Kawaoka, Yoshihiro

    2008-04-26

    Highly pathogenic H5N1 influenza A viruses have spread relentlessly across the globe since 2003, and they are associated with widespread death in poultry, substantial economic loss to farmers, and reported infections of more than 300 people with a mortality rate of 60%. The high pathogenicity of H5N1 influenza viruses and their capacity for transmission from birds to human beings has raised worldwide concern about an impending human influenza pandemic similar to the notorious H1N1 Spanish influenza of 1918. Since many aspects of H5N1 influenza research are rapidly evolving, we aim in this Seminar to provide an up-to-date discussion on select topics of interest to influenza clinicians and researchers. We summarise the clinical features and diagnosis of infection and present therapeutic options for H5N1 infection of people. We also discuss ideas relating to virus transmission, host restriction, and pathogenesis. Finally, we discuss vaccine development in view of the probable importance of vaccination in pandemic control.

  11. A review of simulation modelling approaches used for the spread of zoonotic influenza viruses in animal and human populations.

    PubMed

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

    2013-09-01

    Increasing incidences of emerging and re-emerging diseases that are mostly zoonotic (e.g. severe acute respiratory syndrome, avian influenza H5N1, pandemic influenza) has led to the need for a multidisciplinary approach to tackling these threats to public and animal health. Accordingly, a global movement of 'One-Health/One-Medicine' has been launched to foster collaborative efforts amongst animal and human health officials and researchers to address these problems. Historical evidence points to the fact that pandemics caused by influenza A viruses remain a major zoonotic threat to mankind. Recently, a range of mathematical and computer simulation modelling methods and tools have increasingly been applied to improve our understanding of disease transmission dynamics, contingency planning and to support policy decisions on disease outbreak management. This review provides an overview of methods, approaches and software used for modelling the spread of zoonotic influenza viruses in animals and humans, particularly those related to the animal-human interface. Modelling parameters used in these studies are summarized to provide references for future work. This review highlights the limited application of modelling research to influenza in animals and at the animal-human interface, in marked contrast to the large volume of its research in human populations. Although swine are widely recognized as a potential host for generating novel influenza viruses, and that some of these viruses, including pandemic influenza A/H1N1 2009, have been shown to be readily transmissible between humans and swine, only one study was found related to the modelling of influenza spread at the swine-human interface. Significant gaps in the knowledge of frequency of novel viral strains evolution in pigs, farm-level natural history of influenza infection, incidences of influenza transmission between farms and between swine and humans are clearly evident. Therefore, there is a need to direct

  12. FAO-OIE-WHO Joint Technical Consultation on Avian Influenza at the Human-Animal Interface.

    PubMed

    Anderson, Tara; Capua, Ilaria; Dauphin, Gwenaëlle; Donis, Ruben; Fouchier, Ron; Mumford, Elizabeth; Peiris, Malik; Swayne, David; Thiermann, Alex

    2010-05-01

    For the past 10 years, animal health experts and human health experts have been gaining experience in the technical aspects of avian influenza in mostly separate fora. More recently, in 2006, in a meeting of the small WHO Working Group on Influenza Research at the Human Animal Interface (Meeting report available from: http://www.who.int/csr/resources/publications/influenza/WHO_CDS_EPR_GIP_2006_3/en/index.html) in Geneva allowed influenza experts from the animal and public health sectors to discuss together the most recent avian influenza research. Ad hoc bilateral discussions on specific technical issues as well as formal meetings such as the Technical Meeting on HPAI and Human H5N1 Infection (Rome, June, 2007; information available from: http://www.fao.org/avianflu/en/conferences/june2007/index.html) have increasingly brought the sectors together and broadened the understanding of the topics of concern to each sector. The sectors have also recently come together at the broad global level, and have developed a joint strategy document for working together on zoonotic diseases (Joint strategy available from: ftp://ftp.fao.org/docrep/fao/011/ajl37e/ajl37e00.pdf). The 2008 FAO-OIE-WHO Joint Technical Consultation on Avian Influenza at the Human Animal Interface described here was the first opportunity for a large group of influenza experts from the animal and public health sectors to gather and discuss purely technical topics of joint interest that exist at the human-animal interface. During the consultation, three influenza-specific sessions aimed to (1) identify virological characteristics of avian influenza viruses (AIVs) important for zoonotic and pandemic disease, (2) evaluate the factors affecting evolution and emergence of a pandemic influenza strain and identify existing monitoring systems, and (3) identify modes of transmission and exposure sources for human zoonotic influenza infection (including discussion of specific exposure risks by affected countries). A

  13. Prediction of biological functions on glycosylation site migrations in human influenza H1N1 viruses.

    PubMed

    Sun, Shisheng; Wang, Qinzhe; Zhao, Fei; Chen, Wentian; Li, Zheng

    2012-01-01

    Protein glycosylation alteration is typically employed by various viruses for escaping immune pressures from their hosts. Our previous work had shown that not only the increase of glycosylation sites (glycosites) numbers, but also glycosite migration might be involved in the evolution of human seasonal influenza H1N1 viruses. More importantly, glycosite migration was likely a more effectively alteration way for the host adaption of human influenza H1N1 viruses. In this study, we provided more bioinformatics and statistic evidences for further predicting the significant biological functions of glycosite migration in the host adaptation of human influenza H1N1 viruses, by employing homology modeling and in silico protein glycosylation of representative HA and NA proteins as well as amino acid variability analysis at antigenic sites of HA and NA. The results showed that glycosite migrations in human influenza viruses have at least five possible functions: to more effectively mask the antigenic sites, to more effectively protect the enzymatic cleavage sites of neuraminidase (NA), to stabilize the polymeric structures, to regulate the receptor binding and catalytic activities and to balance the binding activity of hemagglutinin (HA) with the release activity of NA. The information here can provide some constructive suggestions for the function research related to protein glycosylation of influenza viruses, although these predictions still need to be supported by experimental data.

  14. Antigenic Patterns and Evolution of the Human Influenza A (H1N1) Virus.

    PubMed

    Liu, Mi; Zhao, Xiang; Hua, Sha; Du, Xiangjun; Peng, Yousong; Li, Xiyan; Lan, Yu; Wang, Dayan; Wu, Aiping; Shu, Yuelong; Jiang, Taijiao

    2015-09-28

    The influenza A (H1N1) virus causes seasonal epidemics that result in severe illnesses and deaths almost every year. A deep understanding of the antigenic patterns and evolution of human influenza A (H1N1) virus is extremely important for its effective surveillance and prevention. Through development of antigenicity inference method for human influenza A (H1N1), named PREDAC-H1, we systematically mapped the antigenic patterns and evolution of the human influenza A (H1N1) virus. Eight dominant antigenic clusters have been inferred for seasonal H1N1 viruses since 1977, which demonstrated sequential replacements over time with a similar pattern in Asia, Europe and North America. Among them, six clusters emerged first in Asia. As for China, three of the eight antigenic clusters were detected in South China earlier than in North China, indicating the leading role of South China in H1N1 transmission. The comprehensive view of the antigenic evolution of human influenza A (H1N1) virus can help formulate better strategy for its prevention and control.

  15. Overexpression of α-2,6 sialyltransferase stimulates propagation of human influenza viruses in Vero cells.

    PubMed

    Li, N; Qi, Y; Zhang, F Y; Yu, X H; Wu, Y G; Chen, Y; Jiang, C L; Kong, W

    2011-01-01

    Human influenza viruses are major concern as the leading cause of global pandemics. In infecting cells, they preferentially bind to sialyloligosaccharides containing terminal N-acetyl sialic acid linked to galactose by an α-2,6-linkage (NeuAcα2,6Gal). The amount of NeuAcα2,6Gal in Vero cells, which are predominantly used for production of influenza vaccines over the past 30 years, may not be as high as that in epithelial cells of human respiratory tract, what leads to the suboptimal virus growth in Vero cells. In this study, we stably transfected Vero cells with cDNA of human α-2,6-sialyltransferase (SIAT1), an enzyme catalyzing α-2,6-sialylation of galactose on glycoproteins. Overexpression of SIAT1 in the transfected Vero cells (Vero-SIAT1 cells) was confirmed by Western blot analysis and immunofluorescence microscopy. Vero-SIAT1 cells expressed 7 times higher amounts of NeuAcα2,6Gal, but 3 times lower amounts of NeuAcα2,3Gal as compared to parental Vero cells. Furthermore, the influenza viruses A (H1N1 and H3N2) and B grew in Vero-SIAT1 cells to the higher titers than in Vero cells. Taken together, these results imply that Vero-SIAT1 cells are useful not only for the propagation of human influenza viruses, but also for the preparation of influenza vaccines.

  16. Introductions and evolution of human-origin seasonal influenza A viruses in multinational swine populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The capacity of influenza A viruses to cross species barriers presents a continual threat to human and animal health. Knowledge of the human-swine interface is particularly important for understanding how viruses with pandemic potential evolve in swine hosts. We sequenced the genomes of 141 influen...

  17. Eccentric exercise as an adjuvant to influenza vaccination in humans.

    PubMed

    Edwards, Kate M; Burns, Victoria E; Allen, Louise M; McPhee, Jamie S; Bosch, Jos A; Carroll, Douglas; Drayson, Mark; Ring, Christopher

    2007-02-01

    The immune response to vaccination in animals can be enhanced by exposure to acute stress at the time of vaccination. The efficacy of this adjuvant strategy for vaccination in humans requires investigation. The current study employed a randomised controlled trial design to examine the effects of eccentric exercise prior to influenza vaccination on the antibody and cell-mediated responses. Sixty young healthy adults (29 men, 31 women) performed eccentric contractions of the deltoid and biceps brachii muscles of the non-dominant arm (exercise group) or rested quietly (control group), and were vaccinated 6h later in the non-dominant arm. Change in arm circumference and pain were measured to assess the physiological response to exercise. Antibody titres were measured pre-vaccination and at 6- and 20-week follow-ups. Interferon-gamma in response to in vitro stimulation by the whole vaccine, an index of the cell-mediated response, was measured 8 weeks post-vaccination. Interferon-gamma responses were enhanced by exercise in men, whereas antibody titres were enhanced by eccentric exercise in women but not in men. Men showed greater increase in arm circumference after eccentric exercise than women but there was no difference in reported pain. The interferon-gamma response was positively associated with the percentage increase in arm circumference among the exercise group. Eccentric exercise exerted differential effects on the response to vaccination in men and women, with enhancement of the antibody response in women, but enhancement of the cell-mediated response in men. Eccentric exercise of the muscle at the site of vaccine administration should be explored further as a possible behavioural adjuvant to vaccination.

  18. Reassortment between swine influenza A viruses increased their adaptation to humans in pandemic H1N1/09.

    PubMed

    Furuse, Yuki; Suzuki, Akira; Oshitani, Hitoshi

    2010-05-01

    In April 2009, pandemic H1N1/09 influenza, which originated from swine influenza, appeared in North America, and it has since spread globally among humans. It is important to know how swine influenza A virus broke the host barrier to cause a pandemic. We analyzed 673 strains of human, avian, and swine influenza viruses and assessed the internal genes PB2, PB1, PA, NP, M, and NS. Here we found accumulation of mutations in segments that were retained as well as introduced due to genetic reassortment of viruses. The retained segments may have to mutate to accommodate new segments. The mutations caused by interaction among segments retained and introduced due to reassortment between swine influenza viruses may have increased the adaptation of the virus to humans, leading to pandemic H1N1/09. We indicate the sites that probably contributed to the acquisition of efficient human-to-human transmission.

  19. The expression of essential components for human influenza virus internalisation in Vero and MDCK cells.

    PubMed

    Ugiyadi, Maharani; Tan, Marselina I; Giri-Rachman, Ernawati A; Zuhairi, Fawzi R; Sumarsono, Sony H

    2014-05-01

    MDCK and Vero cell lines have been used as substrates for influenza virus replication. However, Vero cells produced lower influenza virus titer yield compared to MDCK. Influenza virus needs molecules for internalisation of the virus into the host cell, such as influenza virus receptor and clathrin. Human influenza receptor is usually a membrane protein containing Sia(α2,6) Gal, which is added into the protein in the golgi apparatus by α2,6 sialyltransferase (SIAT1). Light clathrin A (LCA), light clathrin B (LCB) and heavy clathrin (HC) are the main components needed for virus endocytosis. Therefore, it is necessary to compare the expression of SIAT1 and clathrin in Vero and MDCK cells. This study is reporting the expression of SIAT1 and clathrin observed in both cells with respect to the levels of (1) RNA by using RT-PCR, (2) protein by using dot blot analysis and confocal microscope. The results showed that Vero and MDCK cells expressed both SIAT1 and clathrin proteins, and the expression of SIAT1 in MDCK was higher compared to Vero cells. On the other hand, the expressions of LCA, LCB and HC protein in MDCK cells were not significantly different to Vero cells. This result showed that the inability of Vero cells to internalize H1N1 influenza virus was possibly due to the lack of transmembrane protein receptor which contained Sia(α2,6) Gal.

  20. Timing of influenza A(H5N1) in poultry and humans and seasonal influenza activity worldwide, 2004-2013.

    PubMed

    Durand, Lizette O; Glew, Patrick; Gross, Diane; Kasper, Matthew; Trock, Susan; Kim, Inkyu K; Bresee, Joseph S; Donis, Ruben; Uyeki, Timothy M; Widdowson, Marc-Alain; Azziz-Baumgartner, Eduardo

    2015-02-01

    Co-circulation of influenza A(H5N1) and seasonal influenza viruses among humans and animals could lead to co-infections, reassortment, and emergence of novel viruses with pandemic potential. We assessed the timing of subtype H5N1 outbreaks among poultry, human H5N1 cases, and human seasonal influenza in 8 countries that reported 97% of all human H5N1 cases and 90% of all poultry H5N1 outbreaks. In these countries, most outbreaks among poultry (7,001/11,331, 62%) and half of human cases (313/625, 50%) occurred during January-March. Human H5N1 cases occurred in 167 (45%) of 372 months during which outbreaks among poultry occurred, compared with 59 (10%) of 574 months that had no outbreaks among poultry. Human H5N1 cases also occurred in 59 (22%) of 267 months during seasonal influenza periods. To reduce risk for co-infection, surveillance and control of H5N1 should be enhanced during January-March, when H5N1 outbreaks typically occur and overlap with seasonal influenza virus circulation.

  1. Avian influenza A (H7N9) virus infection in humans: epidemiology, evolution, and pathogenesis.

    PubMed

    Husain, Matloob

    2014-12-01

    New human influenza A virus strains regularly emerge causing seasonal epidemics and occasional pandemics. Lately, several zoonotic avian influenza A strains have been reported to directly infect humans. In early 2013, a novel avian influenza A virus (H7N9) strain was discovered in China to cause severe respiratory disease in humans. Since then, over 450 human cases of H7N9 infection have been discovered and 165 of them have died. Multiple epidemiological, phylogenetic, in vivo, and in vitro studies have been done to determine the origin and pathogenesis of novel H7N9 strain. This article reviews the literature related to the epidemiology, evolution, and pathogenesis of the H7N9 strain since its discovery in February 2013 till August 2014. The data available so far indicate that H7N9 was originated by a two-step reassortment process in birds and transmitted to humans through direct contact with live-bird markets. H7N9 is a low-pathogenic avian virus and contains several molecular signatures for adaptation in mammals. The severity of the respiratory disease caused by novel H7N9 virus in humans can be partly attributed to the age, sex, and underlying medical conditions of the patients. A universal influenza vaccine is not available, though several strain-specific H7N9 candidate vaccine viruses have been developed. Further, novel H7N9 virus is resistant to antiviral drug amantadine and some H7N9 isolates have acquired the resistance to neuraminidase-inhibitors. Therefore, constant surveillance and prompt control measures combined with novel research approaches to develop alternative and effective anti-influenza strategies are needed to overcome influenza A virus.

  2. Avian influenza virus (H5N1): a threat to human health.

    PubMed

    Peiris, J S Malik; de Jong, Menno D; Guan, Yi

    2007-04-01

    Pandemic influenza virus has its origins in avian influenza viruses. The highly pathogenic avian influenza virus subtype H5N1 is already panzootic in poultry, with attendant economic consequences. It continues to cross species barriers to infect humans and other mammals, often with fatal outcomes. Therefore, H5N1 virus has rightly received attention as a potential pandemic threat. However, it is noted that the pandemics of 1957 and 1968 did not arise from highly pathogenic influenza viruses, and the next pandemic may well arise from a low-pathogenicity virus. The rationale for particular concern about an H5N1 pandemic is not its inevitability but its potential severity. An H5N1 pandemic is an event of low probability but one of high human health impact and poses a predicament for public health. Here, we review the ecology and evolution of highly pathogenic avian influenza H5N1 viruses, assess the pandemic risk, and address aspects of human H5N1 disease in relation to its epidemiology, clinical presentation, pathogenesis, diagnosis, and management.

  3. Post-pandemic seroprevalence of human influenza viruses in domestic cats.

    PubMed

    Ibrahim, Mahmoud; Ali, Ahmed; Daniels, Joshua B; Lee, Chang-Won

    2016-12-30

    The continuous exposure of cats to diverse influenza viruses raises the concern of a potential role of cats in the epidemiology of these viruses. Our previous seroprevalence study of domestic cat sera collected during the 2009 H1N1 pandemic wave (September 2009-September 2010) revealed a high prevalence of pandemic H1N1, as well as seasonal H1N1 and H3N2 human flu virus infection (22.5%, 33.0%, and 43.5%, respectively). In this study, we extended the serosurvey of influenza viruses in cat sera collected post-pandemic (June 2011-August 2012). A total of 432 cat sera were tested using the hemagglutination inhibition assay. The results showed an increase in pandemic H1N1 prevalence (33.6%) and a significant reduction in both seasonal H1N1 and H3N2 prevalence (10.9% and 17.6%, respectively) compared to our previous survey conducted during the pandemic wave. The pandemic H1N1 prevalence in cats showed an irregular seasonality pattern in the post-pandemic phase. Pandemic H1N1 reactivity was more frequent among female cats than male cats. In contrast to our earlier finding, no significant association between clinical respiratory disease and influenza virus infection was observed. Our study highlights a high susceptibility among cats to human influenza virus infection that is correlated with influenza prevalence in the human population.

  4. Broad neutralizing human monoclonal antibodies against influenza virus from vaccinated healthy donors

    SciTech Connect

    Kubota-Koketsu, Ritsuko; Mizuta, Hiroyuki; Oshita, Masatoshi; Ideno, Shoji; Yunoki, Mikihiro; Kuhara, Motoki; Yamamoto, Naomasa; Okuno, Yoshinobu; Ikuta, Kazuyoshi

    2009-09-11

    Human monoclonal antibodies (HuMAbs) prepared from patients with viral infections could provide information on human epitopes important for the development of vaccines as well as potential therapeutic applications. Through the fusion of peripheral blood mononuclear cells from a total of five influenza-vaccinated volunteers, with newly developed murine-human chimera fusion partner cells, named SPYMEG, we obtained 10 hybridoma clones stably producing anti-influenza virus antibodies: one for influenza A H1N1, four for influenza A H3N2 and five for influenza B. Surprisingly, most of the HuMAbs showed broad reactivity within subtype and four (two for H3N2 and two for B) showed broad neutralizing ability. Importantly, epitope mapping revealed that the two broad neutralizing antibodies to H3N2 derived from different donors recognized the same epitope located underneath the receptor-binding site of the hemagglutinin globular region that is highly conserved among H3N2 strains.

  5. Post-pandemic seroprevalence of human influenza viruses in domestic cats

    PubMed Central

    Ibrahim, Mahmoud; Ali, Ahmed; Daniels, Joshua B.

    2016-01-01

    The continuous exposure of cats to diverse influenza viruses raises the concern of a potential role of cats in the epidemiology of these viruses. Our previous seroprevalence study of domestic cat sera collected during the 2009 H1N1 pandemic wave (September 2009–September 2010) revealed a high prevalence of pandemic H1N1, as well as seasonal H1N1 and H3N2 human flu virus infection (22.5%, 33.0%, and 43.5%, respectively). In this study, we extended the serosurvey of influenza viruses in cat sera collected post-pandemic (June 2011–August 2012). A total of 432 cat sera were tested using the hemagglutination inhibition assay. The results showed an increase in pandemic H1N1 prevalence (33.6%) and a significant reduction in both seasonal H1N1 and H3N2 prevalence (10.9% and 17.6%, respectively) compared to our previous survey conducted during the pandemic wave. The pandemic H1N1 prevalence in cats showed an irregular seasonality pattern in the post-pandemic phase. Pandemic H1N1 reactivity was more frequent among female cats than male cats. In contrast to our earlier finding, no significant association between clinical respiratory disease and influenza virus infection was observed. Our study highlights a high susceptibility among cats to human influenza virus infection that is correlated with influenza prevalence in the human population. PMID:27030198

  6. Human swine influenza A [H1N1]: practical advice for clinicians early in the pandemic.

    PubMed

    Fitzgerald, Dominic A

    2009-09-01

    The influenza pandemic the world was waiting for may have arrived, but the early indications are that the first wave of human swine influenza A [H1N1], also referred to as H1N1 Mexico 09 or "swine flu", is highly transmissible but of no greater virulence than seasonal influenza to date. The new swine flu H1N1 virus is a mixture of avian, porcine and human influenza RNA. With twenty thousand confirmed cases worldwide and 117 deaths within 7 weeks of the first acknowledgement of a possible pandemic by Mexican and WHO experts, the mortality rate is less than 0.1% and the majority of deaths centred upon the origin of the epidemic in Mexico [83%]. Swine flu is thus far a relatively mild illness seen predominantly in those who are healthy and under 25 years of age, perhaps reflecting protection from previous human influenza exposure in older people. As the virus spreads internationally, border protection issues have surfaced and public health initiatives are being progressively rolled out to minimise the transmission. Vaccines are being developed which will be trialled in the coming months with a likely availability by August 2009, in time for the northern hemisphere autumn and winter. Vigilance without alarm appears to be the recommendation so far.

  7. Avian Influenza Virus (H5N1): a Threat to Human Health

    PubMed Central

    Peiris, J. S. Malik; de Jong, Menno D.; Guan, Yi

    2007-01-01

    Pandemic influenza virus has its origins in avian influenza viruses. The highly pathogenic avian influenza virus subtype H5N1 is already panzootic in poultry, with attendant economic consequences. It continues to cross species barriers to infect humans and other mammals, often with fatal outcomes. Therefore, H5N1 virus has rightly received attention as a potential pandemic threat. However, it is noted that the pandemics of 1957 and 1968 did not arise from highly pathogenic influenza viruses, and the next pandemic may well arise from a low-pathogenicity virus. The rationale for particular concern about an H5N1 pandemic is not its inevitability but its potential severity. An H5N1 pandemic is an event of low probability but one of high human health impact and poses a predicament for public health. Here, we review the ecology and evolution of highly pathogenic avian influenza H5N1 viruses, assess the pandemic risk, and address aspects of human H5N1 disease in relation to its epidemiology, clinical presentation, pathogenesis, diagnosis, and management. PMID:17428885

  8. Influenza Virus Isolations from Dogs During a Human Epidemic in Taiwan

    DTIC Science & Technology

    1976-01-01

    DURING A HUMAN EPIDEMIC IN TAIWAN C.P. CHANG, DVM; A.E. NEw, DVM, MS; J. F. TAYLOR, DVM; and H.S. CHIANG, DVM The susceptibility of dogs and cats to...of influenza virus from dogs and cats during a human epidemic of influenza A/Hong ,Kong/68 (H3N2) which occurred in June and July 1971 in Taiwan.0-0...MATERIALS AND METHODS Collection of specimens: From mid-June to mid-July 1971, throat swabs were taken from 372 dogs and 28 cats at veterinary

  9. THE INCIDENCE OF NEUTRALIZING ANTIBODIES FOR SWINE INFLUENZA VIRUS IN THE SERA OF HUMAN BEINGS OF DIFFERENT AGES

    PubMed Central

    Shope, Richard E.

    1936-01-01

    Sera from a very high proportion of the human adults and new-born infants studied neutralized swine influenza virus; sera from children below the age of 12 years seldom exerted such an effect. The results of neutralization experiments with human sera and the virus of swine influenza have been compared with the outcome of similar tests with the virus of human influenza, and it seems evident that the presence of antibodies neutralizing swine influenza virus cannot be deemed the result of repeated exposures to the current human type of virus. From the known history of swine influenza and the similarity of its etiologic virus to that obtained from man it seems likely that the virus of swine influenza is the surviving prototype of the agent primarily responsible for the great human pandemic of 1918, as Laidlaw has already suggested. The presence in human sera of antibodies neutralizing swine influenza virus is believed to indicate a previous immunizing exposure to, or infection with, an influenza virus of the 1918 type. PMID:19870496

  10. Swine influenza H1N1 virus induces acute inflammatory immune responses in pig lungs: a potential animal model for human H1N1 influenza virus.

    PubMed

    Khatri, Mahesh; Dwivedi, Varun; Krakowka, Steven; Manickam, Cordelia; Ali, Ahmed; Wang, Leyi; Qin, Zhuoming; Renukaradhya, Gourapura J; Lee, Chang-Won

    2010-11-01

    Pigs are capable of generating reassortant influenza viruses of pandemic potential, as both the avian and mammalian influenza viruses can infect pig epithelial cells in the respiratory tract. The source of the current influenza pandemic is H1N1 influenza A virus, possibly of swine origin. This study was conducted to understand better the pathogenesis of H1N1 influenza virus and associated host mucosal immune responses during acute infection in humans. Therefore, we chose a H1N1 swine influenza virus, Sw/OH/24366/07 (SwIV), which has a history of transmission to humans. Clinically, inoculated pigs had nasal discharge and fever and shed virus through nasal secretions. Like pandemic H1N1, SwIV also replicated extensively in both the upper and lower respiratory tracts, and lung lesions were typical of H1N1 infection. We detected innate, proinflammatory, Th1, Th2, and Th3 cytokines, as well as SwIV-specific IgA antibody in lungs of the virus-inoculated pigs. Production of IFN-γ by lymphocytes of the tracheobronchial lymph nodes was also detected. Higher frequencies of cytotoxic T lymphocytes, γδ T cells, dendritic cells, activated T cells, and CD4+ and CD8+ T cells were detected in SwIV-infected pig lungs. Concomitantly, higher frequencies of the immunosuppressive T regulatory cells were also detected in the virus-infected pig lungs. The findings of this study have relevance to pathogenesis of the pandemic H1N1 influenza virus in humans; thus, pigs may serve as a useful animal model to design and test effective mucosal vaccines and therapeutics against influenza virus.

  11. Influenza virus budding from the tips of cellular microvilli in differentiated human airway epithelial cells.

    PubMed

    Kolesnikova, Larissa; Heck, Sonja; Matrosovich, Tatyana; Klenk, Hans-Dieter; Becker, Stephan; Matrosovich, Mikhail

    2013-05-01

    The epithelium of conducting airways represents the main target for influenza virus in mammals. However, the peculiarities of virus interactions with differentiated airway epithelial cells remain largely unknown. Here, influenza virus budding was studied in differentiated cultures of human tracheobronchial epithelial cells using transmission electron microscopy. Budding of spherical and filamentous virions was observed on the apical surfaces of cells with no association with cilia and secretory granules. Quantitative analysis of the distribution of viral buds on the cell surface indicated that the tips of the microvilli represented a prominent site of influenza virus budding in the human airway epithelium. As the microvilli of differentiated cells are involved in many fundamental cell functions, these data will prompt further studies on the biological significance of microvilli-associated budding for virus replication, transmission and pathogenicity.

  12. A Reverse Genetics Approach for the Design of Methyltransferase-Defective Live Attenuated Avian Metapneumovirus Vaccines.

    PubMed

    Zhang, Yu; Sun, Jing; Wei, Yongwei; Li, Jianrong

    2016-01-01

    Avian metapneumovirus (aMPV), also known as avian pneumovirus or turkey rhinotracheitis virus, is the causative agent of turkey rhinotracheitis and is associated with swollen head syndrome in chickens. aMPV belongs to the family Paramyxoviridae which includes many important human pathogens such as human respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and human parainfluenza virus type 3 (PIV3). The family also includes highly lethal emerging pathogens such as Nipah virus and Hendra virus, as well as agriculturally important viruses such as Newcastle disease virus (NDV). For many of these viruses, there is no effective vaccine. Here, we describe a reverse genetics approach to develop live attenuated aMPV vaccines by inhibiting the viral mRNA cap methyltransferase. The viral mRNA cap methyltransferase is an excellent target for the attenuation of paramyxoviruses because it plays essential roles in mRNA stability, efficient viral protein translation and innate immunity. We have described in detail the materials and methods used to generate recombinant aMPVs that lack viral mRNA cap methyltransferase activity. We have also provided methods to evaluate the genetic stability, pathogenesis, and immunogenicity of live aMPV vaccine candidates in turkeys.

  13. [Polymorphism of current human influenza A and B virus population].

    PubMed

    Grinbaum, E B; Litvinova, O M; Bannikov, A I; Konovalenko, I B; Chernookaia, N Iu; Iukhnova, L G; Kiselev, O I

    1994-01-01

    During the past years, the etiological situation has been significantly complicated. It is characterized by simultaneous circulation of A(H1N1), A(H3N2) and influenza B viruses and by the isolation of reassortant strains and viruses, which are atypical in relation to the process of their natural variability. The antigenic properties of epidemic strains and unusual isolates were investigated. The marked heterogeneity of the A(H3N2) influenza viruses was demonstrated. It was determined by the circulation of several antigenic variants during the epidemic. Two separate antigenic lineage of the influenza B viruses--b/Victoria/2/87 and B/Yamagata/16/88--cocirculated in our country in 1991. Since 1986, all the influenza A(H1N1) viruses have been considered to be varieties of the reference strain A/Taiwan/1/86. A direct correlation was found between some atypical viruses and the vaccine strains previously used.

  14. Activation of influenza viruses by proteases from host cells and bacteria in the human airway epithelium.

    PubMed

    Böttcher-Friebertshäuser, Eva; Klenk, Hans-Dieter; Garten, Wolfgang

    2013-11-01

    Influenza is an acute infection of the respiratory tract, which affects each year millions of people. Influenza virus infection is initiated by the surface glycoprotein hemagglutinin (HA) through receptor binding and fusion of viral and endosomal membranes. HA is synthesized as a precursor protein and requires cleavage by host cell proteases to gain its fusion capacity. Although cleavage of HA is crucial for virus infectivity, little was known about relevant proteases in the human airways for a long time. Recent progress in the identification and characterization of HA-activating host cell proteases has been considerable however and supports the idea of targeting HA cleavage as a novel approach for influenza treatment. Interestingly, certain bacteria have been demonstrated to support HA activation either by secreting proteases that cleave HA or due to activation of cellular proteases and thereby may contribute to virus spread and enhanced pathogenicity. In this review, we give an overview on activation of influenza viruses by proteases from host cells and bacteria with the main focus on recent progress on HA cleavage by proteases HAT and TMPRSS2 in the human airway epithelium. In addition, we outline investigations of HA-activating proteases as potential drug targets for influenza treatment.

  15. Bovine and human-derived passive immunization could help slow a future avian influenza pandemic.

    PubMed

    Alisky, Joseph

    2009-01-01

    An epidemic of human transmitted avian influenza could have casualties on a scale seen in the great Spanish influenza pandemic of 1918. This paper proposes that should such occur before effective vaccines and antiviral drugs are available, the outbreak could be significantly slowed by consumption of raw milk produced by herds of pathogen-free lactating cows intranasally inoculated with heat-sterilized sputa pooled from avian influenza patients, supplemented by parenteral serum immune globulin from the same cows. Efficiency of bovine antibody production could be enhanced using cholera toxin subunit b, and milk production could be rapidly accelerated using recombinant bovine somatotropin hormone. In this way, it would be possible to quickly create and distribute large quantities of milk-based and serum-based passive immune globulin active against the strains of avian influenza present in a particular geographic area and gain time for production of human convalescent plasma and other public health measures. This novel approach might also have utility for other serious respiratory infectious diseases, including non-avian influenza, SARS, hantavirus, respiratory syncytial virus, antibiotic-resistant Streptococcus pneumoniae and pneumonia-causing Staphylococcus aureus.

  16. Avian biology, the human influence on global avian influenza transmission, and performing surveillance in wild birds.

    PubMed

    Gibbs, Samantha E J

    2010-06-01

    This paper takes a closer look at three interrelated areas of study: avian host biology, the role of human activities in virus transmission, and the surveillance activities centered on avian influenza in wild birds. There are few ecosystems in which birds are not found. Correspondingly, avian influenza viruses are equally global in distribution, relying on competent avian hosts. The immune systems, annual cycles, feeding behaviors, and migration patterns of these hosts influence the ecology of the disease. Decreased biodiversity has also been linked to heightened disease transmission in several disease systems, and it is evident that active destruction and modification of wetland environments for human use is impacting avian populations drastically. Legal and illegal trade in wild birds present a significant risk for introduction and maintenance of exotic diseases. After the emergence of HPAI H5N1 in Hong Kong in 1996 and the ensuing geographic spread of outbreaks after 2003, both infected countries and those at risk of introduction began intensifying avian influenza surveillance efforts. Several techniques for sampling wild birds for influenza viruses have been applied. Benefits, problems, and biases exist for each method. The wild bird avian influenza surveillance programs taking place across the continents are now scaling back due to the rise of other spending priorities; hopefully the lessons learned from this work will be preserved and will inform future research and disease outbreak response priorities.

  17. IL-2 and IL-6 cooperate to enhance the generation of influenza-specific CD8 T cells responding to live influenza virus in aged mice and humans

    PubMed Central

    Zhou, Xin; Hopkins, Jacob W.; Wang, Chongkai; Brahmakshatriya, Vinayak; Swain, Susan L.; Kuchel, George A.; Haynes, Laura; McElhaney, Janet E.

    2016-01-01

    An age-related decline in cytolytic activity has been described in CD8+ T cells and we have previously shown that the poor CD8+ effector T cell responses to influenza A/H3N2 challenge result from a decline in the proportion and function of these cytolytic T lymphocytes (CTL). Here, we describe that addition of exogenous cytokines to influenza-stimulated PBMC from both aged mice and humans, enhances the generation of influenza specific CD8 CTL by increasing their proliferation and survival. Our data show that the addition of IL-2 and IL-6 to splenocytes from mice previously infected with influenza virus restores the aged CD8+ T cell response to that observed in young mice. In humans, IL-2 plus IL-6 also reduces the proportion of apoptotic effector CD8+ T cells to levels resembling those of younger adults. In HLA-A2+ donors, MHC Class I tetramer staining showed that adding both exogenous IL-2 and IL-6 resulted in greater differentiation into influenza-specific effector CD8+ T cells. Since this effect of IL-2/IL-6 supplementation can be reproduced with the addition of Toll-like receptor agonists, it may be possible to exploit this mechanism and design new vaccines to improve the CD8 T cell response to influenza vaccination in older adults. PMID:27322555

  18. Comparison of the FilmArray RP, Verigene RV+, and Prodesse ProFLU+/FAST+ multiplex platforms for detection of influenza viruses in clinical samples from the 2011-2012 influenza season in Belgium.

    PubMed

    Van Wesenbeeck, Liesbeth; Meeuws, Hanne; Van Immerseel, Andrea; Ispas, Gabriela; Schmidt, Kristiane; Houspie, Lieselot; Van Ranst, Marc; Stuyver, Lieven

    2013-09-01

    Respiratory tract infections (RTIs) are caused by a plethora of viral and bacterial pathogens. In particular, lower RTIs are a leading cause of hospitalization and mortality. Timely detection of the infecting respiratory pathogens is crucial to optimize treatment and care. In this study, three U.S. Food and Drug Administration-approved molecular multiplex platforms (Prodesse ProFLU+/FAST+, FilmArray RP, and Verigene RV+) were evaluated for influenza virus detection in 171 clinical samples collected during the Belgian 2011-2012 influenza season. Sampling was done using mid-turbinate flocked swabs, and the collected samples were stored in universal transport medium. The amount of viral RNA present in the swab samples ranged between 3.07 and 8.82 log10 copies/ml. Sixty samples were concordant influenza A virus positive, and 8 samples were found to be concordant influenza B virus positive. Other respiratory viruses that were detected included human rhinovirus/enterovirus, respiratory syncytial virus, parainfluenza virus type 1, human metapneumovirus, and coronavirus NL63. Twenty-five samples yielded discordant results across the various assays which required further characterization by sequencing. The FilmArray RP and Prodesse ProFLU+/FAST+ assays were convenient to perform with regard to sensitivity, ease of use, and low percentages of invalid results. Although the limit of sensitivity is of utmost importance, many other factors should be taken into account in selecting the most convenient molecular diagnostic assay for the detection of respiratory pathogens in clinical samples.

  19. Receptor Binding Profiles of Avian Influenza Virus Hemagglutinin Subtypes on Human Cells as a Predictor of Pandemic Potential ▿ ‖

    PubMed Central

    Shelton, Holly; Ayora-Talavera, Guadalupe; Ren, Junyuan; Loureiro, Silvia; Pickles, Raymond J.; Barclay, Wendy S.; Jones, Ian M.

    2011-01-01

    The host adaptation of influenza virus is partly dependent on the sialic acid (SA) isoform bound by the viral hemagglutinin (HA). Avian influenza viruses preferentially bind the α-2,3 SA and human influenza viruses the α-2,6 isoform. Each isoform is predominantly associated with different surface epithelial cell types of the human upper airway. Using recombinant HAs and human tracheal airway epithelial cells in vitro and ex vivo, we show that many avian HA subtypes do not adhere to this canonical view of SA specificity. The propensity of avian viruses to adapt to human receptors may thus be more widespread than previously supposed. PMID:21106732

  20. Attenuation of a human H9N2 influenza virus in mammalian host by reassortment with an avian influenza virus.

    PubMed

    Saito, T; Lim, W; Tashiro, M

    2004-07-01

    In order to develop a surrogate virus strain for production of an inactivated influenza vaccine against a human H9N2 virus, A/Hong Kong/1073/99 (HK1073: H9N2) was co-infected in embryonated chicken eggs with an apathogenic avian influenza virus, A/Duck/Czechoslovakia/56 (Dk/Cz: H4N6), for gene segment reassortment. Multiple-gene reassortants obtained were examined for replication in mammalian hosts in vitro and in vivo by infecting MDCK cells and by intranasal administration to hamsters, respectively. A 2-6 gene reassortant with both surface glycoproteins of HK1073 origin and the rest of Dk/Cz origin, HK/CZ-13, was shown to replicate poorly in the mammalian hosts both in vivo and in vitro comparing with HK1073, although this reassortant replicated as efficiently as each parental strain in embryonated eggs. No sequence difference was observed in the HA1 region between HK1073 and HK/CZ-13, indicating that the reassortant would be equivalent in its immunogenicity to the parental HK1073 strain when it is used as an inactivated vaccine. A virus strain with attenuation in mammalian hosts is preferable for production of an H9 vaccine, since it should reduce the risk of manufacturing-related infections of employees during the vaccine production. HK/CZ-13 can therefore be a surrogate strain for production of an inactivated vaccine as well as diagnostic antigens in case of a possible future pandemic caused by an HK1073-like H9 influenza virus.

  1. Continual re-introduction of human pandemic H1N1 influenza A viruses into US swine, 2009-2014

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human-to-swine transmission of pandemic H1N1 influenza viruses (pH1N1) increased the genetic diversity of influenza A viruses in swine (swIAVs) globally and is linked to the emergence of new pandemic threats, including H3N2v variants. Through phylogenetic analysis of contemporary swIAVs in the Unit...

  2. Glyconanoparticles for the plasmonic detection and discrimination between human and avian influenza virus.

    PubMed

    Marín, María J; Rashid, Abdul; Rejzek, Martin; Fairhurst, Shirley A; Wharton, Stephen A; Martin, Stephen R; McCauley, John W; Wileman, Thomas; Field, Robert A; Russell, David A

    2013-11-07

    A plasmonic bioassay for the specific detection of human influenza virus has been developed based on gold nanoparticles functionalised with a designed and synthesised thiolated trivalent α2,6-thio-linked sialic acid derivative. The glyconanoparticles consist of the thiolated trivalent α2,6-thio-linked sialic acid derivative and a thiolated polyethylene glycol (PEG) derivative self-assembled onto the gold surface. Varying ratios of the trivalent α2,6-thio-linked sialic acid ligand and the PEG ligand were used; a ratio of 25:75 was found to be optimum for the detection of human influenza virus X31 (H3N2). In the presence of the influenza virus a solution of the glyconanoparticles aggregate following the binding of the trivalent α2,6-thio-linked sialic acid ligand to the haemagglutinin on the surface of the virus. The aggregation of the glycoparticles with the influenza virus induces a colour change of the solution within 30 min. Non-purified influenza virus in allantoic fluid was successfully detected using the functionalised glyconanoparticles. A comparison between the trivalent and a monovalent α2,6-thio-linked sialic acid functionalised nanoparticles confirmed that more rapid results, with greater sensitivity, were achieved using the trivalent ligand for the detection of the X31 virus. Importantly, the glyconanoparticles were able to discriminate between human (α2,6 binding) and avian (α2,3 binding) RG14 (H5N1) influenza virus highlighting the binding specificity of the trivalent α2,6-thio-linked sialic acid ligand.

  3. Human influenza A(H7N9) virus infection associated with poultry farm, Northeastern China.

    PubMed

    Fan, Ming; Huang, Biao; Wang, Ao; Deng, Liquan; Wu, Donglin; Lu, Xinrong; Zhao, Qinglong; Xu, Shuang; Havers, Fiona; Wang, Yanhui; Wu, Jing; Yin, Yuan; Sun, Bingxin; Yao, Jianyi; Xiang, Nijuan

    2014-11-01

    We report on a case of human infection with influenza A(H7N9) virus in Jilin Province in northeastern China. This case was associated with a poultry farm rather than a live bird market, which may point to a new focus for public health surveillance and interventions in this evolving outbreak.

