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Sample records for human influenza metapneumovirus

  1. Human metapneumovirus in children with influenza-like illness in Yucatan, Mexico.

    PubMed

    Talavera, Guadalupe Ayora; Mézquita, Nelson E Dorantes

    2007-01-01

    The present study suggests that human metapneumovirus (hMPV) is an important cause of community acquired respiratory infections in children. We report the detection of hMPV in a pediatric population with influenza-like illness in the subtropical area of Yucatan in Mexico. Our data also shows that hMPV circulates in the community with other respiratory pathogens.

  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 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

  4. 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.

  5. 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

  6. Human metapneumovirus infections in children.

    PubMed

    Heikkinen, Terho; Osterback, Riikka; Peltola, Ville; Jartti, Tuomas; Vainionpää, Raija

    2008-01-01

    Human metapneumovirus (hMPV) is an important cause of lower respiratory tract infections in hospitalized children, but the age-related incidence and effect of hMPV in unselected children in the community have not been evaluated. We studied a cohort of 1,338 children <13 years of age throughout 1 respiratory season in Finland during 2000-2001. We examined children and obtained a nasal swab for viral detection at any sign of respiratory infection. hMPV was detected in 47 (3.5%) of the 1,338 children. The age-related incidence of hMPV infection was highest (7.6%) in children <2 years of age, in whom hMPV accounted for 1.7% of all infections during the season. During the epidemic peak, hMPV caused 7.1% of all respiratory infections in the cohort. Acute otitis media developed in 61% of hMPV-infected children <3 years of age. Our findings demonstrate that the effect of hMPV in the community is greatest in children <2 years of age.

  7. Human Metapneumovirus Infections in Children

    PubMed Central

    Österback, Riikka; Peltola, Ville; Jartti, Tuomas; Vainionpää, Raija

    2008-01-01

    Human metapneumovirus (hMPV) is an important cause of lower respiratory tract infections in hospitalized children, but the age-related incidence and effect of hMPV in unselected children in the community have not been evaluated. We studied a cohort of 1,338 children <13 years of age throughout 1 respiratory season in Finland during 2000–2001. We examined children and obtained a nasal swab for viral detection at any sign of respiratory infection. hMPV was detected in 47 (3.5%) of the 1,338 children. The age-related incidence of hMPV infection was highest (7.6%) in children <2 years of age, in whom hMPV accounted for 1.7% of all infections during the season. During the epidemic peak, hMPV caused 7.1% of all respiratory infections in the cohort. Acute otitis media developed in 61% of hMPV-infected children <3 years of age. Our findings demonstrate that the effect of hMPV in the community is greatest in children <2 years of age. PMID:18258088

  8. Human Metapneumovirus Infection in Chimpanzees, United States

    PubMed Central

    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.

    2014-01-01

    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. PMID:25417845

  9. 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

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

    PubMed Central

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

    2015-01-01

    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, PMID:26488420

  11. 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

  12. Molecular epidemiology of human metapneumovirus in Ireland.

    PubMed

    Carr, Michael J; Waters, Allison; Fenwick, Fiona; Toms, Geoffrey L; Hall, William W; O'Kelly, Edwin

    2008-03-01

    Human metapneumovirus (hMPV) is a cause of respiratory illness ranging from wheezing to bronchiolitis and pneumonia in children. A quantitative real-time reverse-transcriptase polymerase chain reaction (RT-PCR) assay was developed for the detection of all four main genetic lineages of hMPV and employed to validate an indirect immunofluorescence (IF) assay to detect hMPV positive specimens. The IF assay detected 24 positives from a screen of 625 randomly selected pediatric respiratory specimens collected (3.8% prevalence). From this cohort of 625 specimens, 229 were also tested by real-time RT-PCR assay. This included the 24 IF positive specimens and 205 randomly selected specimens from both study periods. In addition to confirming all the IF positives, the real-time assay detected an additional six hMPV positive specimens giving rise to a combined prevalence of 4.8%. Phylogenetic analysis showed that hMPV subtypes A2b and B2 to be the most prevalent genotypes circulating in our population and surprisingly no hMPV subgroups A1 or B1 were detected during this study period. Based on this phylogenetic analysis, we propose the existence of sub-clusters of hMPV genotype B2 present in our population which we term subtypes B2a and B2b. The mean log 10 copies/ml of quantitative RT-PCR determinations from these 30 hMPV positive respiratory specimens was 6.35 (range = 4.44-8.15). Statistical analysis of quantitative RT-PCR determinations of viral load from these 30 respiratory specimens suggests that hMPV genotype B specimens have a higher viral load than hMPV genotype A isolates (P < 0.03).

  13. 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

  14. 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

  15. [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

  16. 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.

  17. Current developments and prospects on human metapneumovirus vaccines.

    PubMed

    Márquez-Escobar, Verónica Araceli

    2017-05-01

    Human metapneumovirus (hMPV) has become one of the major pathogens causing acute respiratory infections (ARI) mainly affecting young children, immunocompromised patients, and the elderly. Currently there are no licensed vaccines against this virus. Areas covered: Since the discovery of hMPV in 2001, many groups have focused on developing vaccines against this pathogen. This review presents the outcomes and perspectives derived from preclinical studies performed in cell cultures and animals as well as the only candidate that has reached evaluation in a clinical trial. Limitations of the current vaccine candidates are discussed and perspectives for the development of plant-based vaccines are analyzed. Expert commentary: Several hMPV vaccine candidates are under development with the potential to progress into clinical trials. In parallel, the molecular farming field offers new opportunities to generate innovative vaccines that will offer several advantages in the fight against hMPV.

  18. 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.

  19. 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.

  20. 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

  1. Respiratory Tract Infections Due to Human Metapneumovirus in Immunocompromised Children

    PubMed Central

    Chu, Helen Y.; Renaud, Christian; Ficken, Elle; Thomson, Blythe; Kuypers, Jane; Englund, Janet A.

    2014-01-01

    Background The clinical presentation and management of human metapneumovirus (hMPV) infections in immunocompromised children is not well understood. Methods We performed a retrospective evaluation of pediatric patients with laboratory-confirmed hMPV infections and underlying hematologic malignancy, solid tumors, solid organ transplant, rheumatologic disease, and/or receipt of chronic immunosuppressants. Data were analyzed using t tests and Fisher's exact tests. Results Overall, 55 patients (median age: 5 years; range: 5 months–19 years) with hMPV infection documented between 2006 and 2010 were identified, including 24 (44%) with hematologic malignancy, 9 (16%) undergoing hematopoietic stem cell transplant, 9 (16%) with solid tumors, and 8 (15%) with solid organ transplants. Three (5%) presented with fever alone, 35 (64%) presented with upper respiratory tract infections, and 16 (29%) presented with lower respiratory tract infections (LRTI). Twelve (23%) patients required intensive care unit admission and/or supplemental oxygen ≥28% FiO2. Those with severe disease were more likely to be neutropenic (P = .02), but otherwise did not differ by age (P = .27), hematopoietic stem cell transplant recipient status (P = .19), or presence of lymphopenia (P = .09). Nine (16%) patients received treatment with ribavirin, intravenous immunoglobulin, or both. Three children (5%) died of hMPV pneumonia. Conclusions Immunocompromised pediatric patients with hMPV infection have high rates of LRTI and mortality. The benefits of treatment with ribavirin and intravenous immunoglobulin in this patient population require further evaluation. PMID:25419459

  2. 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

  3. 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.

  4. Human metapneumovirus in Hospitalized Children in Amman, Jordan

    PubMed Central

    Ali, Syed Asad; Williams, John V.; Chen, Qingxia; Faori, Sameer; Shehabi, Assem; Al Jundi, Eshan; Khuri-Bulos, Najwa; Halasa, Natasha

    2012-01-01

    Human metapneumovirus (HMPV) has recently been identified as an important cause of acute respiratory infections (ARI) in children worldwide. However, there is little systematic data on its frequency and importance as a cause of ARI in the Middle East. We conducted a viral surveillance study in children <5 years of age admitted with respiratory symptoms and/or fever at two major tertiary care hospitals in Amman, Jordan from 1/18-3/29/07. Nose and throat swabs were collected and tested for HMPV and other respiratory viruses by real-time RT-PCR. A total of 743 subjects were enrolled. Forty-four (6%) subjects were positive for HMPV, 467 (64%) were positive for RSV and 13 (1.3%) had co-infection with both HMPV and RSV. The frequency of HMPV in January, February, and March was4.1%, 3.0%, and 11.9% respectively. Clinical features associated with HMPV infection were similar to those of other respiratory viruses, except children with HMPV were more likely to present with fever than children not infected with HMPV. Children with HMPV and RSV co-infection were administered supplemental oxygen and were admitted to the ICU more frequently than children infected with HMPV alone or RSV alone, though these differences did not reach statistical significance. We conclude that HMPV is an important cause of acute respiratory infections in children in Amman, Jordan. Longer surveillance studies are needed to better understand the seasonal epidemiology of HMPV and to assess if co-infection with HMPV and RSV leads to more severe illness. PMID:20419816

  5. Human metapneumovirus in hospitalized children in Amman, Jordan.

    PubMed

    Ali, Syed Asad; Williams, John V; Chen, Qingxia; Faouri, Sameer; Faori, Sameer; Shehabi, Assem; Jundi, Eshan Al; Khuri-Bulos, Najwa; Halasa, Natasha

    2010-05-01

    Human metapneumovirus (HMPV) has recently been identified as an important cause of acute respiratory infections (ARI) in children worldwide. However, there is little systematic data on its frequency and importance as a cause of ARI in the Middle East. We conducted a viral surveillance study in children <5 years of age admitted with respiratory symptoms and/or fever at two major tertiary care hospitals in Amman, Jordan from 1/18-3/29/07. Nose and throat swabs were collected and tested for HMPV and other respiratory viruses by real-time RT-PCR. A total of 743 subjects were enrolled. Forty-four (6%) subjects were positive for HMPV, 467 (64%) were positive for RSV and 13 (1.3%) had co-infection with both HMPV and RSV. The frequency of HMPV in January, February, and March was 4.1%, 3.0%, and 11.9% respectively. Clinical features associated with HMPV infection were similar to those of other respiratory viruses, except children with HMPV were more likely to present with fever than children not infected with HMPV. Children with HMPV and RSV co-infection were administered supplemental oxygen and were admitted to the ICU more frequently than children infected with HMPV alone or RSV alone, though these differences did not reach statistical significance. We conclude that HMPV is an important cause of acute respiratory infections in children in Amman, Jordan. Longer surveillance studies are needed to better understand the seasonal epidemiology of HMPV and to assess if co-infection with HMPV and RSV leads to more severe illness. (c) 2010 Wiley-Liss, Inc.