  4. Using experimental human influenza infections to validate a viral dynamic model and the implications for prediction.

    PubMed

    Chen, S C; You, S H; Liu, C Y; Chio, C P; Liao, C M

    2012-09-01

    The aim of this work was to use experimental infection data of human influenza to assess a simple viral dynamics model in epithelial cells and better understand the underlying complex factors governing the infection process. The developed study model expands on previous reports of a target cell-limited model with delayed virus production. Data from 10 published experimental infection studies of human influenza was used to validate the model. Our results elucidate, mechanistically, the associations between epithelial cells, human immune responses, and viral titres and were supported by the experimental infection data. We report that the maximum total number of free virions following infection is 10(3)-fold higher than the initial introduced titre. Our results indicated that the infection rates of unprotected epithelial cells probably play an important role in affecting viral dynamics. By simulating an advanced model of viral dynamics and applying it to experimental infection data of human influenza, we obtained important estimates of the infection rate. This work provides epidemiologically meaningful results, meriting further efforts to understand the causes and consequences of influenza A infection.

  5. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection

    EPA Science Inventory

    Exposure to oxidant air pollution is associated with Increased respiratory morbiditses and susceptibility to Infections Ozone is a commonly encountered oxidant air pollutant, yet Its effects on influenza infections in humans are not known ‘the greater Mexico City area was the pri...

  6. Human Influenza A(H7N9) Virus Infection Associated with Poultry Farm, Northeastern China

    PubMed Central

    Fan, Ming; Huang, Biao; Wang, Ao; Deng, Liquan; Wu, Donglin; Lu, Xinrong; Zhao, Qinglong; Xu, Shuang; Havers, Fiona; Wang, Yanhui; Wu, Jing; Yin, Yuan; Sun, Bingxin; Yao, Jianyi

    2014-01-01

    We report on a case of human infection with influenza A(H7N9) virus in Jilin Province in northeastern China. This case was associated with a poultry farm rather than a live bird market, which may point to a new focus for public health surveillance and interventions in this evolving outbreak. PMID:25340624

  7. Heterogeneous shedding of influenza by human subjects and its implications for epidemiology and control

    PubMed Central

    Canini, Laetitia; Woolhouse, Mark E. J.; Maines, Taronna R.; Carrat, Fabrice

    2016-01-01

    Heterogeneity of infectiousness is an important feature of the spread of many infections, with implications for disease dynamics and control, but its relevance to human influenza virus is still unclear. For a transmission event to occur, an infected individual needs to release infectious particles via respiratory symptoms. Key factors to take into account are virus dynamics, particle release in relation to respiratory symptoms, the amount of virus shed and, importantly, how these vary between infected individuals. A quantitative understanding of the process of influenza transmission is relevant to designing effective mitigation measures. Here we develop an influenza infection dynamics model fitted to virological, systemic and respiratory symptoms to investigate how within-host dynamics relates to infectiousness. We show that influenza virus shedding is highly heterogeneous between subjects. From analysis of data on experimental infections, we find that a small proportion (<20%) of influenza infected individuals are responsible for the production of 95% of infectious particles. Our work supports targeting mitigation measures at most infectious subjects to efficiently reduce transmission. The effectiveness of public health interventions targeted at highly infectious individuals would depend on accurate identification of these subjects and on how quickly control measures can be applied. PMID:27966651

  8. Peptide Sharing Between Influenza A H1N1 Hemagglutinin and Human Axon Guidance Proteins

    PubMed Central

    Kanduc, Darja

    2014-01-01

    Epidemiologic data suggest that maternal microbial infections may cause fetal neurodevelopmental disorders, potentially increasing susceptibility to heavy psychopathologies such as schizophrenia, schizophreniform disorder, autism, pervasive developmental disorders, bipolar disorders, psychosis, epilepsy, language and speech disorders, and cognitive impairment in adult offspring. However, the molecular pathomechanisms underlying such a relationship are not clear. Here we analyze the potential role of the maternal immune response to viral infection in determining fetal brain injuries that increase the risk of neurological disorders in the adult. We use influenza infection as a disease model and human axon guidance pathway, a key process in the formation of neural network during midgestation, as a potential fetal target of immune insults. Specifically, we examined influenza A H1N1 hemagglutinin (HA), an antigenic viral protein, for amino acid sequence similarity to a random library of 188 axon guidance proteins. We obtain the results that (1) contrary to any theoretical expectations, 45 viral pentapeptide matches are distributed throughout a subset of 36 guidance molecules; (2) in 24 guidance proteins, the peptide sharing with HA antigen involves already experimentally validated influenza HA epitopes; and (3) most of the axon guidance vs HA peptide overlap is conserved among influenza A viral strains and subsets. Taken together, our data indicate that immune cross-reactivity between influenza HA and axon guidance molecules is possible and may well represent a pathologic mechanism capable of determining neurodevelopmental disruption in the fetus. PMID:23378012

  9. Prevalence of gastrointestinal symptoms in patients with influenza, clinical significance, and pathophysiology of human influenza viruses in faecal samples: what do we know?

    PubMed

    Minodier, Laetitia; Charrel, Remi N; Ceccaldi, Pierre-Emmanuel; van der Werf, Sylvie; Blanchon, Thierry; Hanslik, Thomas; Falchi, Alessandra

    2015-12-12

    This review provides for the first time an assessment of the current understanding about the occurrence and the clinical significance of gastrointestinal (GI) symptoms in influenza patients, and their correlation with the presence of human influenza viruses in stools of patients with confirmed influenza virus infection. Studies exploring how human influenza viruses spread to the patient's GI tract after a primary respiratory infection have been summarized. We conducted a systematic search of published peer-reviewed literature up to June 2015 with regard to the above-mentioned aspects, focusing on human influenza viruses (A(H1N1), A(H1N1)pdm09, A(H3N2), and B). Forty-four studies were included in this systematic review and meta-analysis. The pooled prevalence of any digestive symptoms ranged from 30.9% (95% CI, 9.8 to 57.5; I(2) = 97.5%) for A(H1N1)pdm09 to 2.8% (95% CI, 0.6 to 6.5; I(2) = 75.4%) for A(H1N1). The pooled prevalence of influenza viruses in stool was 20.6% (95% CI, 8.9 to 35.5; I(2) = 96.8%), but their correlation with GI symptoms has rarely been explored. The presence of viral RNA in stools because of haematogenous dissemination to organs via infected lymphocytes is likely, but the potential to cause direct intestinal infection and faecal-oral transmission warrants further investigation. This review highlights the gaps in our knowledge, and the high degree of uncertainty about the prevalence and significance of GI symptoms in patients with influenza and their correlation with viral RNA positivity in stool because of the high level of heterogeneity among studies.

  10. Human monoclonal antibodies derived from a patient infected with 2009 pandemic influenza A virus broadly cross-neutralize group 1 influenza viruses

    SciTech Connect

    Pan, Yang; Sasaki, Tadahiro; Du, Anariwa; and others

    2014-07-18

    Highlights: • Influenza infection can elicit heterosubtypic antibodies to group 1 influenza virus. • Three human monoclonal antibodies were generated from an H1N1-infected patient. • The antibodies predominantly recognized α-helical stem of viral hemagglutinin (HA). • The antibodies inhibited HA structural activation during the fusion process. • The antibodies are potential candidates for future antibody therapy to influenza. - Abstract: Influenza viruses are a continuous threat to human public health because of their ability to evolve rapidly through genetic drift and reassortment. Three human monoclonal antibodies (HuMAbs) were generated in this study, 1H11, 2H5 and 5G2, and they cross-neutralize a diverse range of group 1 influenza A viruses, including seasonal H1N1, 2009 pandemic H1N1 (H1N1pdm) and avian H5N1 and H9N2. The three HuMAbs were prepared by fusing peripheral blood lymphocytes from an H1N1pdm-infected patient with a newly developed fusion partner cell line, SPYMEG. All the HuMAbs had little hemagglutination inhibition activity but had strong membrane-fusion inhibition activity against influenza viruses. A protease digestion assay showed the HuMAbs targeted commonly a short α-helix region in the stalk of the hemagglutinin. Furthermore, Ile45Phe and Glu47Gly double substitutions in the α-helix region made the HA unrecognizable by the HuMAbs. These two amino acid residues are highly conserved in the HAs of H1N1, H5N1 and H9N2 viruses. The HuMAbs reported here may be potential candidates for the development of therapeutic antibodies against group 1 influenza viruses.

  11. nextflu: real-time tracking of seasonal influenza virus evolution in humans

    PubMed Central

    Neher, Richard A.; Bedford, Trevor

    2015-01-01

    Summary: Seasonal influenza viruses evolve rapidly, allowing them to evade immunity in their human hosts and reinfect previously infected individuals. Similarly, vaccines against seasonal influenza need to be updated frequently to protect against an evolving virus population. We have thus developed a processing pipeline and browser-based visualization that allows convenient exploration and analysis of the most recent influenza virus sequence data. This web-application displays a phylogenetic tree that can be decorated with additional information such as the viral genotype at specific sites, sampling location and derived statistics that have been shown to be predictive of future virus dynamics. In addition, mutation, genotype and clade frequency trajectories are calculated and displayed. Availability and implementation: Python and Javascript source code is freely available from https://github.com/blab/nextflu, while the web-application is live at http://nextflu.org. Contact: tbedford@fredhutch.org PMID:26115986

  12. Effect of Influenza-Induced Fever on Human Bioimpedance Values

    PubMed Central

    Marini, Elisabetta; Buffa, Roberto; Contreras, Monica; Magris, Magda; Hidalgo, Glida; Sanchez, Wilmer; Ortiz, Vanessa; Urbaez, Maryluz; Cabras, Stefano; Blaser, Martin J.; Dominguez-Bello, Maria G.

    2015-01-01

    Background and Aims Bioelectrical impedance analysis (BIA) is a widely used technique to assess body composition and nutritional status. While bioelectrical values are affected by diverse variables, there has been little research on validation of BIA in acute illness, especially to understand prognostic significance. Here we report the use of BIA in acute febrile states induced by influenza. Methods Bioimpedance studies were conducted during an H1N1 influenza A outbreak in Venezuelan Amerindian villages from the Amazonas. Measurements were performed on 52 subjects between 1 and 40 years of age, and 7 children were re-examined after starting Oseltamivir treatment. Bioelectrical Impedance Vector Analysis (BIVA) and permutation tests were applied. Results For the entire sample, febrile individuals showed a tendency toward greater reactance (p=0.058) and phase angle (p=0.037) than afebrile individuals, while resistance and impedance were similar in the two groups. Individuals with repeated measurements showed significant differences in bioimpedance values associated with fever, including increased reactance (p<0.001) and phase angle (p=0.007), and decreased resistance (p=0.007) and impedance (p<0.001). Conclusions There are bioelectrical variations induced by influenza that can be related to dehydration, with lower extracellular to intracellular water ratio in febrile individuals, or a direct thermal effect. Caution is recommended when interpreting bioimpedance results in febrile states. PMID:25915945

  13. [Colorimetric detection of human influenza A H1N1 virus by reverse transcription loop mediated isothermal amplification].

    PubMed

    Nie, Kai; Wang, Da-Yan; Qin, Meng; Gao, Rong-Bao; Wang, Miao; Zou, Shu-Mei; Han, Feng; Zhao, Xiang; Li, Xi-Yan; Shu, Yue-Long; Ma, Xue-Jun

    2010-03-01

    A simple, rapid and sensitive colorimetric Reverse Transcription Loop Mediated Isothermal Amplification (RT-LAMP) method was established to detect human influenza A H1N1 virus. The method employed a set of six specially designed primers that recognized eight distinct sequences of the HA gene for amplification of nucleic acid under isothermal conditions at 65 degrees C for one and half hour. The amplification process of RT-LAMP was monitored by the addition of HNB (Hydroxy naphthol blue) dye prior to amplification. A positive reaction was indicated by a color change from violet to sky blue and confirmed by agarose electrophoresis. The specificity of the RT-LAMP assay was validated by cross-reaction with different swine and human influenza virus including human seasonal influenza A /H1N1 A /H3N2, influenza B and swine A /H1N1. The sensitivity of this assay was evaluated by serial dilutions of RNA molecules from in vitro transcription of human influenza A H1N1 HA gene. The assay was further evaluated with 30 clinical specimens with suspected pandemic influenza A H1N1 virus infection in parallel with RT-PCR detection and 26 clinical specimens with seasonal influenza virus infection. Our results showed that the RT-LAMP was able to achieve a sensitivity of 60 RNA copies with high specificity, and detection rate was comparable to that of the RT-PCR with the clinical samples of pandemic influenza A H1N1 infection. The RT-LAMP reaction with HNB could also be measured at 650nm in a microplate reader for quantitative analysis. Thus, we concluded that this colorimetric RT-LAMP assay had potential for the rapid screening of the human influenza A H1N1 virus infection in National influenza monitoring network laboratories and sentinel hospitals of provincial and municipal region in China.

  14. Matriptase Proteolytically Activates Influenza Virus and Promotes Multicycle Replication in the Human Airway Epithelium

    PubMed Central

    Beaulieu, Alexandre; Gravel, Émilie; Cloutier, Alexandre; Marois, Isabelle; Colombo, Éloïc; Désilets, Antoine; Verreault, Catherine; Leduc, Richard; Marsault, Éric

    2013-01-01

    Influenza viruses do not encode any proteases and must rely on host proteases for the proteolytic activation of their surface hemagglutinin proteins in order to fuse with the infected host cells. Recent progress in the understanding of human proteases responsible for influenza virus hemagglutinin activation has led to the identification of members of the type II transmembrane serine proteases TMPRSS2 and TMPRSS4 and human airway trypsin-like protease; however, none has proved to be the sole enzyme responsible for hemagglutinin cleavage. In this study, we identify and characterize matriptase as an influenza virus-activating protease capable of supporting multicycle viral replication in the human respiratory epithelium. Using confocal microscopy, we found matriptase to colocalize with hemagglutinin at the apical surface of human epithelial cells and within endosomes, and we showed that the soluble form of the protease was able to specifically cleave hemagglutinins from H1 virus, but not from H2 and H3 viruses, in a broad pH range. We showed that small interfering RNA (siRNA) knockdown of matriptase in human bronchial epithelial cells significantly blocked influenza virus replication in these cells. Lastly, we provide a selective, slow, tight-binding inhibitor of matriptase that significantly reduces viral replication (by 1.5 log) of H1N1 influenza virus, including the 2009 pandemic virus. Our study establishes a three-pronged model for the action of matriptase: activation of incoming viruses in the extracellular space in its shed form, upon viral attachment or exit in its membrane-bound and/or shed forms at the apical surface of epithelial cells, and within endosomes by its membrane-bound form where viral fusion takes place. PMID:23365447

  15. Exposure to Ozone Modulates Human Airway Protease/Antiprotease Balance Contributing to Increased Influenza A Infection

    PubMed Central

    Kesic, Matthew J.; Meyer, Megan; Bauer, Rebecca; Jaspers, Ilona

    2012-01-01

    Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA) is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs) human airway trypsin-like protease (HAT) and transmembrane protease, serine 2 (TMPRSS2), whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI). Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs) to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility. PMID

  16. Matriptase proteolytically activates influenza virus and promotes multicycle replication in the human airway epithelium.

    PubMed

    Beaulieu, Alexandre; Gravel, Émilie; Cloutier, Alexandre; Marois, Isabelle; Colombo, Éloïc; Désilets, Antoine; Verreault, Catherine; Leduc, Richard; Marsault, Éric; Richter, Martin V

    2013-04-01

    Influenza viruses do not encode any proteases and must rely on host proteases for the proteolytic activation of their surface hemagglutinin proteins in order to fuse with the infected host cells. Recent progress in the understanding of human proteases responsible for influenza virus hemagglutinin activation has led to the identification of members of the type II transmembrane serine proteases TMPRSS2 and TMPRSS4 and human airway trypsin-like protease; however, none has proved to be the sole enzyme responsible for hemagglutinin cleavage. In this study, we identify and characterize matriptase as an influenza virus-activating protease capable of supporting multicycle viral replication in the human respiratory epithelium. Using confocal microscopy, we found matriptase to colocalize with hemagglutinin at the apical surface of human epithelial cells and within endosomes, and we showed that the soluble form of the protease was able to specifically cleave hemagglutinins from H1 virus, but not from H2 and H3 viruses, in a broad pH range. We showed that small interfering RNA (siRNA) knockdown of matriptase in human bronchial epithelial cells significantly blocked influenza virus replication in these cells. Lastly, we provide a selective, slow, tight-binding inhibitor of matriptase that significantly reduces viral replication (by 1.5 log) of H1N1 influenza virus, including the 2009 pandemic virus. Our study establishes a three-pronged model for the action of matriptase: activation of incoming viruses in the extracellular space in its shed form, upon viral attachment or exit in its membrane-bound and/or shed forms at the apical surface of epithelial cells, and within endosomes by its membrane-bound form where viral fusion takes place.

  17. Strain-specific antiviral activity of iminosugars against human influenza A viruses

    PubMed Central

    Hussain, S.; Miller, J. L.; Harvey, D. J.; Gu, Y.; Rosenthal, P. B.; Zitzmann, N.; McCauley, J. W.

    2015-01-01

    Objectives Drugs that target host cell processes can be employed to complement drugs that specifically target viruses, and iminosugar compounds that inhibit host α-glucosidases have been reported to show antiviral activity against multiple viruses. Here the effect and mechanism of two iminosugar α-glucosidase inhibitors, N-butyl-deoxynojirimycin (NB-DNJ) and N-nonyl-deoxynojirimycin (NN-DNJ), on human influenza A viruses was examined. Methods The viruses examined were a recently circulating seasonal influenza A(H3N2) virus strain A/Brisbane/10/2007, an older H3N2 strain A/Udorn/307/72, and A/Lviv/N6/2009, a strain representative of the currently circulating pandemic influenza A(H1N1)pdm09 virus. Results The inhibitors had the strongest effect on Brisbane/10 and NN-DNJ was more potent than NB-DNJ. Both compounds showed antiviral activity in cell culture against three human influenza A viruses in a strain-specific manner. Consistent with its action as an α-glucosidase inhibitor, NN-DNJ treatment resulted in an altered glycan processing of influenza haemagglutinin (HA) and neuraminidase (NA), confirmed by MS. NN-DNJ treatment was found to reduce the cell surface expression of the H3 subtype HA. The level of sialidase activity of NA was reduced in infected cells, but the addition of exogenous sialidase to the cells did not complement the NN-DNJ-mediated inhibition of virus replication. Using reassortant viruses, the drug susceptibility profile was determined to correlate with the origin of the HA. Conclusions NN-DNJ inhibits influenza A virus replication in a strain-specific manner that is dependent on the HA. PMID:25223974

  18. Biochemical characterization of the small hydrophobic protein of avian metapneumovirus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian metapneumovirus (aMPV) is a paramyxovirus that has three membrane-associate proteins: glycoprotein (G), fusion (F), and small hydrophobic (SH) proteins. Among them, the SH protein is a small type II integral membrane protein that is incorporated into virions and is only present in certain para...

  19. Live attenuated influenza vaccine strains elicit a greater innate immune response than antigenically-matched seasonal influenza viruses during infection of human nasal epithelial cell cultures.

    PubMed

    Fischer, William A; Chason, Kelly D; Brighton, Missy; Jaspers, Ilona

    2014-03-26

    Influenza viruses are global pathogens that infect approximately 10-20% of the world's population each year. Vaccines, including the live attenuated influenza vaccine (LAIV), are the best defense against influenza infections. The LAIV is a novel vaccine that actively replicates in the human nasal epithelium and elicits both mucosal and systemic protective immune responses. The differences in replication and innate immune responses following infection of human nasal epithelium with influenza seasonal wild type (WT) and LAIV viruses remain unknown. Using a model of primary differentiated human nasal epithelial cell (hNECs) cultures, we compared influenza WT and antigenically-matched cold adapted (CA) LAIV virus replication and the subsequent innate immune response including host cellular pattern recognition protein expression, host innate immune gene expression, secreted pro-inflammatory cytokine production, and intracellular viral RNA levels. Growth curves comparing virus replication between WT and LAIV strains revealed significantly less infectious virus production during LAIV compared with WT infection. Despite this disparity in infectious virus production the LAIV strains elicited a more robust innate immune response with increased expression of RIG-I, TLR-3, IFNβ, STAT-1, IRF-7, MxA, and IP-10. There were no differences in cytotoxicity between hNEC cultures infected with WT and LAIV strains as measured by basolateral levels of LDH. Elevated levels of intracellular viral RNA during LAIV as compared with WT virus infection of hNEC cultures at 33°C may explain the augmented innate immune response via the up-regulation of pattern recognition receptors and down-stream type I IFN expression. Taken together our results suggest that the decreased replication of LAIV strains in human nasal epithelial cells is associated with a robust innate immune response that differs from infection with seasonal influenza viruses, limits LAIV shedding and plays a role in the silent

  20. [Pathogenic effect of pandemic influenza virus H1N1 under replication in cultures of human cells].

    PubMed

    Zhirnov, O P; Vorob'eva, I V; Safonova, O A; Malyshev, N A; Schwalm, F; Klenk, H -D

    2013-01-01

    The propagation of the pandemic influenza virus H1N1 in cultures of bronchial (Calu-3) and intestinal (Caco-2) differentiated epithelial cells of human origin was studied. The canine epithelial cell lines, MDCK-H and MDCK-2, were comparatively tested. The two human cell lines were found to be highly sensitive to the influenza pandemic strains A/Hamburg/05/09 and A/Moscow/501/2011 and maintained their replication without addition of trypsin to culture medium. Virus strains of seasonal influenza H1N1, such as A/Moscow/450/2003, A/Memphis/14/96, and laboratory strain A/PR/8/34, multiplied in these human cells in similar manner. The intracellular cleavage HA0-->HA1+HA2 by the host virus-activating protease (IAP) occurred in both human cell lines under infection with each influenza virus H1N1 including pandemic ones. Comparatively, this cleavage of all influenza H1N1 virus strains appeared to be either undetectable or low-detectible in MDCK-H and MDCK-2, respectively, thereby implying low levels of active IAP in these cells. Multiplication of pandemic and seasonal influenza H1N1 viruses in Calu-3 and Caco-2 cells caused cytopathic effect, which was accompanied with low autophagy and apoptosis events. These data allow recommending human cell lines, Calu-3 and Caco-2, for optimized isolation and passaging of clinical strains of Influenza pandemic viruses H1N1.

  1. Subtype identification of the novel A H1N1 and other human influenza A viruses using an oligonucleotide microarray.

    PubMed

    Kang, Xiaoping; Li, Yongqiang; Sun, Honghe; Wu, Weili; Liu, Hong; Lin, Fang; Qing, Chenfeng; Chang, Guohui; Zhu, Qingyu; Chen, Weijun; Yang, Yinhui

    2010-01-01

    A novel strain of influenza A (H1N1) virus was isolated in Mexico and the US in March and April 2009. This novel virus spread to many countries and regions in a few months, and WHO raised the level of pandemic alert from phase 5 to phase 6 on June 11, 2009. The accurate identification of H1N1 virus and other human seasonal influenza A viruses is very important for further treatment and control of their infections. In this study, we developed an oligonucleotide microarray to subtype human H1N1, H3N2 and H5N1 influenza viruses, which could distinguish the novel H1N1 from human seasonal H1N1 influenza viruses and swine H1N1 influenza viruses. The microarray utilizes a panel of primers for multiplex PCR amplification of the hemagglutinin (HA), neuraminidase (NA) and matrix (MP) genes of human influenza A viruses. The 59-mer oligonucleotides were designed to distinguish different subtypes of human influenza A viruses. With this microarray, we accurately identified and correctly subtyped the reference virus strains. Moreover, we confirmed 4 out of 39 clinical throat swab specimens from suspected cases of novel H1N1.

  2. MicroRNA Regulation of Human Genes Essential for Influenza A (H7N9) Replication

    PubMed Central

    Wolf, Stefan; Wu, Weilin; Jones, Cheryl; Perwitasari, Olivia; Mahalingam, Suresh; Tripp, Ralph A.

    2016-01-01

    Influenza A viruses are important pathogens of humans and animals. While seasonal influenza viruses infect humans every year, occasionally animal-origin viruses emerge to cause pandemics with significantly higher morbidity and mortality rates. In March 2013, the public health authorities of China reported three cases of laboratory confirmed human infection with avian influenza A (H7N9) virus, and subsequently there have been many cases reported across South East Asia and recently in North America. Most patients experience severe respiratory illness, and morbidity with mortality rates near 40%. No vaccine is currently available and the use of antivirals is complicated due the frequent emergence of drug resistant strains. Thus, there is an imminent need to identify new drug targets for therapeutic intervention. In the current study, a high-throughput screening (HTS) assay was performed using microRNA (miRNA) inhibitors to identify new host miRNA targets that reduce influenza H7N9 replication in human respiratory (A549) cells. Validation studies lead to a top hit, hsa-miR-664a-3p, that had potent antiviral effects in reducing H7N9 replication (TCID50 titers) by two logs. In silico pathway analysis revealed that this microRNA targeted the LIF and NEK7 genes with effects on pro-inflammatory factors. In follow up studies using siRNAs, anti-viral properties were shown for LIF. Furthermore, inhibition of hsa-miR-664a-3p also reduced virus replication of pandemic influenza A strains H1N1 and H3N2. PMID:27166678

  3. Influenza viruses from avian and porcine sources and their possible role in the origin of human pandemic strains.

    PubMed

    Webster, R G; Hinshaw, V S; Bean, W J; Turner, B; Shortridge, K F

    Studies on influenza viruses from feral ducks trapped in Canada in August 1976, gave a 26% isolation rate from cloacal samples of juvenile birds. Several different influenza A viruses were isolated, some of which possessed novel hemagglutinin and/or neuraminidase antigens. Influenza A viruses isolated from the rectum of feral ducks replicate in the upper respiratory tract and also in the intestinal tract of feral and domestic ducks. Representative human influenza viruses of the H0N1, H3N2 and Hsw1 N1 subtypes replicate in the upper respiratory tract of ducks but not in the intestinal tract. The A/Hong Kong/68 [H3N2] influenza virus that has not been isolated from man for several years was recently isolated from pigs originating from The People's Republic of China. A/Victoria/3/75-like influenza viruses that are currently circulating in man were also isolated from pigs. Both the A/Hong Kong/68 and the A/Victoria/75-like viruses transmitted readily from pig to pig in experimental studies. The susceptibility of ducks and pigs to infection with human influenza viruses suggests that these animals may play an important role in the ecology of influenza A viruses.

  4. Risk factors for avian influenza virus contamination of live poultry markets in Zhejiang, China during the 2015–2016 human influenza season

    PubMed Central

    Wang, Xiaoxiao; Wang, Qimei; Cheng, Wei; Yu, Zhao; Ling, Feng; Mao, Haiyan; Chen, Enfu

    2017-01-01

    Live bird markets (LBMs), being a potential source of avian influenza virus, require effective environmental surveillance management. In our study, a total of 2865 environmental samples were collected from 292 LBMs during the 2015–2016 human influenza season from 10 cities in Zhejiang province, China. The samples were tested by real-time quantitative polymerase chain reaction (RT-PCR). Field investigations were carried out to investigate probable risk factors. Of the environmental samples, 1519 (53.0%) were contaminated by A subtype. The highest prevalence of the H9 subtype was 30.2%, and the frequencies of the H5 and H7 subtype were 9.3% and 17.3%, respectively. Hangzhou and Jinhua cities were contaminated more seriously than the others. The prevalence of H5/H7/H9 in drinking water samples was highest, at 50.9%, and chopping board swabs ranked second, at 49.3%. Duration of sales per day, types of live poultry, LBM location and the number of live poultry were the main risk factors for environmental contamination, according to logistic regression analysis. In conclusion, LBMs in Zhejiang were contaminated by avian influenza. Our study has provided clues for avian influenza prevention and control during the human influenza season, especially in areas where LBMs are not closed. PMID:28256584

  5. Risk factors for avian influenza virus contamination of live poultry markets in Zhejiang, China during the 2015-2016 human influenza season.

    PubMed

    Wang, Xiaoxiao; Wang, Qimei; Cheng, Wei; Yu, Zhao; Ling, Feng; Mao, Haiyan; Chen, Enfu

    2017-03-03

    Live bird markets (LBMs), being a potential source of avian influenza virus, require effective environmental surveillance management. In our study, a total of 2865 environmental samples were collected from 292 LBMs during the 2015-2016 human influenza season from 10 cities in Zhejiang province, China. The samples were tested by real-time quantitative polymerase chain reaction (RT-PCR). Field investigations were carried out to investigate probable risk factors. Of the environmental samples, 1519 (53.0%) were contaminated by A subtype. The highest prevalence of the H9 subtype was 30.2%, and the frequencies of the H5 and H7 subtype were 9.3% and 17.3%, respectively. Hangzhou and Jinhua cities were contaminated more seriously than the others. The prevalence of H5/H7/H9 in drinking water samples was highest, at 50.9%, and chopping board swabs ranked second, at 49.3%. Duration of sales per day, types of live poultry, LBM location and the number of live poultry were the main risk factors for environmental contamination, according to logistic regression analysis. In conclusion, LBMs in Zhejiang were contaminated by avian influenza. Our study has provided clues for avian influenza prevention and control during the human influenza season, especially in areas where LBMs are not closed.

  6. Experimental infection with H1N1 European swine influenza virus protects pigs from an infection with the 2009 pandemic H1N1 human influenza virus.

    PubMed

    Busquets, Núria; Segalés, Joaquim; Córdoba, Lorena; Mussá, Tufaria; Crisci, Elisa; Martín-Valls, Gerard E; Simon-Grifé, Meritxell; Pérez-Simó, Marta; Pérez-Maíllo, Monica; Núñez, Jose I; Abad, Francesc X; Fraile, Lorenzo; Pina, Sonia; Majó, Natalia; Bensaid, Albert; Domingo, Mariano; Montoya, María

    2010-01-01

    The recent pandemic caused by human influenza virus A(H1N1) 2009 contains ancestral gene segments from North American and Eurasian swine lineages as well as from avian and human influenza lineages. The emergence of this A(H1N1) 2009 poses a potential global threat for human health and the fact that it can infect other species, like pigs, favours a possible encounter with other influenza viruses circulating in swine herds. In Europe, H1N1, H1N2 and H3N2 subtypes of swine influenza virus currently have a high prevalence in commercial farms. To better assess the risk posed by the A(H1N1) 2009 in the actual situation of swine farms, we sought to analyze whether a previous infection with a circulating European avian-like swine A/Swine/Spain/53207/2004 (H1N1) influenza virus (hereafter referred to as SwH1N1) generated or not cross-protective immunity against a subsequent infection with the new human pandemic A/Catalonia/63/2009 (H1N1) influenza virus (hereafter referred to as pH1N1) 21 days apart. Pigs infected only with pH1N1 had mild to moderate pathological findings, consisting on broncho-interstitial pneumonia. However, pigs inoculated with SwH1N1 virus and subsequently infected with pH1N1 had very mild lung lesions, apparently attributed to the remaining lesions caused by SwH1N1 infection. These later pigs also exhibited boosted levels of specific antibodies. Finally, animals firstly infected with SwH1N1 virus and latter infected with pH1N1 exhibited undetectable viral RNA load in nasal swabs and lungs after challenge with pH1N1, indicating a cross-protective effect between both strains.

  7. Selecting vaccine strains for H3N2 human influenza A virus.

    PubMed

    Suzuki, Yoshiyuki

    2015-06-01

    H3N2 human influenza A virus causes epidemics of influenza mainly in the winter season in temperate regions. Since the antigenicity of this virus evolves rapidly, several attempts have been made to predict the major amino acid sequence of hemagglutinin 1 (HA1) in the target season of vaccination. However, the usefulness of predicted sequence was unclear because its relationship to the antigenicity was unknown. Here the antigenic model for estimating the degree of antigenic difference (antigenic distance) between amino acid sequences of HA1 was integrated into the process of selecting vaccine strains for H3N2 human influenza A virus. When the effectiveness of a potential vaccine strain for a target season was evaluated retrospectively using the average antigenic distance between the strain and the epidemic viruses sampled in the target season, the most effective vaccine strain was identified mostly in the season one year before the target season (pre-target season). Effectiveness of actual vaccines appeared to be lower than that of the strains randomly chosen in the pre-target season on average. It was recommended to replace the vaccine strain for every target season with the strain having the smallest average antigenic distance to the others in the pre-target season. The procedure of selecting vaccine strains for future epidemic seasons described in the present study was implemented in the influenza virus forecasting system (INFLUCAST) (http://www.nsc.nagoya-cu.ac.jp/~yossuzuk/influcast.html).

  8. Hemagglutinin protein of Asian strains of human influenza virus A H1N1 binds to sialic acid--a major component of human airway receptors.

    PubMed

    Chua, K H; Chai, H C

    2012-03-16

    Hemagglutinin (HA) protein plays an important role in binding the influenza virus to infected cells and therefore mediates infection. Deposited HA sequences of 86 Asian strains of influenza A (H1N1) viruses during the first outbreak were obtained from the NCBI database and compared. Interaction of the HA protein of influenza A (H1N1) virus with the human sialic acid receptor was also studied using bioinformatics. Overall, not more than three single-point amino acid variants/changes were observed in the HA protein region of influenza A (H1N1) virus from Asian countries when a selected group sequence comparison was made. The bioinformatics study showed that the HA protein of influenza A (H1N1) binds to the sialic acid receptor in human airway receptors, possibly key to air-borne infection in humans.

  9. A new laboratory-based surveillance system (Respiratory DataMart System) for influenza and other respiratory viruses in England: results and experience from 2009 to 2012.

    PubMed

    Zhao, H; Green, H; Lackenby, A; Donati, M; Ellis, J; Thompson, C; Bermingham, A; Field, J; Sebastianpillai, P; Zambon, M; Watson, Jm; Pebody, R

    2014-01-23

    During the 2009 influenza A(H1N1) pandemic, a new laboratory-based virological sentinel surveillance system, the Respiratory DataMart System (RDMS), was established in a network of 14 Health Protection Agency (now Public Health England (PHE)) and National Health Service (NHS) laboratories in England. Laboratory results (both positive and negative) were systematically collected from all routinely tested clinical respiratory samples for a range of respiratory viruses including influenza, respiratory syncytial virus (RSV), rhinovirus, parainfluenza virus, adenovirus and human metapneumovirus (hMPV). The RDMS also monitored the occurrence of antiviral resistance of influenza viruses. Data from the RDMS for the 2009–2012 period showed that the 2009 pandemic influenza virus caused three waves of activity with different intensities during the pandemic and post pandemic periods. Peaks in influenza A(H1N1)pdm09 positivity (defined as number of positive samples per total number of samples tested) were seen in summer and autumn in 2009, with slightly higher peak positivity observed in the first post-pandemic season in 2010/2011. The influenza A(H1N1)pdm09 virus strain almost completely disappeared in the second postpandemic season in 2011/2012. The RDMS findings are consistent with other existing community-based virological and clinical surveillance systems. With a large sample size, this new system provides a robust supplementary mechanism, through the collection of routinely available laboratory data at minimum extra cost, to monitor influenza as well as other respiratory virus activity. A near real-time, daily reporting mechanism in the RDMS was established during the London 2012 Olympic and Paralympic Games. Furthermore, this system can be quickly adapted and used to monitor future influenza pandemics and other major outbreaks of respiratory infectious disease, including novel pathogens.

  10. Glycan-functionalized graphene-FETs toward selective detection of human-infectious avian influenza virus

    NASA Astrophysics Data System (ADS)

    Ono, Takao; Oe, Takeshi; Kanai, Yasushi; Ikuta, Takashi; Ohno, Yasuhide; Maehashi, Kenzo; Inoue, Koichi; Watanabe, Yohei; Nakakita, Shin-ichi; Suzuki, Yasuo; Kawahara, Toshio; Matsumoto, Kazuhiko

    2017-03-01

    There are global concerns about threat of pandemic caused by the human-infectious avian influenza virus. To prevent the oncoming pandemic, it is crucial to analyze the viral affinity to human-type or avian-type sialoglycans with high sensitivity at high speed. Graphene-FET (G-FET) realizes such high-sensitive electrical detection of the targets, owing to graphene’s high carrier mobility. In the present study, G-FET was functionalized using sialoglycans and employed for the selective detection of lectins from Sambucus sieboldiana and Maackia amurensis as alternatives of the human and avian influenza viruses. Glycan-functionalized G-FET selectively monitored the sialoglycan-specific binding reactions at subnanomolar sensitivity.

  11. The epidemiology and spread of drug resistant human influenza viruses.

    PubMed

    Hurt, Aeron C

    2014-10-01

    Significant changes in the circulation of antiviral-resistant influenza viruses have occurred over the last decade. The emergence and continued circulation of adamantane-resistant A(H3N2) and A(H1N1)pdm09 viruses mean that the adamantanes are no longer recommended for use. Resistance to the newer class of drugs, the neuraminidase inhibitors, is typically associated with poorer viral replication and transmission. But 'permissive' mutations, that compensated for impairment of viral function in A(H1N1) viruses during 2007/2008, enabled them to acquire the H275Y NA resistance mutation without fitness loss, resulting in their rapid global spread. Permissive mutations now appear to be present in A(H1N1)pdm09 viruses thereby increasing the risk that oseltamivir-resistant A(H1N1)pdm09 viruses may also spread globally, a concerning scenario given that oseltamivir is the most widely used influenza antiviral.

  12. H6 Influenza Viruses Pose a Potential Threat to Human Health

    PubMed Central

    Wang, Guojun; Deng, Guohua; Shi, Jianzhong; Luo, Weiyu; Zhang, Guoquan; Zhang, Qianyi; Liu, Liling; Jiang, Yongping; Li, Chengjun; Sriwilaijaroen, Nongluk; Hiramatsu, Hiroaki; Suzuki, Yasuo; Kawaoka, Yoshihiro

    2014-01-01

    ABSTRACT Influenza viruses of the H6 subtype have been isolated from wild and domestic aquatic and terrestrial avian species throughout the world since their first detection in a turkey in Massachusetts in 1965. Since 1997, H6 viruses with different neuraminidase (NA) subtypes have been detected frequently in the live poultry markets of southern China. Although sequence information has been gathered over the last few years, the H6 viruses have not been fully biologically characterized. To investigate the potential risk posed by H6 viruses to humans, here we assessed the receptor-binding preference, replication, and transmissibility in mammals of a series of H6 viruses isolated from live poultry markets in southern China from 2008 to 2011. Among the 257 H6 strains tested, 87 viruses recognized the human type receptor. Genome sequence analysis of 38 representative H6 viruses revealed 30 different genotypes, indicating that these viruses are actively circulating and reassorting in nature. Thirty-seven of 38 viruses tested in mice replicated efficiently in the lungs and some caused mild disease; none, however, were lethal. We also tested the direct contact transmission of 10 H6 viruses in guinea pigs and found that 5 viruses did not transmit to the contact animals, 3 viruses transmitted to one of the three contact animals, and 2 viruses transmitted to all three contact animals. Our study demonstrates that the H6 avian influenza viruses pose a clear threat to human health and emphasizes the need for continued surveillance and evaluation of the H6 influenza viruses circulating in nature. IMPORTANCE Avian influenza viruses continue to present a challenge to human health. Research and pandemic preparedness have largely focused on the H5 and H7 subtype influenza viruses in recent years. Influenza viruses of the H6 subtype have been isolated from wild and domestic aquatic and terrestrial avian species throughout the world since their first detection in the United States in

  13. Novel avian-origin human influenza A(H7N9) can be transmitted between ferrets via respiratory droplets.

    PubMed

    Xu, Lili; Bao, Linlin; Deng, Wei; Dong, Libo; Zhu, Hua; Chen, Ting; Lv, Qi; Li, Fengdi; Yuan, Jing; Xiang, Zhiguang; Gao, Kai; Xu, Yanfeng; Huang, Lan; Li, Yanhong; Liu, Jiangning; Yao, Yanfeng; Yu, Pin; Li, Xiyan; Huang, Weijuan; Zhao, Xiang; Lan, Yu; Guo, Junfeng; Yong, Weidong; Wei, Qiang; Chen, Honglin; Zhang, Lianfeng; Qin, Chuan

    2014-02-15

    The outbreak of human infections caused by novel avian-origin influenza A(H7N9) in China since March 2013 underscores the need to better understand the pathogenicity and transmissibility of these viruses in mammals. In a ferret model, the pathogenicity of influenza A(H7N9) was found to be less than that of an influenza A(H5N1) strain but comparable to that of 2009 pandemic influenza A(H1N1), based on the clinical signs, mortality, virus dissemination, and results of histopathologic analyses. Influenza A(H7N9) could replicate in the upper and lower respiratory tract, the heart, the liver, and the olfactory bulb. It is worth noting that influenza A(H7N9) exhibited a low level of transmission between ferrets via respiratory droplets. There were 4 mutations in the virus isolated from the contact ferret: D678Y in the gene encoding PB2, R157K in the gene encoding hemagglutinin (H3 numbering), I109T in the gene encoding nucleoprotein, and T10I in the gene encoding neuraminidase. These data emphasized that avian-origin influenza A(H7N9) can be transmitted between mammals, highlighting its potential for human-to-human transmissibility.

  14. Fully human broadly neutralizing monoclonal antibodies against influenza A viruses generated from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient

    SciTech Connect

    Hu, Weibin; Chen, Aizhong; Miao, Yi; Xia, Shengli; Ling, Zhiyang; Xu, Ke; Wang, Tongyan; Xu, Ying; Cui, Jun; Wu, Hongqiang; Hu, Guiyu; Tian, Lin; Wang, Lingling; Shu, Yuelong; Ma, Xiaowei; Xu, Bianli; Zhang, Jin; Lin, Xiaojun; Bian, Chao; Sun, Bing

    2013-01-20

    Whether the 2009 pandemic H1N1 influenza vaccine can induce heterosubtypic cross-protective anti-hemagglutinin (HA) neutralizing antibodies is an important issue. We obtained a panel of fully human monoclonal antibodies from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient. Most of the monoclonal antibodies targeted the HA protein but not the HA1 fragment. Among the analyzed antibodies, seven mAbs exhibited neutralizing activity against several influenza A viruses of different subtypes. The conserved linear epitope targeted by the neutralizing mAbs (FIEGGWTGMVDGWYGYHH) is part of the fusion peptide on HA2. Our work suggests that a heterosubtypic neutralizing antibody response primarily targeting the HA stem region exists in recipients of the 2009 pandemic H1N1 influenza vaccine. The HA stem region contains various conserved neutralizing epitopes with the fusion peptide as an important one. This work may aid in the design of a universal influenza A virus vaccine.

  15. [Case report of the first world death due to a new strain of human influenza A H1N1 virus and behavior of human influenzae in pregnant women].

    PubMed

    Noguera Sánchez, Marcelo Fidias; Karchmer Krivitzky, Samuel; EsliRabadán, Martínez Cesar; Antonio Sánchez, Pedro

    2013-01-01

    Influenza A H1N1 is an acute respiratory illness caused by a new strain of H1N1. Human influenza is a subtype of influenza Avirus, from the family of Orthomyxoviridae. This strain is the cause of new influenza pandemic declared by the World Health Organization in June, 2009. This paper reports the first case occurred in Mexico: a 39-year-old woman with a history of diabetes mellitus type 2 and obesity grade II, which suffered atypical and aggressive pneumonia positive to coronavirus. Patient died 98 hours after her admission to the hospital unit. Due to the clinical presentation of the case, the doctors sent samples to the Instituto Nacional de Diagnóstico y Referencia Epidemiológica that sent an aliquot of the National Center for Immunization and Respiratory Diseases of theAgency of Public Health in Canada, that reported positivity to influenza virus, and catalogued it as a new global strain called influenza A virus H1N1. The notice of 229E/NL63 coronavirus and its relationship to the recent outbreaks of avian influenza in humans and the clinical presentation of the case were the epidemiological circumstances that prevented the nation epidemiology system to establish global containment strategies to prevent the spread of this emerging infection. The consequence was the declaration of WHO pandemic alert level 6. Its behavior in pregnancy, reported by Assistant General Direction of Epidemiology in Mexico, has placed this infection as a risk factor for women.

  16. High genetic and antigenic similarity between a swine H3N2 influenza A virus and a prior human influenza vaccine virus: a possible immune pressure-driven cross-species transmission.

    PubMed

    Pan, Chungen; Wang, Guiping; Liao, Ming; Zhang, Gui-Hong; Jiang, Shibo

    2009-07-31

    In late April of 2009, a global outbreak of human influenza was reported. The causative agent is a highly unusual reassortant H1N1 influenza virus carrying genetic segments derived from swine, human and avian influenza viruses. In this study, we compared the HA, NA and other gene segments of a swine H3N2 influenza A virus, A/Swine/Guangdong/z5/2003, which was isolated from pigs in 2003 in Guangdong Province, China, to the predominant human and swine H3N2 viruses. We found that the similarity of gene segments of A/Swine/Guangdong/z5/2003 was closer to Moscow/99-like human H3N2 virus than Europe swine H3N2 viruses during 1999-2002. These results suggest that A/Swine/Guangdong/z5/2003 may be porcine in origin, possibly being driven by human immune pressure induced by either natural H3N2 virus infection or use of A/Moscow/10/99 (H3N2)-based human influenza vaccine. The results further confirm that swine may play a dual role as a "shelter" for hosting influenza virus from humans or birds and as a "mixing vessel" for generating reassortant influenza viruses, such as the one causing current influenza pandemic.

  17. Inhibitory effects of carbocisteine on type A seasonal influenza virus infection in human airway epithelial cells.

    PubMed

    Yamaya, Mutsuo; Nishimura, Hidekazu; Shinya, Kyoko; Hatachi, Yukimasa; Sasaki, Takahiko; Yasuda, Hiroyasu; Yoshida, Motoki; Asada, Masanori; Fujino, Naoya; Suzuki, Takaya; Deng, Xue; Kubo, Hiroshi; Nagatomi, Ryoichi

    2010-08-01

    Type A human seasonal influenza (FluA) virus infection causes exacerbations of bronchial asthma and chronic obstructive pulmonary disease (COPD). l-carbocisteine, a mucolytic agent, reduces the frequency of common colds and exacerbations in COPD. However, the inhibitory effects of l-carbocisteine on FluA virus infection are uncertain. We studied the effects of l-carbocisteine on FluA virus infection in airway epithelial cells. Human tracheal epithelial cells were pretreated with l-carbocisteine and infected with FluA virus (H(3)N(2)). Viral titers in supernatant fluids, RNA of FluA virus in the cells, and concentrations of proinflammatory cytokines in supernatant fluids, including IL-6, increased with time after infection. l-carbocisteine reduced viral titers in supernatant fluids, RNA of FluA virus in the cells, the susceptibility to FluA virus infection, and concentrations of cytokines induced by virus infection. The epithelial cells expressed sialic acid with an alpha2,6-linkage (SAalpha2,6Gal), a receptor for human influenza virus on the cells, and l-carbocisteine reduced the expression of SAalpha2,6Gal. l-carbocisteine reduced the number of acidic endosomes from which FluA viral RNA enters into the cytoplasm and reduced the fluorescence intensity from acidic endosomes. Furthermore, l-carbocisteine reduced NF-kappaB proteins including p50 and p65 in the nuclear extracts of the cells. These findings suggest that l-carbocisteine may inhibit FluA virus infection, partly through the reduced expression of the receptor for human influenza virus in the human airway epithelial cells via the inhibition of NF-kappaB and through increasing pH in endosomes. l-carbocisteine may reduce airway inflammation in influenza virus infection.

  18. Human H7N9 avian influenza virus infection: a review and pandemic risk assessment.

    PubMed

    Yiu Lai, Kang; Wing Yiu Ng, George; Fai Wong, Kit; Fan Ngai Hung, Ivan; Kam Fai Hong, Jeffrey; Fan Cheng, Fanny; Kwok Cheung Chan, John

    2013-08-01

    China is undergoing a recent outbreak of a novel H7N9 avian influenza virus (nH7N9) infection that has thus far involved 132 human patients, including 37 deaths. The nH7N9 virus is a reassortant virus originating from the H7N3, H7N9 and H9N2 avian influenza viruses. nH7N9 isolated from humans contains features related to adaptation to humans, including a Q226L mutation in the hemagglutinin cleavage site and E627K and D701N mutations in the PB2 protein. Live poultry markets provide an environment for the emergence, spread and maintenance of nH7N9 as well as for the selection of mutants that facilitate nH7N9 binding to and replication in the human upper respiratory tract. Innate immune suppression conferred by the internal genes of H9N2 may contribute to the virulence of nH7N9. The quail may serve as the intermediate host during the adaptation of avian influenza viruses from domestic waterfowl to gallinaceous poultry, such as chickens and related terrestrial-based species, due to the selection of viral mutants with a short neuraminidase stalk. Infections in chickens, common quails, red-legged partridges and turkeys may select for mutants with human receptor specificity. Infection in Ratitae species may lead to the selection of PB2-E627K and PB2-D701N mutants and the conversion of nH7N9 to a highly pathogenic avian influenza virus.

  19. Antigenic and genomic characterization of human influenza A and B viruses circulating in Argentina after the introduction of influenza A(H1N1)pdm09.

    PubMed

    Russo, Mara L; Pontoriero, Andrea V; Benedetti, Estefania; Czech, Andrea; Avaro, Martin; Periolo, Natalia; Campos, Ana M; Savy, Vilma L; Baumeister, Elsa G

    2014-12-01

    This study was conducted as part of the Argentinean Influenza and other Respiratory Viruses Surveillance Network, in the context of the Global Influenza Surveillance carried out by the World Health Organization (WHO). The objective was to study the activity and the antigenic and genomic characteristics of circulating viruses for three consecutive seasons (2010, 2011 and 2012) in order to investigate the emergence of influenza viral variants. During the study period, influenza virus circulation was detected from January to December. Influenza A and B, and all current subtypes of human influenza viruses, were present each year. Throughout the 2010 post-pandemic season, influenza A(H1N1)pdm09, unexpectedly, almost disappeared. The haemagglutinin (HA) of the A(H1N1)pdm09 viruses studied were segregated in a different genetic group to those identified during the 2009 pandemic, although they were still antigenically closely related to the vaccine strain A/California/07/2009. Influenza A(H3N2) viruses were the predominant strains circulating during the 2011 season, accounting for nearly 76 % of influenza viruses identified. That year, all HA sequences of the A(H3N2) viruses tested fell into the A/Victoria/208/2009 genetic clade, but remained antigenically related to A/Perth/16/2009 (reference vaccine recommended for this three-year period). A(H3N2) viruses isolated in 2012 were antigenically closely related to A/Victoria/361/2011, recommended by the WHO as the H3 component for the 2013 Southern Hemisphere formulation. B viruses belonging to the B/Victoria lineage circulated in 2010. A mixed circulation of viral variants of both B/Victoria and B/Yamagata lineages was detected in 2012, with the former being predominant. A(H1N1)pdm09 viruses remained antigenically closely related to the vaccine virus A/California/7/2009; A(H3N2) viruses continually evolved into new antigenic clusters and both B lineages, B/Victoria/2/87-like and B/Yamagata/16/88-like viruses, were observed

  20. Integrative genomic analysis of the human immune response to influenza vaccination

    PubMed Central

    Franco, Luis M; Bucasas, Kristine L; Wells, Janet M; Niño, Diane; Wang, Xueqing; Zapata, Gladys E; Arden, Nancy; Renwick, Alexander; Yu, Peng; Quarles, John M; Bray, Molly S; Couch, Robert B; Belmont, John W; Shaw, Chad A

    2013-01-01

    Identification of the host genetic factors that contribute to variation in vaccine responsiveness may uncover important mechanisms affecting vaccine efficacy. We carried out an integrative, longitudinal study combining genetic, transcriptional, and immunologic data in humans given seasonal influenza vaccine. We identified 20 genes exhibiting a transcriptional response to vaccination, significant genotype effects on gene expression, and correlation between the transcriptional and antibody responses. The results show that variation at the level of genes involved in membrane trafficking and antigen processing significantly influences the human response to influenza vaccination. More broadly, we demonstrate that an integrative study design is an efficient alternative to existing methods for the identification of genes involved in complex traits. DOI: http://dx.doi.org/10.7554/eLife.00299.001 PMID:23878721

  1. Statistical analysis of nucleotide sequences of the hemagglutinin gene of human influenza A viruses.

    PubMed Central

    Ina, Y; Gojobori, T

    1994-01-01

    To examine whether positive selection operates on the hemagglutinin 1 (HA1) gene of human influenza A viruses (H1 subtype), 21 nucleotide sequences of the HA1 gene were statistically analyzed. The nucleotide sequences were divided into antigenic and nonantigenic sites. The nucleotide diversities for antigenic and nonantigenic sites of the HA1 gene were computed at synonymous and nonsynonymous sites separately. For nonantigenic sites, the nucleotide diversities were larger at synonymous sites than at nonsynonymous sites. This is consistent with the neutral theory of molecular evolution. For antigenic sites, however, the nucleotide diversities at nonsynonymous sites were larger than those at synonymous sites. These results suggest that positive selection operates on antigenic sites of the HA1 gene of human influenza A viruses (H1 subtype). PMID:8078892

  2. Dynamical analysis of the avian-human influenza epidemic model using the semi-analytical method

    NASA Astrophysics Data System (ADS)

    Jabbari, Azizeh; Kheiri, Hossein; Bekir, Ahmet

    2015-03-01

    In this work, we present a dynamic behavior of the avian-human influenza epidemic model by using efficient computational algorithm, namely the multistage differential transform method(MsDTM). The MsDTM is used here as an algorithm for approximating the solutions of the avian-human influenza epidemic model in a sequence of time intervals. In order to show the efficiency of the method, the obtained numerical results are compared with the fourth-order Runge-Kutta method (RK4M) and differential transform method(DTM) solutions. It is shown that the MsDTM has the advantage of giving an analytical form of the solution within each time interval which is not possible in purely numerical techniques like RK4M.

  3. Effects of closing and reopening live poultry markets on the epidemic of human infection with avian influenza A virus

    PubMed Central

    Lu, Jian; Liu, Wendong; Xia, Rui; Dai, Qigang; Bao, Changjun; Tang, Fenyang; Zhu, yefei; Wang, Qiao

    2016-01-01

    Abstract Live poultry markets (LPMs) are crucial places for human infection of influenza A (H7N9 virus). In Yangtze River Delta, LPMs were closed after the outbreak of human infection with avian influenza A (H7N9) virus, and then reopened when no case was found. Our purpose was to quantify the effect of LPMs’ operations in this region on the transmission of influenza A (H7N9) virus. We obtained information about dates of symptom onset and locations for all human influenza A (H7N9) cases reported from Shanghai, Jiangsu and Zhejiang provinces by May 31, 2014, and acquired dates of closures and reopening of LPMs from official media. A two-phase Bayesian model was fitted by Markov Chain Monte Carlo methods to process the spatial and temporal influence of human cases. A total of 235 cases of influenza A (H7N9) were confirmed in Shanghai, Jiangsu and Zhejiang by May 31, 2014. Using these data, our analysis showed that, after LPM closures, the influenza A (H7N9) outbreak disappeared within two weeks in Shanghai, one week in Jiangsu, and one week in Zhejiang, respectively. Local authorities reopened LPMs when there was no outbreak of influenza A (H7N9), which did not lead to reemergence of human influenza A (H7N9). LPM closures were effective in controlling the H7N9 outbreak. Reopening of LPM in summer did not increase the risk of human infection with H7N9. Our findings showed that LPMs should be closed immediately in areas where the H7N9 virus is confirmed in LPM. When there is no outbreak of H7N9 virus, LPMs can be reopened to satisfy the Chinese traditional culture of buying live poultry. In the long term, local authorities should take a cautious attitude in permanent LPM closure.

  4. Influenza at the animal-human interface: a review of the literature for virological evidence of human infection with swine or avian influenza viruses other than A(H5N1).

    PubMed

    Freidl, G S; Meijer, A; de Bruin, E; de Nardi, M; Munoz, O; Capua, I; Breed, A C; Harris, K; Hill, A; Kosmider, R; Banks, J; von Dobschuetz, S; Stark, K; Wieland, B; Stevens, K; van der Werf, S; Enouf, V; van der Meulen, K; Van Reeth, K; Dauphin, G; Koopmans, M

    2014-05-08

    Factors that trigger human infection with animal influenza virus progressing into a pandemic are poorly understood. Within a project developing an evidence-based risk assessment framework for influenza viruses in animals, we conducted a review of the literature for evidence of human infection with animal influenza viruses by diagnostic methods used. The review covering Medline, Embase, SciSearch and CabAbstracts yielded 6,955 articles, of which we retained 89; for influenza A(H5N1) and A(H7N9), the official case counts of t he World Health Organization were used. An additional 30 studies were included by scanning the reference lists. Here, we present the findings for confirmed infections with virological evidence. We found reports of 1,419 naturally infected human cases, of which 648 were associated with avian influenza virus (AIV) A(H5N1), 375 with other AIV subtypes, and 396 with swine influenza virus (SIV). Human cases naturally infected with AIV spanned haemagglutinin subtypes H5, H6, H7, H9 and H10. SIV cases were associated with endemic SIV of H1 and H3 subtype descending from North American and Eurasian SIV lineages and various reassortants thereof. Direct exposure to birds or swine was the most likely source of infection for the cases with available information on exposure.

  5. A Comparison of Clinical and Epidemiological Characteristics of Fatal Human Infections with H5N1 and Human Influenza Viruses in Thailand, 2004–2006

    PubMed Central

    Shinde, Vivek; Hanshaoworakul, Wanna; Simmerman, James M.; Narueponjirakul, Ubolrat; Sanasuttipun, Wiwan; Kaewchana, Suchada; Areechokechai, Darin; Ungchusak, Kumnuan; Fry, Alicia M.

    2011-01-01

    Background The National Avian Influenza Surveillance (NAIS) system detected human H5N1 cases in Thailand from 2004–2006. Using NAIS data, we identified risk factors for death among H5N1 cases and described differences between H5N1 and human (seasonal) influenza cases. Methods and Findings NAIS identified 11,641 suspect H5N1 cases (e.g. persons with fever and respiratory symptoms or pneumonia, and exposure to sick or dead poultry). All suspect H5N1 cases were tested with polymerase chain reaction (PCR) assays for influenza A(H5N1) and human influenza viruses. NAIS detected 25 H5N1 and 2074 human influenza cases; 17 (68%) and 22 (1%) were fatal, respectively. We collected detailed information from medical records on all H5N1 cases, all fatal human influenza cases, and a sampled subset of 230 hospitalized non-fatal human influenza cases drawn from provinces with ≥1 H5N1 case or human influenza fatality. Fatal versus non-fatal H5N1 cases were more likely to present with low white blood cell (p = 0.05), lymphocyte (p<0.02), and platelet counts (p<0.01); have elevated liver enzymes (p = 0.05); and progress to circulatory (p<0.001) and respiratory failure (p<0.001). There were no differences in age, medical conditions, or antiviral treatment between fatal and non-fatal H5N1 cases. Compared to a sample of human influenza cases, all H5N1 cases had direct exposure to sick or dead birds (60% vs. 100%, p<0.05). Fatal H5N1 and fatal human influenza cases were similar clinically except that fatal H5N1 cases more commonly: had fever (p<0.001), vomiting (p<0.01), low white blood cell counts (p<0.01), received oseltamivir (71% vs. 23%, p<.001), but less often had ≥1 chronic medical conditions (p<0.001). Conclusions In the absence of diagnostic testing during an influenza A(H5N1) epizootic, a few epidemiologic, clinical, and laboratory findings might provide clues to help target H5N1 control efforts. Severe human influenza and H5N1 cases were clinically similar, and

  6. Infection control preparedness for human infection with influenza A H7N9 in Hong Kong.

    PubMed

    Cheng, Vincent C C; Tai, Josepha W M; Lee, W M; Chan, W M; Wong, Sally C Y; Chen, Jonathan H K; Poon, Rosana W S; To, Kelvin K W; Chan, Jasper F W; Ho, P L; Chan, K H; Yuen, K Y

    2015-01-01

    OBJECTIVE To assess the effectiveness of infection control preparedness for human infection with influenza A H7N9 in Hong Kong. DESIGN A descriptive study of responses to the emergence of influenza A H7N9. SETTING A university-affiliated teaching hospital. PARTICIPANTS Healthcare workers (HCWs) with unprotected exposure (not wearing N95 respirator during aerosol-generating procedure) to a patient with influenza A H7N9. METHODS A bundle approach including active and enhanced surveillance, early airborne infection isolation, rapid molecular diagnostic testing, and extensive contact tracing for HCWs with unprotected exposure was implemented. Seventy HCWs with unprotected exposure to an index case were interviewed especially regarding their patient care activities. RESULTS From April 1, 2013, through May 31, 2014, a total of 126 (0.08%) of 163,456 admitted patients were tested for the H7 gene by reverse transcription-polymerase chain reaction per protocol. Two confirmed cases were identified. Seventy (53.8%) of 130 HCWs had unprotected exposure to an index case, whereas 41 (58.6%) and 58 (82.9%) of 70 HCWs wore surgical masks and practiced hand hygiene after patient care, respectively. Sixteen (22.9%) of 70 HCWs were involved in high-risk patient contacts. More HCWs with high-risk patient contacts received oseltamivir prophylaxis (P=0.088) and significantly more had paired sera collected for H7 antibody testing (P<0.001). Ten (14.3%) of 70 HCWs developed influenza-like illness during medical surveillance, but none had positive results by reverse transcription-polymerase chain reaction. Paired sera was available from 33 of 70 HCWs with unprotected exposure, and none showed seroconversion against H7N9. CONCLUSIONS Despite the delay in airborne precautions implementation, no patient-to-HCW transmission of influenza A H7N9 was demonstrated.

  7. Experimental infection of pigs with the human 1918 pandemic influenza virus.

    PubMed

    Weingartl, Hana M; Albrecht, Randy A; Lager, Kelly M; Babiuk, Shawn; Marszal, Peter; Neufeld, James; Embury-Hyatt, Carissa; Lekcharoensuk, Porntippa; Tumpey, Terrence M; García-Sastre, Adolfo; Richt, Jürgen A

    2009-05-01

    Swine influenza was first recognized as a disease entity during the 1918 "Spanish flu" pandemic. The aim of this work was to determine the virulence of a plasmid-derived human 1918 pandemic H1N1 influenza virus (reconstructed 1918, or 1918/rec, virus) in swine using a plasmid-derived A/swine/Iowa/15/1930 H1N1 virus (1930/rec virus), representing the first isolated influenza virus, as a reference. Four-week-old piglets were inoculated intratracheally with either the 1930/rec or the 1918/rec virus or intranasally with the 1918/rec virus. A transient increase in temperature and mild respiratory signs developed postinoculation in all virus-inoculated groups. In contrast to other mammalian hosts (mice, ferrets, and macaques) where infection with the 1918/rec virus was lethal, the pigs did not develop severe respiratory distress or become moribund. Virus titers in the lower respiratory tract as well as macro- and microscopic lesions at 3 and 5 days postinfection (dpi) were comparable between the 1930/rec and 1918/rec virus-inoculated animals. In contrast to the 1930/rec virus-infected animals, at 7 dpi prominent lung lesions were present in only the 1918/rec virus-infected animals, and all the piglets developed antibodies at 7 dpi. Presented data support the hypothesis that the 1918 pandemic influenza virus was able to infect and replicate in swine, causing a respiratory disease, and that the virus was likely introduced into the pig population during the 1918 pandemic, resulting in the current lineage of the classical H1N1 swine influenza viruses.

  8. Serological evidence of pig-to-human influenza virus transmission on Thai swine farms.

    PubMed

    Kitikoon, Pravina; Sreta, Donruethai; Tuanudom, Ranida; Amonsin, Alongkorn; Suradhat, Sanipa; Oraveerakul, Kanisak; Poovorawan, Yong; Thanawongnuwech, Roongroje

    2011-03-24

    We investigated influenza interspecies transmission in two commercial swine farms in Thailand. Sera from swine-exposed workers (n=78), age-matched non-swine-exposed healthy people (n=60) and swine populations in both farms (n=85) were studied. Hemagglutination-inhibition (HI) assay was performed on Thai swine H1 viruses (swH1N1 and swH1N2) isolated from both farms. Thai human H1N1 (huH1N1) and pandemic H1N1 2009 (pH1N1) were also used as test antigens. The hemagglutinin (HA) 1 genes of swH1N1 and swH1N2 viruses were sequenced and shown to be genetically distinct from the Thai huH1N1 and pH1N1 viruses. Evidence of pig-to-human influenza virus transmission was found in farm workers with increased odds of elevated antibody titers to both swH1N1 (OR 42.63, 95% CI, 14.65-124) and swH1N2 (OR 58, 95% CI, 13.12-256.3) viruses. No evidence of human-to-pig influenza virus transmission was detected in this study.

  9. H3N2 Influenza Virus Infection Induces Broadly Reactive Hemagglutinin Stalk Antibodies in Humans and Mice

    PubMed Central

    Margine, Irina; Hai, Rong; Albrecht, Randy A.; Obermoser, Gerlinde; Harrod, A. Carson; Banchereau, Jacques; Palucka, Karolina; García-Sastre, Adolfo; Palese, Peter; Treanor, John J.

    2013-01-01

    Broadly neutralizing antibodies directed against the conserved stalk domain of the viral hemagglutinin have attracted increasing attention in recent years. However, only a limited number of stalk antibodies directed against group 2 influenza hemagglutinins have been isolated so far. Also, little is known about the general level of induction of these antibodies by influenza virus vaccination or infection. To characterize the anti-stalk humoral response in the mouse model as well as in humans, chimeric hemagglutinin constructs previously developed in our group were employed in serological assays. Whereas influenza virus infection induced high titers of stalk-reactive antibodies, immunization with inactivated influenza virus vaccines failed to do so in the mouse model. Analysis of serum samples collected from human individuals who were infected by influenza viruses also revealed the induction of stalk-reactive antibodies. Finally, we show that the hemagglutinin stalk-directed antibodies induced in mice and humans have broad reactivity and neutralizing activity in vitro and in vivo. The results of the study point toward the existence of highly conserved epitopes in the stalk domains of group 2 hemagglutinins, which can be targeted for the development of a universal influenza virus vaccine in humans. PMID:23408625

  10. Validation of Normal Human Bronchial Epithelial Cells as a Model for Influenza A Infections in Human Distal Trachea

    PubMed Central

    Davis, A. Sally; Chertow, Daniel S.; Moyer, Jenna E.; Suzich, Jon; Sandouk, Aline; Dorward, David W.; Logun, Carolea; Shelhamer, James H.

    2015-01-01

    Primary normal human bronchial/tracheal epithelial (NHBE) cells, derived from the distal-most aspect of the trachea at the bifurcation, have been used for a number of studies in respiratory disease research. Differences between the source tissue and the differentiated primary cells may impact infection studies based on this model. Therefore, we examined how well-differentiated NHBE cells compared with their source tissue, the human distal trachea, as well as the ramifications of these differences on influenza A viral pathogenesis research using this model. We employed a histological analysis including morphological measurements, electron microscopy, multi-label immunofluorescence confocal microscopy, lectin histochemistry, and microarray expression analysis to compare differentiated NHBEs to human distal tracheal epithelium. Pseudostratified epithelial height, cell type variety and distribution varied significantly. Electron microscopy confirmed differences in cellular attachment and paracellular junctions. Influenza receptor lectin histochemistry revealed that α2,3 sialic acids were rarely present on the apical aspect of the differentiated NHBE cells, but were present in low numbers in the distal trachea. We bound fluorochrome bioconjugated virus to respiratory tissue and NHBE cells and infected NHBE cells with human influenza A viruses. Both indicated that the pattern of infection progression in these cells correlated with autopsy studies of fatal cases from the 2009 pandemic. PMID:25604814

  11. Human monoclonal antibodies derived from a patient infected with 2009 pandemic influenza A virus broadly cross-neutralize group 1 influenza viruses.

    PubMed

    Pan, Yang; Sasaki, Tadahiro; Kubota-Koketsu, Ritsuko; Inoue, Yuji; Yasugi, Mayo; Yamashita, Akifumi; Ramadhany, Ririn; Arai, Yasuha; Du, Anariwa; Boonsathorn, Naphatsawan; Ibrahim, Madiha S; Daidoji, Tomo; Nakaya, Takaaki; Ono, Ken-ichiro; Okuno, Yoshinobu; Ikuta, Kazuyoshi; Watanabe, Yohei

    2014-07-18

    Influenza viruses are a continuous threat to human public health because of their ability to evolve rapidly through genetic drift and reassortment. Three human monoclonal antibodies (HuMAbs) were generated in this study, 1H11, 2H5 and 5G2, and they cross-neutralize a diverse range of group 1 influenza A viruses, including seasonal H1N1, 2009 pandemic H1N1 (H1N1pdm) and avian H5N1 and H9N2. The three HuMAbs were prepared by fusing peripheral blood lymphocytes from an H1N1pdm-infected patient with a newly developed fusion partner cell line, SPYMEG. All the HuMAbs had little hemagglutination inhibition activity but had strong membrane-fusion inhibition activity against influenza viruses. A protease digestion assay showed the HuMAbs targeted commonly a short α-helix region in the stalk of the hemagglutinin. Furthermore, Ile45Phe and Glu47Gly double substitutions in the α-helix region made the HA unrecognizable by the HuMAbs. These two amino acid residues are highly conserved in the HAs of H1N1, H5N1 and H9N2 viruses. The HuMAbs reported here may be potential candidates for the development of therapeutic antibodies against group 1 influenza viruses.

  12. Mutations in H5N1 Influenza Virus Hemagglutinin that Confer Binding to Human Tracheal Airway Epithelium

    PubMed Central

    Scull, Margaret A.; Ren, Junyuan; Jones, Ian M.; Pickles, Raymond J.; Barclay, Wendy S.

    2009-01-01

    The emergence in 2009 of a swine-origin H1N1 influenza virus as the first pandemic of the 21st Century is a timely reminder of the international public health impact of influenza viruses, even those associated with mild disease. The widespread distribution of highly pathogenic H5N1 influenza virus in the avian population has spawned concern that it may give rise to a human influenza pandemic. The mortality rate associated with occasional human infection by H5N1 virus approximates 60%, suggesting that an H5N1 pandemic would be devastating to global health and economy. To date, the H5N1 virus has not acquired the propensity to transmit efficiently between humans. The reasons behind this are unclear, especially given the high mutation rate associated with influenza virus replication. Here we used a panel of recombinant H5 hemagglutinin (HA) variants to demonstrate the potential for H5 HA to bind human airway epithelium, the predominant target tissue for influenza virus infection and spread. While parental H5 HA exhibited limited binding to human tracheal epithelium, introduction of selected mutations converted the binding profile to that of a current human influenza strain HA. Strikingly, these amino-acid changes required multiple simultaneous mutations in the genomes of naturally occurring H5 isolates. Moreover, H5 HAs bearing intermediate sequences failed to bind airway tissues and likely represent mutations that are an evolutionary “dead end.” We conclude that, although genetic changes that adapt H5 to human airways can be demonstrated, they may not readily arise during natural virus replication. This genetic barrier limits the likelihood that current H5 viruses will originate a human pandemic. PMID:19924306

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

    SciTech Connect

    Hirsch, Gary B.

    2007-03-01

    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.

  14. Whole-Genome Characterization of a Novel Human Influenza A(H1N2) Virus Variant, Brazil

    PubMed Central

    Born, Priscila Silva; Matos, Aline Rocha; Motta, Fernando Couto; Caetano, Braulia Costa; Debur, Maria do Carmo; Riediger, Irina Nastassja; Brown, David; Siqueira, Marilda M.

    2017-01-01

    We report the characterization of a novel reassortant influenza A(H1N2) virus not previously reported in humans. Recovered from a a pig farm worker in southeast Brazil who had influenza-like illness, this virus is a triple reassortant containing gene segments from subtypes H1N2 (hemagglutinin), H3N2 (neuraminidase), and pandemic H1N1 (remaining genes). PMID:27983507

  15. Is avian influenza virus A(H5N1) a real threat to human health?

    PubMed

    Amendola, A; Ranghiero, A; Zanetti, A; Pariani, E

    2011-09-01

    The A(H5N1) influenza remains a disease of birds with a significant species barrier: in the presence of some tens million cases of infection in poultry--with a wide geographical spread--, only a few hundreds cases have occurred in humans. To date, human cases have been reported in 15 countries--mainly in Asia--and all were related to the onset of outbreaks in poultry. A peak of H5N1 human cases was recorded in 2006, then decreasing in subsequent years. Despite this trend, the H5N1 virus still represents a possible threat to human health, considering that more than half of human cases of H5N1 have been fatal. Moreover, despite the drop in the number of cases, the risk of a novel pandemic cannot be excluded, since H5N1 continues to circulate in poultry in countries with elevated human population density and where monitoring systems are not fully appropriate. In addition, there is a major global concern about the potential occurrence of a reassortment between the 2009 pandemic H1N1 and the highly pathogenic H5N1 influenza viruses following a co-infection in a susceptible host. Therefore, the implementation of appropriate surveillance and containment measures is crucial in order to minimize such risk. In conclusion, H5N1 avian influenza is still a rare disease in humans but its clinical severe outcome requires a careful monitoring of the virus's ability to evolve and to trigger a new pandemic.

  16. Equine influenza virus.

    PubMed

    Landolt, Gabriele A

    2014-12-01

    For decades the horse has been viewed as an isolated or "dead-end" host for influenza A viruses, with equine influenza virus being considered as relatively stable genetically. Although equine influenza viruses are genetically more stable than those of human lineage, they are by no means in evolutionary stasis. Moreover, recent transmission of equine-lineage influenza viruses to dogs also challenges the horse's status as a dead-end host. This article reviews recent developments in the epidemiology and evolution of equine influenza virus. In addition, the clinical presentation of equine influenza infection, diagnostic techniques, and vaccine recommendations are briefly summarized.

  17. Predicting transmission of avian influenza A viruses from avian to human by using informative physicochemical properties.

    PubMed

    Wang, Jia; Ma, Chuang; Kou, Zheng; Zhou, Yan-Hong; Liu, Huai-Lan

    2013-01-01

    Some strains of avian influenza A virus (AIV) can directly transmit from their natural hosts to humans. These avian-to-human transmissions have continuously been reported to cause human deaths worldwide since 1997. Predicting whether AIV strains can transmit from avian to human is valuable for early warning of AIV strains with human pandemic potential. In this study, we constructed a computational model to predict avian-to-human transmission of AIV based on physicochemical properties. Initially, ninety signature positions in the inner protein sequences were extracted with the entropy method. These positions were then encoded with 531 physicochemical features. Subsequently, the optimal subset of these physicochemical features was mined with several feature selection methods. Finally, a support vector machine (SVM) model named A2H was established to integrate the selected optimal features. The experimental results of cross-validation and an independent test show that A2H has the capability of predicting transmission of AIV from avian to human.

  18. Rational design of avian metapneumovirus live attenuated vaccines by inhibiting viral messenger RNA cap methyltransferase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian metapneumovirus (aMPV), also known as avian pneumovirus or turkey rhinotracheitis, is a non-segmented negative-sense RNA virus belonging to the family of Paramyxoviridae, the subfamily Pneumovirinae, and the genus Metapneumovirus. aMPV is the causative agent of respiratory tract infection and ...

  19. Broadly neutralizing human antibody that recognizes the receptor-binding pocket of influenza virus hemagglutinin

    SciTech Connect

    Whittle, James R.R.; Zhang, Ruijun; Khurana, Surender; King, Lisa R.; Manischewitz, Jody; Golding, Hana; Dormitzer, Philip R.; Haynes, Barton F.; Walter, Emmanuel B.; Moody, M. Anthony; Kepler, Thomas B.; Liao, Hua-Xin; Harrison, Stephen C.

    2011-09-20

    Seasonal antigenic drift of circulating influenza virus leads to a requirement for frequent changes in vaccine composition, because exposure or vaccination elicits human antibodies with limited cross-neutralization of drifted strains. We describe a human monoclonal antibody, CH65, obtained by isolating rearranged heavy- and light-chain genes from sorted single plasma cells, coming from a subject immunized with the 2007 trivalent influenza vaccine. The crystal structure of a complex of the hemagglutinin (HA) from H1N1 strain A/Solomon Islands/3/2006 with the Fab of CH65 shows that the tip of the CH65 heavy-chain complementarity determining region 3 (CDR3) inserts into the receptor binding pocket on HA1, mimicking in many respects the interaction of the physiological receptor, sialic acid. CH65 neutralizes infectivity of 30 out of 36 H1N1 strains tested. The resistant strains have a single-residue insertion near the rim of the sialic-acid pocket. We conclude that broad neutralization of influenza virus can be achieved by antibodies with contacts that mimic those of the receptor.

  20. Human Infection with Influenza Virus A(H10N8) from Live Poultry Markets, China, 2014

    PubMed Central

    Zhang, Tao; Bi, Yuhai; Tian, Huaiyu; Li, Xiaowen; Liu, Di; Wu, Ying; Jin, Tao; Wang, Yong; Chen, Quanjiao; Chen, Ze; Chang, Jianyu; Gao, George F.

    2014-01-01

    Human infection with avian influenza virus A(H10N8) was initially reported in China in December 2013. We characterized H10N8 strains from a human patient and from poultry in live markets that infected persons had visited. Results of genome sequencing and virus characterization suggest that the virus strains that infected humans originated from these markets. PMID:25425075

  1. Swine-to-human transmission of influenza A(H3N2) virus at agricultural fairs, Ohio, USA, 2012.

    PubMed

    Bowman, Andrew S; Nelson, Sarah W; Page, Shannon L; Nolting, Jacqueline M; Killian, Mary L; Sreevatsan, Srinand; Slemons, Richard D

    2014-09-01

    Agricultural fairs provide an opportunity for bidirectional transmission of influenza A viruses. We sought to determine influenza A virus activity among swine at fairs in the United States. As part of an ongoing active influenza A virus surveillance project, nasal swab samples were collected from exhibition swine at 40 selected Ohio agricultural fairs during 2012. Influenza A(H3N2) virus was isolated from swine at 10 of the fairs. According to a concurrent public health investigation, 7 of the 10 fairs were epidemiologically linked to confirmed human infections with influenza A(H3N2) variant virus. Comparison of genome sequences of the subtype H3N2 isolates recovered from humans and swine from each fair revealed nucleotide identities of >99.7%, confirming zoonotic transmission between swine and humans. All influenza A(H3N2) viruses isolated in this study, regardless of host species or fair, were >99.5% identical, indicating that 1 virus strain was widely circulating among exhibition swine in Ohio during 2012.

  2. Circulation of reassortant influenza A(H7N9) viruses in poultry and humans, Guangdong Province, China, 2013.

    PubMed

    Ke, Changwen; Lu, Jing; Wu, Jie; Guan, Dawei; Zou, Lirong; Song, Tie; Yi, Lina; Zeng, Xianqiao; Liang, Lijun; Ni, Hanzhong; Kang, Min; Zhang, Xin; Zhong, Haojie; He, Jianfeng; Lin, Jinyan; Smith, Derek; Burke, David; Fouchier, Ron A M; Koopmans, Marion; Zhang, Yonghui

    2014-12-01

    Influenza A(H7N9) virus emerged in eastern China in February 2013 and continues to circulate in this region, but its ecology is poorly understood. In April 2013, the Guangdong Provincial Center for Disease Control and Prevention (CDC) implemented environmental and human syndromic surveillance for the virus. Environmental samples from poultry markets in 21 city CDCs (n=8,942) and respiratory samples from persons with influenza-like illness or pneumonia (n=32,342) were tested; viruses isolated from 6 environmental samples and 16 patients were sequenced. Sequence analysis showed co-circulation of 4 influenza A(H7N9) virus strains that evolved by reassortment with avian influenza A(H9N2) viruses circulating in this region. In addition, an increase in human cases starting in late 2013 coincided with an increase in influenza A H7 virus isolates detected by environmental surveillance. Co-circulation of multiple avian influenza viruses that can infect humans highlights the need for increased surveillance of poultry and potential environmental sources.

  3. Circulation of Reassortant Influenza A(H7N9) Viruses in Poultry and Humans, Guangdong Province, China, 2013

    PubMed Central

    Ke, Changwen; Lu, Jing; Wu, Jie; Guan, Dawei; Zou, Lirong; Song, Tie; Yi, Lina; Zeng, Xianqiao; Liang, Lijun; Ni, Hanzhong; Kang, Min; Zhang, Xin; Zhong, Haojie; He, Jianfeng; Lin, Jinyan; Smith, Derek; Burke, David; Fouchier, Ron A.M.; Koopmans, Marion

    2014-01-01

    Influenza A(H7N9) virus emerged in eastern China in February 2013 and continues to circulate in this region, but its ecology is poorly understood. In April 2013, the Guangdong Provincial Center for Disease Control and Prevention (CDC) implemented environmental and human syndromic surveillance for the virus. Environmental samples from poultry markets in 21 city CDCs (n = 8,942) and respiratory samples from persons with influenza-like illness or pneumonia (n = 32,342) were tested; viruses isolated from 6 environmental samples and 16 patients were sequenced. Sequence analysis showed co-circulation of 4 influenza A(H7N9) virus strains that evolved by reassortment with avian influenza A(H9N2) viruses circulating in this region. In addition, an increase in human cases starting in late 2013 coincided with an increase in influenza A H7 virus isolates detected by environmental surveillance. Co-circulation of multiple avian influenza viruses that can infect humans highlights the need for increased surveillance of poultry and potential environmental sources. PMID:25418838

  4. Differentiation of human influenza A viruses including the pandemic subtype H1N1/2009 by conventional multiplex PCR.

    PubMed

    Furuse, Yuki; Odagiri, Takashi; Okada, Takashi; Khandaker, Irona; Shimabukuro, Kozue; Sawayama, Rumi; Suzuki, Akira; Oshitani, Hitoshi

    2010-09-01

    April 2009 witnessed the emergence of a novel H1N1 influenza A virus infecting the human population. Currently, pandemic and seasonal influenza viruses are co-circulating in human populations. Understanding the course of the emerging pandemic virus is important. It is still unknown how the novel virus co-circulates with or outcompetes seasonal viruses. Sustainable and detailed influenza surveillance is required throughout the world including developing countries. In the present study, a multiplex PCR using four primers was developed, which was designed to differentiate the pandemic H1N1 virus from the seasonal H1N1 and H3N2 viruses, to obtain amplicons of different sizes. Multiplex PCR analysis could clearly differentiate the three subtypes of human influenza A virus. This assay was performed using 206 clinical samples collected in 2009 in Japan. Between February and April, four samples were subtyped as seasonal H1N1 and four as seasonal H3N2. All samples collected after July were subtyped as pandemic H1N1. Currently, pandemic viruses seem to have replaced seasonal viruses almost completely in Japan. This is a highly sensitive method and its cost is low. Influenza surveillance using this assay would provide significant information on the epidemiology of both pandemic and seasonal influenza.

  5. Migration and persistence of human influenza A viruses, Vietnam, 2001-2008.

    PubMed

    Le, Mai Quynh; Lam, Ha Minh; Cuong, Vuong Duc; Lam, Tommy Tsan-Yuk; Halpin, Rebecca A; Wentworth, David E; Hien, Nguyen Tran; Thanh, Le Thi; Phuong, Hoang Vu Mai; Horby, Peter; Boni, Maciej F

    2013-11-01

    Understanding global influenza migration and persistence is crucial for vaccine strain selection. Using 240 new human influenza A virus whole genomes collected in Vietnam during 2001-2008, we looked for persistence patterns and migratory connections between Vietnam and other countries. We found that viruses in Vietnam migrate to and from China, Hong Kong, Taiwan, Cambodia, Japan, South Korea, and the United States. We attempted to reduce geographic bias by generating phylogenies subsampled at the year and country levels. However, migration events in these phylogenies were still driven by the presence or absence of sequence data, indicating that an epidemiologic study design that controls for prevalence is required for robust migration analysis. With whole-genome data, most migration events are not detectable from the phylogeny of the hemagglutinin segment alone, although general migratory relationships between Vietnam and other countries are visible in the hemagglutinin phylogeny. It is possible that virus lineages in Vietnam persisted for >1 year.

  6. Complete nucleotide sequence of the polymerase 3 gene of human influenza virus A/WSN/33.

    PubMed Central

    Kaptein, J S; Nayak, D P

    1982-01-01

    The complete nucleotide sequence of polymerase 3 (P3) gene of a human influenza virus (A/WSN/33) has been determined using cDNA clones except for the last 11 nucleotides which were obtained by direct RNA sequencing. The WSN P3 gene contains 2,341 nucleotides and codes for a protein of 759 amino acids (molecular weight 85,800). The WSN P3 protein, as deduced from the plus-strand DNA sequence, is basic and enriched in positively charged amino acids. In addition, it contains clusters of basic amino acids which may provide sites for the interaction of P3 protein with the capped primer, template, and/or other polymerase proteins during the transcriptive and replicative processes of influenza viral RNA. PMID:7045393

  7. Absence of detectable influenza RNA transmitted via aerosol during various human respiratory activities--experiments from Singapore and Hong Kong.