  6. Respiratory Tract Infections Due to Human Metapneumovirus in Immunocompromised Children.

    PubMed

    Chu, Helen Y; Renaud, Christian; Ficken, Elle; Thomson, Blythe; Kuypers, Jane; Englund, Janet A

    2014-12-01

    The clinical presentation and management of human metapneumovirus (hMPV) infections in immunocompromised children is not well understood. We performed a retrospective evaluation of pediatric patients with laboratory-confirmed hMPV infections and underlying hematologic malignancy, solid tumors, solid organ transplant, rheumatologic disease, and/or receipt of chronic immunosuppressants. Data were analyzed using t tests and Fisher's exact tests. Overall, 55 patients (median age: 5 years; range: 5 months-19 years) with hMPV infection documented between 2006 and 2010 were identified, including 24 (44%) with hematologic malignancy, 9 (16%) undergoing hematopoietic stem cell transplant, 9 (16%) with solid tumors, and 8 (15%) with solid organ transplants. Three (5%) presented with fever alone, 35 (64%) presented with upper respiratory tract infections, and 16 (29%) presented with lower respiratory tract infections (LRTI). Twelve (23%) patients required intensive care unit admission and/or supplemental oxygen ≥28% FiO2. Those with severe disease were more likely to be neutropenic (P = .02), but otherwise did not differ by age (P = .27), hematopoietic stem cell transplant recipient status (P = .19), or presence of lymphopenia (P = .09). Nine (16%) patients received treatment with ribavirin, intravenous immunoglobulin, or both. Three children (5%) died of hMPV pneumonia. Immunocompromised pediatric patients with hMPV infection have high rates of LRTI and mortality. The benefits of treatment with ribavirin and intravenous immunoglobulin in this patient population require further evaluation. © The Author 2014. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society.

  7. Epidemiological and phylogenic study of human metapneumovirus infections during three consecutive outbreaks in Normandy, France.

    PubMed

    Legrand, Loïc; Vabret, Astrid; Dina, Julia; Petitjean-Lecherbonnier, Joëlle; Stéphanie, Gouarin; Cuvillon, Delphine; Tripey, Valérie; Brouard, Jacques; Freymuth, François

    2011-03-01

    Human metapneumovirus (hMPV) is responsible for respiratory tract disease, particularly in the young and elderly population. An epidemiological and phylogenic study was performed on children admitted to hospital with an acute lower respiratory tract infection (LRI). Data were obtained and analyzed over three consecutive winters, from 2002-2003 to 2004-2005. Each year during the winter period, from November to March, 2,415 nasal swabs were tested by a direct immunofluorescence assay (DFA) for influenza viruses A and B, respiratory syncytial virus, parainfluenza viruses, and adenoviruses. Rhinoviruses, enteroviruses, and coronaviruses OC43 and 229E were detected by RT-PCR. A RT-PCR designed for the M gene was performed on negative samples for hMPV detection and phylogenic analyses. For the three consecutive winters, hMPV represented 10%, 22.6%, and 8.8% of virus-negative samples, respectively. In most cases, clinical symptoms indicated a LRI with a final diagnosis of bronchiolitis. During the winter of 2003-2004, all viral clusters (A1, A2, B1, and B2) that circulated in France shifted progressively from the A group to the B group. This study determined the prevalence of hMPV in Normandy, its clinical impact and permitted the analysis of the molecular evolution during the successive outbreaks. Copyright © 2011 Wiley-Liss, Inc.

  8. Outbreaks of human metapneumovirus in two skilled nursing facilities -West Virginia and Idaho, 2011-2012.

    PubMed

    2013-11-22

    During January and February 2012, state and local public health agencies in West Virginia and Idaho, with assistance from facility staff members and CDC, investigated outbreaks of unexplained respiratory illness characterized by high proportions of lower respiratory tract infections (LRTIs) at two skilled nursing facilities (SNFs). Investigations were conducted to determine the extent and etiology of each outbreak and make recommendations to prevent further spread. During both outbreaks, influenza was initially suspected; however, human metapneumovirus (hMPV) was identified as the etiologic agent. Among 57 cases of respiratory illness from both facilities, 45 (79%) patients had evidence of LRTI, of whom 25 (56%) had radiologically confirmed pneumonia; five (9%) had evidence of upper respiratory tract infection (URTI), and seven (12%) could not be classified. Six patients (11%) died. These outbreaks demonstrate that hMPV, a recently described pathogen that would not have been detected without the use of molecular diagnostics in these outbreaks, is associated with severe LRTI and should be considered as a possible etiology of respiratory outbreaks in SNFs.

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. [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).

  15. 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.

  16. Visual detection of the human metapneumovirus using reverse transcription loop-mediated isothermal amplification with hydroxynaphthol blue dye

    PubMed Central

    2012-01-01

    Background Human metapneumovirus (hMPV) is a major cause of acute respiratory infections ranging from wheezing to bronchiolitis and pneumonia in children worldwide. The objective of this study is to develop a visual reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of hMPV and applied to the clinical samples. Results In this study, visual RT-LAMP assay for hMPV was performed in one step with the addition of hydroxynaphthol blue (HNB), and were used to detect respiratory samples. Six primers, including two outer primers (F3 and B3), two inner primers (FIP, BIP) and two loop primers (LF and LB), were designed for hMPV N gene by the online software. Moreover, the RT-LAMP assay showed good specificity and no cross-reactivity was observed with human rhinovirus (HRV), human respiratory syncytial Virus (RSV), or influenza virus A/PR/8/34 (H1N1). The detection limit of the RT-LAMP assay was approximately ten viral RNA copies, lower than that of traditional reverse transcriptase polymerase chain reaction (RT-PCR) 100 RNA copies. In the 176 nasopharyngeal samples, 23 (13.1%) were conformed as hMPV positive by RT-LAMP, but 18 (10.2%) positive by RT-PCR. Conclusion Compared with conventional RT-PCR, the visual hMPV RT-LAMP assay performed well in the aspect of detect time, sensitivity, specificity and visibility. It is anticipated that the RT-LAMP will be used for clinical tests in hospital or field testing during outbreaks and in emergency. PMID:22838725

  17. 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

  18. 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

  19. 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

  20. 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.

  1. Novel human metapneumovirus with a 180-nucleotide duplication in the G gene.

    PubMed

    Piñana, María; Vila, Jorgina; Gimferrer, Laura; Valls, María; Andrés, Cristina; Codina, María Gema; Ramón, Javier; Martín, María Carmen; Fuentes, Francisco; Saiz, Rosario; Alcubilla, Pilar; Rodrigo, Carlos; Pumarola, Tomàs; Antón, Andrés

    2017-06-01

    To describe the circulation, genetic diversity and clinical features of human metapneumovirus (HMPV) in pediatric patients that attended the Hospital Universitari Vall d'Hebron, Spain from 2014 to 2016. Partial G gene was sequenced from laboratory-confirmed HMPV respiratory specimens for subsequent phylogenetic analysis. A total of 121 different samples were HMPV laboratory-confirmed out of 6658 specimens received. The highest circulation was from February to April, with a prevalence of 3%. Different genetic groups within both genotypes were detected at variable levels. A 180-nucleotide duplication was first characterized within the G gene in nine cases, mostly related to lower respiratory-tract infection. This study reported on the circulation of a novel HMPV with a 180-nucleotide duplication in the G gene, but no clinical changes in related cases were observed. Their prevalence increased during the last season suggesting changes in viral features.

  2. Human Metapneumovirus Inhibits IFN-β Signaling by Downregulating Jak1 and Tyk2 Cellular Levels

    PubMed Central

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

    2011-01-01

    Human metapneumovirus (hMPV), a leading cause of respiratory tract infections in infants, inhibits type I interferon (IFN) signaling by an unidentified mechanism. In this study, we showed that infection of airway epithelial cells with hMPV decreased cellular level of Janus tyrosine kinase (Jak1) and tyrosine kinase 2 (Tyk2), due to enhanced proteosomal degradation and reduced gene transcription. In addition, hMPV infection also reduced the surface expression of type I IFN receptor (IFNAR). These inhibitory mechanisms are different from the ones employed by respiratory syncytial virus (RSV), which does not affect Jak1, Tyk2 or IFNAR expression, but degrades downstream signal transducer and activator of transcription proteins 2 (STAT2), although both viruses are pneumoviruses belonging to the Paramyxoviridae family. Our study identifies a novel mechanism by which hMPV inhibits STAT1 and 2 activation, ultimately leading to viral evasion of host IFN responses. PMID:21949722

  3. 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

  4. 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.

  5. Single Assay for Simultaneous Detection and Differential Identification of Human and Avian Influenza Virus Types, Subtypes, and Emergent Variants

    DTIC Science & Technology

    2010-02-01

    reassortments and mutations emerging within this reservoir may spawn new influenza virus strains as imminent epidemic or pandemic threats to human health...other pathogens include viruses (adenovirus, enterovirus and rhinovirus, coronavirus, herpesvirus, measles virus , metapneumovirus, parainfluenzavirus...Identifying influenza viruses with re -sequencing microarrays. Emerg Infect Dis 12: 638–646. 10. Freed NE, Myers CA, Russell KL, Walter EA, Irvine M, et al

  6. 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.

  7. 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.

  8. 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. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  9. 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.

  10. 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

  11. 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.

  12. The Human Metapneumovirus Fusion Protein Mediates Entry via an Interaction with RGD-Binding Integrins

    PubMed Central

    Cox, Reagan G.; Livesay, S. Brent; Johnson, Monika; Ohi, Melanie D.