    PubMed

    Tang, Julian W; Gao, Caroline X; Cowling, Benjamin J; Koh, Gerald C; Chu, Daniel; Heilbronn, Cherie; Lloyd, Belinda; Pantelic, Jovan; Nicolle, Andre D; Klettner, Christian A; Peiris, J S Malik; Sekhar, Chandra; Cheong, David K W; Tham, Kwok Wai; Koay, Evelyn S C; Tsui, Wendy; Kwong, Alfred; Chan, Kitty; Li, Yuguo

    2014-01-01

    Two independent studies by two separate research teams (from Hong Kong and Singapore) failed to detect any influenza RNA landing on, or inhaled by, a life-like, human manikin target, after exposure to naturally influenza-infected volunteers. For the Hong Kong experiments, 9 influenza-infected volunteers were recruited to breathe, talk/count and cough, from 0.1 m and 0.5 m distance, onto a mouth-breathing manikin. Aerosolised droplets exhaled from the volunteers and entering the manikin's mouth were collected with PTFE filters and an aerosol sampler, in separate experiments. Virus detection was performed using an in-house influenza RNA reverse-transcription polymerase chain reaction (RT-PCR) assay. No influenza RNA was detected from any of the PTFE filters or air samples. For the Singapore experiments, 6 influenza-infected volunteers were asked to breathe (nasal/mouth breathing), talk (counting in English/second language), cough (from 1 m/0.1 m away) and laugh, onto a thermal, breathing manikin. The manikin's face was swabbed at specific points (around both eyes, the nostrils and the mouth) before and after exposure to each of these respiratory activities, and was cleaned between each activity with medical grade alcohol swabs. Shadowgraph imaging was used to record the generation of these respiratory aerosols from the infected volunteers and their impact onto the target manikin. No influenza RNA was detected from any of these swabs with either team's in-house diagnostic influenza assays. All the influenza-infected volunteers had diagnostic swabs taken at recruitment that confirmed influenza (A/H1, A/H3 or B) infection with high viral loads, ranging from 10(5)-10(8) copies/mL (Hong Kong volunteers/assay) and 10(4)-10(7) copies/mL influenza viral RNA (Singapore volunteers/assay). These findings suggest that influenza RNA may not be readily transmitted from naturally-infected human source to susceptible recipients via these natural respiratory activities, within these

  8. Interferon-induced human protein with homology to protein Mx of influenza virus-resistant mice.

    PubMed Central

    Staeheli, P; Haller, O

    1985-01-01

    Polyclonal and monoclonal antibodies with specificity for protein Mx (a karyophilic 75,000-dalton protein induced by interferon [IFN] in mouse cells carrying the influenza virus resistance allele Mx+) detected an IFN-induced 80,000-dalton protein in peripheral blood lymphocytes and in fibroblasts of healthy human donors. The human protein, like protein Mx, was induced by IFN-alpha but not by IFN-gamma. Unlike the mouse protein, it was predominantly localized in the cell cytoplasm. Images PMID:3939324

  9. Evolution of influenza A virus PB2 genes: implications for evolution of the ribonucleoprotein complex and origin of human influenza A virus.

    PubMed

    Gorman, O T; Donis, R O; Kawaoka, Y; Webster, R G

    1990-10-01

    Phylogenetic analysis of 20 influenza A virus PB2 genes showed that PB2 genes have evolved into the following four major lineages: (i) equine/Prague/56 (EQPR56); (ii and iii) two distinct avian PB2 lineages, one containing FPV/34 and H13 gull virus strains and the other containing North American avian and recent equine strains; and (iv) human virus strains joined with classic swine virus strains (i.e., H1N1 swine virus strains related to swine/Iowa/15/30). The human virus lineage showed the greatest divergence from its root relative to other lineages. The estimated nucleotide evolutionary rate for the human PB2 lineage was 1.82 x 10(-3) changes per nucleotide per year, which is within the range of published estimates for NP and NS genes of human influenza A viruses. At the amino acid level, PB2s of human viruses have accumulated 34 amino acid changes over the past 55 years. In contrast, the avian PB2 lineages showed much less evolution, e.g., recent avian PB2s showed as few as three amino acid changes relative to the avian root. The completion of evolutionary analyses of the PB1, PB2, PA and NP genes of the ribonucleoprotein (RNP) complex permits comparison of evolutionary pathways. Different patterns of evolution among the RNP genes indicate that the genes of the complex are not coevolving as a unit. Evolution of the PB1 and PB2 genes is less correlated with host-specific factors, and their proteins appear to be evolving more slowly than NP and PA. This suggests that protein functional constraints are limiting the evolutionary divergence of PB1 and PB2 genes. The parallel host-specific evolutionary pathways of the NP and PA genes suggest that these proteins are coevolving in response to host-specific factors. PB2s of human influenza A viruses share a common ancestor with classic swine virus PB2s, and the pattern of evolution suggests that the ancestor was an avian virus PB2. This same pattern of evolution appears in the other genes of the RNP complex. Antigenic

  10. Molecular characterization and phylogenetic analysis of human influenza A viruses isolated in Iran during the 2014-2015 season.

    PubMed

    Moasser, Elham; Behzadian, Farida; Moattari, Afagh; Fotouhi, Fatemeh; Rahimi, Amir; Zaraket, Hassan; Hosseini, Seyed Younes

    2017-03-22

    Influenza A viruses are an important cause of severe infectious diseases in humans and are characterized by their fast evolution rate. Global monitoring of these viruses is critical to detect newly emerging variants during annual epidemics. Here, we sought to genetically characterize influenza A/H1N1pdm09 and A/H3N2 viruses collected in Iran during the 2014-2015 influenza season. A total of 200 nasopharyngeal swabs were collected from patients with influenza-like illnesses. Swabs were screened for influenza A and B using real-time PCR. Furthermore, positive specimens with high virus load underwent virus isolation and genetic characterization of their hemagglutinin (HA) and M genes. Of the 200 specimens, 80 were influenza A-positive, including 44 A/H1N1pdm09 and 36 A/H3N2, while 18 were influenza B-positive. Phylogenetic analysis of the HA genes of the A/H1N1pdm09 viruses revealed the circulation of clade 6C, characterized by amino acid substitutions D97N, V234I and K283E. Analysis of the A/H3N2 viruses showed a genetic drift from the vaccine strain A/Texas/50/2012 with 5 mutations (T128A, R142G, N145S, P198S and S219F) belonging to the antigenic sites A, B, and D of the HA protein. The A/H3N2 viruses belonged to phylogenetic clades 3C.2 and 3C.3. The M gene trees of the Iranian A/H1N1pdm09 and A/H3N2 mirrored the clustering patterns of their corresponding HA trees. Our results reveal co-circulation of several influenza A virus strains in Iran during the 2014-2015 influenza season.

  11. Preferential recognition of avian-like receptors in human influenza A H7N9 viruses.

    PubMed

    Xu, Rui; de Vries, Robert P; Zhu, Xueyong; Nycholat, Corwin M; McBride, Ryan; Yu, Wenli; Paulson, James C; Wilson, Ian A

    2013-12-06

    The 2013 outbreak of avian-origin H7N9 influenza in eastern China has raised concerns about its ability to transmit in the human population. The hemagglutinin glycoprotein of most human H7N9 viruses carries Leu(226), a residue linked to adaptation of H2N2 and H3N2 pandemic viruses to human receptors. However, glycan array analysis of the H7 hemagglutinin reveals negligible binding to humanlike α2-6-linked receptors and strong preference for a subset of avian-like α2-3-linked glycans recognized by all avian H7 viruses. Crystal structures of H7N9 hemagglutinin and six hemagglutinin-glycan complexes have elucidated the structural basis for preferential recognition of avian-like receptors. These findings suggest that the current human H7N9 viruses are poorly adapted for efficient human-to-human transmission.

  12. Protection of human influenza vaccines against a reassortant swine influenza virus of pandemic H1N1 origin using a pig model.

    PubMed

    Arunorat, Jirapat; Charoenvisal, Nataya; Woonwong, Yonlayong; Kedkovid, Roongtham; Jittimanee, Supattra; Sitthicharoenchai, Panchan; Kesdangsakonwut, Sawang; Poolperm, Pariwat; Thanawongnuwech, Roongroje

    2017-02-28

    Since the pandemic H1N1 emergence in 2009 (pdmH1N1), many reassortant pdmH1N1 viruses emerged and found circulating in the pig population worldwide. Currently, commercial human subunit vaccines are used commonly to prevent the influenza symptom based on the WHO recommendation. In case of current reassortant swine influenza viruses transmitting from pigs to humans, the efficacy of current human influenza vaccines is of interest. In this study, influenza A negative pigs were vaccinated with selected commercial human subunit vaccines and challenged with rH3N2. All sera were tested with both HI and SN assays using four representative viruses from the surveillance data in 2012 (enH1N1, pdmH1N1, rH1N2 and rH3N2). The results showed no significant differences in clinical signs and macroscopic and microscopic findings among groups. However, all pig sera from vaccinated groups had protective HI titers to the enH1N1, pdmH1N1 and rH1N2 at 21DPV onward and had protective SN titers only to pdmH1N1and rH1N2 at 21DPV onward. SN test results appeared more specific than those of HI tests. All tested sera had no cross-reactivity against the rH3N2. Both studied human subunit vaccines failed to protect and to stop viral shedding with no evidence of serological reaction against rH3N2. SIV surveillance is essential for monitoring a novel SIV emergence potentially for zoonosis.

  13. Avian influenza virus.

    PubMed

    Lee, Chang-Won; Saif, Yehia M

    2009-07-01

    Avian influenza viruses do not typically replicate efficiently in humans, indicating direct transmission of avian influenza virus to humans is unlikely. However, since 1997, several cases of human infections with different subtypes (H5N1, H7N7, and H9N2) of avian influenza viruses have been identified and raised the pandemic potential of avian influenza virus in humans. Although circumstantial evidence of human to human transmission exists, the novel avian-origin influenza viruses isolated from humans lack the ability to transmit efficiently from person-to-person. However, the on-going human infection with avian-origin H5N1 viruses increases the likelihood of the generation of human-adapted avian influenza virus with pandemic potential. Thus, a better understanding of the biological and genetic basis of host restriction of influenza viruses is a critical factor in determining whether the introduction of a novel influenza virus into the human population will result in a pandemic. In this article, we review current knowledge of type A influenza virus in which all avian influenza viruses are categorized.

  14. Computational prediction of vaccine strains for human influenza A (H3N2) viruses.

    PubMed

    Steinbrück, L; Klingen, T R; McHardy, A C

    2014-10-01

    Human influenza A viruses are rapidly evolving pathogens that cause substantial morbidity and mortality in seasonal epidemics around the globe. To ensure continued protection, the strains used for the production of the seasonal influenza vaccine have to be regularly updated, which involves data collection and analysis by numerous experts worldwide. Computer-guided analysis is becoming increasingly important in this problem due to the vast amounts of generated data. We here describe a computational method for selecting a suitable strain for production of the human influenza A virus vaccine. It interprets available antigenic and genomic sequence data based on measures of antigenic novelty and rate of propagation of the viral strains throughout the population. For viral isolates sampled between 2002 and 2007, we used this method to predict the antigenic evolution of the H3N2 viruses in retrospective testing scenarios. When seasons were scored as true or false predictions, our method returned six true positives, three false negatives, eight true negatives, and one false positive, or 78% accuracy overall. In comparison to the recommendations by the WHO, we identified the correct antigenic variant once at the same time and twice one season ahead. Even though it cannot be ruled out that practical reasons such as lack of a sufficiently well-growing candidate strain may in some cases have prevented recommendation of the best-matching strain by the WHO, our computational decision procedure allows quantitative interpretation of the growing amounts of data and may help to match the vaccine better to predominating strains in seasonal influenza epidemics. Importance: Human influenza A viruses continuously change antigenically to circumvent the immune protection evoked by vaccination or previously circulating viral strains. To maintain vaccine protection and thereby reduce the mortality and morbidity caused by infections, regular updates of the vaccine strains are required. We

  15. A replication-incompetent influenza virus bearing the HN glycoprotein of human parainfluenza virus as a bivalent vaccine.

    PubMed

    Kobayashi, Hirofumi; Iwatsuki-Horimoto, Kiyoko; Kiso, Maki; Uraki, Ryuta; Ichiko, Yurie; Takimoto, Toru; Kawaoka, Yoshihiro

    2013-12-16

    Influenza virus and human parainfluenza virus (HPIV) are major etiologic agents of acute respiratory illness in young children. Inactivated and live attenuated influenza vaccines are approved in several countries, yet no vaccine is licensed for HPIV. We previously showed that a replication-incompetent PB2-knockout (PB2-KO) virus that possesses a reporter gene in the coding region of the PB2 segment can serve as a platform for a bivalent vaccine. To develop a bivalent vaccine against influenza and parainfluenza virus, here, we generated a PB2-KO virus possessing the hemagglutinin-neuraminidase (HN) glycoprotein of HPIV type 3 (HPIV3), a major surface antigen of HPIV, in its PB2 segment. We confirmed that this virus replicated only in PB2-expressing cells and expressed HN. We then examined the efficacy of this virus as a bivalent vaccine in a hamster model. High levels of virus-specific IgG antibodies in sera and IgA, IgG, and IgM antibodies in bronchoalveolar lavage fluids against both influenza virus and HPIV3 were detected from hamsters immunized with this virus. The neutralizing capability of these serum antibodies was also confirmed. Moreover, the immunized hamsters were completely protected from virus challenge with influenza virus or HPIV3. These results indicate that PB2-KO virus expressing the HN of HPIV3 has the potential to be a novel bivalent vaccine against influenza and human parainfluenza viruses.

  16. Cigarette smoke extract suppresses the RIG-I-initiated innate immune response to influenza virus in the human lung

    PubMed Central

    Wu, Wenxin; Patel, Krupa B.; Booth, J. Leland; Zhang, Wei

    2011-01-01

    Cigarette smoking is the major cause of chronic obstructive pulmonary disease (COPD) and predisposes subjects to severe respiratory tract infections. Epidemiological studies have shown that cigarette smokers are seven times more likely to contract influenza infection than nonsmokers. The mechanisms underlying this increased susceptibility are poorly characterized. Retinoic acid-inducible gene (RIG)-I is believed to play an important role in the recognition of, and response to, influenza virus and other RNA viruses. Our study focused on how cigarette smoke extract (CSE) alters the influenza-induced proinflammatory response and suppresses host antiviral activity in the human lung using a unique lung organ culture model. We first determined that treatment with 2–20% CSE did not induce cytotoxicity as assessed by LDH release. However, CSE treatment inhibited influenza-induced IFN-inducible protein 10 protein and mRNA expression. Induction of the major antiviral cytokine IFN-β mRNA was also decreased by CSE. CSE also blunted viral-mediated RIG-I mRNA and protein expression. Inhibition of viral-mediated RIG-I induction by CSE was prevented by the antioxidants N-acetyl-cysteine and glutathione. These findings show that CSE suppresses antiviral and innate immune responses in influenza virus-infected human lungs through oxidative inhibition of viral-mediated induction of the pattern recognition receptor RIG-I. This immunosuppressive effect of CSE may play a role in the enhanced susceptibility of smokers to serious influenza infection in the lung. PMID:21335520

  17. An inhibitory activity in human cells restricts the function of an avian-like influenza virus polymerase.

    PubMed

    Mehle, Andrew; Doudna, Jennifer A

    2008-08-14

    Transmission of avian influenza virus into human populations has the potential to cause pandemic outbreaks. A major determinant of species tropism is the identity of amino acid 627 in the PB2 subunit of the heterotrimeric influenza polymerase; glutamic acid predominates in avian PB2, whereas lysine occupies this position in human isolates. We show that a dominant inhibitory activity in human cells potently and selectively restricts the function of polymerases containing an avian-like PB2 with glutamic acid at residue 627. Restricted polymerases fail to assemble into ribonucleoprotein complexes, resulting in decreased genome transcription, replication, and virus production without any significant effect on relative viral infectivity. Understanding the molecular basis of this species-specific restriction should provide strategies to prevent and treat avian influenza outbreaks in humans.

  18. Human T-cells directed to seasonal influenza A virus cross-react with 2009 pandemic influenza A (H1N1) and swine-origin triple-reassortant H3N2 influenza viruses.

    PubMed

    Hillaire, Marine L B; Vogelzang-van Trierum, Stella E; Kreijtz, Joost H C M; de Mutsert, Gerrie; Fouchier, Ron A M; Osterhaus, Albert D M E; Rimmelzwaan, Guus F

    2013-03-01

    Virus-specific CD8(+) T-cells contribute to protective immunity against influenza A virus (IAV) infections. As the majority of these cells are directed to conserved viral proteins, they may afford protection against IAVs of various subtypes. The present study assessed the cross-reactivity of human CD8(+) T-lymphocytes, induced by infection with seasonal A (H1N1) or A (H3N2) influenza virus, with 2009 pandemic influenza A (H1N1) virus [A(H1N1)pdm09] and swine-origin triple-reassortant A (H3N2) [A(H3N2)v] viruses that are currently causing an increasing number of human cases in the USA. It was demonstrated that CD8(+) T-cells induced after seasonal IAV infections exerted lytic activity and produced gamma interferon upon in vitro restimulation with A(H1N1)pdm09 and A(H3N2)v influenza A viruses. Furthermore, CD8(+) T-cells directed to A(H1N1)pdm09 virus displayed a high degree of cross-reactivity with A(H3N2)v viruses. It was concluded that cross-reacting T-cells had the potential to afford protective immunity against A(H1N1)pdm09 viruses during the pandemic and offer some degree of protection against infection with A(H3N2)v viruses.

  19. Recombinant production and characterization of human anti-influenza virus monoclonal antibodies identified from hybridomas fused with human lymphocytes.

    PubMed

    Misaki, Ryo; Fukura, Natsuko; Kajiura, Hiroyuki; Yasugi, Mayo; Kubota-Koketsu, Ritsuko; Sasaki, Tadahiro; Momota, Masatoshi; Ono, Ken-Ichiro; Ohashi, Takao; Ikuta, Kazuyoshi; Fujiyama, Kazuhito

    2016-09-01

    In previous studies, hybridomas producing human immunoglobulin G, the antibodies 5E4 and 5A7 against influenza A and B virus were established using a novel human lymphocyte fusion partner, SPYMEG. In the present study, we succeeded in achieving the recombinant production and secretion of 5E4 and 5A7 in Chinese hamster ovary cells. Our N-glycan analysis by intact-mass detection and liquid chromatography mass spectrometry showed that recombinant 5E4 and 5A7 have one N-glycan and the typical mammalian-type N-glycan structures similar to those in hybridomas. However, the glycan distribution was slightly different among these antibodies. The amount of high-mannose-type structures was under 10% of the total N-glycans of recombinant 5E4 and 5A7, compared to 20% of the 5E4 and 5A7 produced in hybridomas. The amount of galactosylated N-glycans was increased in recombinants. Approximately 80% of the N-glycans of all antibodies was fucosylated, and no sialylated N-glycan was found. Recombinant 5E4 and 5A7 neutralized pandemic influenza A virus specifically, and influenza B virus broadly, quite similar to the 5E4 and 5A7 produced in hybridomas, respectively. Here we demonstrated that recombinants of antibodies identified from hybridomas fused with SPYMEG have normal N-glycans and that their neutralizing activities bear comparison with those of the original antibodies.

  20. Sustained live poultry market surveillance contributes to early warnings for human infection with avian influenza viruses

    PubMed Central

    Fang, Shisong; Bai, Tian; Yang, Lei; Wang, Xin; Peng, Bo; Liu, Hui; Geng, Yijie; Zhang, Renli; Ma, Hanwu; Zhu, Wenfei; Wang, Dayan; Cheng, Jinquan; Shu, Yuelong

    2016-01-01

    Sporadic human infections with the highly pathogenic avian influenza (HPAI) A (H5N6) virus have been reported in different provinces in China since April 2014. From June 2015 to January 2016, routine live poultry market (LPM) surveillance was conducted in Shenzhen, Guangdong Province. H5N6 viruses were not detected until November 2015. The H5N6 virus-positive rate increased markedly beginning in December 2015, and viruses were detected in LPMs in all districts of the city. Coincidently, two human cases with histories of poultry exposure developed symptoms and were diagnosed as H5N6-positive in Shenzhen during late December 2015 and early January 2016. Similar viruses were identified in environmental samples collected in the LPMs and the patients. In contrast to previously reported H5N6 viruses, viruses with six internal genes derived from the H9N2 or H7N9 viruses were detected in the present study. The increased H5N6 virus-positive rate in the LPMs and the subsequent human infections demonstrated that sustained LPM surveillance for avian influenza viruses provides an early warning for human infections. Interventions, such as LPM closures, should be immediately implemented to reduce the risk of human infection with the H5N6 virus when the virus is widely detected during LPM surveillance. PMID:27485495

  1. Sustained live poultry market surveillance contributes to early warnings for human infection with avian influenza viruses.

    PubMed

    Fang, Shisong; Bai, Tian; Yang, Lei; Wang, Xin; Peng, Bo; Liu, Hui; Geng, Yijie; Zhang, Renli; Ma, Hanwu; Zhu, Wenfei; Wang, Dayan; Cheng, Jinquan; Shu, Yuelong

    2016-08-03

    Sporadic human infections with the highly pathogenic avian influenza (HPAI) A (H5N6) virus have been reported in different provinces in China since April 2014. From June 2015 to January 2016, routine live poultry market (LPM) surveillance was conducted in Shenzhen, Guangdong Province. H5N6 viruses were not detected until November 2015. The H5N6 virus-positive rate increased markedly beginning in December 2015, and viruses were detected in LPMs in all districts of the city. Coincidently, two human cases with histories of poultry exposure developed symptoms and were diagnosed as H5N6-positive in Shenzhen during late December 2015 and early January 2016. Similar viruses were identified in environmental samples collected in the LPMs and the patients. In contrast to previously reported H5N6 viruses, viruses with six internal genes derived from the H9N2 or H7N9 viruses were detected in the present study. The increased H5N6 virus-positive rate in the LPMs and the subsequent human infections demonstrated that sustained LPM surveillance for avian influenza viruses provides an early warning for human infections. Interventions, such as LPM closures, should be immediately implemented to reduce the risk of human infection with the H5N6 virus when the virus is widely detected during LPM surveillance.

  2. Structural and functional bases for broad-spectrum neutralization of avian and human influenza A viruses.

    PubMed

    Sui, Jianhua; Hwang, William C; Perez, Sandra; Wei, Ge; Aird, Daniel; Chen, Li-mei; Santelli, Eugenio; Stec, Boguslaw; Cadwell, Greg; Ali, Maryam; Wan, Hongquan; Murakami, Akikazu; Yammanuru, Anuradha; Han, Thomas; Cox, Nancy J; Bankston, Laurie A; Donis, Ruben O; Liddington, Robert C; Marasco, Wayne A

    2009-03-01

    Influenza virus remains a serious health threat, owing to its ability to evade immune surveillance through rapid genetic drift and reassortment. Here we used a human non-immune antibody phage-display library and the H5 hemagglutinin ectodomain to select ten neutralizing antibodies (nAbs) that were effective against all group 1 influenza viruses tested, including H5N1 'bird flu' and the H1N1 'Spanish flu'. The crystal structure of one such nAb bound to H5 shows that it blocks infection by inserting its heavy chain into a conserved pocket in the stem region, thus preventing membrane fusion. Nine of the nAbs employ the germline gene VH1-69, and all seem to use the same neutralizing mechanism. Our data further suggest that this region is recalcitrant to neutralization escape and that nAb-based immunotherapy is a promising strategy for broad-spectrum protection against seasonal and pandemic influenza viruses.

  3. Human mobility and the spatial transmission of influenza in the United States

    PubMed Central

    Charu, Vivek; Zeger, Scott; Gog, Julia; Bjørnstad, Ottar N.; Simonsen, Lone; Grenfell, Bryan T.; Viboud, Cécile

    2017-01-01

    Seasonal influenza epidemics offer unique opportunities to study the invasion and re-invasion waves of a pathogen in a partially immune population. Detailed patterns of spread remain elusive, however, due to lack of granular disease data. Here we model high-volume city-level medical claims data and human mobility proxies to explore the drivers of influenza spread in the US during 2002–2010. Although the speed and pathways of spread varied across seasons, seven of eight epidemics likely originated in the Southern US. Each epidemic was associated with 1–5 early long-range transmission events, half of which sparked onward transmission. Gravity model estimates indicate a sharp decay in influenza transmission with the distance between infectious and susceptible cities, consistent with spread dominated by work commutes rather than air traffic. Two early-onset seasons associated with antigenic novelty had particularly localized modes of spread, suggesting that novel strains may spread in a more localized fashion than previously anticipated. PMID:28187123

  4. Human influenza virus hemagglutinin is expressed in monkey cells using simian virus 40 vectors.

    PubMed Central

    Hartman, J R; Nayak, D P; Fareed, G C

    1982-01-01

    We have cloned and expressed the hemagglutinin (HA) gene of a human influenza virus (A/WSN/33) in monkey kidney cells by linking it to deleted simian virus 40 (SV40) genomes that contain the entire early gene region, the origin of replication, and late leader sequences. The HA gene (1775 base pairs long) was originally inserted by the dG . dC tailing technique into the multicopy plasmid of Escherichia coli, pBR322, using cDNA made from viral RNA. The cloned gene was further modified by treatment with nuclease Bal 31 to remove the dG . dC tails and some of the untranslated sequences and recloned in E. coli after addition of BamHI restriction endonuclease linkers. A number of SV40 and HA recombinants (SV--HA) were constructed by inserting recloned HA DNA into the late gene region of SV40. The SV--HA recombinants, when complemented in a lytic infection of monkey cells by the helper function of SV40 early deletion mutants expressed influenza HA as detected by immunofluorescence and immunoprecipitation of in vivo-labeled proteins using either heterogeneous anti-influenza rabbit antibodies or monoclonal antibodies against HA. Furthermore, the WSN HA expressed by the SV--HA recombinants was also glycosylated and possessed the same molecular weight (approximately 70,000) as the uncleaved HA of WSN virus in monkey cells. Images PMID:6281758

  5. Viral etiology and seasonality of influenza-like illness in Gabon, March 2010 to June 2011

    PubMed Central

    2014-01-01

    Background Surveillance of influenza-like illness (ILI) in Central Africa began only recently, and few data are therefore available on the circulation of influenza virus and other respiratory viruses. In Gabon, a Central African country, we established a surveillance network in four major towns in order to analyze cases of ILI among patients who visited health centers between March 2010 and June 2011, and to determine the viral etiology. Methods Nasal swabs were sent for analysis to the Centre International de Recherches Médicales de Franceville, where they were screened for 17 respiratory viruses in a multiplex real-time reverse transcription polymerase chain reaction for all pathogens according the following pairs: adenovirus/parainfluenza virus 4, respiratory syncytial virus/human metapneumovirus, parainfluenza virus 1/parainfluenza virus 2, pandemic influenza virus A/seasonal influenza virus A (H1N1, H3N2)/seasonal influenza virus B, human coronaviruses 229E/OC43, human coronaviruses NL63/HKU1, rhinovirus/human parechovirus, and enterovirus/parainfluenza virus 3. Results We analyzed a total of 1041 specimens, of which 639 (61%) were positive for at least one virus. Three-quarters of the patients were children under five years old. We therefore focused on this age group, in which 68.1% of patients were positive for at least one virus. The most common viruses were adenoviruses (17.5%), followed by parainfluenza viruses (PIVs) 1–4 (16.8%), enteroviruses (EV) (14.7%), respiratory syncytial virus (RSV) (13.5%), and influenza virus (11.9%). The prevalence of some viruses was subject to geographic and seasonal variations. One-third of positive samples contained more than one virus. Conclusions Like most studies in the world, the virus PIVs, EV, RSV, Influenza virus, HRV were predominant among children under five years old in Gabon. An exception is made for adenoviruses which have a high prevalence in our study. However adenoviruses can be detected in asymptomatic

  6. Using Zebrafish Models of Human Influenza A Virus Infections to Screen Antiviral Drugs and Characterize Host Immune Cell Responses.

    PubMed

    Sullivan, Con; Jurcyzszak, Denise; Goody, Michelle F; Gabor, Kristin A; Longfellow, Jacob R; Millard, Paul J; Kim, Carol H

    2017-01-20

    Each year, seasonal influenza outbreaks profoundly affect societies worldwide. In spite of global efforts, influenza remains an intractable healthcare burden. The principle strategy to curtail infections is yearly vaccination. In individuals who have contracted influenza, antiviral drugs can mitigate symptoms. There is a clear and unmet need to develop alternative strategies to combat influenza. Several animal models have been created to model host-influenza interactions. Here, protocols for generating zebrafish models for systemic and localized human influenza A virus (IAV) infection are described. Using a systemic IAV infection model, small molecules with potential antiviral activity can be screened. As a proof-of-principle, a protocol that demonstrates the efficacy of the antiviral drug Zanamivir in IAV-infected zebrafish is described. It shows how disease phenotypes can be quantified to score the relative efficacy of potential antivirals in IAV-infected zebrafish. In recent years, there has been increased appreciation for the critical role neutrophils play in the human host response to influenza infection. The zebrafish has proven to be an indispensable model for the study of neutrophil biology, with direct impacts on human medicine. A protocol to generate a localized IAV infection in the Tg(mpx:mCherry) zebrafish line to study neutrophil biology in the context of a localized viral infection is described. Neutrophil recruitment to localized infection sites provides an additional quantifiable phenotype for assessing experimental manipulations that may have therapeutic applications. Both zebrafish protocols described faithfully recapitulate aspects of human IAV infection. The zebrafish model possesses numerous inherent advantages, including high fecundity, optical clarity, amenability to drug screening, and availability of transgenic lines, including those in which immune cells such as neutrophils are labeled with fluorescent proteins. The protocols detailed here

  7. Clinical severity of human infection with avian influenza A(H7N9) virus

    PubMed Central

    Yu, Hongjie; Cowling, Benjamin J.; Feng, Luzhao; Lau, Eric H. Y.; Liao, Qiaohong; Tsang, Tim K.; Peng, Zhibin; Wu, Peng; Liu, Fengfeng; Fang, Vicky J.; Zhang, Honglong; Li, Ming; Zeng, Lingjia; Xu, Zhen; Li, Zhongjie; Luo, Huiming; Li, Qun; Feng, Zijian; Cao, Bin; Yang, Weizhong; Wu, Joseph T.; Wang, Yu; Leung, Gabriel M.

    2013-01-01

    Background Characterizing the severity profile of human infections with influenza viruses of animal origin is a part of pandemic risk assessment, and an important part of the assessment of disease epidemiology. Our objective was to assess the clinical severity of human infections with the avian influenza A(H7N9) virus that has recently emerged in China. Methods Among laboratory-confirmed cases of A(H7N9) who were hospitalised, we estimated the risk of fatality, mechanical ventilation, and admission to the intensive care unit based on censored data during the currently ongoing outbreak. We also used information on laboratory-confirmed cases detected through sentinel influenza-like illness (ILI) surveillance to estimate the number of symptomatic A(H7N9) virus infections to date and the symptomatic case fatality risk. Findings Among 123 hospitalised cases, 37 cases had died and 69 had recovered by May 28, 2013. Hospitalised cases had high risks of mortality (36%; 95% confidence interval (CI): 26%–45%), mechanical ventilation or mortality (69%; 95% CI: 60%–77%), and ICU admission or mechanical ventilation or mortality (83%; 95% CI: 76%–90%), and the risk of these severe outcomes increased with age. Depending on assumptions about the coverage of the sentinel ILI network and health-care seeking behavior for cases of ILI associated with A(H7N9) virus infection, we estimated that the symptomatic case fatality risk could be between 160 and 2,800 per 100,000 symptomatic cases. Interpretation We estimated that the severity of A(H7N9) is somewhat lower than A(H5N1) but higher than seasonal influenza viruses and influenza A(H1N1)pdm09 virus. The estimated risks of fatality among hospitalised cases and symptomatic cases are measures of severity that should not be affected by shifts over time in the probability of laboratory-confirmation of mild cases and should inform risk assessment. Funding Ministry of Science and Technology, China; Research Fund for the Control of

  8. Global dynamic analysis of a H7N9 avian-human influenza model in an outbreak region.

    PubMed

    Chen, Yongxue; Wen, Yongxian

    2015-02-21

    In 2013 in China a new type of avian influenza virus, H7N9, began to infect humans and had aroused severe fatality in the infected humans. We know that the spread is from poultry to humans, and the H7N9 avian influenza is low pathogenic in the poultry world but highly pathogenic in the human world, but the transmission mechanism is unclear. Since it has no signs of human-to-human transmission and outbreaks are isolated in some cities in China, in order to investigate the transmission mechanism of human infection with H7N9 avian influenza, an eco-epidemiological model in an outbreak region is proposed and analyzed dynamically. Researches and reports show that gene mutation makes the new virus be capable of infecting humans, therefore the mutation factor is taken into account in the model. The global dynamic analysis is conducted, different thresholds are identified, persistence and global qualitative behaviors are obtained. The impact of H7N9 avian influenza on the people population is concerned. Finally, the numerical simulations are carried out to support the theoretical analysis and to investigate the disease control measures. It seems that we may take people׳s hygiene and prevention awareness factor as a significant policy to achieve the aim of both the disease control and the economic returns.

  9. Genetic evolution of recently emerged novel human-like swine H3 influenza A viruses (IAV) in United States swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction Influenza A virus (IAV) is a major cause of respiratory disease in swine. IAV transmission from humans to swine is a major contributor to swine IAV diversity. In 2012, a novel H3N2 with an HA (hu-H3) and NA derived from human seasonal H3N2 was detected in United States (US) swine. The h...

  10. Receptor recognition mechanism of human influenza A H1N1 (1918), avian influenza A H5N1 (2004), and pandemic H1N1 (2009) neuraminidase.

    PubMed

    Jongkon, Nipa; Sangma, Chak

    2012-01-01

    Influenza A neuraminidase (NA) is a target for anti-influenza drugs. The function of this enzyme is to cleave a glycosidic linkage of a host cell receptor that links sialic acid (Sia) to galactose (Gal), to allow the virus to leave an infected cell and propagate. The receptor is an oligosaccharide on the host cell surface. There are two types of oligosaccharide receptor; the first, which is found mainly on avian epithelial cell surfaces, links Sia with Gal by an α2,3 glycosidic linkage; in the second, found mainly on human epithelial cell surfaces, linkage is via an α2,6 linkage. Some researchers believe that NAs from different viruses show selectivity for each type of linkage, but there is limited information available to confirm this hypothesis. To see if the linkage type is more specific to any particular NA, a number of NA-receptor complexes of human influenza A H1N1 (1918), avian influenza A H5N1 (2004), and a pandemic strain of H1N1 (2009) were constructed using homology modeling and molecular dynamics simulation. The results show that the two types of receptor analogues bound to NAs use different mechanisms. Moreover, it was found that a residue unique to avian virus NA is responsible for the recognition of the Siaα2,3Gal receptor, and a residue unique to human virus NA is responsible for the recognition of Siaα2,6Gal. We believe that this finding could explain how NAs of different virus origins always possess some unique residues.

  11. Human avian influenza in Indonesia: are they really clustered?

    PubMed

    Eyanoer, Putri Chairani; Singhasivanon, Pratap; Kaewkungwal, Jaranit; Apisarnthanarak, Anucha

    2011-05-01

    Understanding the epidemiology of human H5N1 cases in Indonesia is important. The question of whether cases are clustered or not is unclear. An increase in clustered cases suggests greater transmissibility. In the present study, 107 confirmed and 302 suspected human H5N1 cases in Indonesia during 2005-2007 were analyzed for spatial and temporal distribution. Most confirmed cases (97.2%) occurred on two main islands (Java and Sumatera). There were no patterns of disease occurrence over time. There were also no correlations between occurrence patterns in humans and poultry. Statistical analysis showed confirmed cases were clustered within an area on Java island covered by 8 districts along the border of three neighboring provinces (Jakarta, West Java, and Banten). This study shows human H5N1 cases in Indonesia were clustered at two sites where there was a high rate of infection among poultry. These findings are important since they highlight areas of high risk for possible human H5N1 infection in Indonesia, thus, preventive measures may be taken.

  12. Antiviral activity of acidic polysaccharides from Coccomyxa gloeobotrydiformi, a green alga, against an in vitro human influenza A virus infection.

    PubMed

    Komatsu, Takayuki; Kido, Nobuo; Sugiyama, Tsuyoshi; Yokochi, Takashi

    2013-02-01

    The extracts prepared from green algae are reported to possess a variety of biological activities including antioxidant, antitumor and antiviral activities. The acidic polysaccharide fraction from a green alga Coccomyxa gloeobotrydiformi (CmAPS) was isolated and the antiviral action on an in vitro infection of influenza A virus was examined. CmAPS inhibited the growth and yield of all influenza A virus strains tested, such as A/H1N1, A/H2N2, A/H3N2 and A/H1N1 pandemic strains. The 50% inhibitory concentration of CmAPS on the infection of human influenza A virus strains ranged from 26 to 70 µg/mL and the antiviral activity of CmAPS against influenza A/USSR90/77 (H1N1) was the strongest. The antiviral activity of CmAPS was not due to the cytotoxicity against host cells. The antiviral activity of CmAPS required its presence in the inoculation of virus onto MDCK cells. Pretreatment and post-treatment with CmAPS was ineffective for the antiviral activity. CmAPS inhibited influenza A virus-induced erythrocyte hemagglutination and hemolysis. Taken together, CmAPS was suggested to exhibit the anti-influenza virus activity through preventing the interaction of virus and host cells. The detailed antiviral activity of CmAPS is discussed.

  13. [Outbreak of human A (H1N1) influenza in turkeys of a commercial poultry farm, Valparaiso, Chile: August 2009].

    PubMed

    Pedroni, Elena; Muñoz, Ximena; Sotomayor, Viviana; Muñoz, Juan C; Arenas, Myriam; Fasce, Rodrigo; Olea, Andrea

    2012-08-01

    The Chilean Ministry of Health (MINSAL) led an investigation to identify associated factors to human influenza A (H1N1) infection in turkeys from poultry farms, Valparaíso. The Agriculture and Livestock Farming Service (SAG) informed the detection of influenza A (low pathogenicity) in turkeys and the Public Health Institute (ISP) confirmed influenza A (H1N1).The study included 100% of operative wards: 31% presented positive event (influenza A (H1N1)); 60% if considered only reproductive wards. Dissemination and dispersion velocity of 13 wards in 18 days evidenced a continuous common source. Interviews were performed to 89% of workers of whom 20% presented influenza-like disease: 26% from reproductive wards and 4% from raising and rearing farms. Of15 risk factors studied insemination and age in females showed statistically significant RR in low oviposition index wards. A man-bird transmission is proposed, through direct transmission of saliva during manual insemination or indirect transmission through contaminated semen. To the authors, this is the first turkey 2009 influenza H1N1 outbreak detected worldwide,in this case with a documented cloacal transmission path.

  14. Avian Influenza.

    PubMed

    Zeitlin, Gary Adam; Maslow, Melanie Jane

    2005-05-01

    The current epidemic of H5N1 highly pathogenic avian influenza in Southeast Asia raises serious concerns that genetic reassortment will result in the next influenza pandemic. There have been 164 confirmed cases of human infection with avian influenza since 1996. In 2004, there were 45 cases of human H5N1 in Vietnam and Thailand, with a mortality rate more than 70%. In addition to the potential public health hazard, the current zoonotic epidemic has caused severe economic losses. Efforts must be concentrated on early detection of bird outbreaks with aggressive culling, quarantining, and disinfection. To prepare for and prevent an increase in human cases, it is essential to improve detection methods and stockpile effective antivirals. Novel therapeutic modalities, including short-interfering RNAs and new vaccine strategies that use plasmid-based genetic systems, offer promise should a pandemic occur.

  15. Avian influenza.

    PubMed

    Zeitlin, Gary A; Maslow, Melanie J

    2006-03-01

    The current epidemic of H5N1 highly pathogenic avian influenza in Southeast Asia raises serious concerns that genetic reassortment will result in the next influenza pandemic. There have been 164 confirmed cases of human infection with avian influenza since 1996. In 2004 alone, there were 45 cases of human H5N1 in Vietnam and Thailand, with a mortality rate over 70%. In addition to the potential public health hazard, the current zoonotic epidemic has caused severe economic losses. Efforts must be concentrated on early detection of bird outbreaks with aggressive culling, quarantines, and disinfection. To prepare for and prevent increased human cases, it is essential to improve detection methods and stockpile effective antivirals. Novel therapeutic modalities, including short, interfering RNAs and new vaccine strategies that use plasmid-based genetic systems offer promise, should a pandemic occur.

  16. Immunization of humans with polyribophosphate, the capsular antigen of Hemophilus influenzae, type b.

    PubMed

    Anderson, P; Peter, G; Johnston, R B; Wetterlow, L H; Smith, D H

    1972-01-01

    In human volunteers, single injections of purified polyribophosphate elicited antibodies detectable by passive hemagglutination and by serum bactericidal and opsonizing activities against viable Hemophilus influenzae, type b. All three activities rose by 2 wk to maximal levels, at which they remained for at least 6 months. Doses of 1 mug elicited antibody responses in nearly all recipients; higher doses of the antigen, however, produced larger increases in titer. Booster doses of 1 mug given at 6 months did not further increase the antibody titers. A tuberculin-like response was often observed at the site of injections given intradermally.

  17. Cytotoxic T lymphocytes established by seasonal human influenza cross-react against 2009 pandemic H1N1 influenza virus.

    PubMed

    Tu, Wenwei; Mao, Huawei; Zheng, Jian; Liu, Yinping; Chiu, Susan S; Qin, Gang; Chan, Ping-Lung; Lam, Kwok-Tai; Guan, Jing; Zhang, Lijuan; Guan, Yi; Yuen, Kwok-Yung; Peiris, J S Malik; Lau, Yu-Lung

    2010-07-01

    While few children and young adults have cross-protective antibodies to the pandemic H1N1 2009 (pdmH1N1) virus, the illness remains mild. The biological reasons for these epidemiological observations are unclear. In this study, we demonstrate that the bulk memory cytotoxic T lymphocytes (CTLs) established by seasonal influenza viruses from healthy individuals who have not been exposed to pdmH1N1 can directly lyse pdmH1N1-infected target cells and produce gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha). Using influenza A virus matrix protein 1 (M1(58-66)) epitope-specific CTLs isolated from healthy HLA-A2(+) individuals, we further found that M1(58-66) epitope-specific CTLs efficiently killed both M1(58-66) peptide-pulsed and pdmH1N1-infected target cells ex vivo. These M1(58-66)-specific CTLs showed an effector memory phenotype and expressed CXCR3 and CCR5 chemokine receptors. Of 94 influenza A virus CD8 T-cell epitopes obtained from the Immune Epitope Database (IEDB), 17 epitopes are conserved in pdmH1N1, and more than half of these conserved epitopes are derived from M1 protein. In addition, 65% (11/17) of these epitopes were 100% conserved in seasonal influenza vaccine H1N1 strains during the last 20 years. Importantly, seasonal influenza vaccination could expand the functional M1(58-66) epitope-specific CTLs in 20% (4/20) of HLA-A2(+) individuals. Our results indicated that memory CTLs established by seasonal influenza A viruses or vaccines had cross-reactivity against pdmH1N1. These might explain, at least in part, the unexpected mild pdmH1N1 illness in the community and also might provide some valuable insights for the future design of broadly protective vaccines to prevent influenza, especially pandemic influenza.

  18. The emergence of influenza A H7N9 in human beings 16 years after influenza A H5N1: a tale of two cities.

    PubMed

    To, Kelvin K W; Chan, Jasper F W; Chen, Honglin; Li, Lanjuan; Yuen, Kwok-Yung

    2013-09-01

    Infection with either influenza A H5N1 virus in 1997 or avian influenza A H7N9 virus in 2013 caused severe pneumonia that did not respond to typical or atypical antimicrobial treatment, and resulted in high mortality. Both viruses are reassortants with internal genes derived from avian influenza A H9N2 viruses that circulate in Asian poultry. Both viruses have genetic markers of mammalian adaptation in their haemagglutinin and polymerase PB2 subunits, which enhanced binding to human-type receptors and improved replication in mammals, respectively. Hong Kong (affected by H5N1 in 1997) and Shanghai (affected by H7N9 in 2013) are two rapidly flourishing cosmopolitan megacities that were increasing in human population and poultry consumption before the outbreaks. Both cities are located along the avian migratory route at the Pearl River delta and Yangtze River delta. Whether the widespread use of the H5N1 vaccine in east Asia-with suboptimum biosecurity measures in live poultry markets and farms-predisposed to the emergence of H7N9 or other virus subtypes needs further investigation. Why H7N9 seems to be more readily transmitted from poultry to people than H5N1 is still unclear.

  19. Characterization of H7N9 influenza A viruses isolated from humans

    PubMed Central

    Watanabe, Tokiko; Kiso, Maki; Fukuyama, Satoshi; Nakajima, Noriko; Imai, Masaki; Yamada, Shinya; Murakami, Shin; Yamayoshi, Seiya; Iwatsuki-Horimoto, Kiyoko; Sakoda, Yoshihiro; Takashita, Emi; McBride, Ryan; Noda, Takeshi; Hatta, Masato; Imai, Hirotaka; Zhao, Dongming; Kishida, Noriko; Shirakura, Masayuki; de Vries, Robert P.; Shichinohe, Shintaro; Okamatsu, Masatoshi; Tamura, Tomokazu; Tomita, Yuriko; Fujimoto, Naomi; Goto, Kazue; Katsura, Hiroaki; Kawakami, Eiryo; Ishikawa, Izumi; Watanabe, Shinji; Ito, Mutsumi; Sakai-Tagawa, Yuko; Sugita, Yukihiko; Uraki, Ryuta; Yamaji, Reina; Eisfeld, Amie J.; Zhong, Gongxun; Fan, Shufang; Ping, Jihui; Maher, Eileen A.; Hanson, Anthony; Uchida, Yuko; Saito, Takehiko; Ozawa, Makoto; Neumann, Gabriele; Kida, Hiroshi; Odagiri, Takato; Paulson, James C.; Hasegawa, Hideki; Tashiro, Masato; Kawaoka, Yoshihiro

    2013-01-01

    Summary Avian influenza A viruses rarely infect humans, but if they do and transmit among them, worldwide outbreaks (pandemics) can result. The recent sporadic infections of humans in China with a previously unrecognized avian influenza A virus of the H7N9 subtype (A(H7N9)) have caused concern due to the appreciable case fatality rate associated with these infections (>25%), potential instances of human-to-human transmission1, and the lack of pre-existing immunity among humans to viruses of this subtype. Here, we therefore characterized two early human A(H7N9) isolates, A/Anhui/1/2013 and A/Shanghai/1/2013 (H7N9; hereafter referred to as Anhui/1 and Shanghai/1, respectively). In mice, Anhui/1 and Shanghai/1 were more pathogenic than a control avian H7N9 virus (A/duck/Gunma/466/2011; H7N9; Dk/GM466) and a representative pandemic 2009 H1N1 virus (A/California/04/2009; H1N1; CA04). Anhui/1, Shanghai/1, and Dk/GM466 replicated well in the nasal turbinates of ferrets. In nonhuman primates (NHPs), Anhui/1 and Dk/GM466 replicated efficiently in the upper and lower respiratory tracts, whereas the replicative ability of conventional human influenza viruses is typically restricted to the upper respiratory tract of infected primates. By contrast, Anhui/1 did not replicate well in miniature pigs upon intranasal inoculation. Most critically, Anhui/1 transmitted via respiratory droplets in one of three pairs of ferrets. Glycan arrays demonstrated that Anhui/1, Shanghai/1, and A/Hangzhou/1/2013 (a third human A(H7N9) virus tested in this assay) bind to human virus-type receptors, a property that may be critical for virus transmissibility in ferrets. Anhui/1 was less sensitive than a pandemic 2009 H1N1 virus to neuraminidase inhibitors, although both viruses were equally susceptible to an experimental antiviral polymerase inhibitor. The robust replicative ability in mice, ferrets, and NHPs and the limited transmissibility in ferrets of Anhui/1 suggest that A(H7N9) viruses have

  20. Recognition of influenza H3N2 variant virus by human neutralizing antibodies

    PubMed Central

    Bangaru, Sandhya; Nieusma, Travis; Kose, Nurgun; Thornburg, Natalie J.; Kaplan, Bryan S.; King, Hannah G.; Singh, Vidisha; Lampley, Rebecca M.; Cisneros, Alberto; Edwards, Kathryn M.; Edupuganti, Srilatha; Lai, Lilin; Richt, Juergen A.; Webby, Richard J.; Ward, Andrew B.; Crowe, James E.

    2016-01-01

    Since 2011, over 300 human cases of infection, especially in exposed children, with the influenza A H3N2 variant (H3N2v) virus that circulates in swine in the US have been reported. The structural and genetic basis for the lack of protection against H3N2v induced by vaccines containing seasonal H3N2 antigens is poorly understood. We isolated 17 human monoclonal antibodies (mAbs) that neutralized H3N2v virus from subjects experimentally immunized with an H3N2v candidate vaccine. Six mAbs exhibited very potent neutralizing activity (IC50 < 200 ng/ml) against the H3N2v virus but not against current human H3N2 circulating strains. Fine epitope mapping and structural characterization of antigen-antibody complexes revealed that H3N2v specificity was attributable to amino acid polymorphisms in the 150-loop and the 190-helix antigenic sites on the hemagglutinin protein. H3N2v-specific antibodies also neutralized human H3N2 influenza strains naturally circulating between 1995 and 2005. These results reveal a high level of antigenic relatedness between the swine H3N2v virus and previously circulating human strains, consistent with the fact that early human H3 seasonal strains entered the porcine population in the 1990s and reentered the human population, where they had not been circulating, as H3N2v about a decade later. The data also explain the increased susceptibility to H3N2v viruses in young children, who lack prior exposure to human seasonal strains from the 1990s. PMID:27482543

  1. Agglutination of human O erythrocytes by influenza A(H1N1) viruses freshly isolated from patients.

    PubMed

    Murakami, T; Haruki, K; Seto, Y; Kimura, T; Minoshiro, S; Shibe, K

    1991-04-01

    The hemagglutinin titers of 10 influenza A (H1N1) viruses were examined using the erythrocytes of several species. Human O erythrocytes showed the highest agglutination titer to the viruses, whereas chicken erythrocytes showed a low titer. These findings were noted for at least 10 passages by serial dilutions of the viruses in Madin-Darby canine kidney (MDCK) cells. All influenza A(H1N1) viruses, plaque-cloned directly from throat-washing specimens of patients, also agglutinated human O but not chicken erythrocytes. The results of a hemadsorption test indicated that chicken erythrocytes possess less affinity to MDCK cells infected with the A/Osaka City/2/88(H1N1) stain than to those infected with the A/Yamagata/120/86(H1N1) strain which is used as an inactivated influenza vaccine in Japan. However, there were no significant differences between the A/Osaka City/2/88 and the A/Yamagata/120/86 strains in the hemagglutination inhibition test. Since human O erythrocytes have high agglutination activity to influenza A(H1N1) and also to A(H3N2) and B viruses in MDCK cells, these erythrocytes may be useful for the serological diagnosis of influenza.

  2. United States of America Department of Health and Human Services support for advancing influenza vaccine manufacturing in the developing world.

    PubMed

    Perdue, Michael L; Bright, Rick A

    2011-07-01

    five years of age. In addition to achievements described in this issue of Vaccine, the programme has been successful from the US perspective because the working relationships established between the US Department of Health and Human Services' (HHS) Assistant Secretary for Preparedness and Response Biomedical Advanced Research and Development Authority (BARDA) and its partners have assisted in advancing influenza vaccine development at many different levels. A few examples of BARDA's support include: establishment of egg-based influenza vaccine production from "scratch", enhancement of live attenuated influenza vaccine (LAIV) production techniques and infrastructure, completion of fill/finish operations for imported bulk vaccine, and training in advanced bio-manufacturing techniques. These HHS-supported programmes have been well-received internationally, and we and our partners hope the successes will stimulate even more interest within the international community in maximizing global production levels for influenza vaccines.

  3. Sero-prevalence of avian influenza in animals and human in Egypt.

    PubMed

    El-Sayed, A; Prince, A; Fawzy, A; Nadra-Elwgoud; Abdou, M I; Omar, L; Fayed, A; Salem, M

    2013-06-01

    In opposite to most countries, avian influenza virus H5N1 became endemic in Egypt. Since, its first emerge in 2006 in Egypt, the virus could infect different species of birds and animals and even human. Beside the great economic losses to the local poultry industry in Egypt, the virus infected 166 confirmed human cases, 59 cases ended fatally. In the present study, the persistence of the avian influenza in the Egyptian environment was studied. For this purpose, serum samples were collected from human, cattle, buffaloes, sheep, goat, horses, donkeys, swine, sewage rats, stray dogs and stray cats. The sera were collected from Cairo and the surrounding governorates to be examined for the presence of anti-H5N1 antibodies by Haemagglutination Inhibition Test (HI) and ELISA test. Clear differences in the seroprevalence were noticed among different species and also between the results obtained by both techniques indicating the difference in test accuracy. The present data indicate wide spread of the H5N1 virus in the Egyptian environment.

  4. Investigation of avian influenza infections in wild birds, poultry and humans in Eastern Dongting Lake, China.

    PubMed

    Shi, Jinghong; Gao, Lidong; Zhu, Yun; Chen, Tao; Liu, Yunzhi; Dong, Libo; Liu, Fuqiang; Yang, Hao; Cai, Yahui; Yu, Mingdong; Yao, Yi; Xu, Cuilin; Xiao, Xiangming; Shu, Yuelong

    2014-01-01

    We investigated avian influenza infections in wild birds, poultry, and humans at Eastern Dongting Lake, China. We analyzed 6,621 environmental samples, including fresh fecal and water samples, from wild birds and domestic ducks that were collected from the Eastern Dongting Lake area from November 2011 to April 2012. We also conducted two cross-sectional serological studies in November 2011 and April 2012, with 1,050 serum samples collected from people exposed to wild birds and/or domestic ducks. Environmental samples were tested for the presence of avian influenza virus (AIV) using quantitative PCR assays and virus isolation techniques. Hemagglutination inhibition assays were used to detect antibodies against AIV H5N1, and microneutralization assays were used to confirm these results. Among the environmental samples from wild birds and domestic ducks, AIV prevalence was 5.19 and 5.32%, respectively. We isolated 39 and 5 AIVs from the fecal samples of wild birds and domestic ducks, respectively. Our analysis indicated 12 subtypes of AIV were present, suggesting that wild birds in the Eastern Dongting Lake area carried a diverse array of AIVs with low pathogenicity. We were unable to detect any antibodies against AIV H5N1 in humans, suggesting that human infection with H5N1 was rare in this region.

  5. Poultry food products--a source of avian influenza virus transmission to humans?

    PubMed

    Harder, T C; Buda, S; Hengel, H; Beer, M; Mettenleiter, T C

    2016-02-01

    Global human mobility and intercontinental connectivity, expansion of livestock production and encroachment of wildlife habitats by invasive agricultural land use contribute to shape the complexity of influenza epidemiology. The OneHealth approach integrates these and further elements into considerations to improve disease control and prevention. Food of animal origin for human consumption is another integral aspect; if produced from infected livestock such items may act as vehicles of spread of animal pathogens, and, in case of zoonotic agents, as a potential human health hazard. Notifiable zoonotic avian influenza viruses (AIV) have become entrenched in poultry populations in several Asian and northern African countries since 2003. Highly pathogenic (HP) AIV (e.g. H5N1) cause extensive poultry mortality and severe economic losses. HPAIV and low pathogenic AIV (e.g. H7N9) with zoonotic propensities pose risks for human health. More than 1500 human cases of AIV infection have been reported, mainly from regions with endemically infected poultry. Intense human exposure to AIV-infected poultry, e.g. during rearing, slaughtering or processing of poultry, is a major risk factor for acquiring AIV infection. In contrast, human infections through consumption of AIV-contaminated food have not been substantiated. Heating poultry products according to kitchen standards (core temperatures ≥70°C, ≥10 s) rapidly inactivates AIV infectivity and renders fully cooked products safe. Nevertheless, concerted efforts must ensure that poultry products potentially contaminated with zoonotic AIV do not reach the food chain. Stringent and sustained OneHealth measures are required to better control and eventually eradicate, HPAIV from endemic regions.

  6. Quantitative analysis of cellular proteome alterations in human influenza A virus-infected mammalian cell lines.

    PubMed

    Vester, Diana; Rapp, Erdmann; Gade, Dörte; Genzel, Yvonne; Reichl, Udo

    2009-06-01

    Over the last years virus-host cell interactions were investigated in numerous studies. Viral strategies for evasion of innate immune response, inhibition of cellular protein synthesis and permission of viral RNA and protein production were disclosed. With quantitative proteome technology, comprehensive studies concerning the impact of viruses on the cellular machinery of their host cells at protein level are possible. Therefore, 2-D DIGE and nanoHPLC-nanoESI-MS/MS analysis were used to qualitatively and quantitatively determine the dynamic cellular proteome responses of two mammalian cell lines to human influenza A virus infection. A cell line used for vaccine production (MDCK) was compared with a human lung carcinoma cell line (A549) as a reference model. Analyzing 2-D gels of the proteomes of uninfected and influenza-infected host cells, 16 quantitatively altered protein spots (at least +/-1.7-fold change in relative abundance, p<0.001) were identified for both cell lines. Most significant changes were found for keratins, major components of the cytoskeleton system, and for Mx proteins, interferon-induced key components of the host cell defense. Time series analysis of infection processes allowed the identification of further proteins that are described to be involved in protein synthesis, signal transduction and apoptosis events. Most likely, these proteins are required for supporting functions during influenza viral life cycle or host cell stress response. Quantitative proteome-wide profiling of virus infection can provide insights into complexity and dynamics of virus-host cell interactions and may accelerate antiviral research and support optimization of vaccine manufacturing processes.

  7. Novel Polymerase Gene Mutations for Human Adaptation in Clinical Isolates of Avian H5N1 Influenza Viruses

    PubMed Central

    Arai, Yasuha; Kawashita, Norihito; Daidoji, Tomo; Ibrahim, Madiha S.; El-Gendy, Emad M.; Takagi, Tatsuya; Takahashi, Kazuo; Suzuki, Yasuo; Ikuta, Kazuyoshi; Nakaya, Takaaki; Shioda, Tatsuo; Watanabe, Yohei

    2016-01-01

    A major determinant in the change of the avian influenza virus host range to humans is the E627K substitution in the PB2 polymerase protein. However, the polymerase activity of avian influenza viruses with a single PB2-E627K mutation is still lower than that of seasonal human influenza viruses, implying that avian viruses require polymerase mutations in addition to PB2-627K for human adaptation. Here, we used a database search of H5N1 clade 2.2.1 virus sequences with the PB2-627K mutation to identify other polymerase adaptation mutations that have been selected in infected patients. Several of the mutations identified acted cooperatively with PB2-627K to increase viral growth in human airway epithelial cells and mouse lungs. These mutations were in multiple domains of the polymerase complex other than the PB2-627 domain, highlighting a complicated avian-to-human adaptation pathway of avian influenza viruses. Thus, H5N1 viruses could rapidly acquire multiple polymerase mutations that function cooperatively with PB2-627K in infected patients for optimal human adaptation. PMID:27097026

  8. Novel Polymerase Gene Mutations for Human Adaptation in Clinical Isolates of Avian H5N1 Influenza Viruses.

    PubMed

    Arai, Yasuha; Kawashita, Norihito; Daidoji, Tomo; Ibrahim, Madiha S; El-Gendy, Emad M; Takagi, Tatsuya; Takahashi, Kazuo; Suzuki, Yasuo; Ikuta, Kazuyoshi; Nakaya, Takaaki; Shioda, Tatsuo; Watanabe, Yohei

    2016-04-01

    A major determinant in the change of the avian influenza virus host range to humans is the E627K substitution in the PB2 polymerase protein. However, the polymerase activity of avian influenza viruses with a single PB2-E627K mutation is still lower than that of seasonal human influenza viruses, implying that avian viruses require polymerase mutations in addition to PB2-627K for human adaptation. Here, we used a database search of H5N1 clade 2.2.1 virus sequences with the PB2-627K mutation to identify other polymerase adaptation mutations that have been selected in infected patients. Several of the mutations identified acted cooperatively with PB2-627K to increase viral growth in human airway epithelial cells and mouse lungs. These mutations were in multiple domains of the polymerase complex other than the PB2-627 domain, highlighting a complicated avian-to-human adaptation pathway of avian influenza viruses. Thus, H5N1 viruses could rapidly acquire multiple polymerase mutations that function cooperatively with PB2-627K in infected patients for optimal human adaptation.

  9. Dynamic transcriptional signatures and network responses for clinical symptoms in influenza-infected human subjects using systems biology approaches

    PubMed Central

    Linel, Patrice; Wu, Shuang; Deng, Nan

    2015-01-01

    Recent studies demonstrate that human blood transcriptional signatures may be used to support diagnosis and clinical decisions for acute respiratory viral infections such as influenza. In this article, we propose to use a newly developed systems biology approach for time course gene expression data to identify significant dynamically response genes and dynamic gene network responses to viral infection. We illustrate the methodological pipeline by reanalyzing the time course gene expression data from a study with healthy human subjects challenged by live influenza virus. We observed clear differences in the number of significant dynamic response genes (DRGs) between the symptomatic and asymptomatic subjects and also identified DRG signatures for symptomatic subjects with influenza infection. The 505 common DRGs shared by the symptomatic subjects have high consistency with the signature genes for predicting viral infection identified in previous works. The temporal response patterns and network response features were carefully analyzed and investigated. PMID:25015847

  10. Dynamic transcriptional signatures and network responses for clinical symptoms in influenza-infected human subjects using systems biology approaches.

    PubMed

    Linel, Patrice; Wu, Shuang; Deng, Nan; Wu, Hulin

    2014-10-01

    Recent studies demonstrate that human blood transcriptional signatures may be used to support diagnosis and clinical decisions for acute respiratory viral infections such as influenza. In this article, we propose to use a newly developed systems biology approach for time course gene expression data to identify significant dynamically response genes and dynamic gene network responses to viral infection. We illustrate the methodological pipeline by reanalyzing the time course gene expression data from a study with healthy human subjects challenged by live influenza virus. We observed clear differences in the number of significant dynamic response genes (DRGs) between the symptomatic and asymptomatic subjects and also identified DRG signatures for symptomatic subjects with influenza infection. The 505 common DRGs shared by the symptomatic subjects have high consistency with the signature genes for predicting viral infection identified in previous works. The temporal response patterns and network response features were carefully analyzed and investigated.

  11. Continuing challenges in influenza

    PubMed Central

    Webster, Robert G.; Govorkova, Elena A.

    2014-01-01

    Influenza is an acute respiratory disease in mammals and domestic poultry that emerges from zoonotic reservoirs in aquatic birds and bats. Although influenza viruses are among the most intensively studied pathogens, existing control options require further improvement. Influenza vaccines must be regularly updated because of continuous antigenic drift and sporadic antigenic shifts in the viral surface glycoproteins. Currently, influenza therapeutics are limited to neuraminidase inhibitors; novel drugs and vaccine approaches are therefore urgently needed. Advances in vaccinology and structural analysis have revealed common antigenic epitopes on hemagglutinins across all influenza viruses and suggest that a universal influenza vaccine is possible. In addition, various immunomodulatory agents and signaling pathway inhibitors are undergoing preclinical development. Continuing challenges in influenza include the emergence of pandemic H1N1 influenza in 2009, human infections with avian H7N9 influenza in 2013, and sporadic human cases of highly pathogenic avian H5N1 influenza. Here, we review the challenges facing influenza scientists and veterinary and human public health officials; we also discuss the exciting possibility of achieving the ultimate goal of controlling influenza’s ability to change its antigenicity. PMID:24891213

  12. Highly pathogenic avian influenza A(H5N1) mutants transmissible by air are susceptible to human and animal neutralizing antibodies.

    PubMed

    Du, Lanying; Li, Ye; Zhao, Guangyu; Wang, Lili; Zou, Peng; Lu, Lu; Zhou, Yusen; Jiang, Shibo

    2013-10-15

    A laboratory-generated reassortant H5 hemagglutinin (HA)/influenza A(H1N1) strain containing 4 mutations in influenza A(H5N1) HA has become transmissible by air among mammals. Here, we constructed 15 influenza A(H5N1) pseudoviruses containing a single mutation or a combination of mutations and showed that the pseudoviruses were susceptible to neutralizing antibodies from patients with influenza A(H5N1) infection and from mice immunized with a vaccine containing the conserved HA1 sequence of influenza A(H5N1). These results indicate that antibodies in patients currently infected by influenza A(H5N1) and antibodies induced by vaccines containing conserved sequences in HA1 of wild-type influenza A(H5N1) are highly effective in cross-neutralizing future influenza A(H5N1) mutants with airborne transmissibility, suggesting that human influenza pandemics caused by these influenza A(H5N1) variants can be prevented.

  13. Cell Penetrable Human scFv Specific to Middle Domain of Matrix Protein-1 Protects Mice from Lethal Influenza

    PubMed Central

    Dong-din-on, Fonthip; Songserm, Thaweesak; Pissawong, Tippawan; Srimanote, Potjanee; Thanongsaksrikul, Jeeraphong; Thueng-in, Kanyarat; Moonjit, Pattra; Lertwatcharasarakul, Preeda; Seesuay, Watee; Chaicumpa, Wanpen

    2015-01-01

    A new anti-influenza remedy that can tolerate the virus antigenic variation is needed. Influenza virus matrix protein-1 (M1) is highly conserved and pivotal for the virus replication cycle: virus uncoating, assembly and budding. An agent that blocks the M1 functions should be an effective anti-influenza agent. In this study, human scFv that bound to recombinant M1 middle domain (MD) and native M1 of A/H5N1 was produced. Phage mimotope search and computerized molecular docking revealed that the scFv bound to the MD conformational epitope formed by juxtaposed helices 7 and 9 of the M1. The scFv was linked molecularly to a cell penetrable peptide, penetratin (PEN). The PEN-scFv (transbody), when used to treat the cells pre-infected with the heterologous clade/subclade A/H5N1 reduced the viral mRNA intracellularly and in the cell culture fluids. The transbody mitigated symptom severity and lung histopathology of the H5N1 infected mice and caused reduction of virus antigen in the tissues as well as extricated the animals from the lethal challenge in a dose dependent manner. The transbody specific to the M1 MD, either alone or in combination with the cognate human scFvs specific to other influenza virus proteins, should be an effective, safe and mutation tolerable anti-influenza agent. PMID:25594836

  14. Surveillance of human influenza A(H3N2) virus from 1999 to 2009 in southern Italy.

    PubMed

    DE Donno, A; Idolo, A; Quattrocchi, M; Zizza, A; Gabutti, G; Romano, A; Grima, P; Donatelli, I; Guido, M

    2014-05-01

    The aim of this study was to evaluate the presence of influenza virus co-infections in humans and changes in the genetic variability of A(H3N2) virus strains in southern Italy from 1999 to 2009. A partial sequence of the haemagglutinin (HA) gene by human influenza H3N2 strains identified in oropharyngeal swabs from patients with influenza-like illness was analysed by DNA sequencing and a phylogenetic analysis was performed. During the seasons 1999-2000, 2002-2003, 2004-2005 and 2008-2009, the influenza viruses circulating belonged to subtype H3N2. However, A(H1N1) subtype virus and B type were respectively prevalent during the 2000-2001, 2006-2007, 2007-2008 and 2001-2002, 2003-2004, 2005-2006 seasons. The HA sequences appeared to be closely related to the sequence of the influenza A vaccine strain. Only the 2002-2003 season was characterized by co-circulation of two viral lineages: A/New York/55/01(H3N2)-like virus of the previous season and A/Fujian/411/02(H3N2)-like virus, a new H3 variant. In this study, over the decade analysed, no significant change was seen in the sequences of the HA gene of H3 viruses isolated.

  15. Trypsin- and low pH-mediated fusogenicity of avian metapneumovirus fusion proteins is determined by residues at positions 100, 101 and 294.

    PubMed

    Yun, Bingling; Guan, Xiaolu; Liu, Yongzhen; Gao, Yanni; Wang, Yongqiang; Qi, Xiaole; Cui, Hongyu; Liu, Changjun; Zhang, Yanping; Gao, Li; Li, Kai; Gao, Honglei; Gao, Yulong; Wang, Xiaomei

    2015-10-26

    Avian metapneumovirus (aMPV) and human metapneumovirus (hMPV) are members of the genus Metapneumovirus in the subfamily Pneumovirinae. Metapneumovirus fusion (F) protein mediates the fusion of host cells with the virus membrane for infection. Trypsin- and/or low pH-induced membrane fusion is a strain-dependent phenomenon for hMPV. Here, we demonstrated that three subtypes of aMPV (aMPV/A, aMPV/B, and aMPV/C) F proteins promoted cell-cell fusion in the absence of trypsin. Indeed, in the presence of trypsin, only aMPV/C F protein fusogenicity was enhanced. Mutagenesis of the amino acids at position 100 and/or 101, located at a putative cleavage region in aMPV F proteins, revealed that the trypsin-mediated fusogenicity of aMPV F proteins is regulated by the residues at positions 100 and 101. Moreover, we demonstrated that aMPV/A and aMPV/B F proteins mediated cell-cell fusion independent of low pH, whereas the aMPV/C F protein did not. Mutagenesis of the residue at position 294 in the aMPV/A, aMPV/B, and aMPV/C F proteins showed that 294G played a critical role in F protein-mediated fusion under low pH conditions. These findings on aMPV F protein-induced cell-cell fusion provide new insights into the molecular mechanisms underlying membrane fusion and pathogenesis of aMPV.

  16. Human mucosal-associated invariant T cells contribute to antiviral influenza immunity via IL-18–dependent activation

    PubMed Central

    Loh, Liyen; Wang, Zhongfang; Sant, Sneha; Koutsakos, Marios; Jegaskanda, Sinthujan; Liu, Ligong; Fairlie, David P.; Crowe, Jane; Rossjohn, Jamie; Xu, Jianqing; Doherty, Peter C.; Kedzierska, Katherine

    2016-01-01

    Mucosal-associated invariant T (MAIT) cells are innate-like T lymphocytes known to elicit potent immunity to a broad range of bacteria, mainly via the rapid production of inflammatory cytokines. Whether MAIT cells contribute to antiviral immunity is less clear. Here we asked whether MAIT cells produce cytokines/chemokines during severe human influenza virus infection. Our analysis in patients hospitalized with avian H7N9 influenza pneumonia showed that individuals who recovered had higher numbers of CD161+Vα7.2+ MAIT cells in peripheral blood compared with those who succumbed, suggesting a possible protective role for this lymphocyte population. To understand the mechanism underlying MAIT cell activation during influenza, we cocultured influenza A virus (IAV)-infected human lung epithelial cells (A549) and human peripheral blood mononuclear cells in vitro, then assayed them by intracellular cytokine staining. Comparison of influenza-induced MAIT cell activation with the profile for natural killer cells (CD56+CD3−) showed robust up-regulation of IFNγ for both cell populations and granzyme B in MAIT cells, although the individual responses varied among healthy donors. However, in contrast to the requirement for cell-associated factors to promote NK cell activation, the induction of MAIT cell cytokine production was dependent on IL-18 (but not IL-12) production by IAV-exposed CD14+ monocytes. Overall, this evidence for IAV activation via an indirect, IL-18–dependent mechanism indicates that MAIT cells are protective in influenza, and also possibly in any human disease process in which inflammation and IL-18 production occur. PMID:27543331

  17. Synthetic sialylphosphatidylethanolamine derivatives bind to human influenza A viruses and inhibit viral infection.

    PubMed

    Guo, C T; Wong, C H; Kajimoto, T; Miura, T; Ida, Y; Juneja, L R; Kim, M J; Masuda, H; Suzuki, T; Suzuki, Y

    1998-11-01

    We synthesized the sialylphosphatidylethanolamine (sialyl PE) derivatives Neu5Ac-PE, (Neu5Ac)2-PE, Neu5Ac-PE (amide) and Neu5Ac-PE (methyl). We examined the anti-viral effects of the derivatives on human influenza A virus infection by ELISA/virus-binding, hemagglutination inhibition, hemolysis inhibition and neutralization assays. The sialyl PE derivatives that we examined bound to A/Aichi/2/68, A/Singapore/1/57 and A/Memphis/1/71 strains of H3N2 subtype, but not to A/PR/8/34 strain of H1N1 subtype. The derivatives inhibited viral hemagglutination and hemolysis of human erythrocytes with A/Aichi/2/68 and A/Singapore/1/57 (H3N2), but not with A/PR/8/34 (H1N1). The inhibitory activity of the (Neu5Ac)2-PE derivative was the strongest of all sialyl PE derivatives (IC50, 35 microM to 40 microM). Sialyl PE derivatives also inhibited the infection of A/Aichi/2/68 in MDCK cells. Complete inhibition was observed at a concentration between 0.3 to 1.3 mM. IC50 of (Neu5Ac)2-PE was 15 microM in A/Aichi/2/68 strain. Taken together, the synthetic sialyl PE derivatives may be effective reagents against infection of some types of influenza A viruses.

  18. Ability of recombinant human catalase to suppress inflammation of the murine lung induced by influenza A.

    PubMed

    Shi, Xunlong; Shi, Zhihui; Huang, Hai; Zhu, Hongguang; Zhou, Pei; Zhu, Haiyan; Ju, Dianwen

    2014-06-01

    Influenza A virus pandemics and emerging antiviral resistance highlight the urgent need for novel generic pharmacological strategies that reduce both viral replication and inflammation of the lung. We have previously investigated the therapeutic efficacy of recombinant human catalase (rhCAT) against viral pneumonia in mice, but the protection mechanisms involved were not explored. In the present study, we have performed a more in-depth analysis covering survival, lung inflammation, immune cell responses, production of cytokines, and inflammation signaling pathways in mice. Male imprinting control region mice were infected intranasally with high pathogenicity (H1N1) influenza A virus followed by treatment with recombinant human catalase. The administration of rhCAT resulted in a significant reduction in inflammatory cell infiltration (e.g., macrophages and neutrophils), inflammatory cytokine levels (e.g., IL-2, IL-6, TNF-α, IFN-γ), the level of the intercellular adhesion molecule 1 chemokine and the mRNA levels of toll-like receptors TLR-4, TLR-7, and NF-κB, as well as partially maintaining the activity of the antioxidant enzymes system. These findings indicated that rhCAT might play a key protective role in viral pneumonia of mice via suppression of inflammatory immune responses.

  19. Chemoenzymatic synthesis of sialoglycopolypeptides as glycomimetics to block infection by avian and human influenza viruses.

    PubMed

    Ogata, Makoto; Hidari, Kazuya I P J; Murata, Takeomi; Shimada, Shizumi; Kozaki, Wataru; Park, Enoch Y; Suzuki, Takashi; Usui, Taichi

    2009-03-18

    We designed a series of gamma-polyglutamic acid (gamma-PGA)-based glycopolypeptides carrying long/short alpha2,3/6 sialylated glycans to act inhibitors of the influenza virus. As an alternative design, sialoglycopolypeptides carrying long-spacer linked glycans were engineered by replacement of the N-acetyllactosamine (LN) unit by an alkyl chain. The structure-activity relationship of the resulting sialoglycopolypeptides with different glycans in the array has been investigated by in vitro and in vivo infection experiments. The avian viruses specifically bound to glycopolypeptides carrying a short sialoglycan with higher affinity than to a long glycan. In contrast, human viruses, preferentially bound not only to long alpha2,3/6 sialylated glycan with LN repeats in the receptors, but also to more spacer-linked glycan in which the inner sugar has been replaced by a nonsugar structural unit such as a pentylamido group. Taken together, our results indicate that a spaced tandem/triplet pentylamido repeat is a good mimetic of a tandem/triplet LN repeat. Our strategy provides a facile way to design strong polymeric inhibitors of infection by avian and human influenza viruses.

  20. Immunization with influenza A NP-expressing vaccinia virus recombinant protects mice against experimental infection with human and avian influenza viruses.

    PubMed

    Altstein, A D; Gitelman, A K; Smirnov, Y A; Piskareva, L M; Zakharova, L G; Pashvykina, G V; Shmarov, M M; Zhirnov, O P; Varich, N P; Ilyinskii, P O; Shneider, A M

    2006-05-01

    Two-fold immunization of Balb/c mice with a vaccinia virus recombinant expressing the NP protein of influenza A/PR8/34 (H1N1) virus under the control of a strong synthetic promoter induced specific antibodies and protected animals against low-dose challenge by mouse-adapted heterosubtypic variants of human A/Aichi2/68 (H3N2) and avian A/Mallard/Pennsylvania/10218/84 (H5N2) influenza virus strains. The surviving immunized animals had lower anti-hemagglutinin antibody titers compared to non-immunized mice. There was no difference in viral titers in lungs of immunized and non-immunized animals that succumbed to the infection. In order to try to increase immune system presentation of NP-protein-derived peptides, and thereby increase their immunogenicity, we constructed another vaccinia-based NP-expressing recombinant containing a rapid proteolysis signal covalently bound to the NP protein. This sequence, derived from the mouse ornithine decarboxylase gene has been shown to increase degradation of various proteins. However, we found that when used as part of a recombinant NP, this signal neither increased its proteolytic degradation, nor was it more efficient in the induction of a protective response against influenza infection.

  1. The Human Antimicrobial Protein Bactericidal/Permeability-Increasing Protein (BPI) Inhibits the Infectivity of Influenza A Virus

    PubMed Central

    Pinkenburg, Olaf; Meyer, Torben; Bannert, Norbert; Norley, Steven; Bolte, Kathrin; Czudai-Matwich, Volker; Herold, Susanne; Gessner, André; Schnare, Markus

    2016-01-01

    In addition to their well-known antibacterial activity some antimicrobial peptides and proteins (AMPs) display also antiviral effects. A 27 aa peptide from the N-terminal part of human bactericidal/permeability-increasing protein (BPI) previously shown to harbour antibacterial activity inhibits the infectivity of multiple Influenza A virus strains (H1N1, H3N2 and H5N1) the causing agent of the Influenza pneumonia. In contrast, the homologous murine BPI-peptide did not show activity against Influenza A virus. In addition human BPI-peptide inhibits the activation of immune cells mediated by Influenza A virus. By changing the human BPI-peptide to the sequence of the mouse homologous peptide the antiviral activity was completely abolished. Furthermore, the human BPI-peptide also inhibited the pathogenicity of the Vesicular Stomatitis Virus but failed to interfere with HIV and measles virus. Electron microscopy indicate that the human BPI-peptide interferes with the virus envelope and at high concentrations was able to destroy the particles completely. PMID:27273104

  2. The origin of novel avian influenza A (H7N9) and mutation dynamics for its human-to-human transmissible capacity.

    PubMed

    Peng, Jin; Yang, Hao; Jiang, Hua; Lin, Yi-xiao; Lu, Charles Damien; Xu, Ya-wei; Zeng, Jun

    2014-01-01

    In February 2013, H7N9 (A/H7N9/2013_China), a novel avian influenza virus, broke out in eastern China and caused human death. It is a global priority to discover its origin and the point in time at which it will become transmittable between humans. We present here an interdisciplinary method to track the origin of H7N9 virus in China and to establish an evolutionary dynamics model for its human-to-human transmission via mutations. After comparing influenza viruses from China since 1983, we established an A/H7N9/2013_China virus evolutionary phylogenetic tree and found that the human instances of virus infection were of avian origin and clustered into an independent line. Comparing hemagglutinin (HA) and neuraminidase (NA) gene sequences of A/H7N9/2013_China viruses with all human-to-human, avian, and swine influenza viruses in China in the past 30 years, we found that A/H7N9/2013_China viruses originated from Baer's Pochard H7N1 virus of Hu Nan Province 2010 (HA gene, EPI: 370846, similarity with H7N9 is 95.5%) and duck influenza viruses of Nanchang city 2000 (NA gene, EPI: 387555, similarity with H7N9 is 97%) through genetic re-assortment. HA and NA gene sequence comparison indicated that A/H7N9/2013_China virus was not similar to human-to-human transmittable influenza viruses. To simulate the evolution dynamics required for human-to-human transmission mutations of H7N9 virus, we employed the Markov model. The result of this calculation indicated that the virus would acquire properties for human-to-human transmission in 11.3 years (95% confidence interval (CI): 11.2-11.3, HA gene).

  3. Human-Like H1 (Delta-Cluster) Swine Influenza Virus (SIV) Can Efficiently Replicate, Transmit, Cause Lung Pathology and Induce Humoral Immune Responses in the Swine Host

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction. Genomic characterization of recently identified H1 influenza A viruses demonstrated the viruses were triple reassortants with an internal gene constellation similar to contemporary U.S. swine influenza virus (SIV) but hemagglutinin (HA) and neuraminidase (NA) most similar to human seas...

  4. LGP2 downregulates interferon production during infection with seasonal human influenza A viruses that activate interferon regulatory factor 3.

    PubMed

    Malur, Meghana; Gale, Michael; Krug, Robert M

    2012-10-01

    LGP2, a member of the RIG-I-like receptor family, lacks the amino-terminal caspase activation recruitment domains (CARDs) required for initiating the activation of interferon regulatory factor 3 (IRF3) and interferon (IFN) transcription. The role of LGP2 in virus infection is controversial, and the only LGP2 experiments previously carried out with mammalian influenza A viruses employed an attenuated, mouse-adapted H1N1 A/PR/8/34 (PR8) virus that does not encode the NS1 protein. Here we determine whether LGP2 has a role during infection with wild-type, nonattenuated influenza A viruses that have circulated in the human population, specifically two types of seasonal influenza A viruses: (i) H3N2 and H1N1 viruses that activate IRF3 and IFN transcription and (ii) recent H1N1 viruses that block these two activations. In human cells infected with an H3N2 virus that activates IRF3, overexpression of LGP2 or its repressor domain decreased STAT1 activation and IFN-β transcription approximately 10-fold. Overexpression of LGP2 also caused a 10-fold decrease of STAT1 activation during infection with other seasonal influenza A viruses that activate IRF3. Using LGP2(+/+) and LGP2(-/-) mouse cells, we show that endogenous LGP2 decreased IFN production during H3N2 virus infection 3- to 4-fold. In contrast, in both mouse and human cells infected with H1N1 viruses that do not activate IRF3, LGP2 had no detectable role. These results demonstrate that LGP2 downregulates IFN production during infection by seasonal influenza A viruses that activate IRF3 and IFN transcription. It is intriguing that LGP2, a host protein induced during influenza A virus infection, downregulates the host antiviral IFN response.

  5. Clinical severity of human infections with avian influenza A(H7N9) virus, China, 2013/14.

    PubMed

    Feng, L; Wu, J T; Liu, X; Yang, P; Tsang, T K; Jiang, H; Wu, P; Yang, J; Fang, V J; Qin, Y; Lau, E H; Li, M; Zheng, J; Peng, Z; Xie, Y; Wang, Q; Li, Z; Leung, G M; Gao, G F; Yu, H; Cowling, B J

    2014-12-11

    Assessing the severity of emerging infections is challenging because of potential biases in case ascertainment. The first human case of infection with influenza A(H7N9) virus was identified in China in March 2013; since then, the virus has caused two epidemic waves in the country. There were 134 laboratory-confirmed cases detected in the first epidemic wave from January to September 2013. In the second epidemic wave of human infections with avian influenza A(H7N9) virus in China from October 2013 to October 2014, we estimated that the risk of death among hospitalised cases of infection with influenza A(H7N9) virus was 48% (95% credibility interval: 42-54%), slightly higher than the corresponding risk in the first wave. Age-specific risks of death among hospitalised cases were also significantly higher in the second wave. Using data on symptomatic cases identified through national sentinel influenza-like illness surveillance, we estimated that the risk of death among symptomatic cases of infection with influenza A(H7N9) virus was 0.10% (95% credibility interval: 0.029-3.6%), which was similar to previous estimates for the first epidemic wave of human infections with influenza A(H7N9) virus in 2013. An increase in the risk of death among hospitalised cases in the second wave could be real because of changes in the virus, because of seasonal changes in host susceptibility to severe infection, or because of variation in treatment practices between hospitals, while the increase could be artefactual because of changes in ascertainment of cases in different areas at different times.