    2012-01-01

    Paramyxoviruses use a specialized fusion protein to merge the viral envelope with cell membranes and initiate infection. Most paramyxoviruses require the interaction of two viral proteins to enter cells; an attachment protein binds cell surface receptors, leading to the activation of a fusion (F) protein that fuses the viral envelope and host cell plasma membrane. In contrast, human metapneumovirus (HMPV) expressing only the F protein is replication competent, suggesting a primary role for HMPV F in attachment and fusion. We previously identified an invariant arginine-glycine-aspartate (RGD) motif in the HMPV F protein and showed that the RGD-binding integrin αVβ1-promoted HMPV infection. Here we show that both HMPV F-mediated binding and virus entry depend upon multiple RGD-binding integrins and that HMPV F can mediate binding and fusion in the absence of the viral attachment (G) protein. The invariant F-RGD motif is critical for infection, as an F-RAE virus was profoundly impaired. Further, F-integrin binding is required for productive viral RNA transcription, indicating that RGD-binding integrins serve as receptors for the HMPV fusion protein. Thus, HMPV F is triggered to induce virus-cell fusion by interactions with cellular receptors in a manner that is independent of the viral G protein. These results suggest a stepwise mechanism of HMPV entry mediated by the F protein through its interactions with cellular receptors, including RGD-binding integrins. PMID:22933271

  13. Human Metapneumovirus Infection is Associated with Severe Respiratory Disease in Preschool Children with History of Prematurity

    PubMed Central

    Pancham, Krishna; Sami, Iman; Perez, Geovanny F.; Huseni, Shehlanoor; Kurdi, Bassem; Rose, Mary C.; Rodriguez-Martinez, Carlos E.; Nino, Gustavo

    2017-01-01

    Rationale Human metapneumovirus (HMPV) is a recently discovered respiratory pathogen of the family Paramyxoviridae, the same of Respiratory Syncytial Virus (RSV). Premature children are at high risk of severe RSV infections, but it is unclear whether HMPV infection is more severe in hospitalized children with history of severe prematurity. Methods We conducted a retrospective analysis of the clinical respiratory presentation of all PCR-confirmed HMPV infections in preschool age children (≤5 yrs.) with and without history of severe prematurity (<32 weeks gestation). Respiratory distress scores were developed to examine the clinical severity of HMPV infections. Demographic and clinical variables were obtained from reviewing electronic medical records (EMR). Results A total of 571 pre-school children were identified by PCR-confirmed viral respiratory tract infection during the study period. HMPV was identified as a causative organism in 63 cases (11%). Fifty–eight (n=58) preschool age children with HMPV infection were included in this study after excluding those with significant co-morbidities. Our data demonstrated that 32.7% of children admitted with HMPV had history of severe prematurity. Preschool children with history of prematurity had more severe HMPV disease as illustrated by longer hospitalizations, new or increased need for supplemental O2, and higher severity scores independently of age, ethnicity and history of asthma. Conclusion Our study suggests that HMPV infection causes significant disease burden among preschool children with history of prematurity leading to severe respiratory infections and increasing health care resource utilization due to prolonged hospitalizations. PMID:26117550

  14. Premature infants have impaired airway antiviral IFNγ responses to human metapneumovirus compared to respiratory syncytial virus

    PubMed Central

    Pancham, Krishna; Perez, Geovanny F.; Huseni, Shehlanoor; Jain, Amisha; Kurdi, Bassem; Rodriguez-Martinez, Carlos E.; Preciado, Diego; Rose, Mary C.; Nino, Gustavo

    2017-01-01

    BACKGROUND It is unknown why human metapneumovirus (HMPV) and respiratory syncytial virus (RSV) cause severe respiratory infection in children, particularly in premature infants. Our aim was to investigate if there are defective airway antiviral responses to these viruses in young children with history of prematurity. METHODS Nasal airway secretions were collected from 140 children ≤3 y old without detectable virus (n = 80) or with PCR-confirmed HMPV or RSV infection (n = 60). Nasal protein levels of IFNγ, CCL5/RANTES, IL-10, IL-4, and IL-17 were determined using a multiplex magnetic bead immunoassay. RESULTS Full-term children with HMPV and RSV infection had increased levels of nasal airway IFNγ, CCL5, and IL-10 along with an elevation in Th1 (IFNγ)/Th2 (IL-4) ratios, which is expected during antiviral responses. In contrast, HMPV-infected premature children (< 32 wk gestation) did not exhibit increased Th1/Th2 ratios or elevated nasal airway secretion of IFNγ, CCL5, and IL-10 relative to uninfected controls. CONCLUSION Our study is the first to demonstrate that premature infants have defective IFNγ, CCL5/RANTES, and IL-10 airway responses during HMPV infection and provides novel insights about the potential reason why HMPV causes severe respiratory disease in children with history of prematurity. PMID:26086642

  15. 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.

  16. Animal and human influenzas.

    PubMed

    Peiris, M; Yen, H-L

    2014-08-01

    Influenza type A viruses affect humans and other animals and cause significant morbidity, mortality and economic impact. Influenza A viruses are well adapted to cross species barriers and evade host immunity. Viruses that cause no clinical signs in wild aquatic birds may adapt in domestic poultry to become highly pathogenic avian influenza viruses which decimate poultry flocks. Viruses that cause asymptomatic infection in poultry (e.g. the recently emerged A/H7N9 virus) may cause severe zoonotic disease and pose a major pandemic threat. Pandemic influenza arises at unpredictable intervals from animal viruses and, in its global spread, outpaces current technologies for making vaccines against such novel viruses. Confronting the threat of influenza in humans and other animals is an excellent example of a task that requires a One Health approach. Changes in travel, trade in livestock and pets, changes in animal husbandry practices, wet markets and complex marketing chains all contribute to an increased risk of the emergence of novel influenza viruses with the ability to cross species barriers, leading to epizootics or pandemics. Coordinated surveillance at the animal- human interface for pandemic preparedness, risk assessment, risk reduction and prevention at source requires coordinated action among practitioners in human and animal health and the environmental sciences. Implementation of One Health in the field can be challenging because of divergent short-term objectives. Successful implementation requires effort, mutual trust, respect and understanding to ensure that long-term goals are achieved without adverse impacts on agricultural production and food security.

  17. 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.

  18. 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

  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. 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.

  1. Treatment of severe human metapneumovirus (hMPV) pneumonia in an immunocompromised child with oral ribavirin and IVIG.

    PubMed

    Kitanovski, Lidija; Kopriva, Silvester; Pokorn, Marko; Dolničar, Majda B; Rajić, Vladan; Stefanović, Milica; Jazbec, Janez

    2013-10-01

    The clinical manifestations of human metapneumovirus (hMPV) infection resemble those of respiratory syncytial virus with the most severe disease occurring in infants, the elderly, chronically ill, and immunocompromised hosts. We present a case of a 2-year-old girl undergoing intensive chemotherapy for Burkitt lymphoma who developed severe hMPV pneumonia. Rapid and complete recovery was observed after treatment with oral ribavirin and intravenous immunoglobulin. As hMPV can cause severe pneumonia in immunocompromised patients and due to the reports of effective treatment with ribavirin, clinical studies to elucidate the role of ribavirin in treatment of hMPV pneumonia may be needed.

  2. Genetic diversity and molecular evolution of the major human metapneumovirus surface glycoproteins over a decade.

    PubMed

    Papenburg, Jesse; Carbonneau, Julie; Isabel, Sandra; Bergeron, Michel G; Williams, John V; De Serres, Gaston; Hamelin, Marie-Ève; Boivin, Guy

    2013-11-01

    Human metapneumovirus (HMPV) is a recently discovered paramyxovirus that is a major cause of respiratory infections worldwide. We aim to describe the molecular evolution of the HMPV F (fusion) and G (attachment) surface glycoproteins because they are targets for vaccines, monoclonal antibodies and antivirals currently in development. Nasopharyngeal aspirates were collected in children <3 years old with acute respiratory infection in Quebec City during 2001-2010. HMPV-positive samples (n = 163) underwent HMPV-F and -G gene sequencing. Furthermore, HMPV-F (n = 124) and -G (n = 217) sequences were obtained from GenBank and other studies. Evolutionary analyses (phylogenetic reconstruction, sequence identity, detection of recombination and adaptive evolution) were computed. Sequences clustered into 5 genetic lineages (A1, A2a, A2b, B1 and B2). Multiple lineages circulated each year in Quebec City. With the exception of B1, each of the 5 subgroups was the predominant lineage during ≥1 season. The A1 lineage was not detected since 2002-2003 in our local cohort. There was no evidence of inter- or intragenic recombination. HMPV-F was highly conserved, whereas HMPV-G exhibited greater diversity. HMPV-F demonstrated strong evidence of purifying selection, both overall and in an abundance of negatively selected amino acid sites. In contrast, sites under diversifying selection were detected in all HMPV-G lineages (range, 4-15), all of which were located in the ectodomain. Predominant circulating HMPV lineages vary by year. HMPV-F is highly constrained and undergoes significant purifying selection. Given its high genetic variability, we found a modest number of positively selected sites in HMPV-G. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Burden of human metapneumovirus infections in patients with cancer: Risk factors and outcomes.