  6. Poultry Market Closures and Human Infection with Influenza A(H7N9) Virus, China, 2013–14

    PubMed Central

    Wu, Peng; Jiang, Hui; Wu, Joseph T.; Chen, Enfu; He, Jianfeng; Zhou, Hang; Wei, Lan; Yang, Juan; Yang, Bingyi; Qin, Ying; Fang, Vicky J.; Li, Ming; Tsang, Tim K.; Zheng, Jiandong; Lau, Eric H. Y.; Cao, Yu; Chai, Chengliang; Zhong, Haojie; Li, Zhongjie; Leung, Gabriel M.; Feng, Luzhao; Gao, George F.; Cowling, Benjamin J.

    2014-01-01

    Closure of live poultry markets was implemented in areas affected by the influenza virus A(H7N9) outbreak in China during winter, 2013–14. Our analysis showed that closing live poultry markets in the most affected cities of Guangdong and Zhejiang provinces was highly effective in reducing the risk for H7N9 infection in humans. PMID:25340354

  7. 76 FR 51374 - Direct Discovery of HLA Associated Influenza Epitopes Isolated From Human Cells for Vaccine and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-18

    ... will provide the regulatory science to facilitate development and evaluation of direct discovery of HLA... HUMAN SERVICES Food and Drug Administration Direct Discovery of HLA Associated Influenza Epitopes... University of Oklahoma Health Sciences Center. The goal of the FDA, Center for Drug Evaluation and...

  8. Evolution of the H3 influenza virus hemagglutinin from human and nonhuman hosts.

    PubMed

    Bean, W J; Schell, M; Katz, J; Kawaoka, Y; Naeve, C; Gorman, O; Webster, R G

    1992-02-01

    The nucleotide and amino acid sequences of 40 influenza virus hemagglutinin genes of the H3 serotype from mammalian and avian species and 9 genes of the H4 serotype were compared, and their evolutionary relationships were evaluated. From these relationships, the differences in the mutational characteristics of the viral hemagglutinin in different hosts were examined and the RNA sequence changes that occurred during the generation of the progenitor of the 1968 human pandemic strain were examined. Three major lineages were defined: one containing only equine virus isolates; one containing only avian virus isolates; and one containing avian, swine, and human virus isolates. The human pandemic strain of 1968 was derived from an avian virus most similar to those isolated from ducks in Asia, and the transfer of this virus to humans probably occurred in 1965. Since then, the human viruses have diverged from this progenitor, with the accumulation of approximately 7.9 nucleotide and 3.4 amino acid substitutions per year. Reconstruction of the sequence of the hypothetical ancestral strain at the avian-human transition indicated that only 6 amino acids in the mature hemagglutinin molecule were changed during the transition between an avian virus strain and a human pandemic strain. All of these changes are located in regions of the molecule known to affect receptor binding and antigenicity. Unlike the human H3 influenza virus strains, the equine virus isolates have no close relatives in other species and appear to have diverged from the avian viruses much earlier than did the human virus strains. Mutations were estimated to have accumulated in the equine virus lineage at approximately 3.1 nucleotides and 0.8 amino acids per year. Four swine virus isolates in the analysis each appeared to have been introduced into pigs independently, with two derived from human viruses and two from avian viruses. A comparison of the coding and noncoding mutations in the mammalian and avian

  9. OpenFluDB, a database for human and animal influenza virus.

    PubMed

    Liechti, Robin; Gleizes, Anne; Kuznetsov, Dmitry; Bougueleret, Lydie; Le Mercier, Philippe; Bairoch, Amos; Xenarios, Ioannis

    2010-07-06

    Although research on influenza lasted for more than 100 years, it is still one of the most prominent diseases causing half a million human deaths every year. With the recent observation of new highly pathogenic H5N1 and H7N7 strains, and the appearance of the influenza pandemic caused by the H1N1 swine-like lineage, a collaborative effort to share observations on the evolution of this virus in both animals and humans has been established. The OpenFlu database (OpenFluDB) is a part of this collaborative effort. It contains genomic and protein sequences, as well as epidemiological data from more than 27,000 isolates. The isolate annotations include virus type, host, geographical location and experimentally tested antiviral resistance. Putative enhanced pathogenicity as well as human adaptation propensity are computed from protein sequences. Each virus isolate can be associated with the laboratories that collected, sequenced and submitted it. Several analysis tools including multiple sequence alignment, phylogenetic analysis and sequence similarity maps enable rapid and efficient mining. The contents of OpenFluDB are supplied by direct user submission, as well as by a daily automatic procedure importing data from public repositories. Additionally, a simple mechanism facilitates the export of OpenFluDB records to GenBank. This resource has been successfully used to rapidly and widely distribute the sequences collected during the recent human swine flu outbreak and also as an exchange platform during the vaccine selection procedure. Database URL: http://openflu.vital-it.ch.

  10. Haemophilus influenzae pneumonia in human immunodeficiency virus-infected patients. The Grupo Andaluz para el Estudio de las Enfermedades Infecciosas.

    PubMed

    Cordero, E; Pachón, J; Rivero, A; Girón, J A; Gómez-Mateos, J; Merino, M D; Torres-Tortosa, M; González-Serrano, M; Aliaga, L; Collado, A; Hernández-Quero, J; Barrera, A; Nuño, E

    2000-03-01

    Although Haemophilus influenzae is a common etiologic agent of pneumonia in patients infected with human immunodeficiency virus (HIV), the characteristics of this pneumonia have not been adequately assessed. We have prospectively studied features of H. influenzae pneumonia in 26 consecutive HIV-infected inpatients. Most of these patients were severely immunosuppressed; 73.1% had a CD4+ cell count <100/microL. A subacute clinical presentation was observed in 27% of the patients and was associated with a higher degree of immunosuppression (P=.04). Bilateral lung infiltrates were noted radiographically in 57.7% of the cases. The mortality attributable to H. influenzae pneumonia was 11.5%. Thus, pneumonia caused by H. influenzae affects mainly patients with advanced HIV disease, and since its clinical and radiological features may be diverse, this etiology should be considered when pneumonia occurs in patients with advanced HIV infection. The mortality rate associated with H. influenzae pneumonia is not higher than that occurring in the general population.

  11. Influenza A Viruses Control Expression of Proviral Human p53 Isoforms p53β and Δ133p53α

    PubMed Central

    Marcel, Virginie; Cartet, Gaëlle; Lane, David P.; Lina, Bruno; Rosa-Calatrava, Manuel

    2012-01-01

    Previous studies have described the role of p53 isoforms, including p53β and Δ133p53α, in the modulation of the activity of full-length p53, which regulates cell fate. In the context of influenza virus infection, an interplay between influenza viruses and p53 has been described, with p53 being involved in the antiviral response. However, the role of physiological p53 isoforms has never been explored in this context. Here, we demonstrate that p53 isoforms play a role in influenza A virus infection by using silencing and transient expression strategies in human lung epithelial cells. In addition, with the help of a panel of different influenza viruses from different subtypes, we also show that infection differentially regulates the expressions of p53β and Δ133p53α. Altogether, our results highlight the role of p53 isoforms in the viral cycle of influenza A viruses, with p53β and Δ133p53α acting as regulators of viral production in a p53-dependent manner. PMID:22647703

  12. Human vs. animal outbreaks of the 2009 swine-origin H1N1 influenza A epidemic.

    PubMed

    Scotch, Matthew; Brownstein, John S; Vegso, Sally; Galusha, Deron; Rabinowitz, Peter

    2011-09-01

    The majority of emerging infectious diseases are zoonotic in origin, including recently emerging influenza viruses such as the 2009 swine-origin H1N1 influenza A epidemic. The epidemic that year affected both human and animal populations as it spread globally. In fact, before the end of 2009, 14 different countries reported H1N1 infected swine. In order to better understand the zoonotic nature of the epidemic and the relationship between human and animal disease surveillance data streams, we compared 2009 reports of H1N1 infection to define the temporal relationship between reported cases in animals and humans. Generally, human cases preceded animal cases at a country-level, supporting the potential of H1N1 infection to be a "reverse zoonosis", and the value of integrating human and animal disease report data.

  13. In vitro enhancement of human natural cell-mediated cytotoxicity by purified influenza virus glycoproteins.

    PubMed Central

    Arora, D J; Houde, M; Justewicz, D M; Mandeville, R

    1984-01-01

    The role of the glycoproteins of influenza virus, hemagglutinin (HA), and neuraminidase (NA) in the in vitro stimulation of natural cell-mediated cytotoxicity (NCMC) or natural killer activity of human peripheral blood lymphocytes was evaluated with radiolabeled K562 cells as target cells in an overnight chromium release assay. Three different approaches were used. (i) Purified viral proteins were obtained by extraction with Nonidet P-40, separation on a sucrose gradient, and further purification by affinity chromatography. Ficoll-Hypaque-purified peripheral blood lymphocytes exposed to HA or NA individually or to a mixture of both significantly increased NCMC (32 to 50%). (ii) Treatment of HA and NA with their respective homologous antisera or F(ab')2 antibody abrogated the stimulation of NCMC by these glycoproteins. (iii) Virions treated with proteolytic enzymes resulted in viral cores lacking either HA or NA or both activities. Compared to whole virions, viral cores devoid of HA activity only induced a 50% increase in NCMC, whereas viral cores lacking HA activity and with traces of NA activity stimulated only 10% of the NCMC. These results suggest that influenza virus-induced cell-mediated cytotoxicity is largely due to its glycoproteins. PMID:6387178

  14. Productive infection of human skeletal muscle cells by pandemic and seasonal influenza A(H1N1) viruses.

    PubMed

    Desdouits, Marion; Munier, Sandie; Prevost, Marie-Christine; Jeannin, Patricia; Butler-Browne, Gillian; Ozden, Simona; Gessain, Antoine; Van Der Werf, Sylvie; Naffakh, Nadia; Ceccaldi, Pierre-Emmanuel

    2013-01-01

    Besides the classical respiratory and systemic symptoms, unusual complications of influenza A infection in humans involve the skeletal muscles. Numerous cases of acute myopathy and/or rhabdomyolysis have been reported, particularly following the outbreak of pandemic influenza A(H1N1) in 2009. The pathogenesis of these influenza-associated myopathies (IAM) remains unkown, although the direct infection of muscle cells is suspected. Here, we studied the susceptibility of cultured human primary muscle cells to a 2009 pandemic and a 2008 seasonal influenza A(H1N1) isolate. Using cells from different donors, we found that differentiated muscle cells (i. e. myotubes) were highly susceptible to infection by both influenza A(H1N1) isolates, whereas undifferentiated cells (i. e. myoblasts) were partially resistant. The receptors for influenza viruses, α2-6 and α2-3 linked sialic acids, were detected on the surface of myotubes and myoblasts. Time line of viral nucleoprotein (NP) expression and nuclear export showed that the first steps of the viral replication cycle could take place in muscle cells. Infected myotubes and myoblasts exhibited budding virions and nuclear inclusions as observed by transmission electron microscopy and correlative light and electron microscopy. Myotubes, but not myoblasts, yielded infectious virus progeny that could further infect naive muscle cells after proteolytic treatment. Infection led to a cytopathic effect with the lysis of muscle cells, as characterized by the release of lactate dehydrogenase. The secretion of proinflammatory cytokines by muscle cells was not affected following infection. Our results are compatible with the hypothesis of a direct muscle infection causing rhabdomyolysis in IAM patients.

  15. Avian metapneumovirus RT-nested-PCR: a novel false positive reducing inactivated control virus with potential applications to other RNA viruses and real time methods.

    PubMed

    Falchieri, Marco; Brown, Paul A; Catelli, Elena; Naylor, Clive J

    2012-12-01

    Using reverse genetics, an avian metapneumovirus (AMPV) was modified for use as a positive control for validating all stages of a popular established RT-nested PCR, used in the detection of the two major AMPV subtypes (A and B). Resultant amplicons were of increased size and clearly distinguishable from those arising from unmodified virus, thus allowing false positive bands, due to control virus contamination of test samples, to be identified readily. Absorption of the control virus onto filter paper and subsequent microwave irradiation removed all infectivity while its function as an efficient RT-nested-PCR template was unaffected. Identical amplicons were produced after storage for one year. The modified virus is likely to have application as an internal standard as well as in real time methods. Additions to AMPV of RNA from other RNA viruses, including hazardous examples such HIV and influenza, are likely to yield similar safe RT-PCR controls.

  16. Possible role of songbirds and parakeets in transmission of influenza A(H7N9) virus to humans.

    PubMed

    Jones, Jeremy C; Sonnberg, Stephanie; Koçer, Zeynep A; Shanmuganatham, Karthik; Seiler, Patrick; Shu, Yuelong; Zhu, Huachen; Guan, Yi; Peiris, Malik; Webby, Richard J; Webster, Robert G

    2014-03-01

    Avian-origin influenza A(H7N9) recently emerged in China, causing severe human disease. Several subtype H7N9 isolates contain influenza genes previously identified in viruses from finch-like birds. Because wild and domestic songbirds interact with humans and poultry, we investigated the susceptibility and transmissibility of subtype H7N9 in these species. Finches, sparrows, and parakeets supported replication of a human subtype H7N9 isolate, shed high titers through the oropharyngeal route, and showed few disease signs. Virus was shed into water troughs, and several contact animals seroconverted, although they shed little virus. Our study demonstrates that a human isolate can replicate in and be shed by such songbirds and parakeets into their environment. This finding has implications for these birds' potential as intermediate hosts with the ability to facilitate transmission and dissemination of A(H7N9) virus.

  17. High conservation level of CD8(+) T cell immunogenic regions within an unusual H1N2 human influenza variant.

    PubMed

    Komadina, Naomi; Quiñones-Parra, Sergio M; Kedzierska, Katherine; McCaw, James M; Kelso, Anne; Leder, Karin; McVernon, Jodie

    2016-10-01

    Current seasonal influenza vaccines require regular updates due to antigenic drift causing loss of effectiveness and therefore providing little or no protection against novel influenza A subtypes. Next generation vaccines capable of eliciting CD8(+) T cell (CTL) mediated cross-protective immunity may offer a long-term alternative strategy. However, measuring pre- and existing levels of CTL cross-protection in humans is confounded by differences in infection histories across individuals. During 2000-2003, H1N2 viruses circulated persistently in the human population for the first time and we hypothesized that the viral nucleoprotein (NP) contained novel CTL epitopes that may have contributed to the survival of the viruses. This study describes the immunogenic NP peptides of H1N1, H2N2, and H3N2 influenza viruses isolated from humans over the past century, 1918-2003, by comparing this historical dataset to reference NP peptides from H1N2 that circulated in humans during 2000-2003. Observed peptides sequences ranged from highly conserved (15%) to highly variable (12%), with variation unrelated to reported immunodominance. No unique NP peptides which were exclusive to the H1N2 viruses were noted. However, the virus had inherited the NP from a recently emerged H3N2 variant containing novel peptides, which may have assisted its persistence. Any advantage due to this novelty was subsequently lost with emergence of a newer H3N2 variant in 2003. Our approach has potential to provide insight into the population context in which influenza viruses emerge, and may help to inform immunogenic peptide selection for CTL-inducing influenza vaccines. J. Med. Virol. 88:1725-1732, 2016. © 2016 Wiley Periodicals, Inc.

  18. Positive Selection in CD8+ T-Cell Epitopes of Influenza Virus Nucleoprotein Revealed by a Comparative Analysis of Human and Swine Viral Lineages

    PubMed Central

    Machkovech, Heather M.; Bedford, Trevor; Suchard, Marc A.

    2015-01-01

    ABSTRACT Numerous experimental studies have demonstrated that CD8+ T cells contribute to immunity against influenza by limiting viral replication. It is therefore surprising that rigorous statistical tests have failed to find evidence of positive selection in the epitopes targeted by CD8+ T cells. Here we use a novel computational approach to test for selection in CD8+ T-cell epitopes. We define all epitopes in the nucleoprotein (NP) and matrix protein (M1) with experimentally identified human CD8+ T-cell responses and then compare the evolution of these epitopes in parallel lineages of human and swine influenza viruses that have been diverging since roughly 1918. We find a significant enrichment of substitutions that alter human CD8+ T-cell epitopes in NP of human versus swine influenza virus, consistent with the idea that these epitopes are under positive selection. Furthermore, we show that epitope-altering substitutions in human influenza virus NP are enriched on the trunk versus the branches of the phylogenetic tree, indicating that viruses that acquire these mutations have a selective advantage. However, even in human influenza virus NP, sites in T-cell epitopes evolve more slowly than do nonepitope sites, presumably because these epitopes are under stronger inherent functional constraint. Overall, our work demonstrates that there is clear selection from CD8+ T cells in human influenza virus NP and illustrates how comparative analyses of viral lineages from different hosts can identify positive selection that is otherwise obscured by strong functional constraint. IMPORTANCE There is a strong interest in correlates of anti-influenza immunity that are protective against diverse virus strains. CD8+ T cells provide such broad immunity, since they target conserved viral proteins. An important question is whether T-cell immunity is sufficiently strong to drive influenza virus evolution. Although many studies have shown that T cells limit viral replication in animal

  19. Emergence in China of human disease due to avian influenza A(H10N8)--cause for concern?

    PubMed

    To, Kelvin K W; Tsang, Alan K L; Chan, Jasper F W; Cheng, Vincent C C; Chen, Honglin; Yuen, Kwok-Yung

    2014-03-01

    In December 2013, China reported the first human case of avian influenza A(H10N8). A 73-year-old female with chronic diseases who had visited a live poultry market succumbed with community-acquired pneumonia. While human infections with avian influenza viruses are usually associated with subtypes prevalent in poultries, A(H10N8) isolates were mostly found in migratory birds and only recently in poultries. Although not possible to predict whether this single intrusion by A(H10N8) is an accident or the start of another epidemic like the preceding A(H7N9) and A(H5N1), several features suggest that A(H10N8) is a potential threat to humans. Recombinant H10 could attach to human respiratory epithelium, and A(H10N4) virus could cause severe infections in minks and chickens. A(H10N8) viruses contain genetic markers for mammalian adaptation and virulence in the haemagglutinin (A135T, S138A[H3 numbering]), M1(N30D, T215A), NS1(P42S) and PB2(E627K) protein. Studies on this human A(H10N8) isolate will reveal its adaptability to humans. Clinicians should alert the laboratory to test for A(H5,6,7,9,10) viruses in patients with epidemiological exposure in endemic geographical areas especially when human influenza A(H1,3) and B are negative. Vigilant virological and serological surveillance for A(H10N8) in human, poultry and wild bird is important for following the trajectory of this emerging influenza virus.

  20. Structures and receptor binding of hemagglutinins from human-infecting H7N9 influenza viruses.

    PubMed

    Shi, Yi; Zhang, Wei; Wang, Fei; Qi, Jianxun; Wu, Ying; Song, Hao; Gao, Feng; Bi, Yuhai; Zhang, Yanfang; Fan, Zheng; Qin, Chengfeng; Sun, Honglei; Liu, Jinhua; Haywood, Joel; Liu, Wenjun; Gong, Weimin; Wang, Dayan; Shu, Yuelong; Wang, Yu; Yan, Jinghua; Gao, George F

    2013-10-11

    An avian-origin human-infecting influenza (H7N9) virus was recently identified in China. We have evaluated the viral hemagglutinin (HA) receptor-binding properties of two human H7N9 isolates, A/Shanghai/1/2013 (SH-H7N9) (containing the avian-signature residue Gln(226)) and A/Anhui/1/2013 (AH-H7N9) (containing the mammalian-signature residue Leu(226)). We found that SH-H7N9 HA preferentially binds the avian receptor analog, whereas AH-H7N9 HA binds both avian and human receptor analogs. Furthermore, an AH-H7N9 mutant HA (Leu(226) → Gln) was found to exhibit dual receptor-binding property, indicating that other amino acid substitutions contribute to the receptor-binding switch. The structures of SH-H7N9 HA, AH-H7N9 HA, and its mutant in complex with either avian or human receptor analogs show how AH-H7N9 can bind human receptors while still retaining the avian receptor-binding property.

  1. Substrate Specificity of Equine and Human Influenza A Virus Sialidase to Molecular Species of Sialic Acid.

    PubMed

    Takahashi, Tadanobu; Unuma, Saori; Kawagishi, Sawako; Kurebayashi, Yuuki; Takano, Maiko; Yoshino, Hiroki; Minami, Akira; Yamanaka, Takashi; Otsubo, Tadamune; Ikeda, Kiyoshi; Suzuki, Takashi

    2016-01-01

    Most equine influenza A viruses (IAVs) show strong binding to glycoconjugates containing N-glycolylneuraminic acid (Neu5Gc) as well as N-acetylneuraminic acid (Neu5Ac). Therefore, the progeny of equine IAV is thought to be released from the infected cell surface through removal of sialic acids by the viral sialidase. In the present study, equine IAV sialidases showed significantly lower substrate affinity than that of human IAV sialidases to artificial and natural Neu5Gc-conjugated substrates. The substrate specificity of equine IAV sialidases is in disagreement with their binding specificity to molecular species of sialic acid. The results suggest that substrate specificity of equine IAV sialidase for Neu5Ac, rather than for Neu5Gc, is important for an advantage at the early infection stage and the process of progeny virus release from the surface of infected cells.

  2. Human/bovine chimeric MxA-like GTPases reveal a contribution of N-terminal domains to the magnitude of anti-influenza A activity.

    PubMed

    Garigliany, Mutien-Marie; Cornet, Anne; Desmecht, Daniel

    2012-07-01

    Type I interferons (IFN-α/β) provide powerful and universal innate intracellular defense mechanisms against viruses. Among the antiviral effectors induced by IFN-α/β, Mx proteins of some species appear as key components of defense against influenza A viruses. The body of work published to date suggests that to exert anti-influenza activity, an Mx protein should possess a GTP-binding site, structural bases allowing multimerisation, and a specific C-terminal GTPase effector domain (GED). Both the human MxA and bovine Mx1 proteins meet these minimal requirements, but the bovine protein is more active against influenza viruses. Here, we measured the anti-influenza activity exerted by 2 human/bovine chimeric Mx proteins. We show that substituting the bovine GED for the human one in human MxA does not affect the magnitude of anti-influenza activity. Strikingly, however, substituting the human GED for the bovine one in bovine Mx1 yields a chimeric protein with a much higher anti-influenza activity than the human protein. We conclude, in contradiction to the hypothesis currently in vogue in the literature, that the GED is not the sole determinant controlling the magnitude of the anti-influenza activity exercised by an Mx protein that can bind GTP and multimerise. Our results suggest that 1 or several motifs that remain to be discovered, located N-terminally with regard to the GED, may interact with a viral component or a cellular factor so as to alter the viral cycle. Identifying, in the N-terminal portion of bovine Mx1, the motif(s) responsible for its higher anti-influenza activity could contribute to the development of new anti-influenza molecules.

  3. Host-Specific and Segment-Specific Evolutionary Dynamics of Avian and Human Influenza A Viruses: A Systematic Review.

    PubMed

    Kim, Kiyeon; Omori, Ryosuke; Ueno, Keisuke; Iida, Sayaka; Ito, Kimihito

    2016-01-01

    Understanding the evolutionary dynamics of influenza viruses is essential to control both avian and human influenza. Here, we analyze host-specific and segment-specific Tajima's D trends of influenza A virus through a systematic review using viral sequences registered in the National Center for Biotechnology Information. To avoid bias from viral population subdivision, viral sequences were stratified according to their sampling locations and sampling years. As a result, we obtained a total of 580 datasets each of which consists of nucleotide sequences of influenza A viruses isolated from a single population of hosts at a single sampling site within a single year. By analyzing nucleotide sequences in the datasets, we found that Tajima's D values of viral sequences were different depending on hosts and gene segments. Tajima's D values of viruses isolated from chicken and human samples showed negative, suggesting purifying selection or a rapid population growth of the viruses. The negative Tajima's D values in rapidly growing viral population were also observed in computer simulations. Tajima's D values of PB2, PB1, PA, NP, and M genes of the viruses circulating in wild mallards were close to zero, suggesting that these genes have undergone neutral selection in constant-sized population. On the other hand, Tajima's D values of HA and NA genes of these viruses were positive, indicating HA and NA have undergone balancing selection in wild mallards. Taken together, these results indicated the existence of unknown factors that maintain viral subtypes in wild mallards.

  4. Human exposure to live poultry and psychological and behavioral responses to influenza A(H7N9), China.

    PubMed

    Wang, Liping; Cowling, Benjamin J; Wu, Peng; Yu, Jianxing; Li, Fu; Zeng, Lingjia; Wu, Joseph T; Li, Zhongjie; Leung, Gabriel M; Yu, Hongjie

    2014-08-01

    To investigate human exposure to live poultry and changes in risk perception and behavior after the April 2013 influenza A(H7N9) outbreak in China, we surveyed 2,504 urban residents in 5 cities and 1,227 rural residents in 4 provinces and found that perceived risk for influenza A(H7N9) was low. The highest rate of exposure to live poultry was reported in Guangzhou, where 47% of those surveyed reported visiting a live poultry market > or =1 times in the previous year. Most (77%) urban respondents reported that they visited live markets less often after influenza A(H7N9) cases were first identified in China in March 2013, but only 30% supported permanent closure of the markets to control the epidemic. In rural areas, 48% of respondents reported that they raised backyard poultry. Exposure to live commercial and private poultry is common in urban and rural China and remains a potential risk factor for human infection with novel influenza viruses.

  5. Human Exposure to Live Poultry and Psychological and Behavioral Responses to Influenza A(H7N9), China

    PubMed Central

    Wang, Liping; Cowling, Benjamin J.; Wu, Peng; Yu, Jianxing; Li, Fu; Zeng, Lingjia; Wu, Joseph T.; Li, Zhongjie; Leung, Gabriel M.

    2014-01-01

    To investigate human exposure to live poultry and changes in risk perception and behavior after the April 2013 influenza A(H7N9) outbreak in China, we surveyed 2,504 urban residents in 5 cities and 1,227 rural residents in 4 provinces and found that perceived risk for influenza A(H7N9) was low. The highest rate of exposure to live poultry was reported in Guangzhou, where 47% of those surveyed reported visiting a live poultry market >1 times in the previous year. Most (77%) urban respondents reported that they visited live markets less often after influenza A(H7N9) cases were first identified in China in March 2013, but only 30% supported permanent closure of the markets to control the epidemic. In rural areas, 48% of respondents reported that they raised backyard poultry. Exposure to live commercial and private poultry is common in urban and rural China and remains a potential risk factor for human infection with novel influenza viruses. PMID:25076186

  6. Human CD4+ T-cell repertoire of responses to influenza A virus hemagglutinin after recent natural infection.

    PubMed Central

    Gelder, C M; Welsh, K I; Faith, A; Lamb, J R; Askonas, B A

    1995-01-01

    The human CD4+ T-cell repertoire of responses to hemagglutinin (HA) of influenza virus A/Beijing/32/92 was examined 3 to 6 months after natural infection by using a panel of 16-mer peptides overlapping by 11 residues. Short-term CD4+ T-cell lines were derived by using full-length HAs of virus A/Beijing/32/92 from 12 unrelated, major histocompatibility complex (MHC) class I and II haplotyped adults with a history of influenza in November and December 1993 and from 6 adults with no history of influenza during the preceding 4 years but who responded to HA. In contrast to recent murine studies, the human CD4+ T-cell repertoire of responses was dominated by the recognition of highly conserved epitopes. The HA2 subunit, widely regarded as nonimmunogenic, induced strong responses in every donor. This resulted in functional cross-reactivity among influenza A viruses. Our study included one pair of unrelated donors expressing identical HLA DRB1 and DQB1 alleles and two pairs of donors sharing low-resolution MHC class II types. These pairs responded to identical peptides; furthermore, clearly identifiable patterns of response were seen in donors sharing single class II haplotypes, irrespective of the presence of other alleles and exposure history. Two conserved regions which induced responses in 17 of 18 donors were identified (residues 295 to 328 and 407 to 442). Possible implications for cross-reactive T-cell vaccines are discussed. PMID:7494256

  7. Respiratory Syncytial Virus and Other Respiratory Viral Infections in Older Adults With Moderate to Severe Influenza-like Illness

    PubMed Central

    Falsey, Ann R.; McElhaney, Janet E.; Beran, Jiri; van Essen, Gerrit A.; Duval, Xavier; Esen, Meral; Galtier, Florence; Gervais, Pierre; Hwang, Shinn-Jang; Kremsner, Peter; Launay, Odile; Leroux-Roels, Geert; McNeil, Shelly A.; Nowakowski, Andrzej; Richardus, Jan Hendrik; Ruiz-Palacios, Guillermo; St Rose, Suzanne; Devaster, Jeanne-Marie; Oostvogels, Lidia; Durviaux, Serge; Taylor, Sylvia

    2014-01-01

    Background. Few studies have prospectively assessed viral etiologies of acute respiratory infections in community-based elderly individuals. We assessed viral respiratory pathogens in individuals ≥65 years with influenza-like illness (ILI). Methods. Multiplex reverse-transcriptase polymerase chain reaction identified viral pathogens in nasal/throat swabs from 556 episodes of moderate-to-severe ILI, defined as ILI with pneumonia, hospitalization, or maximum daily influenza symptom severity score (ISS) >2. Cases were selected from a randomized trial of an adjuvanted vs nonadjuvanted influenza vaccine conducted in elderly adults from 15 countries. Results. Respiratory syncytial virus (RSV) was detected in 7.4% (41/556) moderate-to-severe ILI episodes in elderly adults. Most (39/41) were single infections. There was a significant association between country and RSV detection (P = .004). RSV prevalence was 7.1% (2/28) in ILI with pneumonia, 12.5% (8/64) in ILI with hospitalization, and 6.7% (32/480) in ILI with maximum ISS > 2. Any virus was detected in 320/556 (57.6%) ILI episodes: influenza A (104/556, 18.7%), rhinovirus/enterovirus (82/556, 14.7%), coronavirus and human metapneumovirus (each 32/556, 5.6%). Conclusions. This first global study providing data on RSV disease in ≥65 year-olds confirms that RSV is an important respiratory pathogen in the elderly. Preventative measures such as vaccination could decrease severe respiratory illnesses and complications in the elderly. PMID:24482398

  8. Avian Influenza Virus H3 Hemagglutinin May Enable High Fitness of Novel Human Virus Reassortants

    PubMed Central

    Kreibich, Anne; Stech, Olga; Hundt, Jana; Ziller, Mario; Mettenleiter, Thomas C.; Stech, Juergen

    2013-01-01

    Reassortment of influenza A virus genes enables antigenic shift resulting in the emergence of pandemic viruses with novel hemagglutinins (HA) acquired from avian strains. Here, we investigated whether historic and contemporary avian strains with different replication capacity in human cells can donate their hemagglutinin to a pandemic human virus. We performed double-infections with two avian H3 strains as HA donors and a human acceptor strain, and determined gene compositions and replication of HA reassortants in mammalian cells. To enforce selection for the avian virus HA, we generated a strictly elastase-dependent HA cleavage site mutant from A/Hong Kong/1/68 (H3N2) (Hk68-Ela). This mutant was used for co-infections of human cells with A/Duck/Ukraine/1/63 (H3N8) (DkUkr63) or the more recent A/Mallard/Germany/Wv64-67/05 (H3N2) (MallGer05) in the absence of elastase but presence of trypsin. Among 21 plaques analyzed from each assay, we found 12 HA reassortants with DkUkr63 (4 genotypes) and 14 with MallGer05 (10 genotypes) that replicated in human cells comparable to the parental human virus. Although DkUkr63 replicated in mammalian cells at a reduced level compared to MallGer05 and Hk68, it transmitted its HA to the human virus, indicating that lower replication efficiency of an avian virus in a mammalian host may not constrain the emergence of viable HA reassortants. The finding that HA and HA/NA reassortants replicated efficiently like the human virus suggests that further HA adaptation remains a relevant barrier for emergence of novel HA reassortants. PMID:24265752

  9. The threat of human influenza: the viruses, disease impacts, and vaccine solutions.

    PubMed

    Yin, Jiehui Kevin; Salkeld, Glenn; Heron, Leon; Khandaker, Gulam; Rashid, Harunor; Booy, Robert

    2014-01-01

    Influenza is an acute respiratory illness that remains an important cause of excessive morbidity and mortality with substantial economic cost to the population. Influenza, being a virus that frequently mutates, is not amenable to elimination. Vaccination remains the most effective preventive measure. This review summarises the latest developments in the fields of biology and epidemiology relating to clinical and economic impacts of influenza disease, and vaccination. We suggest that future efforts should focus on developing safer, more effective, and cost-effective prophylactic vaccines for influenza.

  10. Transmissibility of Variant Influenza From Swine to Humans: A Modeling Approach

    PubMed Central

    Wong, Karen K.; Gambhir, Manoj; Finelli, Lyn; Swerdlow, David L.; Ostroff, Stephen; Reed, Carrie

    2015-01-01

    Background Respiratory illness was reported among humans and swine at an agricultural fair in 2011; 3 human infections with an influenza A(H3N2) variant (H3N2v) virus were confirmed. Using epidemiologic investigation data, we sought to estimate H3N2v transmissibility from swine to humans. Methods We developed a model of H3N2v transmission among swine and humans and fit it to data from a cohort of 100 agricultural club members reporting swine contact to estimate transmissibility. A sensitivity analysis was performed varying H3N2v prevalence in the club cohort. Using the best-fit transmission probability, we simulated the number of swine-acquired infections among all fair attendees. Results We estimated the best-fit probability of swine-to-human H3N2v transmission per minute of swine contact. Applying this probability to 14 910 people with swine contact at the fair, we estimate that there were 80 (95% confidence interval [CI], 40–133) H3N2v infections among persons aged <20 years and 58 (95% CI, 29–96) H3N2v infections among person aged ≥20 years. Conclusions Using early data from investigation of a new virus with unclear transmission properties, we estimated the transmissibility of H3N2v from swine to humans and the burden of H3N2v among fair attendees. Although the risk of H3N2v virus infection is small for fair attendees with minimal swine contact, large populations attend agricultural events each year, and human cases will likely occur when infected swine are present. PMID:23794727

  11. Prevalence and control of H7 avian influenza viruses in birds and humans.

    PubMed

    Abdelwhab, E M; Veits, J; Mettenleiter, T C

    2014-05-01

    The H7 subtype HA gene has been found in combination with all nine NA subtype genes. Most exhibit low pathogenicity and only rarely high pathogenicity in poultry (and humans). During the past few years infections of poultry and humans with H7 subtypes have increased markedly. This review summarizes the emergence of avian influenza virus H7 subtypes in birds and humans, and the possibilities of its control in poultry. All H7Nx combinations were reported from wild birds, the natural reservoir of the virus. Geographically, the most prevalent subtype is H7N7, which is endemic in wild birds in Europe and was frequently reported in domestic poultry, whereas subtype H7N3 is mostly isolated from the Americas. In humans, mild to fatal infections were caused by subtypes H7N2, H7N3, H7N7 and H7N9. While infections of humans have been associated mostly with exposure to domestic poultry, infections of poultry have been linked to wild birds or live-bird markets. Generally, depopulation of infected poultry was the main control tool; however, inactivated vaccines were also used. In contrast to recent cases caused by subtype H7N9, human infections were usually self-limiting and rarely required antiviral medication. Close genetic and antigenic relatedness of H7 viruses of different origins may be helpful in development of universal vaccines and diagnostics for both animals and humans. Due to the wide spread of H7 viruses and their zoonotic importance more research is required to better understand the epidemiology, pathobiology and virulence determinants of these viruses and to develop improved control tools.

  12. [Genetic Diversity and Evolution of the M Gene of Human Influenza A Viruses from 2009 to 2013 in Hangzhou, China].

    PubMed

    Shao, Tiejuan; Li, Jun; Pu, Xiaoying; Yu, Xinfen; Kou, Yu; Zhou, Yinyan; Qian, Xin

    2015-03-01

    We investigated the genetic diversity and evolution of the M gene of human influenza A viruses in Hangzhou (Zhejiang province, China) from 2009 to 2013, including subtypes of A(H1N1) pdm09 strains and seasonal A(H3N2) strains. Subtypes of analyzed viruses were identified by cell culture and real-time reverse transcription-polymerase chain reaction, followed by cloning, sequencing and phylogenetic analyses of the M gene. Assessment of 5675 throat swabs revealed a positive rate for the influenza virus of 20.46%, and 827 cases were diagnosed as. infections due to influenza A viruses. Seventy-six influenza-A strains were selected randomly from nine stages during six phases of a virus epidemic. Sequences of the M gene showed high homology among six epidemics with identities of amino-acid sequences of 98.98-100%. All strains contained the adamantine-resistant mutation S31N in its M2 protein. Two of the A(H1N1)pdm09 strains had double mutants of V27A/S31N or V271/S31N. One of the seasonal A(H3N2) viruses had another form of double-mutant R45H/S31N. Evolutionary rate of the M gene was much lower than that of the HA gene and NA gene. Compared with A(H3N2) strains, higher positive pressure on the M1 and M2 proteins of A(H1N1) pdm09 viruses was observed. Separate analyses of M1 and M2 proteins revealed very different selection pressures. Knowledge of the genetic diversity and evolution of the M gene of human influenza-A viruses will be valuable for the control and prevention of diseases.

  13. Avian and pandemic human influenza policy in South-East Asia: the interface between economic and public health imperatives.

    PubMed

    Pongcharoensuk, Petcharat; Adisasmito, Wiku; Sat, Le Minh; Silkavute, Pornpit; Muchlisoh, Lilis; Cong Hoat, Pham; Coker, Richard

    2012-08-01

    The aim of this study was to analyse the contemporary policies regarding avian and human pandemic influenza control in three South-East Asia countries: Thailand, Indonesia and Vietnam. An analysis of poultry vaccination policy was used to explore the broader policy of influenza A H5N1 control in the region. The policy of antiviral stockpiling with oseltamivir, a scarce regional resource, was used to explore human pandemic influenza preparedness policy. Several policy analysis theories were applied to analyse the debate on the use of vaccination for poultry and stockpiling of antiviral drugs in each country case study. We conducted a comparative analysis across emergent themes. The study found that whilst Indonesia and Vietnam introduced poultry vaccination programmes, Thailand rejected this policy approach. By contrast, all three countries adopted similar strategic policies for antiviral stockpiling in preparation. In relation to highly pathogenic avian influenza, economic imperatives are of critical importance. Whilst Thailand's poultry industry is large and principally an export economy, Vietnam's and Indonesia's are for domestic consumption. The introduction of a poultry vaccination policy in Thailand would have threatened its potential to trade and had a major impact on its economy. Powerful domestic stakeholders in Vietnam and Indonesia, by contrast, were concerned less about international trade and more about maintaining a healthy domestic poultry population. Evidence on vaccination was drawn upon differently depending upon strategic economic positioning either to support or oppose the policy. With influenza A H5N1 endemic in some countries of the region, these policy differences raise questions around regional coherence of policies and the pursuit of an agreed overarching goal, be that eradication or mitigation. Moreover, whilst economic imperatives have been critically important in guiding policy formulation in the agriculture sector, questions arise

  14. Influenza in Children.

    PubMed

    Kumar, Virendra

    2017-02-01

    In children, influenza is one among the commonest causes of acute respiratory illness and loss of school days. Influenza A, B, and C are 3 types of viruses responsible for illness. Type A virus has many subtypes based on antigens but Type B and Type C viruses have no known subtypes. Currently, influenza A/H1N1, A/H3N2, and influenza type B viruses are circulating in humans. Transmission of influenza occurs through droplets from infected person or through direct contact with person or fomites. Clinically, influenza is characterized by acute onset fever, chills, running nose, cough, sore throat, headache and myalgia. Mostly, febrile illness lasts for 3-4 d with resolution of disease in 7-10 d. Confirmation of influenza can be done either by virus culture, RT-PCR or specific neutralizing antibodies in blood. Basic principles of management include prompt institution of infection control measures, early identification of children at higher risk, supportive care and antiviral drugs. Vaccine and chemoprophylaxis are two commonly used methods for prevention of influenza. Currently, inactivated influenza vaccine (IIV) and live attenuated influenza vaccine (LAIV) are available for use with good efficacy. Cough etiquette, use of face masks and hand hygiene are the most important measures to reduce the risk of infection transmission from person to person.

  15. Improving pandemic influenza risk assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Assessing the pandemic risk posed by specific non-human influenza A viruses remains a complex challenge. As influenza virus genome sequencing becomes cheaper, faster and more readily available, the ability to predict pandemic potential from sequence data could transform pandemic influenza risk asses...

  16. Characterization of Influenza A (H7N9) Viruses Isolated from Human Cases Imported into Taiwan

    PubMed Central

    Yang, Ji-Rong; Kuo, Chuan-Yi; Huang, Hsiang-Yi; Wu, Fu-Ting; Huang, Yi-Lung; Cheng, Chieh-Yu; Su, Yu-Ting; Wu, Ho-Sheng; Liu, Ming-Tsan

    2015-01-01

    A novel avian influenza A (H7N9) virus causes severe human infections and was first identified in March 2013 in China. The H7N9 virus has exhibited two epidemiological peaks of infection, occurring in week 15 of 2013 and week 5 of 2014. Taiwan, which is geographically adjacent to China, faces a large risk of being affected by this virus. Through extensive surveillance, launched in April 2013, four laboratory-confirmed H7N9 cases imported from China have been identified in Taiwan. The H7N9 virus isolated from imported case 1 in May 2013 (during the first wave) was found to be closest genetically to a virus from wild birds and differed from the prototype virus, A/Anhui/1/2013, in the MP gene. The other three imported cases were detected in December 2013 and April 2014 (during the second wave). The viruses isolated from cases 2 and 4 were similar in the compositions of their 6 internal genes and distinct from A/Anhui/1/2013 in the PB2 and MP genes, whereas the virus isolated from case 3 exhibited a novel reassortment that has not been identified previously and was different from A/Anhui/1/2013 in the PB2, PA and MP genes. The four imported H7N9 viruses share similar antigenicity with A/Anhui/1/2013, and their HA and NA genes grouped together in their respective phylogenies. In contrast with the HA and NA genes, which exhibited a smaller degree of diversity, the internal genes were heterogeneous and provided potential distinctions between transmission sources in terms of both geography and hosts. It is important to strengthen surveillance of influenza and to share viral genetic data in real-time for reducing the threat of rapid and continuing evolution of H7N9 viruses. PMID:25748033

  17. Contact variables for exposure to avian influenza H5N1 virus at the human-animal interface.

    PubMed

    Rabinowitz, P; Perdue, M; Mumford, E

    2010-06-01

    Although the highly pathogenic avian influenza H5N1 virus continues to cause infections in both avian and human populations, the specific zoonotic risk factors remain poorly understood. This review summarizes available evidence regarding types of contact associated with transmission of H5N1 virus at the human-animal interface. A systematic search of the published literature revealed five analytical studies and 15 case reports describing avian influenza transmission from animals to humans for further review. Risk factors identified in analytical studies were compared, and World Health Organization-confirmed cases, identified in case reports, were classified according to type of contact reported using a standardized algorithm. Although cases were primarily associated with direct contact with sick/unexpectedly dead birds, some cases reported only indirect contact with birds or contaminated environments or contact with apparently healthy birds. Specific types of contacts or activities leading to exposure could not be determined from data available in the publications reviewed. These results support previous reports that direct contact with sick birds is not the only means of human exposure to avian influenza H5N1 virus. To target public health measures and disease awareness messaging for reducing the risk of zoonotic infection with avian influenza H5N1 virus, the specific types of contacts and activities leading to transmission need to be further understood. The role of environmental virus persistence, shedding of virus by asymptomatic poultry and disease pathophysiology in different avian species relative to human zoonotic risk, as well as specific modes of zoonotic transmission, should be determined.

  18. Characteristics of human infection with avian influenza viruses and development of new antiviral agents

    PubMed Central

    Liu, Qiang; Liu, Dong-ying; Yang, Zhan-qiu

    2013-01-01

    Since 1997, several epizootic avian influenza viruses (AIVs) have been transmitted to humans, causing diseases and even deaths. The recent emergence of severe human infections with AIV (H7N9) in China has raised concerns about efficient interpersonal viral transmission, polygenic traits in viral pathogenicity and the management of newly emerging strains. The symptoms associated with viral infection are different in various AI strains: H5N1 and newly emerged H7N9 induce severe pneumonia and related complications in patients, while some H7 and H9 subtypes cause only conjunctivitis or mild respiratory symptoms. The virulence and tissue tropism of viruses as well as the host responses contribute to the pathogenesis of human AIV infection. Several preventive and therapeutic approaches have been proposed to combat AIV infection, including antiviral drugs such as M2 inhibitors, neuraminidase inhibitors, RNA polymerase inhibitors, attachment inhibitors and signal-transduction inhibitors etc. In this article, we summarize the recent progress in researches on the epidemiology, clinical features, pathogenicity determinants, and available or potential antivirals of AIV. PMID:24096642

  19. Avian influenza A H5N1 virus: a continuous threat to humans

    PubMed Central

    To, Kelvin KW; Ng, Kenneth HL; Que, Tak-Lun; Chan, Jacky MC; Tsang, Kay-Yan; Tsang, Alan KL; Chen, Honglin; Yuen, Kwok-Yung

    2012-01-01

    We report the first case of severe pneumonia due to co-infection with the emerging avian influenza A (H5N1) virus subclade 2.3.2.1 and Mycoplasma pneumoniae. The patient was a returning traveller who had visited a poultry market in South China. We then review the epidemiology, virology, interspecies barrier limiting poultry-to-human transmission, clinical manifestation, laboratory diagnosis, treatment and control measures of H5N1 clades that can be transmitted to humans. The recent controversy regarding the experiments involving aerosol transmission of recombinant H5N1 virus between ferrets is discussed. We also review the relative contribution of the poor response to antiviral treatment and the virus-induced hyperinflammatory damage to the pathogenesis and the high mortality of this infection. The factors related to the host, virus or medical intervention leading to the difference in disease mortality of different countries remain unknown. Because most developing countries have difficulty in instituting effective biosecurity measures, poultry vaccination becomes an important control measure. The rapid evolution of the virus would adversely affect the efficacy of poultry vaccination unless a correctly matched vaccine was chosen, manufactured and administered in a timely manner. Vigilant surveillance must continue to allow better preparedness for another poultry or human pandemic due to new viral mutants. PMID:26038430

  20. Genotypic and phenotypic diversity of the noncapsulated Haemophilus influenzae: adaptation and pathogenesis in the human airways.

    PubMed

    Garmendia, Junkal; Martí-Lliteras, Pau; Moleres, Javier; Puig, Carmen; Bengoechea, José A

    2012-12-01

    The human respiratory tract contains a highly adapted microbiota including commensal and opportunistic pathogens. Noncapsulated or nontypable Haemophilus influenzae (NTHi) is a human-restricted member of the normal airway microbiota in healthy carriers and an opportunistic pathogen in immunocompromised individuals. The duality of NTHi as a colonizer and as a symptomatic infectious agent is closely related to its adaptation to the host, which in turn greatly relies on the genetic plasticity of the bacterium and is facilitated by its condition as a natural competent. The variable genotype of NTHi accounts for its heterogeneous gene expression and variable phenotype, leading to differential host-pathogen interplay among isolates. Here we review our current knowledge of NTHi diversity in terms of genotype, gene expression, antigenic variation, and the phenotypes associated with colonization and pathogenesis. The potential benefits of NTHi diversity studies discussed herein include the unraveling of pathogenicity clues, the generation of tools to predict virulence from genomic data, and the exploitation of a unique natural system for the continuous monitoring of long-term bacterial evolution in human airways exposed to noxious agents. Finally, we highlight the challenge of monitoring both the pathogen and the host in longitudinal studies, and of applying comparative genomics to clarify the meaning of the vast NTHi genetic diversity and its translation to virulence phenotypes.

  1. Structural basis for preferential avian receptor binding by the human-infecting H10N8 avian influenza virus.

    PubMed

    Wang, Min; Zhang, Wei; Qi, Jianxun; Wang, Fei; Zhou, Jianfang; Bi, Yuhai; Wu, Ying; Sun, Honglei; Liu, Jinhua; Huang, Chaobin; Li, Xiangdong; Yan, Jinghua; Shu, Yuelong; Shi, Yi; Gao, George F

    2015-01-09

    Since December 2013, at least three cases of human infections with H10N8 avian influenza virus have been reported in China, two of them being fatal. To investigate the epidemic potential of H10N8 viruses, we examined the receptor binding property of the first human isolate, A/Jiangxi-Donghu/346/2013 (JD-H10N8), and determined the structures of its haemagglutinin (HA) in complex with both avian and human receptor analogues. Our results suggest that JD-H10N8 preferentially binds the avian receptor and that residue R137-localized within the receptor-binding site of HA-plays a key role in this preferential binding. Compared with the H7N9 avian influenza viruses, JD-H10N8 did not exhibit the enhanced binding to human receptors observed with the prevalent H7N9 virus isolate Anhui-1, but resembled the receptor binding activity of the early-outbreak H7N9 isolate (Shanghai-1). We conclude that the H10N8 virus is a typical avian influenza virus.

  2. Generation of recombinant avian metapneumovirus subgroup C (aMPV-C) viruses containing different length of the G gene.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic variation in length of the G gene among different avian metapneumovirus subgroup C isolates has been reported. However, its biological significance in virus replication, pathogenicity and immunity is unknown. In this study, we developed a reverse genetics system for avian metapneumovirus C a...

  3. Filamentous Influenza Viruses

    PubMed Central

    Badham, Matthew D.; Rossman, Jeremy S.

    2016-01-01

    Influenza A virus is a pathogen of global medical importance causing significant health and socio-economic costs every year. Influenza virus is an unusual pathogen in that it is pleomorphic, capable of forming virions ranging in shape from spherical to filamentous. Despite decades of research on the influenza virus, much remains unknown about the formation of filamentous influenza viruses and their role in the viral replication cycle. Here, we discuss what is known about influenza virus assembly and budding, focusing on the viral and host factors that are involved in the determination of viral morphology. Whilst the biological function of the filamentous morphology remains unknown, recent results suggest a role in facilitating viral spread in vivo. We discuss these results and speculate on the consequences of viral morphology during influenza virus infection of the human respiratory tract. PMID:28042529

  4. Clinical severity of human infections with avian influenza A(H7N9) virus, winter 2013–2014

    PubMed Central

    Feng, Luzhao; Wu, Joseph T.; Liu, Xiaoqing; Yang, Peng; Tsang, Tim K.; Jiang, Hui; Wu, Peng; Yang, Juan; Fang, Vicky J.; Qin, Ying; Lau, Eric H. Y.; Li, Ming; Zheng, Jiandong; Peng, Zhibin; Xie, Yun; Wang, Quanyi; Li, Zhongjie; Leung, Gabriel M.; Gao, George F.; Yu, Hongjie; Cowling, Benjamin J

    2015-01-01

    Assessing the severity of emerging infections is challenging because of potential biases in case ascertainment. In the second epidemic of human infections with avian influenza A(H7N9) virus in China in 2013–14, we estimated that the risk of death among hospitalized H7N9 cases was 48% (95% credibility interval: 42%–54%). Using data on symptomatic cases identified through national sentinel influenza-like illness surveillance, we estimated that the risk of death among symptomatic H7N9 cases was 0.10% (95% credibility interval: 0.029%–3.6%). These estimates of severity were quite similar to previous estimates for the first epidemic wave of human infections with H7N9 in 2013. PMID:25523971

  5. Global concern regarding the fifth case of human infection with avian influenza A (H7N9) virus in China.

    PubMed

    Shen, Yinzhong; Lu, Hongzhou

    2017-02-28

    Since the first case of human infection with the avian influenza A (H7N9) virus was identified in 2013, five seasonal outbreaks have occurred in China. The fifth outbreak started earlier than usual. A sudden increase in cases of human infection with the avian influenza A (H7N9) virus has been reported in China since September 2016, and the number of cases reported this season is exceeding that reported in previous seasons. This increase in the number of new cases of H7N9 infection has caused domestic and international concern. This paper summarizes the current prevalence of H7N9 in China and it also discusses measures that China has taken to control those outbreaks. This paper also describes steps China must take in the future. This paper can serve as a reference for prevention and control of H7N9 outbreaks around the world.

  6. Novel Avian-Origin Influenza A (H7N9) Virus Attaches to Epithelium in Both Upper and Lower Respiratory Tract of Humans

    PubMed Central

    van Riel, Debby; Leijten, Lonneke M.E.; de Graaf, Miranda; Siegers, Jurre Y.; Short, Kirsty R.; Spronken, Monique I.J.; Schrauwen, Eefje J.A.; Fouchier, Ron A.M.; Osterhaus, Albert D.M.E.; Kuiken, Thijs

    2014-01-01

    Influenza A viruses from animal reservoirs have the capacity to adapt to humans and cause influenza pandemics. The occurrence of an influenza pandemic requires efficient virus transmission among humans, which is associated with virus attachment to the upper respiratory tract. Pandemic severity depends on virus ability to cause pneumonia, which is associated with virus attachment to the lower respiratory tract. Recently, a novel avian-origin H7N9 influenza A virus with unknown pandemic potential emerged in humans. We determined the pattern of attachment of two genetically engineered viruses containing the hemagglutinin of either influenza virus A/Shanghai/1/13 or A/Anhui/1/13 to formalin-fixed human respiratory tract tissues using histochemical analysis. Our results show that the emerging H7N9 virus attached moderately or abundantly to both upper and lower respiratory tract, a pattern not seen before for avian influenza A viruses. With the caveat that virus attachment is only the first step in the virus replication cycle, these results suggest that the emerging H7N9 virus has the potential both to transmit efficiently among humans and to cause severe pneumonia. PMID:24029490

  7. The coming era of quadrivalent human influenza vaccines: who will benefit?

    PubMed

    Barr, Ian G; Jelley, Lauren L

    2012-12-03

    Influenza vaccines form the mainstay of public health and personal protection against infection with seasonal influenza viruses. These vaccines are designed to protect people against infection with the currently circulating influenza viruses. Since the late 1970s, this has required the use of a trivalent vaccine consisting of two influenza A viruses and one influenza B virus. However, since the early 2000s, a second lineage of B viruses has regularly circulated in many countries that is quite distinct, with only low levels of cross protection between the two lineages. Due to the difficulties in determining which B lineage will circulate, and matching this with the vaccine to be administered some 6-9 months later, there has been an increasing interest in the development of quadrivalent influenza vaccines, containing two influenza B viruses representing both lineages. Development has been rapid and we are now on the cusp of a new generation of influenza vaccines becoming available. This paper discusses the issues and rationale behind this welcome development and who is likely to benefit most.

  8. Brief literature review for the WHO global influenza research agenda--highly pathogenic avian influenza H5N1 risk in humans.

    PubMed

    Van Kerkhove, Maria D

    2013-09-01

    Highly pathogenic avian influenza A H5N1 viruses remain a significant health threat to humans given the continued rare occurrence of human cases with a high case fatality rate. This brief literature review summarizes available evidence of risk factors for H5N1 infection in humans and updates a recent systematic review published in early 2011. Several epidemiologic studies have been published to evaluate the risk factors for H5N1 infection in humans, including contact with poultry and poultry products and non-poultry-related contact such as from H5N1-contaminated water. While most H5N1 cases are attributed to exposure to sick poultry, it is unclear how many may be due to human-to-human transmission. The collective results of published literature suggest that transmission risk of H5N1 from poultry to humans may be highest among individuals who may have been in contact with the highest potential concentrations of virus shed by poultry. This suggests that there may be a threshold of virus concentration needed for effective transmission and that circulating H5N1 strains have not yet mutated to transmit readily from either poultry to human or from human to human. However, the mode of potential transmission can be quite varied throughout different countries and by study with exposures ranging from visiting a wet market, preparing infected poultry for consumption, to swimming or bathing in ponds frequented by poultry. Several important data gaps remain in the understanding of the epidemiology of H5N1 in humans and limit our ability to interpret the results of the available H5N1 seroepidemiologic studies.

  9. Use of fractional factorial design to study the compatibility of viral ribonucleoprotein gene segments of human H7N9 virus and circulating human influenza subtypes.

    PubMed

    Chin, Alex W H; Mok, Chris K P; Zhu, Huachen; Guan, Yi; Peiris, Joseph S M; Poon, Leo L M

    2014-09-01

    Avian H7N9 influenza viruses may pose a further threat to humans by reassortment with human viruses, which could lead to generation of novel reassortants with enhanced polymerase activity. We previously established a novel statistical approach to study the polymerase activity of reassorted vRNPs (Influenza Other Respir Viruses. 2013;7:969-78). Here, we report the use of this method to study recombinant vRNPs with subunits derived from human H1N1, H3N2, and H7N9 viruses. Our results demonstrate that some reassortant vRNPs with subunits derived from the H7N9 and other human viruses can have much higher polymerase activities than the wild-type levels.

  10. Structure and anti-metapneumovirus activity of sulfated galactans from the red seaweed Cryptonemia seminervis.

    PubMed

    Mendes, Gabriella S; Duarte, Maria E R; Colodi, Franciely G; Noseda, Miguel D; Ferreira, Luciana G; Berté, Siliane D; Cavalcanti, Jéssica F; Santos, Norma; Romanos, Maria T V

    2014-01-30

    The anti-HMPV (human metapneumovirus) activity was determined for sulfated dl-hybrid galactans obtained from the red seaweed Cryptonemia seminervis and their depolymerized products obtained by reductive partial hydrolysis. Structural studies carried out in three homogeneous depolymerized fractions DS-1, DS-2e and DS-3 (Mw of 51.6-63.8 kDa) showed that these galactans present different chemical characteristics, as monosaccharide composition, content of sulfate groups (14.1-29.9%) and agaran:carrageenan molar ratio diads, 2.7:1 for DS-1 and DS-2e and 1:1 for DS-3. The sulfate groups are located principally on C-2 of β-d-galactopyranose and 4,6-O-(1'-carboxyethylidene)-β-d-galactopyranose residues and on C-6 of α-galactose residues. Sulfated dl-galactans and their depolymerized products exhibited antiviral activity at a very early stage of the viral infection cycle. All fractions, except DS-2e inhibited HMPV replication by binding to the viral particle. Besides depolymerized galactans DS-2e and DS-3 inhibited the recognition of cell receptor by HMPV and penetration to the host cell, respectively.

  11. Full-genome analysis of avian influenza A(H5N1) virus from a human, North America, 2013.

    PubMed

    Pabbaraju, Kanti; Tellier, Raymond; Wong, Sallene; Li, Yan; Bastien, Nathalie; Tang, Julian W; Drews, Steven J; Jang, Yunho; Davis, C Todd; Fonseca, Kevin; Tipples, Graham A

    2014-05-01

    Full-genome analysis was conducted on the first isolate of a highly pathogenic avian influenza A(H5N1) virus from a human in North America. The virus has a hemagglutinin gene of clade 2.3.2.1c and is a reassortant with an H9N2 subtype lineage polymerase basic 2 gene. No mutations conferring resistance to adamantanes or neuraminidase inhibitors were found.

  12. Heterosubtypic Protection against Pathogenic Human and Avian Influenza Viruses via In Vivo Electroporation of Synthetic Consensus DNA Antigens

    PubMed Central

    Laddy, Dominick J.; Yan, Jian; Kutzler, Michele; Kobasa, Darwyn; Kobinger, Gary P.; Khan, Amir S.; Greenhouse, Jack; Sardesai, Niranjan Y.; Draghia-Akli, Ruxandra; Weiner, David B.

    2008-01-01

    Background The persistent evolution of highly pathogenic avian influenza (HPAI) highlights the need for novel vaccination techniques that can quickly and effectively respond to emerging viral threats. We evaluated the use of optimized consensus influenza antigens to provide broad protection against divergent strains of H5N1 influenza in three animal models of mice, ferrets, and non-human primates. We also evaluated the use of in vivo electroporation to deliver these vaccines to overcome the immunogenicity barrier encountered in larger animal models of vaccination. Methods and Findings Mice, ferrets and non-human primates were immunized with consensus plasmids expressing H5 hemagglutinin (pH5HA), N1 neuraminidase (pN1NA), and nucleoprotein antigen (pNP). Dramatic IFN-γ-based cellular immune responses to both H5 and NP, largely dependent upon CD8+ T cells were seen in mice. Hemaggutination inhibition titers classically associated with protection (>1:40) were seen in all species. Responses in both ferrets and macaques demonstrate the ability of synthetic consensus antigens to induce antibodies capable of inhibiting divergent strains of the H5N1 subtype, and studies in the mouse and ferret demonstrate the ability of synthetic consensus vaccines to induce protection even in the absence of such neutralizing antibodies. After challenge, protection from morbidity and mortality was seen in mice and ferrets, with significant reductions in viral shedding and disease progression seen in vaccinated animals. Conclusions By combining several consensus influenza antigens with in vivo electroporation, we demonstrate that these antigens induce both protective cellular and humoral immune responses in mice, ferrets and non-human primates. We also demonstrate the ability of these antigens to protect from both morbidity and mortality in a ferret model of HPAI, in both the presence and absence of neutralizing antibody, which will be critical in responding to the antigenic drift that

  13. Origin and molecular characterization of the human-infecting H6N1 influenza virus in Taiwan.

    PubMed

    Shi, Weifeng; Shi, Yi; Wu, Ying; Liu, Di; Gao, George F

    2013-11-01

    In June 2013, the first human H6N1 influenza virus infection was confirmed in Taiwan. However, the origin and molecular characterization of this virus, A/Taiwan/2/2013 (H6N1), have not been well studied thus far. In the present report, we performed phylogenetic and coalescent analyses of this virus and compared its molecular profile/characteristics with other closely related strains. Molecular characterization of H6N1 revealed that it is a typical avian influenza virus of low pathogenicity, which might not replicate and propagate well in the upper airway in mammals. Phylogenetic analysis revealed that the virus clusters with A/chicken/Taiwan/A2837/2013 (H6N1) in seven genes, except PB1. For the PB1 gene, A/Taiwan/2/2013 was clustered with a different H6N1 lineage from A/chicken/Taiwan/ A2837/2013. Although a previous study demonstrated that the PB2, PA, and M genes of A/Taiwan/2/2013 might be derived from the H5N2 viruses, coalescent analyses revealed that these H5N2 viruses were derived from more recent strains than that of the ancestor of A/Taiwan/2/2013. Therefore, we propose that A/Taiwan/2/2013 is a reassortant from different H6N1 lineages circulating in chickens in Taiwan. Furthermore, compared to avian isolates, a single P186L (H3 numbering) substitution in the hemagglutinin H6 of the human isolate might increase the mammalian receptor binding and, hence, this strain's pathogenicity in humans. Overall, human infection with this virus seems an accidental event and is unlikely to cause an influenza pandemic. However, its co-circulation and potential reassortment with other influenza subtypes are still worthy of attention.

  14. Human infection with an avian influenza A (H9N2) virus in the middle region of China.

    PubMed

    Huang, Yiwei; Li, Xiaodan; Zhang, Hong; Chen, Bozhong; Jiang, Yonglin; Yang, Lei; Zhu, Wenfei; Hu, Shixiong; Zhou, Siyu; Tang, Yunli; Xiang, Xingyu; Li, Fangcai; Li, Wenchao; Gao, Lidong

    2015-10-01

    During the epidemic period of the novel H7N9 viruses, an influenza A (H9N2) virus was isolated from a 7-year-old boy with influenza-like illness in Yongzhou city of Hunan province in November 2013. To identify the possible source of infection, environmental specimens collected from local live poultry markets epidemiologically linked to the human case in Yongzhou city were tested for influenza type A and its subtypes H5, H7, and H9 using real-time RT-PCR methods as well as virus isolation, and four other H9N2 viruses were isolated. The real-time RT-PCR results showed that the environment was highly contaminated with avian influenza H9 subtype viruses (18.0%). Sequencing analyses revealed that the virus isolated from the patient, which was highly similar (98.5-99.8%) to one of isolates from environment in complete genome sequences, was of avian origin. Based on phylogenetic and antigenic analyses, it belonged to genotype S and Y280 lineage. In addition, the virus exhibited high homology (95.7-99.5%) of all six internal gene lineages with the novel H7N9 and H10N8 viruses which caused epidemic and endemic in China. Meanwhile, it carried several mammalian adapted molecular residues including Q226L in HA protein, L13P in PB1 protein, K356R, S409N in PA protein, V15I in M1 protein, I28V, L55F in M2 protein, and E227K in NS protein. These findings reinforce the significance of continuous surveillance of H9N2 influenza viruses.

  15. A Combination of Serological Assays to Detect Human Antibodies to the Avian Influenza A H7N9 Virus

    PubMed Central

    Gao, Rongbao; Dong, Jie; Zhang, Ye; Guo, Junfeng; Zou, Shumei; Zhou, Jianfang; Zhu, Yun; Xin, Li; Li, Xiaodan; Xu, Cuiling; Wang, Dayan; Shu, Yuelong

    2014-01-01

    Human infection with avian influenza A H7N9 virus was first identified in March 2013 and represents an ongoing threat to public health. There is a need to optimize serological methods for this new influenza virus. Here, we compared the sensitivity and specificity of the hemagglutinin inhibition (HI), microneutralization (MN), and Western blot (WB) assays for the detection of human antibodies against avian influenza A (H7N9) virus. HI with horse erythrocytes (hRBCs) and a modified MN assay possessed greater sensitivity than turkey erythrocytes and the standard MN assay, respectively. Using these assays, 80% of tested sera from confirmed H7N9 cases developed detectable antibody to H7N9 after 21 days. To balance sensitivity and specificity, we found serum titers of ≥20 (MN) or 160 (HI) samples were most effective in determining seropositive to H7N9 virus. Single serum with HI titers of 20–80 or MN titer of 10 could be validated by each other or WB assay. Unlike serum collected from adult or elderly populations, the antibody response in children with mild disease was low or undetectable. These combinations of assays will be useful in case diagnosis and serologic investigation of human cases. PMID:24755627

  16. The effective rate of influenza reassortment is limited during human infection.

    PubMed

    Sobel Leonard, Ashley; McClain, Micah T; Smith, Gavin J D; Wentworth, David E; Halpin, Rebecca A; Lin, Xudong; Ransier, Amy; Stockwell, Timothy B; Das, Suman R; Gilbert, Anthony S; Lambkin-Williams, Rob; Ginsburg, Geoffrey S; Woods, Christopher W; Koelle, Katia; Illingworth, Christopher J R

    2017-02-01

    We characterise the evolutionary dynamics of influenza infection described by viral sequence data collected from two challenge studies conducted in human hosts. Viral sequence data were collected at regular intervals from infected hosts. Changes in the sequence data observed across time show that the within-host evolution of the virus was driven by the reversion of variants acquired during previous passaging of the virus. Treatment of some patients with oseltamivir on the first day of infection did not lead to the emergence of drug resistance variants in patients. Using an evolutionary model, we inferred the effective rate of reassortment between viral segments, measuring the extent to which randomly chosen viruses within the host exchange genetic material. We find strong evidence that the rate of effective reassortment is low, such that genetic associations between polymorphic loci in different segments are preserved during the course of an infection in a manner not compatible with epistasis. Combining our evidence with that of previous studies we suggest that spatial heterogeneity in the viral population may reduce the extent to which reassortment is observed. Our results do not contradict previous findings of high rates of viral reassortment in vitro and in small animal studies, but indicate that in human hosts the effective rate of reassortment may be substantially more limited.

  17. Human importin alpha and RNA do not compete for binding to influenza A virus nucleoprotein

    SciTech Connect

    Boulo, Sebastien; Akarsu, Hatice; Lotteau, Vincent; Mueller, Christoph W.; Ruigrok, Rob W.H.; Baudin, Florence

    2011-01-05

    Influenza virus has a segmented genome composed of eight negative stranded RNA segments. Each segment is covered with NP forming ribonucleoproteins (vRNPs) and carries a copy of the heterotrimeric polymerase complex. As a rare phenomenon among the RNA viruses, the viral replication occurs in the nucleus and therefore implies interactions between host and viral factors, such as between importin alpha and nucleoprotein. In the present study we report that through binding with the human nuclear receptor importin {alpha}5 (Imp{alpha}5), the viral NP is no longer oligomeric but maintained as a monomer inside the complex. In this regard, Imp{alpha}5 acts as a chaperone until NP is delivered in the nucleus for viral RNA encapsidation. Moreover, we show that the association of NP with the host transporter does not impair the binding of NP to RNA. The complex human Imp{alpha}5-NP binds RNA with the same affinity as wt NP alone, whereas engineered monomeric NP through point mutations binds RNA with a strongly reduced affinity.

  18. Human rhinoviruses and enteroviruses in influenza-like illness in Latin America

    PubMed Central

    2013-01-01

    Background Human rhinoviruses (HRVs) belong to the Picornaviridae family with high similarity to human enteroviruses (HEVs). Limited data is available from Latin America regarding the clinical presentation and strains of these viruses in respiratory disease. Methods We collected nasopharyngeal swabs at clinics located in eight Latin American countries from 3,375 subjects aged 25 years or younger who presented with influenza-like illness. Results Our subjects had a median age of 3 years and a 1.2:1.0 male:female ratio. HRV was identified in 16% and HEV was identified in 3%. HRVs accounted for a higher frequency of isolates in those of younger age, in particular children < 1 years old. HRV-C accounted for 38% of all HRVs detected. Phylogenetic analysis revealed a high proportion of recombinant strains between HRV-A/HRV-C and between HEV-A/HEV-B. In addition, both EV-D68 and EV-A71 were identified. Conclusions In Latin America as in other regions, HRVs and HEVs account for a substantial proportion of respiratory viruses identified in young people with ILI, a finding that provides additional support for the development of pharmaceuticals and vaccines targeting these pathogens. PMID:24119298

  19. The effective rate of influenza reassortment is limited during human infection

    PubMed Central

    Sobel Leonard, Ashley; McClain, Micah T.; Wentworth, David E.; Halpin, Rebecca A.; Lin, Xudong; Ransier, Amy; Gilbert, Anthony S.; Woods, Christopher W.; Koelle, Katia

    2017-01-01

    We characterise the evolutionary dynamics of influenza infection described by viral sequence data collected from two challenge studies conducted in human hosts. Viral sequence data were collected at regular intervals from infected hosts. Changes in the sequence data observed across time show that the within-host evolution of the virus was driven by the reversion of variants acquired during previous passaging of the virus. Treatment of some patients with oseltamivir on the first day of infection did not lead to the emergence of drug resistance variants in patients. Using an evolutionary model, we inferred the effective rate of reassortment between viral segments, measuring the extent to which randomly chosen viruses within the host exchange genetic material. We find strong evidence that the rate of effective reassortment is low, such that genetic associations between polymorphic loci in different segments are preserved during the course of an infection in a manner not compatible with epistasis. Combining our evidence with that of previous studies we suggest that spatial heterogeneity in the viral population may reduce the extent to which reassortment is observed. Our results do not contradict previous findings of high rates of viral reassortment in vitro and in small animal studies, but indicate that in human hosts the effective rate of reassortment may be substantially more limited. PMID:28170438

  20. Lineage Structure of the Human Antibody Repertoire in Response to Influenza Vaccination

    PubMed Central

    Jiang, Ning; He, Jiankui; Weinstein, Joshua A.; Penland, Lolita; Sasaki, Sanae; He, Xiao-Song; Dekker, Cornelia L.; Zheng, Nai-ying; Huang, Min; Sullivan, Meghan; Wilson, Patrick C.; Greenberg, Harry B.; Davis, Mark M.; Fisher, Daniel S.; Quake, Stephen R.

    2013-01-01

    The human antibody repertoire is one of the most important defenses against infectious disease, and the development of vaccines has enabled the conferral of targeted protection to specific pathogens. However, there are many challenges to measuring and analyzing the immunoglobulin sequence repertoire, such as the fact that each B cell contains a distinct antibody sequence encoded in its genome, that the antibody repertoire is not constant but changes over time, and the high similarity between antibody sequences. We have addressed this challenge by using high-throughput long read sequencing to perform immunogenomic characterization of expressed human antibody repertoires in the context of influenza vaccination. Informatic analysis of 5 million antibody heavy chain sequences from healthy individuals allowed us to perform global characterizations of isotype distributions, determine the lineage structure of the repertoire and measure age and antigen related mutational activity. Our analysis of the clonal structure and mutational distribution of individuals’ repertoires shows that elderly subjects have a decreased number of lineages but an increased pre-vaccination mutation load in their repertoire and that some of these subjects have an oligoclonal character to their repertoire in which the diversity of the lineages is greatly reduced relative to younger subjects. We have thus shown that global analysis of the immune system’s clonal structure provides direct insight into the effects of vaccination and provides a detailed molecular portrait of age-related effects. PMID:23390249

  1. Rapid multiplex reverse transcription-PCR typing of influenza A and B virus, and subtyping of influenza A virus into H1, 2, 3, 5, 7, 9, N1 (human), N1 (animal), N2, and N7, including typing of novel swine origin influenza A (H1N1) virus, during the 2009 outbreak in Milwaukee, Wisconsin.

    PubMed

    He, Jie; Bose, Michael E; Beck, Eric T; Fan, Jiang; Tiwari, Sagarika; Metallo, Jacob; Jurgens, Lisa A; Kehl, Sue C; Ledeboer, Nathan; Kumar, Swati; Weisburg, William; Henrickson, Kelly J

    2009-09-01

    A large outbreak of novel influenza A (H1N1) virus (swine origin influenza virus [S-OIV]) infection in Milwaukee, WI, occurred in late April 2009. We had recently developed a rapid multiplex reverse transcription-PCR enzyme hybridization assay (FluPlex) to determine the type (A or B) and subtype (H1, H2, H3, H5, H7, H9, N1 [human], N1 [animal], N2, or N7) of influenza viruses, and this assay was used to confirm the diagnoses for the first infected patients in the state. The analytical sensitivity was excellent at 1.5 to 116 copies/reaction, or 10(-3) to 10(-1) 50% tissue culture infective doses/ml. The testing of all existing hemagglutinin and neuraminidase subtypes of influenza A virus and influenza B virus (41 influenza virus strains) and 24 common respiratory pathogens showed only one low-level H3 cross-reaction with an H10N7 avian strain and only at 5.2 x 10(6) copies/reaction, not at lower concentrations. Comparisons of the FluPlex results with results from multiple validated in-house molecular assays, CDC-validated FDA-approved assays, and gene sequencing demonstrated 100% positive agreement for the typing of 179 influenza A viruses and 3 influenza B viruses, the subtyping of 110 H1N1 (S-OIV; N1 [animal]), 62 H1N1 (human), and 6 H3N2 (human) viruses, and the identification of 24 negative clinical samples and 100% negative agreement for all viruses tested except H1N1 (human) (97.7%). The small number of false-positive H1N1 (human) samples most likely represent increased sensitivity over that of other in-house assays, with four of four results confirmed by the CDC's influenza virus subtyping assay. The FluPlex is a rapid, inexpensive, sensitive, and specific method for the typing and subtyping of influenza viruses and demonstrated outstanding utility during the first 2 weeks of an S-OIV infection outbreak. Methods for rapid detection and broad subtyping of influenza viruses, including animal subtypes, are needed to address public concern over the emergence of

  2. Respiratory viruses in patients with influenza-like illness in Senegal: Focus on human respiratory adenoviruses

    PubMed Central

    Niang, Mbayame Ndiaye; Diop, Ndeye Sokhna; Fall, Amary; Kiori, Davy E.; Sarr, Fatoumata Diene; Sy, Sara; Goudiaby, Déborah; Barry, Mamadou Aliou; Fall, Malick; Dia, Ndongo

    2017-01-01

    Background Human adenoviruses (HAdVs) are highly contagious pathogens that are associated with a wide spectrum of human illnesses involving the respiratory tract. In the present study, we investigate the epidemiologic and viral molecular features of HAdVs circulating in Senegal after 4 consecutive years of sentinel surveillance of influenza-like Illness cases. Methodology and results From January 2012 to December 2015 swabs were collected from consenting ILI outpatients. Adenoviral detection is performed by rRT-PCR with the Anyplex™ II RV16 Detection kit (Seegene) and molecular characterization was performed using a partial hexon gene sequence. 6381 samples were collected. More than half of patients (51.7%; 3297/6381) were children of ≤ 5 years. 1967 (30.8%) were positive for HAdV with 1561 (79.4%) found in co-infection with at least one another respiratory virus. The most common co-detections were with influenza viruses (53.1%; 1045/1967), rhinoviruses (30%; 591/1967), enteroviruses (18.5%; 364/1967) and RSV (13.5%; 266/1967). Children under 5 were the most infected group (62.2%; 1224/1967; p <0.05). We noted that HAdV was detected throughout the year at a high level with detection peaks of different amplitudes without any clear seasonality. Phylogenetic analysis revealed species HAdV-C in majority, species HAdV-B and one HAdV- 4 genome type. The 9 HAdV-B species like strains from Senegal grouped with genome types HAdV-7, HAdV-55 and HAdV-11 as shown by a phylogenetic branch with a high bootstrap value of (88%). Conclusion In conclusion, the results of the present study suggest strong year-round HAdV activity in Senegal, especially in children up to 5 years of age. Molecular studies revealed that the dominant species in circulation in patients with ILI appears to be HAdV-C and HAdV-B species. The circulation of though HAdV-7 and HAdV-55 genome types is of note as these serotypes are recognized causes of more severe and even fatal acute respiratory infections

  3. Use of Hangeul Twitter to Track and Predict Human Influenza Infection

    PubMed Central

    Kim, Eui-Ki; Seok, Jong Hyeon; Oh, Jang Seok; Lee, Hyong Woo; Kim, Kyung Hyun

    2013-01-01

    Influenza epidemics arise through the accumulation of viral genetic changes. The emergence of new virus strains coincides with a higher level of influenza-like illness (ILI), which is seen as a peak of a normal season. Monitoring the spread of an epidemic influenza in populations is a difficult and important task. Twitter is a free social networking service whose messages can improve the accuracy of forecasting models by providing early warnings of influenza outbreaks. In this study, we have examined the use of information embedded in the Hangeul Twitter stream to detect rapidly evolving public awareness or concern with respect to influenza transmission and developed regression models that can track levels of actual disease activity and predict influenza epidemics in the real world. Our prediction model using a delay mode provides not only a real-time assessment of the current influenza epidemic activity but also a significant improvement in prediction performance at the initial phase of ILI peak when prediction is of most importance. PMID:23894447

  4. Will the next human influenza pandemic be caused by the virus of the avian flu A/H5N1? Arguments pro and counter.

    PubMed

    Doerr, H W; Varwig, Domenica; Allwinn, Regina; Cinatl, J

    2006-06-01

    In 1997, the avian influenza A subtype H5N1 that caused big outbreaks of fowl pest in mass poultry farming had emerged in Hong Kong. Its spread throughout Eurasia had given rise to concerns in terms of the possible imminence of the next human influenza pandemic. In this article, epidemiological and virological arguments supporting or declining this fear are outlined and discussed with regard to viral infectivity and pathogenicity.

  5. Influenza-Sediment Interactions

    NASA Astrophysics Data System (ADS)

    Trusiak, A.; Block, K. A.; Katz, A.; Gottlieb, P.; Alimova, A.; Galarza, J.; Wei, H.; Steiner, J. C.

    2013-12-01

    A typical water fowl can secrete 1012 influenza virions per day. Therefore it is not unexpected that influenza virions interact with sediments in the water column. The influence of sediments on avian influenza virions is not known. With the threat of avian influenza emerging into the human population, it is crucial to understand virus survivability and residence time in a body of water. Influenza and clay sediments are colloidal particles and thus aggregate as explained by DLVO (Derjaguin & Landau, Verwey & Overbeek) theory. Of great importance is an understanding of the types of particulate or macromolecular components that bind the virus particles, and whether the virus remains biologically active. We present results of hetero-aggregation and transmission electron microscopy experiments performed with influenza A/PR8/38. Influenza particles are suspended with sediment and minimal nutrients for several days, after which the components are evaluated to determine influenza concentration and survivability. Transmission electron microscopy results are reported on the influenza-sediment aggregates to elucidate structure and morphology of the components.

  6. [The circulation of influenza virus in human communities subjected to the action of noxious chemical substances].

    PubMed

    Moisa, I; Petrescu, A; Pârvu, C; Bârnaure, F; Sîrbu, D

    1987-01-01

    Investigations were conducted during 1985 and 1986 years on the effect of some noxious chemicals on the influenza virus circulation in an industrial enterprise community. The presence of influenza virus type A (H1N1), A (H3N2) and B was revealed by immunofluorescence in exfoliated cells collected from nasopharynx. The kinetic of type specific hemagglutination inhibiting antibodies was followed monthly. Chick embryos were used to isolate influenza virus strains. Meaning of the results is discussed from an epidemiological point of view.

  7. Molecular detection and isolation of avian metapneumovirus in Mexico.

    PubMed

    Rivera-Benitez, José Francisco; Martínez-Bautista, Rebeca; Ríos-Cambre, Francisco; Ramírez-Mendoza, Humberto

    2014-01-01

    We conducted a longitudinal study to detect and isolate avian metapneumovirus (aMPV) in two highly productive poultry areas in Mexico. A total of 968 breeder hens and pullets from 2 to 73 weeks of age were analysed. Serology was performed to detect aMPV antibodies and 105 samples of tracheal tissue were collected, pooled by age, and used for attempted virus isolation and aMPV nested reverse transcriptase-polymerase chain reaction (nRT-PCR). The serological analysis indicated that 100% of the sampled chickens showed aMPV antibodies by 12 weeks of age. Five pools of pullet samples collected at 3 to 8 weeks of age were positive by nRT-PCR and the sequences obtained indicated 98 to 99% similarity with the reported sequences for aMPV subtype A. Virus isolation of nRT-PCR-positive samples was successfully attempted using chicken embryo lung and trachea mixed cultures with subsequent adaptation to Vero cells. This is the first report of detection and isolation of aMPV in Mexico.

  8. A first-generation physiologically based pharmacokinetic (PBPK) model of alpha-tocopherol in human influenza vaccine adjuvant.

    PubMed

    Tegenge, Million A; Mitkus, Robert J

    2015-04-01

    Alpha (α)-tocopherol is a component of a new generation of squalene-containing oil-in-water (SQ/W) emulsion adjuvants that have been licensed for use in certain influenza vaccines. Since regulatory pharmacokinetic studies are not routinely required for influenza vaccines, the in vivo fate of this vaccine constituent is largely unknown. In this study, we constructed a physiologically based pharmacokinetic (PBPK) model for emulsified α-tocopherol in human adults and infants. An independent sheep PBPK model was also developed to inform the local preferential lymphatic transfer and for the purpose of model evaluation. The PBPK model predicts that α-tocopherol will be removed from the injection site within 24h and rapidly transfer predominantly into draining lymph nodes. A much lower concentration of α-tocopherol was estimated to peak in plasma within 8h. Any systemically absorbed α-tocopherol was predicted to accumulate slowly in adipose tissue, but not in other tissues. Model evaluation and uncertainty analyses indicated acceptable fit, with the fraction of dose taken up into the lymphatics as most influential on plasma concentration. In summary, this study estimates the in vivo fate of α-tocopherol in adjuvanted influenza vaccine, may be relevant in explaining its immunodynamics in humans, and informs current regulatory risk-benefit analyses.

  9. Estimating the Distribution of the Incubation Periods of Human Avian Influenza A(H7N9) Virus Infections

    PubMed Central

    Virlogeux, Victor; Li, Ming; Tsang, Tim K.; Feng, Luzhao; Fang, Vicky J.; Jiang, Hui; Wu, Peng; Zheng, Jiandong; Lau, Eric H. Y.; Cao, Yu; Qin, Ying; Liao, Qiaohong; Yu, Hongjie; Cowling, Benjamin J.