    PubMed

    El Chaer, Firas; Shah, Dimpy P; Kmeid, Joumana; Ariza-Heredia, Ella J; Hosing, Chitra M; Mulanovich, Victor E; Chemaly, Roy F

    2017-06-15

    Human metapneumovirus (hMPV) causes upper and lower respiratory tract infections (URIs and LRIs, respectively) in healthy and immunocompromised patients; however, its clinical burden in patients with cancer remains unknown. In a retrospective study of all laboratory-confirmed hMPV infections treated at the authors' institution between April 2012 and May 2015, clinical characteristics, risk factors for progression to an LRI, treatment, and outcomes in patients with cancer were determined. In total, 181 hMPV infections were identified in 90 patients (50%) with hematologic malignancies (HMs), in 57 (31%) hematopoietic cell transplantation (HCT) recipients, and in 34 patients (19%) with solid tumors. Most patients (92%) had a community-acquired infection and presented with URIs (67%), and 43% developed LRIs (59 presented with LRIs and 19 progressed from a URI to an LRI). On multivariable analysis, an underlying HM (adjusted odds ratio [aOR], 3.11; 95% confidence interval [CI], 1.12-8.64; P = .029), nosocomial infection (aOR, 26.9; 95% CI, 2.79-259.75; P = .004), and hypoxia (oxygen saturation [SpO2], ≤ 92%) at presentation (aOR, 9.61; 95% CI, 1.98-46.57; P = .005) were identified as independent factors associated with LRI. All-cause mortality at 30 days from hMPV diagnosis was low (4%), and patients with LRIs had a 10% mortality rate at day 30 from diagnosis; whereas patients with URIs had a 0% mortality rate. hMPV infections in patients with cancer may cause significant morbidity, especially for those with underlying HM who may develop an LRI. Despite high morbidity and the lack of directed antiviral therapy for hMPV infections, mortality at day 30 from this infection remained low in this studied population. Cancer 2017;123:2329-2337. © 2017 American Cancer Society. © 2017 American Cancer Society.

  4. 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.

  5. Human Metapneumovirus Infection in Jordanian Children: Epidemiology and Risk Factors for Severe Disease

    PubMed Central

    Schuster, Jennifer E.; Khuri-Bulos, Najwa; Faouri, Samir; Shehabi, Asem; Johnson, Monika; Wang, Li; Fonnesbeck, Christopher; Williams, John V.; Halasa, Natasha

    2016-01-01

    Background Human metapneumovirus (HMPV) is a leading cause of acute respiratory tract infection (ARTI) in young children. Our objectives were to define HMPV epidemiology and circulating strains and determine markers of severe disease in Jordanian children. Methods We conducted a prospective study March 16, 2010-March 31, 2013 using quantitative RT-PCR to determine the frequency of HMPV infection among children <2 years old admitted with fever and/or acute respiratory illness to a major government hospital in Amman, Jordan. Results HMPV was present in 273/3168 (8.6%) of children presenting with ARTI. HMPV A2, B1, and B2, but not A1, were detected during the 3-year period. HMPV-infected children were older and more likely to be diagnosed with bronchopneumonia than HMPV-negative children. HMPV-infected children with lower respiratory tract infection (LRTI) had higher rates of cough and shortness of breath than children with LRTI infected with other or no identifiable viruses. Symptoms and severity were not different between children with HMPV only compared with HMPV co-infection. Children with HMPV subgroup A infection were more likely to require supplemental oxygen. In a multivariate analysis, HMPV subgroup A and age <6 months were independently associated with supplemental oxygen requirement. Conclusions HMPV is a leading cause of acute respiratory tract disease in Jordanian children <2 years old. HMPV A and young age were associated with severe disease. Ninety percent of HMPV-infected hospitalized children were full-term and otherwise healthy, in contrast to high-income nations; thus, factors contributing to disease severity likely vary depending on geographic and resource differences. PMID:26372450

  6. 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

  7. Potential Electrostatic Interactions in Multiple Regions Affect Human Metapneumovirus F-Mediated Membrane Fusion

    PubMed Central

    Chang, Andres; Hackett, Brent A.; Winter, Christine C.; Buchholz, Ursula J.

    2012-01-01

    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 F2 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. PMID:22761366

  8. Generation of temperature-sensitive human metapneumovirus strains that provide protective immunity in hamsters.

    PubMed

    Herfst, Sander; de Graaf, Miranda; Schrauwen, Eefje J A; Sprong, Leo; Hussain, Karim; van den Hoogen, Bernadette G; Osterhaus, Albert D M E; Fouchier, Ron A M

    2008-07-01

    Human metapneumovirus (HMPV) causes acute respiratory tract illness primarily in young children, immunocompromised individuals and the elderly. Vaccines would be desirable to prevent severe illnesses in these risk groups. Here, we describe the generation and evaluation of cold-passage (cp) temperature-sensitive (ts) HMPV strains as vaccine candidates. Repeated passage of HMPV at low temperatures in Vero cells resulted in the accumulation of mutations in the viral genome. Introduction of these mutations in a recombinant HMPV by reverse genetics resulted in a ts-phenotype, judged on the decreased shut-off temperature for virus replication in vitro. As an alternative approach, three previously described cp-respiratory syncytial virus (cp-HRSV) mutations were introduced in a recombinant HMPV, which also resulted in a low shut-off temperature in vitro. Replication of these ts-viruses containing either the cp-HMPV or cp-HRSV mutations was reduced in the upper respiratory tract (URT) and undetectable in the lower respiratory tract (LRT) of hamsters. Nevertheless, high titres of HMPV-specific antibodies were induced by both ts-viruses. Upon immunization with the ts-viruses, the LRT of hamsters were completely protected against challenge infection with a heterologous HMPV strain, and URT viral titres were reduced by 10 000-fold. In conclusion, we provide proof-of-principle for two candidate live-attenuated HMPV vaccines that induce cross-protective immunity to prevent infection of the LRT in Syrian golden hamsters. Further mapping of the molecular determinants of attenuation of HMPV should be the subject of future studies.

  9. 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.

  10. Preceding human metapneumovirus infection increases adherence of Streptococcus pneumoniae and severity of murine pneumococcal pneumonia.

    PubMed

    Lai, Shen-Hao; Liao, Sui-Ling; Wong, Kin-Sun; Lin, Tzou-Yien

    2016-04-01

    Coinfection with respiratory virus and Streptococcus pneumoniae has been frequently reported in several epidemiologic studies. The aim of this study was to explore the effect of preceding human metapneumovirus (hMPV) inoculation on subsequent pneumococcal infection. Hep-2 and A549 cells were infected with hMPV then inoculated with S. pneumoniae. Bacterial adhesion was measured using colony forming unit and cytometric-fluorescence assays. In vivo bacterial adhesion was examined in hMPV-infected mice after inoculation of fluorescence-conjugated S. pneumoniae. Pulmonary inflammation (bacterial titers, cytokine levels, and histopathology) of hMPV-infected mice was investigated after inoculation with S. pneumoniae. In vitro results of bacterial infection with S. pneumoniae on A549 and Hep-2 monolayer cells showed that even though cellular adherence was variable among different serotypes, there was significantly enhanced bacterial adherence in A549 cells with preceding hMPV infection. In addition, in vivo study of hMPV-infected mice showed increased adhesion of S. pneumoniae on the bronchial epithelium with delayed bacterial clearance and exacerbated histopathology. Furthermore, mice with preceding hMPV infection showed repressed recruitment of airway neutrophils with decreased expression of neutrophil chemoattractants during pneumococcal infection. These results suggest that hMPV-infected airway cells, especially the lower airway epithelium, express increased adherence with S. pneumoniae. Furthermore, hMPV-infected mice showed impaired recruitment of airway neutrophils, possibly leading to delayed bacterial clearance and exacerbated pulmonary inflammation, after secondary infection with pneumococcal isolates. Copyright © 2014. Published by Elsevier B.V.

  11. 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

  12. Avian Influenza A Virus Infections in Humans

    MedlinePlus

    ... Avian Swine/Variant Pandemic Other Avian Influenza A Virus Infections in Humans Language: English (US) Español ... with Avian Influenza A Viruses Avian Influenza A Virus Infections in Humans Although avian influenza A viruses ...

  13. 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.

  14. 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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  16. 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

  17. 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

  18. Efficient isolation of human metapneumovirus using MNT-1, a human malignant melanoma cell line exhibiting early and distinct cytopathic effect.

    PubMed

    Sato, Ko; Watanabe, Oshi; Ohmiya, Suguru; Chiba, Fumiko; Suzuki, Akira; Okamoto, Michiko; Younghuang, Jiang; Hata, Akihiro; Nonaka, Hiroyuki; Kitaoka, Setsuko; Nagai, Yukio; Kawamura, Kazuhisa; Hayashi, Masahiro; Kumaki, Satoru; Suzuki, Tamio; Kawakami, Kazuyoshi; Nishimura, Hidekazu

    2017-09-20

    Isolation of human metapneumovirus (HMPV) from clinical specimens is currently inefficient due to the lack of a cell culture system exhibiting a distinct cytopathic effect (CPE). The cell lines LLC-MK2, Vero, and Vero E6 are used for isolation of HMPV; however, the CPE in these cell lines is subtle and usually requires a long observation period and sometimes blind passages. Thus, a cell line that exhibits an early and distinct CPE following HMPV inoculation is highly desired by clinical virology laboratories. We demonstrate that the human malignant melanoma cell line MNT-1 shows obvious syncytium formation shortly after inoculation with HMPV-positive clinical specimens. In addition, the growth and isolation efficiency of HMPV was higher using MNT-1 than any other conventional cell line. Addition of this cell line to our routine viral isolation system for clinical specimens markedly enhanced isolation frequency, allowing isolation-based surveillance. MNT-1 has the potential to facilitate clinical and epidemiological studies of HMPV. © 2017 The Societies and Wiley Publishing Asia Pty Ltd.

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

    PubMed Central

    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.

    2016-01-01

    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. PMID:26772634

  20. Use of a universal virus detection assay to identify human metapneumovirus in a hematopoietic stem cell transplant recipient with pneumonia of unknown origin.

    PubMed

    Uhlenhaut, Christine; Cohen, Jeffrey I; Fedorko, Daniel; Nanda, Santosh; Krause, Philip R

    2009-04-01

    Development of uncommon viral infections in immunocompromised transplant recipients can pose major diagnostic challenges. We present a case report of an immunocompromised patient suffering from pneumonia, for which the causative agent was not identified by routine methods. To identify the potential cause of the pneumonia using a degenerate oligonucleotide primer (DOP)-PCR assay that is designed to detect all viruses. DOP-PCR was applied to bronchoalveolar lavage fluid from this patient. Generic PCR products were cloned and sequenced. The novel universal virus assay detected human metapneumovirus in the clinical sample. The finding was confirmed by two independent metapneumovirus specific PCRs targeting different regions of the viral genome. The DOP-PCR was used to detect and identify the sequence of an unidentified virus. This study provides proof of concept for the use of clinically relevant specimens in this unbiased universal assay, which requires no previous viral sequence information.