    2015-01-01

    A novel avian influenza virus, influenza A(H7N9), emerged in China in early 2013 and caused severe disease in humans, with infections occurring most frequently after recent exposure to live poultry. The distribution of A(H7N9) incubation periods is of interest to epidemiologists and public health officials, but estimation of the distribution is complicated by interval censoring of exposures. Imputation of the midpoint of intervals was used in some early studies, resulting in estimated mean incubation times of approximately 5 days. In this study, we estimated the incubation period distribution of human influenza A(H7N9) infections using exposure data available for 229 patients with laboratory-confirmed A(H7N9) infection from mainland China. A nonparametric model (Turnbull) and several parametric models accounting for the interval censoring in some exposures were fitted to the data. For the best-fitting parametric model (Weibull), the mean incubation period was 3.4 days (95% confidence interval: 3.0, 3.7) and the variance was 2.9 days; results were very similar for the nonparametric Turnbull estimate. Under the Weibull model, the 95th percentile of the incubation period distribution was 6.5 days (95% confidence interval: 5.9, 7.1). The midpoint approximation for interval-censored exposures led to overestimation of the mean incubation period. Public health observation of potentially exposed persons for 7 days after exposure would be appropriate. PMID:26409239

  10. Human Monoclonal Antibody 81.39a Effectively Neutralizes Emerging Influenza A Viruses of Group 1 and 2 Hemagglutinins

    PubMed Central

    Marjuki, Henju; Mishin, Vasiliy P.; Chai, Ning; Tan, Man-Wah; Newton, Elizabeth M.; Tegeris, John; Erlandson, Karl; Willis, Melissa; Jones, Joyce; Davis, Todd; Stevens, James

    2016-01-01

    ABSTRACT The pandemic threat posed by emerging zoonotic influenza A viruses necessitates development of antiviral agents effective against various antigenic subtypes. Human monoclonal antibody (hMAb) targeting the hemagglutinin (HA) stalk offers a promising approach to control influenza virus infections. Here, we investigated the ability of the hMAb 81.39a to inhibit in vitro replication of human and zoonotic viruses, representing 16 HA subtypes. The majority of viruses were effectively neutralized by 81.39a at a 50% effective concentration (EC50) of <0.01 to 4.9 μg/ml. Among group 2 HA viruses tested, a single A(H7N9) virus was not neutralized at 50 μg/ml; it contained HA2-Asp19Gly, an amino acid position previously associated with resistance to neutralization by the group 2 HA-neutralizing MAb CR8020. Notably, among group 1 HA viruses, H11-H13 and H16 subtypes were not neutralized at 50 μg/ml; they shared the substitution HA2-Asp19Asn/Ala. Conversely, H9 viruses harboring HA2-Asp19Ala were fully susceptible to neutralization. Therefore, amino acid variance at HA2-Asp19 has subtype-specific adverse effects on in vitro neutralization. Mice given a single injection (15 or 45 mg/kg of body weight) at 24 or 48 h after infection with recently emerged A(H5N2), A(H5N8), A(H6N1), or A(H7N9) viruses were protected from mortality and showed drastically reduced lung viral titers. Furthermore, 81.39a protected mice infected with A(H7N9) harboring HA2-Asp19Gly, although the antiviral effect was lessened. A(H1N1)pdm09-infected ferrets receiving a single dose (25 mg/kg) had reduced viral titers and showed less lung tissue injury, despite 24- to 72-h-delayed treatment. Taken together, this study provides experimental evidence for the therapeutic potential of 81.39a against diverse influenza A viruses. IMPORTANCE Zoonotic influenza viruses, such as A(H5N1) and A(H7N9) subtypes, have caused severe disease and deaths in humans, raising public health concerns. Development of novel

  11. Radiological Features of Human Infection with Avian Influenza A H7N9 Virus: A Report of Three Cases

    PubMed Central

    WU, Dandan; XU, Feng; LIU, Jin

    2014-01-01

    Abstract Human infection with avian influenza A H7N9 virus has emerged in China with high morbidity rates. Patients usually present with severe and rapidly progressive pneumonia. Therefore, radiological findings are important to diagnose and evaluate disease severity. The clinical characteristics of three new cases of H7N9 virus infection were analyzed, especially the radiological findings, and previously published studies regarding H7N9 virus infection were summarized. Ground-glass opacification and areas of consolidation were the most common image features. Although drug resistance has been found in some H7N9 viruses, oseltamivir administration is still recommended as soon as possible. Moreover, timely epidemiological surveillance is needed, and a new vaccine is expected for the management of avian influenza. PMID:26060749

  12. Influenza Infection in Wild Raccoons

    PubMed Central

    Bentler, Kevin T.; Landolt, Gabrielle; Elmore, Stacey A.; Minnis, Richard B.; Campbell, Tyler A.; Barras, Scott C.; Root, J. Jeffrey; Pilon, John; Pabilonia, Kristy; Driscoll, Cindy; Slate, Dennis; Sullivan, Heather; McLean, Robert G.

    2008-01-01

    Raccoons (Procyon lotor) are common, widely distributed animals that frequently come into contact with wild waterfowl, agricultural operations, and humans. Serosurveys showed that raccoons are exposed to avian influenza virus. We found antibodies to a variety of influenza virus subtypes (H10N7, H4N6, H4N2, H3, and H1) with wide geographic variation in seroprevalence. Experimental infection studies showed that raccoons become infected with avian and human influenza A viruses, shed and transmit virus to virus-free animals, and seroconvert. Analyses of cellular receptors showed that raccoons have avian and human type receptors with a similar distribution as found in human respiratory tracts. The potential exists for co-infection of multiple subtypes of influenza virus with genetic reassortment and creation of novel strains of influenza virus. Experimental and field data indicate that raccoons may play an important role in influenza disease ecology and pose risks to agriculture and human health. PMID:19046505

  13. Influenza infection in wild raccoons

    USGS Publications Warehouse

    Hall, J.S.; Bentler, K.T.; Landolt, G.; Elmore, S.A.; Minnis, R.B.; Campbell, T.A.; Barras, S.C.; Root, J.J.; Pilon, J.; Pabilonia, K.; Driscoll, C.; Slate, D.; Sullivan, H.; McLean, R.G.

    2008-01-01

    Raccoons (Procyon lotor) are common, widely distributed animals that frequently come into contact with wild waterfowl, agricultural operations, and humans. Serosurveys showed that raccoons are exposed to avian influenza virus. We found antibodies to a variety of influenza virus subtypes (H10N7, H4N6, H4N2, H3, and H1) with wide geographic variation in seroprevalence. Experimental infection studies showed that raccoons become infected with avian and human influenza A viruses, shed and transmit virus to virus-free animals, and seroconvert. Analyses of cellular receptors showed that raccoons have avian and human type receptors with a similar distribution as found in human respiratory tracts. The potential exists for co-infection of multiple subtypes of influenza virus with genetic reassortment and creation of novel strains of influenza virus. Experimental and field data indicate that raccoons may play an important role in influenza disease ecology and pose risks to agriculture and human health.

  14. Novel Human-like Influenza A Viruses Circulate in Swine in Mexico and Chile

    PubMed Central

    Nelson, Martha; Culhane, Marie R.; Rovira, Albert; Torremorell, Montserrat; Guerrero, Pedro; Norambuena, Julio

    2015-01-01

    Introduction: Further understanding of the genetic diversity and evolution of influenza A viruses circulating in swine (IAV-S) is important for the development of effective vaccines and our knowledge of pandemic threats. Until recently, very little was known of IAV-S diversity in Latin America, owing to a lack of surveillance. Methods: To address this gap, we sequenced and conducted a phylogenetic analysis of 69 hemagglutinin (HA) sequences from IAV-S isolates collected in swine in Mexico and Chile during 2010-2014, including the H1N1, H1N2, and H3N2 subtypes. Results: Our analysis identified multiple IAV-S lineages that appear to have been circulating undetected in swine for decades, including four novel IAV-S lineages of human seasonal virus origin that have not been previously identified in any swine populations globally. We also found evidence of repeated introductions of pandemic H1N1 viruses from humans into swine in Mexico and Chile since 2009, and incursions of H1 and H3 viruses from North American swine into Mexico. Discussion: Overall, our findings indicate that at least 12 genetically distinct HA lineages circulate in Latin American swine herds, only two of which have been found in North American swine herds. Human-to-swine transmission, spatial migration via swine movements, and genomic reassortment are the key evolutionary mechanisms that generate this viral diversity. Additional antigenic characterization and whole-genome sequencing is greatly needed to understand the diversity and independent evolution of IAV-S in Latin America.  PMID:26345598

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

    PubMed

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

    2016-02-01

    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

  16. Oncolytic Activity of Avian Influenza Virus in Human Pancreatic Ductal Adenocarcinoma Cell Lines

    PubMed Central

    Pizzuto, Matteo S.; Silic-Benussi, Micol; Pavone, Silvia; Ciminale, Vincenzo; Capua, Ilaria

    2014-01-01

    ABSTRACT Pancreatic ductal adenocarcinoma (PDA) is the most lethal form of human cancer, with dismal survival rates due to late-stage diagnoses and a lack of efficacious therapies. Building on the observation that avian influenza A viruses (IAVs) have a tropism for the pancreas in vivo, the present study was aimed at testing the efficacy of IAVs as oncolytic agents for killing human PDA cell lines. Receptor characterization confirmed that human PDA cell lines express the alpha-2,3- and the alpha-2,6-linked glycan receptor for avian and human IAVs, respectively. PDA cell lines were sensitive to infection by human and avian IAV isolates, which is consistent with this finding. Growth kinetic experiments showed preferential virus replication in PDA cells over that in a nontransformed pancreatic ductal cell line. Finally, at early time points posttreatment, infection with IAVs caused higher levels of apoptosis in PDA cells than gemcitabine and cisplatin, which are the cornerstone of current therapies for PDA. In the BxPC-3 PDA cell line, apoptosis resulted from the engagement of the intrinsic mitochondrial pathway. Importantly, IAVs did not induce apoptosis in nontransformed pancreatic ductal HPDE6 cells. Using a model based on the growth of a PDA cell line as a xenograft in SCID mice, we also show that a slightly pathogenic avian IAV significantly inhibited tumor growth following intratumoral injection. Taken together, these results are the first to suggest that IAVs may hold promise as future agents of oncolytic virotherapy against pancreatic ductal adenocarcinomas. IMPORTANCE Despite intensive studies aimed at designing new therapeutic approaches, PDA still retains the most dismal prognosis among human cancers. In the present study, we provide the first evidence indicating that avian IAVs of low pathogenicity display a tropism for human PDA cells, resulting in viral RNA replication and a potent induction of apoptosis in vitro and antitumor effects in vivo. These

  17. Host-Specific and Segment-Specific Evolutionary Dynamics of Avian and Human Influenza A Viruses: A Systematic Review

    PubMed Central

    Kim, Kiyeon; Omori, Ryosuke; Ueno, Keisuke; Iida, Sayaka; Ito, Kimihito

    2016-01-01

    Understanding the evolutionary dynamics of influenza viruses is essential to control both avian and human influenza. Here, we analyze host-specific and segment-specific Tajima’s D trends of influenza A virus through a systematic review using viral sequences registered in the National Center for Biotechnology Information. To avoid bias from viral population subdivision, viral sequences were stratified according to their sampling locations and sampling years. As a result, we obtained a total of 580 datasets each of which consists of nucleotide sequences of influenza A viruses isolated from a single population of hosts at a single sampling site within a single year. By analyzing nucleotide sequences in the datasets, we found that Tajima’s D values of viral sequences were different depending on hosts and gene segments. Tajima’s D values of viruses isolated from chicken and human samples showed negative, suggesting purifying selection or a rapid population growth of the viruses. The negative Tajima’s D values in rapidly growing viral population were also observed in computer simulations. Tajima’s D values of PB2, PB1, PA, NP, and M genes of the viruses circulating in wild mallards were close to zero, suggesting that these genes have undergone neutral selection in constant-sized population. On the other hand, Tajima’s D values of HA and NA genes of these viruses were positive, indicating HA and NA have undergone balancing selection in wild mallards. Taken together, these results indicated the existence of unknown factors that maintain viral subtypes in wild mallards. PMID:26760775

  18. Roles of the phosphorylation of specific serines and threonines in the NS1 protein of human influenza A viruses.

    PubMed

    Hsiang, Tien-Ying; Zhou, Ligang; Krug, Robert M

    2012-10-01

    We demonstrate that phosphorylation of the NS1 protein of a human influenza A virus occurs not only at the threonine (T) at position 215 but also at serines (Ss), specifically at positions 42 and 48. By generating recombinant influenza A/Udorn/72 (Ud) viruses that encode mutant NS1 proteins, we determined the roles of these phosphorylations in virus replication. At position 215 only a T-to-A substitution attenuated replication, whereas other substitutions (T to E to mimic constitutive phosphorylation, T to N, and T to P, the amino acid in avian influenza A virus NS1 proteins) had no effect. We conclude that attenuation resulting from the T-to-A substitution at position 215 is attributable to a deleterious structural change in the NS1 protein that is not caused by other amino acid substitutions and that phosphorylation of T215 does not affect virus replication. At position 48 neither an S-to-A substitution nor an S-to-D substitution that mimics constitutive phosphorylation affected virus replication. In contrast, at position 42, an S-to-D, but not an S-to-A, substitution caused attenuation. The S-to-D substitution eliminates detectable double-stranded RNA binding by the NS1 protein, accounting for attenuation of virus replication. We show that protein kinase C α (PKCα) catalyzes S42 phosphorylation. Consequently, the only phosphorylation of the NS1 protein of this human influenza A virus that regulates its replication is S42 phosphorylation catalyzed by PKCα. In contrast, phosphorylation of Ts or Ss in the NS1 protein of the 2009 H1N1 pandemic virus was not detected, indicating that NS1 phosphorylation probably does not play any role in the replication of this virus.

  19. Putative Human and Avian Risk Factors for Avian Influenza Virus Infections in Backyard Poultry in Egypt

    PubMed Central

    Sheta, Basma M.; Fuller, Trevon L.; Larison, Brenda; Njabo, Kevin Y.; Ahmed, Ahmed Samy; Harrigan, Ryan; Chasar, Anthony; Aziz, Soad Abdel; Khidr, Abdel-Aziz A.; Elbokl, Mohamed M.; Habbak, Lotfy Z.; Smith, Thomas B.

    2014-01-01

    Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n=1,084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010–2012. Cloacal and tracheal swabs and serum samples from domestic (n=1242)and wild birds (n=807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n=306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n = 51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F = 15.7, p< 0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F= 29.5, p< 0.0001). PMID:24315038

  20. Putative human and avian risk factors for avian influenza virus infections in backyard poultry in Egypt.

    PubMed

    Sheta, Basma M; Fuller, Trevon L; Larison, Brenda; Njabo, Kevin Y; Ahmed, Ahmed Samy; Harrigan, Ryan; Chasar, Anthony; Abdel Aziz, Soad; Khidr, Abdel-Aziz A; Elbokl, Mohamed M; Habbak, Lotfy Z; Smith, Thomas B

    2014-01-10

    Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n=1084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010-2012. Cloacal and tracheal swabs and serum samples from domestic (n=1242) and wild birds (n=807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n=306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n=51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F=15.7, p<0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F=29.5, p<0.0001).

  1. Use of ex vivo and in vitro cultures of the human respiratory tract to study the tropism and host responses of highly pathogenic avian influenza A (H5N1) and other influenza viruses.

    PubMed

    Chan, Renee W Y; Chan, Michael C W; Nicholls, John M; Malik Peiris, J S

    2013-12-05

    The tropism of influenza viruses for the human respiratory tract is a key determinant of host-range, and consequently, of pathogenesis and transmission. Insights can be obtained from clinical and autopsy studies of human disease and relevant animal models. Ex vivo cultures of the human respiratory tract and in vitro cultures of primary human cells can provide complementary information provided they are physiologically comparable in relevant characteristics to human tissues in vivo, e.g. virus receptor distribution, state of differentiation. We review different experimental models for their physiological relevance and summarize available data using these cultures in relation to highly pathogenic avian influenza H5N1, in comparison where relevant, with other influenza viruses. Transformed continuous cell-lines often differ in important ways to the corresponding tissues in vivo. The state of differentiation of primary human cells (respiratory epithelium, macrophages) can markedly affect virus tropism and host responses. Ex vivo cultures of human respiratory tissues provide a close resemblance to tissues in vivo and may be used to risk assess animal viruses for pandemic threat. Physiological factors (age, inflammation) can markedly affect virus receptor expression and virus tropism. Taken together with data from clinical studies on infected humans and relevant animal models, data from ex vivo and in vitro cultures of human tissues and cells can provide insights into virus transmission and pathogenesis and may provide understanding that leads to novel therapeutic interventions.

  2. [Rhabdomyolysis and acute renal failure in human influenza A H1N1 mediated infection].

    PubMed

    Carrillo-Esper, Raúl; Ornelas-Arroyo, Sofía; Pérez-Bustos, Estela; Sánchez-Zúñiga, Jesús; Uribe-Esquivel, Misael

    2009-01-01

    Rabdomiolysis and acute renal failure secondary to influenza infection are rare. Up to now, few cases have been reported and most of them are primarily among children. Myositis associated to influenza infection is caused by the toxic effect of the virus in the muscular fiber, dysregulation of inflammatory cytokines and a cross reaction between the muscle fiber and the viral particles. We present the case of a 57 year old male with a diagnosis of H1N1 influenza who developed polyuria, oligoanuria, elevation of lactic dehydrogenase, myoglobin, creatinin phosphokinase and an electromyography with a myopathic pattern. The diagnosis of rabdomyolisis and acute renal failure were made, hemodyalisis was started and the patient improved satisfactorily. This is the first report of a patient with radmoyolisis and acute renal failure secondary to A H1N1 influenza treated during the Mexico epidemic.

  3. Adaptation of avian influenza A (H6N1) virus from avian to human receptor-binding preference

    PubMed Central

    Wang, Fei; Qi, Jianxun; Bi, Yuhai; Zhang, Wei; Wang, Min; Zhang, Baorong; Wang, Ming; Liu, Jinhua; Yan, Jinghua; Shi, Yi; Gao, George F

    2015-01-01

    The receptor-binding specificity of influenza A viruses is a major determinant for the host tropism of the virus, which enables interspecies transmission. In 2013, the first human case of infection with avian influenza A (H6N1) virus was reported in Taiwan. To gather evidence concerning the epidemic potential of H6 subtype viruses, we performed comprehensive analysis of receptor-binding properties of Taiwan-isolated H6 HAs from 1972 to 2013. We propose that the receptor-binding properties of Taiwan-isolated H6 HAs have undergone three major stages: initially avian receptor-binding preference, secondarily obtaining human receptor-binding capacity, and recently human receptor-binding preference, which has been confirmed by receptor-binding assessment of three representative virus isolates. Mutagenesis work revealed that E190V and G228S substitutions are important to acquire the human receptor-binding capacity, and the P186L substitution could reduce the binding to avian receptor. Further structural analysis revealed how the P186L substitution in the receptor-binding site of HA determines the receptor-binding preference change. We conclude that the human-infecting H6N1 evolved into a human receptor preference. PMID:25940072

  4. Adaptation of avian influenza A (H6N1) virus from avian to human receptor-binding preference.

    PubMed

    Wang, Fei; Qi, Jianxun; Bi, Yuhai; Zhang, Wei; Wang, Min; Zhang, Baorong; Wang, Ming; Liu, Jinhua; Yan, Jinghua; Shi, Yi; Gao, George F

    2015-06-12

    The receptor-binding specificity of influenza A viruses is a major determinant for the host tropism of the virus, which enables interspecies transmission. In 2013, the first human case of infection with avian influenza A (H6N1) virus was reported in Taiwan. To gather evidence concerning the epidemic potential of H6 subtype viruses, we performed comprehensive analysis of receptor-binding properties of Taiwan-isolated H6 HAs from 1972 to 2013. We propose that the receptor-binding properties of Taiwan-isolated H6 HAs have undergone three major stages: initially avian receptor-binding preference, secondarily obtaining human receptor-binding capacity, and recently human receptor-binding preference, which has been confirmed by receptor-binding assessment of three representative virus isolates. Mutagenesis work revealed that E190V and G228S substitutions are important to acquire the human receptor-binding capacity, and the P186L substitution could reduce the binding to avian receptor. Further structural analysis revealed how the P186L substitution in the receptor-binding site of HA determines the receptor-binding preference change. We conclude that the human-infecting H6N1 evolved into a human receptor preference.

  5. A possible outbreak of swine influenza, 1892

    PubMed Central

    Morens, David M; Taubenberger, Jeffery K

    2014-01-01

    Influenza A viruses are globally enzootic in swine populations. Swine influenza has been recognised only since 1918, but an anecdotal report suggests that a swine-influenza epizootic might have occurred in England in 1892, at the same time as an explosive epidemic (or pandemic recurrence) of human influenza. This outbreak suggests that the ecobiological association between human and swine influenza could extend to before 1918. By contrast with the recent documentation of swine influenza, influenza in horses has been well documented for hundreds of years, and was often linked temporally and geographically to epidemics of human influenza. Both decreased contact between people and horses, and the concomitant increase in swine production over the past century, might have altered the character and dynamics of influenza host-switch events between people and domestic mammals. PMID:24290840

  6. A possible outbreak of swine influenza, 1892.

    PubMed

    Morens, David M; Taubenberger, Jeffery K

    2014-02-01

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

  7. Extrapolating theoretical efficacy of inactivated influenza A/H5N1 virus vaccine from human immunogenicity studies.

    PubMed

    Feldstein, Leora R; Matrajt, Laura; Elizabeth Halloran, M; Keitel, Wendy A; Longini, Ira M

    2016-07-19

    Influenza A virus subtype H5N1 has been a public health concern for almost 20years due to its potential ability to become transmissible among humans. Phase I and II clinical trials have assessed safety, reactogenicity and immunogenicity of inactivated influenza A/H5N1 virus vaccines. A shortage of vaccine is likely to occur during the first months of a pandemic. Hence, determining whether to give one dose to more people or two doses to fewer people to best protect the population is essential. We use hemagglutination-inhibition antibody titers as an immune correlate for avian influenza vaccines. Using an established relationship to obtain a theoretical vaccine efficacy from immunogenicity data from thirteen arms of six phase I and phase II clinical trials of inactivated influenza A/H5N1 virus vaccines, we assessed: (1) the proportion of theoretical vaccine efficacy achieved after a single dose (defined as primary response level), and (2) whether theoretical efficacy increases after a second dose, with and without adjuvant. Participants receiving vaccine with AS03 adjuvant had higher primary response levels (range: 0.48-0.57) compared to participants receiving vaccine with MF59 adjuvant (range: 0.32-0.47), with no observed trends in primary response levels by antigen dosage. After the first and second doses, vaccine with AS03 at dosage levels 3.75, 7.5 and 15mcg had the highest estimated theoretical vaccine efficacy: Dose (1) 45% (95% CI: 36-57%), 53% (95% CI: 42-63%) and 55% (95% CI: 44-64%), respectively and Dose (2) 93% (95% CI: 89-96%), 97% (95% CI: 95-98%) and 97% (95% CI: 96-100%), respectively. On average, the estimated theoretical vaccine efficacy of lower dose adjuvanted vaccines (AS03 and MF59) was 17% higher than that of higher dose unadjuvanted vaccines, suggesting that including an adjuvant is dose-sparing. These data indicate adjuvanted inactivated influenza A/H5N1 virus vaccine produces high theoretical efficacy after two doses to protect individuals

  8. In vitro validation of self designed "universal human Influenza A siRNA".

    PubMed

    Jain, Bhawana; Jain, Amita; Prakash, Om; Singh, Ajay Kr; Dangi, Tanushree; Singh, Mastan; Singh, K P

    2015-08-01

    The genomic variability of Influenza A virus (IAV) makes it difficult for the existing vaccines or anti-influenza drugs to control. The siRNA targeting viral gene induces RNAi mechanism in the host and silent the gene by cleaving mRNA. In this study, we developed an universal siRNA and validated its efficiency in vitro. The siRNA was designed rationally, targeting the most conserved region (delineated with the help of multiple sequence alignment) of M gene of IAV strains. Three level screening method was adopted, and the most efficient one was selected on the basis of its unique position in the conserved region. The siRNA efficacy was confirmed in vitro with the Madin Darby Canine Kidney (MDCK) cell line for IAV propagation using two clinical isolates i.e., Influenza A/H3N2 and Influenza A/pdmH1N1. Of the total 168 strains worldwide and 33 strains from India, 97 bp long (position 137-233) conserved region was identified. The longest ORF of matrix gene was targeted by the selected siRNA, which showed 73.6% inhibition in replication of Influenza A/pdmH1N1 and 62.1% inhibition in replication of Influenza A/H3N2 at 48 h post infection on MDCK cell line. This study provides a basis for the development of siRNA which can be used as universal anti-IAV therapeutic agent.

  9. Comparisons of Highly Virulent H5N1 Influenza A Viruses Isolated from Humans and Chickens from Hong Kong

    PubMed Central

    Suarez, David L.; Perdue, Michael L.; Cox, Nancy; Rowe, Thomas; Bender, Catherine; Huang, Jing; Swayne, David E.

    1998-01-01

    Genes of an influenza A (H5N1) virus from a human in Hong Kong isolated in May 1997 were sequenced and found to be all avian-like (K. Subbarao et al., Science 279:393–395, 1998). Gene sequences of this human isolate were compared to those of a highly pathogenic chicken H5N1 influenza virus isolated from Hong Kong in April 1997. Sequence comparisons of all eight RNA segments from the two viruses show greater than 99% sequence identity between them. However, neither isolate’s gene sequence was closely (>95% sequence identity) related to any other gene sequences found in the GenBank database. Phylogenetic analysis demonstrated that the nucleotide sequences of at least four of the eight RNA segments clustered with Eurasian origin avian influenza viruses. The hemagglutinin gene phylogenetic analysis also included the sequences from an additional three human and two chicken H5N1 virus isolates from Hong Kong, and the isolates separated into two closely related groups. However, no single amino acid change separated the chicken origin and human origin isolates, but they all contained multiple basic amino acids at the hemagglutinin cleavage site, which is associated with a highly pathogenic phenotype in poultry. In experimental intravenous inoculation studies with chickens, all seven viruses were highly pathogenic, killing most birds within 24 h. All infected chickens had virtually identical pathologic lesions, including moderate to severe diffuse edema and interstitial pneumonitis. Viral nucleoprotein was most frequently demonstrated in vascular endothelium, macrophages, heterophils, and cardiac myocytes. Asphyxiation from pulmonary edema and generalized cardiovascular collapse were the most likely pathogenic mechanisms responsible for illness and death. In summary, a small number of changes in hemagglutinin gene sequences defined two closely related subgroups, with both subgroups having human and chicken members, among the seven viruses examined from Hong Kong, and

  10. The genesis and source of the H7N9 influenza viruses causing human infections in China.

    PubMed

    Lam, Tommy Tsan-Yuk; Wang, Jia; Shen, Yongyi; Zhou, Boping; Duan, Lian; Cheung, Chung-Lam; Ma, Chi; Lycett, Samantha J; Leung, Connie Yin-Hung; Chen, Xinchun; Li, Lifeng; Hong, Wenshan; Chai, Yujuan; Zhou, Linlin; Liang, Huyi; Ou, Zhihua; Liu, Yongmei; Farooqui, Amber; Kelvin, David J; Poon, Leo L M; Smith, David K; Pybus, Oliver G; Leung, Gabriel M; Shu, Yuelong; Webster, Robert G; Webby, Richard J; Peiris, Joseph S M; Rambaut, Andrew; Zhu, Huachen; Guan, Yi

    2013-10-10

    A novel H7N9 influenza A virus first detected in March 2013 has since caused more than 130 human infections in China, resulting in 40 deaths. Preliminary analyses suggest that the virus is a reassortant of H7, N9 and H9N2 avian influenza viruses, and carries some amino acids associated with mammalian receptor binding, raising concerns of a new pandemic. However, neither the source populations of the H7N9 outbreak lineage nor the conditions for its genesis are fully known. Using a combination of active surveillance, screening of virus archives, and evolutionary analyses, here we show that H7 viruses probably transferred from domestic duck to chicken populations in China on at least two independent occasions. We show that the H7 viruses subsequently reassorted with enzootic H9N2 viruses to generate the H7N9 outbreak lineage, and a related previously unrecognized H7N7 lineage. The H7N9 outbreak lineage has spread over a large geographic region and is prevalent in chickens at live poultry markets, which are thought to be the immediate source of human infections. Whether the H7N9 outbreak lineage has, or will, become enzootic in China and neighbouring regions requires further investigation. The discovery here of a related H7N7 influenza virus in chickens that has the ability to infect mammals experimentally, suggests that H7 viruses may pose threats beyond the current outbreak. The continuing prevalence of H7 viruses in poultry could lead to the generation of highly pathogenic variants and further sporadic human infections, with a continued risk of the virus acquiring human-to-human transmissibility.

  11. Cellular Human CLE/C14orf166 Protein Interacts with Influenza Virus Polymerase and Is Required for Viral Replication ▿

    PubMed Central

    Rodriguez, Ariel; Pérez-González, Alicia; Nieto, Amelia

    2011-01-01

    The influenza A virus polymerase associates with a number of cellular transcription-related factors, including RNA polymerase II. We previously described the interaction of influenza virus polymerase subunit PA with human CLE/C14orf166 protein (hCLE), a positive modulator of this cellular RNA polymerase. Here, we show that hCLE also interacts with the influenza virus polymerase complex and colocalizes with viral ribonucleoproteins. Silencing of hCLE causes reduction of viral polymerase activity, viral RNA transcription and replication, virus titer, and viral particle production. Altogether, these findings indicate that the cellular transcription factor hCLE is an important protein for influenza virus replication. PMID:21900157

  12. The effects of a deleterious mutation load on patterns of influenza A/H3N2's antigenic evolution in humans.

    PubMed

    Koelle, Katia; Rasmussen, David A

    2015-09-15

    Recent phylogenetic analyses indicate that RNA virus populations carry a significant deleterious mutation load. This mutation load has the potential to shape patterns of adaptive evolution via genetic linkage to beneficial mutations. Here, we examine the effect of deleterious mutations on patterns of influenza A subtype H3N2's antigenic evolution in humans. By first analyzing simple models of influenza that incorporate a mutation load, we show that deleterious mutations, as expected, act to slow the virus's rate of antigenic evolution, while making it more punctuated in nature. These models further predict three distinct molecular pathways by which antigenic cluster transitions occur, and we find phylogenetic patterns consistent with each of these pathways in influenza virus sequences. Simulations of a more complex phylodynamic model further indicate that antigenic mutations act in concert with deleterious mutations to reproduce influenza's spindly hemagglutinin phylogeny, co-circulation of antigenic variants, and high annual attack rates.

  13. Canine susceptibility to human influenza viruses (A/pdm 09H1N1, A/H3N2 and B).

    PubMed

    Song, Daesub; Kim, Hyekwon; Na, Woonsung; Hong, Minki; Park, Seong-Jun; Moon, Hyoungjoon; Kang, Bokyu; Lyoo, Kwang-Soo; Yeom, Minjoo; Jeong, Dae Gwin; An, Dong-Jun; Kim, Jeong-Ki

    2015-02-01

    We investigated the infectivity and transmissibility of the human seasonal H3N2, pandemic (pdm) H1N1 (2009) and B influenza viruses in dogs. Dogs inoculated with human seasonal H3N2 and pdm H1N1 influenza viruses exhibited nasal shedding and were seroconverted against the viruses; this did not occur in the influenza B virus-inoculated dogs. Transmission of human H3N2 virus between dogs was demonstrated by observing nasal shedding and seroconversion in naïve dogs after contact with inoculated dogs. The seroprevalence study offered evidence of human H3N2 infection occurring in dogs since 2008. Furthermore, serological evidence of pdm H1N1 influenza virus infection alone and in combination with canine H3N2 virus was found in the serum samples collected from field dogs during 2010 and 2011. Our results suggest that dogs may be hosts for human seasonal H3N2 and pdm H1N1 influenza viruses.

  14. Molecular cloning of the first human monoclonal antibodies neutralizing with high potency swine-origin influenza A pandemic virus (S-OIV).

    PubMed

    Burioni, Roberto; Canducci, Filippo; Mancini, Nicasio; Clementi, Nicola; Sassi, Monica; De Marco, Donata; Saita, Diego; Diotti, Roberta Antonia; Sautto, Giuseppe; Sampaolo, Michela; Clementi, Massimo

    2009-10-01

    The pandemic caused by the new H1N1 swine-origin influenza virus (S-OIV) strain is a worldwide health emergency and alternative therapeutic and prophylactic options are greatly needed. Two human monoclonal antibody Fab fragments (HMab) neutralizing the novel H1N1 influenza strain at very low concentrations were cloned from a patient who had a broad-range anti-H1N1 serum neutralizing activity. The two HMabs neutralized S-OIV with an IC50 of 2.8 and 4 microg/mL. The genes coding for the neutralizing HMabs could be used for generating full human monoclonal IgGs that can be safely administered with the potentially of representing a novel drug to be used in the prophylaxis and the treatment of this human infection. This is the first report of molecular cloning of human monoclonal antibodies against the new pandemic swine-origin influenza virus.

  15. Expression of crossreactive idiotypes by human antibodies specific for the capsular polysaccharide of Hemophilus influenzae B.

    PubMed Central

    Lucas, A H

    1988-01-01

    Human antibodies specific, for polyribosyl-ribitol-phosphate (PRP), the capsular polysaccharide of Hemophilus influenzae b, were studied using idiotypic analysis. Antisera were prepared against purified F(ab')2 anti-PRP from two unrelated adults, H.H. and P.T. After repeated absorption with IgG myeloma proteins and with PRP-absorbed normal human Ig and donor Ig, anti-idiotypic (anti-Id) sera were obtained that specifically reacted with anti-PRP antibodies. Anti-IdHH and anti-IdPT reciprocally crossreacted with H.H. and P.T. anti-PRP antibodies and F(ab')2 fragments, and also reacted with the serum anti-PRP antibodies from three additional adults unrelated to P.T. and H.H. Both anti-Id sera partially inhibited anti-PRP paratopes but not anti-tetanus toxoid paratopes. PRP did not inhibit anti-Id recognition of shared or crossreactive idiotypic (CRI) determinants. Naturally occurring and PRP immunization-induced anti-PRP antibodies expressed CRI. While CRI titer increased after immunization, the increase was usually less than the rise in total anti-PRP antibody. Quantitative differences in CRI expression were also apparent between natural and immunization-induced H.H. and P.T. anti-PRP antibodies as shown by their differential inhibitability by anti-Id. Our data demonstrate that anti-PRP antibodies from five unrelated adults express CRI determinants that are probably distant from the PRP combining site. Naturally occurring and immunization-induced anti-PRP antibodies share CRI and therefore appear to be clonally related, although immunization apparently induces the expression CRI-negative antibodies as well. These results, taken with previous studies showing restricted and identical anti-PRP isoelectric focusing spectrotypes in unrelated adults, suggest that some PRP-specific V domains are structurally conserved and probably germ-line encoded. PMID:3257499

  16. The avian influenza H9N2 at avian-human interface: A possible risk for the future pandemics

    PubMed Central

    RahimiRad, Shaghayegh; Alizadeh, Ali; Alizadeh, Effat; Hosseini, Seyyed Masoud

    2016-01-01

    The avian influenza subtype H9N2 is considered a low pathogenic virus which is endemic in domestic poultry of a majority of Asian countries. Many reports of seropositivity in occupationally poultry-exposed workers and a number of confirmed human infections with an H9N2 subtype of avian influenza have been documented up to now. Recently, the human infections with both H7N9 and H10N8 viruses highlighted that H9N2 has a great potential for taking a part in the emergence of new human-infecting viruses. This review aimed at discussing the great potential of H9N2 virus which is circulating at avian-human interface, for cross-species transmission, contribution in the production of new reassortants and emergence of new pandemic subtypes. An intensified surveillance is needed for controlling the future risks which would be created by H9N2 circulation at avian-human interfaces. PMID:28083072

  17. Systemic and mucosal immune responses following oral adenoviral delivery of influenza vaccine to the human intestine by radio controlled capsule

    PubMed Central

    Kim, Leesun; Martinez, C. Josefina; Hodgson, Katie A.; Trager, George R.; Brandl, Jennifer R.; Sandefer, Erik P.; Doll, Walter J.; Liebowitz, Dave; Tucker, Sean N.

    2016-01-01

    There are several benefits of oral immunization including the ability to elicit mucosal immune responses that may protect against pathogens that invade through a mucosal surface. Our understanding of human immune biology is hampered by the difficulty in isolating mucosal cells from humans, and the fact that animal models may or may not completely mirror human intestinal immunobiology. In this human pharmacodynamic study, a novel adenovirus vector-based platform expressing influenza hemagglutinin was explored. We used radio-controlled capsules to deliver the vaccine to either the jejunum or the ileum. The resulting immune responses induced by immunization at each of the intestinal sites were investigated. Both intestinal sites were capable of inducing mucosal and systemic immune responses to influenza hemagglutinin, but ileum delivery induced higher numbers of antibody secreting cells of IgG and IgA isotypes, increased mucosal homing B cells, and higher number of vaccine responders. Overall, these data provided substantial insights into human mucosal inductive sites, and aided in the design and selection of indications that could be used with this oral vaccine platform. PMID:27881837

  18. Human Sentinel Surveillance of Influenza and Other Respiratory Viral Pathogens in Border Areas of Western Cambodia

    PubMed Central

    Chuang, Ilin; Samon, Nou; Uthaimongkol, Nichapat; Klungthong, Chonticha; Manasatienkij, Wudtichai; Thaisomboonsuk, Butsaya; Tyner, Stuart D.; Rith, Sareth; Horm, Viseth Srey; Jarman, Richard G.; Bethell, Delia; Chanarat, Nitima; Pavlin, Julie; Wongstitwilairoong, Tippa; Saingam, Piyaporn; El, But Sam; Fukuda, Mark M.; Touch, Sok; Sovann, Ly; Fernandez, Stefan; Buchy, Philippe; Chanthap, Lon; Saunders, David

    2016-01-01

    Little is known about circulation of influenza and other respiratory viruses in remote populations along the Thai-Cambodia border in western Cambodia. We screened 586 outpatients (median age 5, range 1–77) presenting with influenza-like-illness (ILI) at 4 sentinel sites in western Cambodia between May 2010 and December 2012. Real-time reverse transcriptase (rRT) PCR for influenza was performed on combined nasal and throat specimens followed by viral culture, antigenic analysis, antiviral susceptibility testing and full genome sequencing for phylogenetic analysis. ILI-specimens negative for influenza were cultured, followed by rRT-PCR for enterovirus and rhinovirus (EV/RV) and EV71. Influenza was found in 168 cases (29%) and occurred almost exclusively in the rainy season from June to November. Isolated influenza strains had close antigenic and phylogenetic relationships, matching vaccine and circulating strains found elsewhere in Cambodia. Influenza vaccination coverage was low (<20%). Western Cambodian H1N1(2009) isolate genomes were more closely related to 10 earlier Cambodia isolates (94.4% genome conservation) than to 13 Thai isolates (75.9% genome conservation), despite sharing the majority of the amino acid changes with the Thai references. Most genes showed signatures of purifying selection. Viral culture detected only adenovirus (5.7%) and parainfluenza virus (3.8%), while non-polio enteroviruses (10.3%) were detected among 164 culture-negative samples including coxsackievirus A4, A6, A8, A9, A12, B3, B4 and echovirus E6 and E9 using nested RT-PCR methods. A single specimen of EV71 was found. Despite proximity to Thailand, influenza epidemiology of these western Cambodian isolates followed patterns observed elsewhere in Cambodia, continuing to support current vaccine and treatment recommendations from the Cambodian National Influenza Center. Amino acid mutations at non-epitope sites, particularly hemagglutinin genes, require further investigation in light

  19. Aging-dependent alterations in gene expression and a mitochondrial signature of responsiveness to human influenza vaccination.

    PubMed

    Thakar, Juilee; Mohanty, Subhasis; West, A Phillip; Joshi, Samit R; Ueda, Ikuyo; Wilson, Jean; Meng, Hailong; Blevins, Tamara P; Tsang, Sui; Trentalange, Mark; Siconolfi, Barbara; Park, Koonam; Gill, Thomas M; Belshe, Robert B; Kaech, Susan M; Shadel, Gerald S; Kleinstein, Steven H; Shaw, Albert C

    2015-01-01

    To elucidate gene expression pathways underlying age-associated impairment in influenza vaccine response, we screened young (age 21-30) and older (age≥65) adults receiving influenza vaccine in two consecutive seasons and identified those with strong or absent response to vaccine, including a subset of older adults meeting criteria for frailty. PBMCs obtained prior to vaccination (Day 0) and at day 2 or 4, day 7 and day 28 post-vaccine were subjected to gene expression microarray analysis. We defined a response signature and also detected induction of a type I interferon response at day 2 and a plasma cell signature at day 7 post-vaccine in young responders. The response signature was dysregulated in older adults, with the plasma cell signature induced at day 2, and was never induced in frail subjects (who were all non-responders). We also identified a mitochondrial signature in young vaccine responders containing genes mediating mitochondrial biogenesis and oxidative phosphorylation that was consistent in two different vaccine seasons and verified by analyses of mitochondrial content and protein expression. These results represent the first genome-wide transcriptional profiling analysis of age-associated dynamics following influenza vaccination, and implicate changes in mitochondrial biogenesis and function as a critical factor in human vaccine responsiveness.

  20. A potent broad-spectrum protective human monoclonal antibody crosslinking two haemagglutinin monomers of influenza A virus

    PubMed Central

    Wu, Ying; Cho, MyungSam; Shore, David; Song, Manki; Choi, JungAh; Jiang, Tao; Deng, Yong-Qiang; Bourgeois, Melissa; Almli, Lynn; Yang, Hua; Chen, Li-Mei; Shi, Yi; Qi, Jianxu; Li, An; Yi, Kye Sook; Chang, MinSeok; Bae, Jin Soo; Lee, HyunJoo; Shin, JiYoung; Stevens, James; Hong, SeoungSuh; Qin, Cheng-Feng; Gao, George F.; Chang, Shin Jae; Donis, Ruben O.

    2015-01-01

    Effective annual influenza vaccination requires frequent changes in vaccine composition due to both antigenic shift for different subtype hemagglutinins (HAs) and antigenic drift in a particular HA. Here we present a broadly neutralizing human monoclonal antibody with an unusual binding modality. The antibody, designated CT149, was isolated from convalescent patients infected with pandemic H1N1 in 2009. CT149 is found to neutralize all tested group 2 and some group 1 influenza A viruses by inhibiting low pH-induced, HA-mediated membrane fusion. It promotes killing of infected cells by Fc-mediated antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. X-ray crystallographic data reveal that CT149 binds primarily to the fusion domain in HA2, and the light chain is also largely involved in binding. The epitope recognized by this antibody comprises amino-acid residues from two adjacent protomers of HA. This binding characteristic of CT149 will provide more information to support the design of more potent influenza vaccines. PMID:26196962