  1. 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

  2. The Human Metapneumovirus Small Hydrophobic Protein Has Properties Consistent with Those of a Viroporin and Can Modulate Viral Fusogenic Activity

    PubMed Central

    Masante, Cyril; El Najjar, Farah; Chang, Andres; Jones, Angela; Moncman, Carole L.

    2014-01-01

    ABSTRACT Human metapneumovirus (HMPV) encodes three glycoproteins: the glycoprotein, which plays a role in glycosaminoglycan binding, the fusion (F) protein, which is necessary and sufficient for both viral binding to the target cell and fusion between the cellular plasma membrane and the viral membrane, and the small hydrophobic (SH) protein, whose function is unclear. The SH protein of the closely related respiratory syncytial virus has been suggested to function as a viroporin, as it forms oligomeric structures consistent with a pore and alters membrane permeability. Our analysis indicates that both the full-length HMPV SH protein and the isolated SH protein transmembrane domain can associate into higher-order oligomers. In addition, HMPV SH expression resulted in increases in permeability to hygromycin B and alteration of subcellular localization of a fluorescent dye, indicating that SH affects membrane permeability. These results suggest that the HMPV SH protein has several characteristics consistent with a putative viroporin. Interestingly, we also report that expression of the HMPV SH protein can significantly decrease HMPV F protein-promoted membrane fusion activity, with the SH extracellular domain and transmembrane domain playing a key role in this inhibition. These results suggest that the HMPV SH protein could regulate both membrane permeability and fusion protein function during viral infection. IMPORTANCE Human metapneumovirus (HMPV), first identified in 2001, is a causative agent of severe respiratory tract disease worldwide. The small hydrophobic (SH) protein is one of three glycoproteins encoded by all strains of HMPV, but the function of the HMPV SH protein is unknown. We have determined that the HMPV SH protein can alter the permeability of cellular membranes, suggesting that HMPV SH is a member of a class of proteins termed viroporins, which modulate membrane permeability to facilitate critical steps in a viral life cycle. We also demonstrated

  3. 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.

  4. Human Metapneumovirus (HMPV) Binding and Infection Are Mediated by Interactions between the HMPV Fusion Protein and Heparan Sulfate

    PubMed Central

    Chang, Andres; Masante, Cyril; Buchholz, Ursula J.

    2012-01-01

    Human metapneumovirus (HMPV) is a major worldwide respiratory pathogen that causes acute upper and lower respiratory tract disease. The mechanism by which this virus recognizes and gains access to its target cell is still largely unknown. In this study, we addressed the initial steps in virus binding and infection and found that the first binding partner for HMPV is heparan sulfate (HS). While wild-type CHO-K1 cells are permissive to HMPV infection, mutant cell lines lacking the ability to synthesize glycosaminoglycans (GAGs), specifically, heparan sulfate proteoglycans (HSPGs), were resistant to binding and infection by HMPV. The permissiveness to HMPV infection was also abolished when CHO-K1 cells were treated with heparinases. Importantly, using recombinant HMPV lacking both the G and small hydrophobic (SH) proteins, we report that this first virus-cell binding interaction is driven primarily by the fusion protein (HMPV F) and that this interaction is needed to establish a productive infection. Finally, HMPV binding to cells did not require β1 integrin expression, and RGD-mediated interactions were not essential in promoting HMPV F-mediated cell-to-cell membrane fusion. Cells lacking β1 integrin, however, were less permissive to HMPV infection, indicating that while β1 integrins play an important role in promoting HMPV infection, the interaction between integrins and HMPV occurs after the initial binding of HMPV F to heparan sulfate proteoglycans. PMID:22238303

  5. 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

  6. 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.

  7. The human side of influenza

    PubMed Central

    Oshansky, Christine M.; Thomas, Paul G.

    2012-01-01

    A clear understanding of immunity in individuals infected with influenza virus is critical for the design of effective vaccination and treatment strategies. Whereas myriad studies have teased apart innate and adaptive immune responses to influenza infection in murine models, much less is known about human immunity as a result of the ethical and technical constraints of human research. Still, these murine studies have provided important insights into the critical correlates of protection and pathogenicity in human infection and helped direct the human studies that have been conducted. Here, we examine and review the current literature on immunity in humans infected with influenza virus, noting evidence offered by select murine studies and suggesting directions in which future research is most warranted. PMID:22362872

  8. 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.

  9. 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.

  10. Human Metapneumovirus Virus-Like Particles Induce Protective B and T Cell Responses in a Mouse Model

    PubMed Central

    Cox, Reagan G.; Erickson, John J.; Hastings, Andrew K.; Becker, Jennifer C.; Johnson, Monika; Craven, Ryan E.; Tollefson, Sharon J.; Boyd, Kelli L.

    2014-01-01

    ABSTRACT Human metapneumovirus (HMPV) is a leading cause of respiratory disease in infants, children, and the elderly worldwide, yet no licensed vaccines exist. Live-attenuated vaccines present safety challenges, and protein subunit vaccines induce primarily antibody responses. Virus-like particles (VLPs) are an attractive alternative vaccine approach because of reduced safety concerns compared with live vaccines. We generated HMPV VLPs by expressing viral proteins in suspension-adapted human embryonic kidney epithelial (293-F) cells and found that the viral matrix (M) and fusion (F) proteins were sufficient to form VLPs. We previously reported that the VLPs resemble virus morphology and incorporate fusion-competent F protein (R. G. Cox, S. B. Livesay, M. Johnson, M. D. Ohi, and J. V. Williams, J. Virol. 86:12148–12160, 2012), which we hypothesized would elicit F-specific antibody and T cell responses. In this study, we tested whether VLP immunization could induce protective immunity to HMPV by using a mouse model. C57BL/6 mice were injected twice intraperitoneally with VLPs alone or with adjuvant and subsequently challenged with HMPV. Mice were euthanized 5 days postinfection, and virus titers, levels of neutralizing antibodies, and numbers of CD3+ T cells were quantified. Mice immunized with VLPs mounted an F-specific antibody response and generated CD8+ T cells recognizing an F protein-derived epitope. VLP immunization induced a neutralizing-antibody response that was enhanced by the addition of either TiterMax Gold or α-galactosylceramide adjuvant, though adjuvant reduced cellular immune responses. Two doses of VLPs conferred complete protection from HMPV replication in the lungs of mice and were not associated with a Th2-skewed cytokine response. These results suggest that nonreplicating VLPs are a promising vaccine candidate for HMPV. IMPORTANCE Human metapneumovirus (HMPV) is a leading cause of acute respiratory infection in infants, children, and the

  11. 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.

  12. 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.

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

    PubMed

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

    2017-01-01

    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). 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. 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. 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.

  14. 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.

  15. 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

  16. Variant (Swine Origin) Influenza Viruses in Humans

    MedlinePlus

    ... Types Seasonal Avian Swine Variant Other 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. ...

  17. 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

  18. Incidence and Risk Factors for Respiratory Syncytial Virus and Human Metapneumovirus Infections among Children in the Remote Highlands of Peru

    PubMed Central

    Wu, Andrew; Budge, Philip J.; Williams, John; Griffin, Marie R.; Edwards, Kathryn M.; Johnson, Monika; Zhu, Yuwei; Hartinger, Stella; Verastegui, Hector; Gil, Ana I.; Lanata, Claudio F.; Grijalva, Carlos G.

    2015-01-01

    Introduction The disease burden and risk factors for respiratory syncytial virus (RSV) and human metapneumovirus (MPV) infections among children living in remote, rural areas remain unclear. Materials and Methods We conducted a prospective, household-based cohort study of children aged <3 years living in remote rural highland communities in San Marcos, Cajamarca, Peru. Acute respiratory illnesses (ARI), including lower respiratory tract infection (LRTI), were monitored through weekly household visits from March 2009 through September 2011. Nasal swabs collected during ARI/LRTI were tested for RSV, MPV, and other respiratory viruses using real-time RT-PCR. Incidence rates and rate ratios were calculated using mixed effects Poisson regression. Results Among 892 enrolled children, incidence rates of RSV and MPV ARI were 30 and 17 episodes per 100 child-years, respectively. The proportions of RSV and MPV ARI that presented as LRTI were 12.5% and 8.9%, respectively. Clinic visits for ARI and hospitalizations were significantly more frequent (all p values <0.05) among children with RSV (clinic 41% and hospital 5.3%) and MPV ARI (38% and 3.5%) when compared with other viral infections (23% and 0.7%) and infections without virus detected (24% and 0.6%). In multivariable analysis, risk factors for RSV detection included younger age (RR 1.02, 95% CI: 1.00-1.03), the presence of a smoker in the house (RR 1.63, 95% CI: 1.12-2.38), residing at higher altitudes (RR 1.93, 95% CI: 1.25-3.00 for 2nd compared to 1st quartile residents; RR 1.98, 95% CI: 1.26-3.13 for 3rd compared to 1st quartile residents). Having an unemployed household head was significantly associated with MPV risk (RR 2.11, 95% CI: 1.12-4.01). Conclusion In rural high altitude communities in Peru, childhood ARI due to RSV or MPV were common and associated with higher morbidity than ARI due to other viruses or with no viral detections. The risk factors identified in this study may be considered for interventional

  19. Crosstalk between animal and human influenza viruses

    PubMed Central

    Ozawa, Makoto; Kawaoka, Yoshihiro

    2017-01-01

    Although outbreaks of highly pathogenic avian influenza in wild and domestic birds have been posing the threat of a new influenza pandemic for the last decade, the first pandemic of the 21st 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 assessed the pandemic potential of H5N1 highly pathogenic avian influenza viruses. PMID:25387011

  20. 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.

  1. 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.

  2. 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.

  3. A Sendai virus recombinant vaccine expressing a gene for truncated human metapneumovirus (hMPV) fusion protein protects cotton rats from hMPV challenge.

    PubMed

    Russell, Charles J; Jones, Bart G; Sealy, Robert E; Surman, Sherri L; Mason, John N; Hayden, Randall T; Tripp, Ralph A; Takimoto, Toru; Hurwitz, Julia L

    2017-09-01

    Human metapneumovirus (hMPV) infections pose a serious health risk to young children, particularly in cases of premature birth. No licensed vaccine exists and there is no standard treatment for hMPV infections apart from supportive hospital care. We describe the production of a Sendai virus (SeV) recombinant that carries a gene for a truncated hMPV fusion (F) protein (SeV-MPV-Ft). The vaccine induces binding and neutralizing antibody responses toward hMPV and protection against challenge with hMPV in a cotton rat system. Results encourage advanced development of SeV-MPV-Ft to prevent the morbidity and mortality caused by hMPV infections in young children. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. 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

  5. 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.

  6. Seroprevalence of human respiratory syncytial virus and human metapneumovirus in healthy population analyzed by recombinant fusion protein-based enzyme linked immunosorbent assay

    PubMed Central

    2012-01-01

    Background Human respiratory syncytial virus (hRSV) and human metapneumovirus (hMPV) are two of the most frequent respiratory pathogens that circulate worldwide. Infection with either virus can lead to hospitalization of young children, immunocompromised people and the elderly. A better understanding of the epidemiological aspects, such as prevalence of these viruses in the population will be of significant importance to the scientific community. The aim of this study was to gain some detailed knowledge on the humoral immune response to both viruses in different populations of individuals. Findings The fusion protein (F) of hRSV and hMPV was expressed in the baculovirus and Escherichia coli systems, respectively, and used as antigen in two independent enzyme-linked immunosorbent assays (ELISAs) for detection of specific antibodies in human sera. The seroprevalence of each virus in a large cohort of individuals with ages ranging from 0 to 89 years old was determined. Although the general distribution of the antibody response to each virus in the different age group was similar, the prevalence of hRSV appeared to be higher than that of hMPV in most of them. The group of children with ages between 0 and 2 showed the highest seronegative rates. After this age, an increase in the antibody response was observed, most likely as the result of new infections or even due to reinfections. Conclusions The use of these specific F-ELISAs in seroepidemiological studies might be helpful for a better understanding of the human antibody response to these viruses. PMID:22748150

  7. Seroprevalence of human respiratory syncytial virus and human metapneumovirus in healthy population analyzed by recombinant fusion protein-based enzyme linked immunosorbent assay.

    PubMed

    Sastre, Patricia; Ruiz, Tamara; Schildgen, Oliver; Schildgen, Verena; Vela, Carmen; Rueda, Paloma

    2012-07-02

    Human respiratory syncytial virus (hRSV) and human metapneumovirus (hMPV) are two of the most frequent respiratory pathogens that circulate worldwide. Infection with either virus can lead to hospitalization of young children, immunocompromised people and the elderly.A better understanding of the epidemiological aspects, such as prevalence of these viruses in the population will be of significant importance to the scientific community. The aim of this study was to gain some detailed knowledge on the humoral immune response to both viruses in different populations of individuals. The fusion protein (F) of hRSV and hMPV was expressed in the baculovirus and Escherichia coli systems, respectively, and used as antigen in two independent enzyme-linked immunosorbent assays (ELISAs) for detection of specific antibodies in human sera. The seroprevalence of each virus in a large cohort of individuals with ages ranging from 0 to 89 years old was determined. Although the general distribution of the antibody response to each virus in the different age group was similar, the prevalence of hRSV appeared to be higher than that of hMPV in most of them. The group of children with ages between 0 and 2 showed the highest seronegative rates. After this age, an increase in the antibody response was observed, most likely as the result of new infections or even due to reinfections. The use of these specific F-ELISAs in seroepidemiological studies might be helpful for a better understanding of the human antibody response to these viruses.

  8. [Is avian influenza a risk for humans?].

    PubMed

    Allwinn, R; Doerr, H W

    2005-04-15

    Avian influenza is an infectious disease of birds, caused by type A strains of the influenza virus. The disease, which was first identified in Italy more than 100 years ago, occurs worldwide. Avian influenza viruses are mainly distributed by migratory birds. Different mammals like swine, horse and finally humans are susceptible for avian influenza viruses. The high possibility of genomic changes like gene shift and drift is caused by the segmented RNA genome. During the avian flu outbreak in East Asia at the end of 2003 the virus also killed several humans in Vietnam and Thailand. That avian influenza could also infect humans has been known since 1997. The H5N1 flu outbreak seemed successfully controlled, but currently new cases in poultry and humans in Vietnam, Thailand, China and Indonesia are recognized. Also another avian influenza A strain type H9N2 was prevalent in chickens of local markets in Hong Kong. Because of the natural virus reservoir like wild and/ or domesticated ducks and others, actually there is little chance of eradicating avian influenza. Furthermore the virus could mutate and jump to humans with the threat of a global influenza pandemic.

  9. Modeling human influenza infection in the laboratory.

    PubMed

    Radigan, Kathryn A; Misharin, Alexander V; Chi, Monica; Budinger, Gr Scott

    2015-01-01

    Influenza is the leading cause of death from an infectious cause. Because of its clinical importance, many investigators use animal models to understand the biologic mechanisms of influenza A virus replication, the immune response to the virus, and the efficacy of novel therapies. This review will focus on the biosafety, biosecurity, and ethical concerns that must be considered in pursuing influenza research, in addition to focusing on the two animal models - mice and ferrets - most frequently used by researchers as models of human influenza infection.

  10. Modeling human influenza infection in the laboratory

    PubMed Central

    Radigan, Kathryn A; Misharin, Alexander V; Chi, Monica; Budinger, GR Scott

    2015-01-01

    Influenza is the leading cause of death from an infectious cause. Because of its clinical importance, many investigators use animal models to understand the biologic mechanisms of influenza A virus replication, the immune response to the virus, and the efficacy of novel therapies. This review will focus on the biosafety, biosecurity, and ethical concerns that must be considered in pursuing influenza research, in addition to focusing on the two animal models – mice and ferrets – most frequently used by researchers as models of human influenza infection. PMID:26357484

  11. 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.

  12. 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

  13. 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

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

    2016-09-01

    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 Ca(2+)-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. On the surface of CHO cells, glycosaminoglycans (GAGs) function as the major attachment factor for human metapneumoviruses (HMPV), promoting dynamin-independent infection

  14. 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

  15. Cell-type specific recognition of human Metapneumoviruses by RIG-I and TLR7 and viral interference of RIG-I ligand recognition by HMPVB1 Phosphoprotein

    PubMed Central

    Goutagny, Nadege; Jiang, Zhaozhao; Tian, Jane; Parroche, Peggy; Schlicki, Jeanne; Monks, Brian G.; Ulbrandt, Nancy; Ji, Hong; Kiener, Peter; Coyle, Anthony J.; Fitzgerald, Katherine A.

    2010-01-01

    Human Metapneumoviruses (HMPV) are recently identified Paramyxoviridae that contribute to respiratory tract infections in children. No effective treatments or vaccines are available. Successful defense against virus infection relies on early detection by germline encoded pattern recognition receptors and activation of cytokine and type I interferon genes. Recently, the RNA helicase Retinoic acid inducible gene (RIG-I) has been shown to sense HMPV. In this study, we investigated the ability of two prototype strains of HMPV (A1 [NL\\1\\00] and B1 [NL\\1\\99]) to activate RIG-I and induce type I interferons (IFN). Despite the ability of both HMPV-A1 and B1 to infect and replicate in cell lines and primary cells, only the HMPV-A1 strain triggered RIG-I to induce IFNA/B gene transcription. The failure of the HMPV-B1 strain to elicit type I IFN production was dependent on the B1 phosphoprotein, which specifically prevented RIG-I-mediated sensing of HMPV viral 5’ triphosphate RNA. In contrast to most cell types, plasmacytoid dendritic cells (PDC) displayed a unique ability to sense both the A1 and B1 strains and in this case sensing was via Toll-like receptor (TLR)-7 rather than RIG-I. Collectively, these data reveal differential mechanisms of sensing for two closely related viruses, which operate in cell-type specific manners. PMID:20042593

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Characterization of the Fusion and Attachment Glycoproteins of Human Metapneumovirus and Human Serosurvey to Determine Reinfection Rates

    DTIC Science & Technology

    2007-06-27

    glycoproteins are major antigenic determinants for all the paramyxoviruses, as well as for other viruses such as human immunodeficiency virus , Ebola ...acute respiratory illness in children, and is second only to respiratory syncytial virus (RSV) as a cause of lower respiratory tract disease . 3...Rhabdoviridae plant virus , replicate in the cytoplasm (66). The Paramyxoviridae are enveloped viruses and have been defined by the fusion glycoprotein

  1. 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.

  2. Roles of the Putative Integrin-Binding Motif of the Human Metapneumovirus Fusion (F) Protein in Cell-Cell Fusion, Viral Infectivity, and Pathogenesis

    PubMed Central

    Wei, Yongwei; Zhang, Yu; Cai, Hui; Mirza, Anne M.; Iorio, Ronald M.; Peeples, Mark E.; Niewiesk, Stefan

    2014-01-01

    ABSTRACT Human metapneumovirus (hMPV) is a relatively recently identified paramyxovirus that causes acute upper and lower respiratory tract infection. Entry of hMPV is unusual among the paramyxoviruses, in that fusion is accomplished by the fusion (F) protein without the attachment glycoprotein (G protein). It has been suggested that hMPV F protein utilizes integrin αvβ1 as a cellular receptor. Consistent with this, the F proteins of all known hMPV strains possess an integrin-binding motif (329RGD331). The role of this motif in viral entry, infectivity, and pathogenesis is poorly understood. Here, we show that α5β1 and αv integrins are essential for cell-cell fusion and hMPV infection. Mutational analysis found that residues R329 and G330 in the 329RGD331 motif are essential for cell-cell fusion, whereas mutations at D331 did not significantly impact fusion activity. Furthermore, fusion-defective RGD mutations were either lethal to the virus or resulted in recombinant hMPVs that had defects in viral replication in cell culture. In cotton rats, recombinant hMPV with the R329K mutation in the F protein (rhMPV-R329K) and rhMPV-D331A exhibited significant defects in viral replication in nasal turbinates and lungs. Importantly, inoculation of cotton rats with these mutants triggered a high level of neutralizing antibodies and protected against hMPV challenge. Taken together, our data indicate that (i) α5β1 and αv integrins are essential for cell-cell fusion and viral replication, (ii) the first two residues in the RGD motif are essential for fusion activity, and (iii) inhibition of the interaction of the integrin-RGD motif may serve as a new target to rationally attenuate hMPV for the development of live attenuated vaccines. IMPORTANCE Human metapneumovirus (hMPV) is one of the major causative agents of acute respiratory disease in humans. Currently, there is no vaccine or antiviral drug for hMPV. hMPV enters host cells via a unique mechanism, in that viral

  3. 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.

  4. 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

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

    USDA-ARS?s Scientific Manuscript database

    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...

  6. Influenza virus in human exhaled breath: an observational study.

    PubMed

    Fabian, Patricia; McDevitt, James J; DeHaan, Wesley H; Fung, Rita O P; Cowling, Benjamin J; Chan, Kwok Hung; Leung, Gabriel M; Milton, Donald K

    2008-07-16

    Recent studies suggest that humans exhale fine particles during tidal breathing but little is known of their composition, particularly during infection. We conducted a study of influenza infected patients to characterize influenza virus and particle concentrations in their exhaled breath. Patients presenting with influenza-like-illness, confirmed influenza A or B virus by rapid test, and onset within 3 days were recruited at three clinics in Hong Kong, China. We collected exhaled breath from each subject onto Teflon filters and measured exhaled particle concentrations using an optical particle counter. Filters were analyzed for influenza A and B viruses by quantitative polymerase chain reaction (qPCR). Twelve out of thirteen rapid test positive patients provided exhaled breath filter samples (7 subjects infected with influenza B virus and 5 subjects infected with influenza A virus). We detected influenza virus RNA in the exhaled breath of 4 (33%) subjects--three (60%) of the five patients infected with influenza A virus and one (14%) of the seven infected with influenza B virus. Exhaled influenza virus RNA generation rates ranged from <3.2 to 20 influenza virus RNA particles per minute. Over 87% of particles exhaled were under 1 microm in diameter. These findings regarding influenza virus RNA suggest that influenza virus may be contained in fine particles generated during tidal breathing, and add to the body of literature suggesting that fine particle aerosols may play a role in influenza transmission.

  7. 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

  8. Methadone enhances human influenza A virus replication.

    PubMed

    Chen, Yun-Hsiang; Wu, Kuang-Lun; Tsai, Ming-Ta; Chien, Wei-Hsien; Chen, Mao-Liang; Wang, Yun

    2017-01-01

    Growing evidence has indicated that opioids enhance replication of human immunodeficiency virus and hepatitis C virus in target cells. However, it is unknown whether opioids can enhance replication of other clinically important viral pathogens. In this study, the interaction of opioid agonists and human influenza A/WSN/33 (H1N1) virus was examined in human lung epithelial A549 cells. Cells were exposed to morphine, methadone or buprenorphine followed by human H1N1 viral infection. Exposure to methadone differentially enhanced viral propagation, consistent with an increase in virus adsorption, susceptibility to virus infection and viral protein synthesis. In contrast, morphine or buprenorphine did not alter H1N1 replication. Because A549 cells do not express opioid receptors, methadone-enhanced H1N1 replication in human lung cells may not be mediated through these receptors. The interaction of methadone and H1N1 virus was also examined in adult mice. Treatment with methadone significantly increased H1N1 viral replication in lungs. Our data suggest that use of methadone facilitates influenza A viral infection in lungs and might raise concerns regarding the possible consequence of an increased risk of serious influenza A virus infection in people who receive treatment in methadone maintenance programs. © 2015 Society for the Study of Addiction.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. Detection of human influenza virus in Yucatan, Mexico.

    PubMed

    Ayora-Talavera, Guadalupe; Góngora-Biachi, Renán A; López-Martínez, Irma; Moguel-Rodríguez, William; Pérez-Carrillo, Humberto; Vázquez-Zapata, Víctor; Bastarrachea-Vázquez, Diliana; Canto-Cab, Armando

    2002-01-01

    Influenza virus is the most common cause of Acute Respiratory Infections (ARI) world wide. In patients with chronic condition, infection by the influenza virus can cause complications such as pneumonia which may have fatal outcome. The aim of this work was to determine the frequency of human influenza virus in outpatients with influenza-like illness (ILI) and in those patients admitted to hospital with community acquired pneumonia (CAP) in Yucatan, Mexico (October 1998-July 1999). Throat swabs were collected from ILI and CAP patients and processed to detect respiratory viruses. All clinical samples were tested for seven respiratory viruses using a rapid indirect immunofluorescence test (IFI). Clinical samples with positive results for influenza virus by IFI were inoculated into chick embryo eggs and/or MDCK cells for viral isolation. All influenza virus isolates were typed using the WHO influenza Kit 1998-1999. A total of 288 clinical samples were collected. Influenza virus type A was diagnosed in 29 clinical samples (10%), no other respiratory viruses were identified. Influenza virus was present with 8.9% (17 out of 189) in ILI patients, whereas with 12.12% (12 out of 99) in CAP patients. Influenza virus was detected from December to July. Six viral isolates were obtained and identified as influenza A (H3N2). Human influenza virus is certainly a cause of ARI and pneumonia in Yucatan, Mexico. The results showed that influenza virus contributes to at least 8.9% of the ARI, and more importantly to 12% of CAP patients. Positive cases were present in a different pattern to temperate zones where the peak of incidence occurs during autumn and winter.

  18. 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).

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  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. Global transmission of influenza viruses from humans to swine

    PubMed Central

    Gramer, Marie R.; Vincent, Amy L.; Holmes, Edward C.

    2012-01-01

    To determine the extent to which influenza viruses jump between human and swine hosts, we undertook a large-scale phylogenetic analysis of pandemic A/H1N1/09 (H1N1pdm09) influenza virus genome sequence data. From this, we identified at least 49 human-to-swine transmission events that occurred globally during 2009–2011, thereby highlighting the ability of the H1N1pdm09 virus to transmit repeatedly from humans to swine, even following adaptive evolution in humans. Similarly, we identified at least 23 separate introductions of human seasonal (non-pandemic) H1 and H3 influenza viruses into swine globally since 1990. Overall, these results reveal the frequency with which swine are exposed to human influenza viruses, indicate that humans make a substantial contribution to the genetic diversity of influenza viruses in swine, and emphasize the need to improve biosecurity measures at the human–swine interface, including influenza vaccination of swine workers. PMID:22791604

  5. [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.

  6. 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.

  7. The contrasting phylodynamics of human influenza B viruses

    PubMed Central

    Vijaykrishna, Dhanasekaran; Holmes, Edward C; Joseph, Udayan; Fourment, Mathieu; Su, Yvonne CF; Halpin, Rebecca; Lee, Raphael TC; 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 JD; Barr, Ian G

    2015-01-01

    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. DOI: http://dx.doi.org/10.7554/eLife.05055.001 PMID:25594904

  8. [An overview of swine influenza virus infection in humans].

    PubMed

    Zhu, Wen-fei; Shu, Yue-long

    2013-09-01

    Since the first report of a swine influenza virus (SIV) infection in humans in 1958, cases have occurred continuously and increased significantly after the 2009 H1N1 pandemic. Although exposure to swine is thought to be a risk factor for human SIVs infections, approximately half of the reported cases had no known exposure to pigs. Besides, epidemiological investigation showed that several cases had limited human-to-human transmission. Based on the analyses of data on swine influenza virus infection in humans in this review, both the improved SIVs surveillance in humans and swine population and wider vaccination coverage among occupational workers are critical strategies in pandemic preparedness and response.

  9. Homologous recombination evidence in human and swine influenza A viruses.

    PubMed

    He, Cheng-Qiang; Han, Guan-Zhu; Wang, Dong; Liu, Wei; Li, Guo-Rong; Liu, Xi-Ping; Ding, Nai-Zheng

    2008-10-10

    Dynamic gene mutation and the reassortment of genes have been considered as the key factors responsible for influenza A virus virulence and host tropism change. This study reports several significant evidence demonstrating that homologous recombination also takes place between influenza A viruses in human and swine lineages. Moreover, in a mosaic descended from swine H1N1 subtype and human H2N2, we found that its minor putative parent might be a derivative from the human cold-adapted vaccine lineage, which suggests that live vaccine is capable of playing a role in genetic change of influenza A virus via recombination with circulating viruses. These results would be important for knowing the molecular mechanism of mammal influenza A virus heredity and evolution.

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

    PubMed

    Bedford, Trevor; Rambaut, Andrew; Pascual, Mercedes

    2012-04-30

    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. 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. 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.

  11. 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

  12. 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

  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. 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. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. 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.

  16. 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

  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. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. 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.

  20. Isolation of a Novel Swine Influenza Virus from Oklahoma in 2011 Which Is Distantly Related to Human Influenza C Viruses

    PubMed Central

    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

    2013-01-01

    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. PMID:23408893

  1. Physician's knowledge, attitudes, and practices regarding seasonal influenza, pandemic influenza, and highly pathogenic avian influenza A (H5N1) virus infections of humans in Indonesia.

    PubMed

    Mangiri, Amalya; Iuliano, A Danielle; Wahyuningrum, Yunita; Praptiningsih, Catharina Y; Lafond, Kathryn E; Storms, Aaron D; Samaan, Gina; Ariawan, Iwan; Soeharno, Nugroho; Kreslake, Jennifer M; Storey, J Douglas; Uyeki, Timothy M

    2017-01-01

    Indonesia has reported highest number of fatal human cases of highly pathogenic avian influenza (HPAI) A (H5N1) virus infection worldwide since 2005. There are limited data available on seasonal and pandemic influenza in Indonesia. During 2012, we conducted a survey of clinicians in two districts in western Java, Indonesia, to assess knowledge, attitudes, and practices (KAP) of clinical diagnosis, testing, and treatment of patients with seasonal influenza, pandemic influenza, or HPAI H5N1 virus infections. Overall, a very low percentage of physician participants reported ever diagnosing hospitalized patients with seasonal, pandemic, or HPAI H5N1 influenza. Use of influenza testing was low in outpatients and hospitalized patients, and use of antiviral treatment was very low for clinically diagnosed influenza patients. Further research is needed to explore health system barriers for influenza diagnostic testing and availability of antivirals for treatment of influenza in Indonesia. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  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. Lack of Correlation between Virus Barosensitivity and the Presence of a Viral Envelope during Inactivation of Human Rotavirus, Vesicular Stomatitis Virus, and Avian Metapneumovirus by High-Pressure Processing▿

    PubMed Central

    Lou, Fangfei; Neetoo, Hudaa; Li, Junan; Chen, Haiqiang; Li, Jianrong

    2011-01-01

    High-pressure processing (HPP) is a nonthermal technology that has been shown to effectively inactivate a wide range of microorganisms. However, the effectiveness of HPP on inactivation of viruses is relatively less well understood. We systematically investigated the effects of intrinsic (pH) and processing (pressure, time, and temperature) parameters on the pressure inactivation of a nonenveloped virus (human rotavirus [HRV]) and two enveloped viruses (vesicular stomatitis virus [VSV] and avian metapneumovirus [aMPV]). We demonstrated that HPP can efficiently inactivate all tested viruses under optimal conditions, although the pressure susceptibilities and the roles of temperature and pH substantially varied among these viruses regardless of the presence of a viral envelope. We found that VSV was much more stable than most food-borne viruses, whereas aMPV was highly susceptible to HPP. When viruses were held for 2 min under 350 MPa at 4°C, 1.1-log, 3.9-log, and 5.0-log virus reductions were achieved for VSV, HRV, and aMPV, respectively. Both VSV and aMPV were more susceptible to HPP at higher temperature and lower pH. In contrast, HRV was more easily inactivated at higher pH, although temperature did not have a significant impact on inactivation. Furthermore, we demonstrated that the damage of virion structure by disruption of the viral envelope and/or capsid is the primary mechanism underlying HPP-induced viral inactivation. In addition, VSV glycoprotein remained antigenic although VSV was completely inactivated. Taken together, our findings suggest that HPP is a promising technology to eliminate viral contaminants in high-risk foods, water, and other fomites. PMID:22003028

  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. Influenza A Viruses of Human Origin in Swine, Brazil

    PubMed Central

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

    2015-01-01

    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. PMID:26196759

  8. Influenza vaccine induces intracellular immune memory of human NK cells.

    PubMed

    Dou, Yaling; Fu, Binqing; Sun, Rui; Li, Wenting; Hu, Wanfu; Tian, Zhigang; Wei, Haiming

    2015-01-01

    Influenza vaccines elicit antigen-specific antibodies and immune memory to protect humans from infection with drift variants. However, what supports or limits vaccine efficacy and duration is unclear. Here, we vaccinated healthy volunteers with annual vaccine formulations and investigated the dynamics of T cell, natural killer (NK) cell and antibody responses upon restimulation with heterologous or homologous influenza virus strains. Influenza vaccines induced potential memory NK cells with increased antigen-specific recall IFN-γ responses during the first 6 months. In the absence of significant changes in other NK cell markers (CD45RO, NKp44, CXCR6, CD57, NKG2C, CCR7, CD62L and CD27), influenza vaccines induced memory NK cells with the distinct feature of intracellular NKp46 expression. Indeed, surface NKp46 was internalized, and the dynamic increase in NKp46(intracellular)+CD56dim NK cells positively correlated with increased IFN-γ production to influenza virus restimulation after vaccination. In addition, anti-NKp46 antibodies blocked IFN-γ responses. These findings provide insights into a novel mechanism underlying vaccine-induced immunity and NK-related diseases, which may help to design persisting and universal vaccines in the future.

  9. 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

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

    USDA-ARS?s Scientific Manuscript database

    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...

  11. Human Monoclonal Antibodies Broadly Neutralizing against Influenza B Virus

    PubMed Central

    Yasugi, Mayo; Kubota-Koketsu, Ritsuko; Yamashita, Akifumi; Kawashita, Norihito; Du, Anariwa; Sasaki, Tadahiro; Nishimura, Mitsuhiro; Misaki, Ryo; Kuhara, Motoki; Boonsathorn, Naphatsawan; Fujiyama, Kazuhito; Okuno, Yoshinobu; Nakaya, Takaaki; Ikuta, Kazuyoshi

    2013-01-01

    Influenza virus has the ability to evade host immune surveillance through rapid viral genetic drift and reassortment; therefore, it remains a continuous public health threat. The development of vaccines producing broadly reactive antibodies, as well as therapeutic strategies using human neutralizing monoclonal antibodies (HuMAbs) with global reactivity, has been gathering great interest recently. Here, three hybridoma clones producing HuMAbs against influenza B virus, designated 5A7, 3A2 and 10C4, were prepared using peripheral lymphocytes from vaccinated volunteers, and were investigated for broad cross-reactive neutralizing activity. Of these HuMAbs, 3A2 and 10C4, which recognize the readily mutable 190-helix region near the receptor binding site in the hemagglutinin (HA) protein, react only with the Yamagata lineage of influenza B virus. By contrast, HuMAb 5A7 broadly neutralizes influenza B strains that were isolated from 1985 to 2006, belonging to both Yamagata and Victoria lineages. Epitope mapping revealed that 5A7 recognizes 316G, 318C and 321W near the C terminal of HA1, a highly conserved region in influenza B virus. Indeed, no mutations in the amino acid residues of the epitope region were induced, even after the virus was passaged ten times in the presence of HuMAb 5A7. Moreover, 5A7 showed significant therapeutic efficacy in mice, even when it was administered 72 hours post-infection. These results indicate that 5A7 is a promising candidate for developing therapeutics, and provide insight for the development of a universal vaccine against influenza B virus. PMID:23408886

  12. 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.

  13. 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

  14. Human and avian influenza viruses target different cells in the lower respiratory tract of humans and other mammals.

    PubMed

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

    2007-10-01

    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.

  15. 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

  16. 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.

  17. 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

  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. Influenza Virus Reservoirs and Intermediate Hosts: Dogs, Horses, and New Possibilities for Influenza Virus Exposure of Humans

    PubMed Central

    Murcia, Pablo R.; Holmes, Edward C.

    2014-01-01

    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. PMID:25540375

  20. 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.

  1. Fc functional antibodies in humans with severe H7N9 and seasonal influenza

    PubMed Central

    Vanderven, Hillary A.; Liu, Lu; Ana-Sosa-Batiz, Fernanda; Nguyen, Thi H.O.; Wan, Yanmin; Hogarth, P. Mark; Tilmanis, Danielle; Parsons, Matthew S.; Hurt, Aeron C.; Davenport, Miles P.; Kotsimbos, Tom; Cheng, Allen C.; Kedzierska, Katherine; Zhang, Xiaoyan; Xu, Jianqing; Kent, Stephen J.

    2017-01-01

    BACKGROUND. Both seasonal and novel avian influenza viruses can result in severe infections requiring hospitalization. Anti-influenza antibodies (Abs) with Fc-mediated effector functions, such as Ab-dependent cellular cytotoxicity (ADCC), are of growing interest in control of influenza but have not previously been studied during severe human infections. As such, the objective of this study was to examine Fc-mediated Ab functions in humans hospitalized with influenza infection. METHODS. Serum Ab response was studied in subjects hospitalized with either pandemic H7N9 avian influenza virus in China (n = 18) or circulating seasonal influenza viruses in Melbourne, Australia (n = 16). Recombinant soluble Fc receptor dimer ELISAs, natural killer (NK) cell activation assays, and Ab-dependent killing assays with influenza-infected target cells were used to assess the Fc functionality of anti-influenza hemagglutinin (HA) Abs during severe human influenza infection. RESULTS. We found that the peak generation of Fc functional HA Abs preceded that of neutralizing Abs for both severe H7N9 and seasonal influenza infections. Subjects who succumbed to complications of H7N9 infection demonstrated reduced HA-specific Fc receptor–binding Abs (in magnitude and breadth) immediately prior to death compared with those who survived. Subjects who recovered from H7N9 and severe seasonal influenza infections demonstrated increased Fc receptor–binding Abs not only against the homologous infecting strain but against HAs from different influenza A subtypes. CONCLUSION. Collectively, survivors of severe influenza infection rapidly generate a functional Ab response capable of mediating ADCC against divergent influenza viruses. Broadly binding HA Abs with Fc-mediated functions may be a useful component of protective immunity to severe influenza infection. FUNDING. The National Health and Medical Research Council ([NHMRC] grants 1023294, 1041832, and 1071916), the Australian Department of Health

  2. 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

  3. 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

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

    PubMed

    Hensley, Scott E

    2014-10-01

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Spatial dynamics of human-origin H1 influenza A v irus in North American swine

    USDA-ARS?s Scientific Manuscript database

    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...

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

    PubMed Central

    Sun, Xiangjie; Zeng, Hui; Kumar, Amrita; Belser, Jessica A.; Maines, Taronna R.

    2016-01-01

    ABSTRACT 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. IMPORTANCE Avian influenza viruses, including H5N1 and H7N9, have been associated with severe respiratory disease and fatal outcomes in humans. Although acute respiratory distress syndrome (ARDS) and progressive pulmonary

  7. Genotyping and detection of common avian and human origin-influenza viruses using a portable chemiluminescence imaging microarray.

    PubMed

    Zhang, Yingjie; Liu, Qiqi; Wang, Dou; Chen, Suhong; Wang, Xiaobo; Wang, Shengqi

    2016-01-01

    Influenza viruses are divided into three types, A, B, and C. Human influenza A and B viruses can cause seasonal epidemics, but influenza C causes only a mild respiratory illness. Influenza A virus can infect various host species. In 2013, human-infectious avian influenza A (H7N9) was first reported in China. By the second week of 2014, there were 210 laboratory-confirmed human cases in the country, and the mortality rate eventually reached 22 %. Rapid and accurate diagnosis of influenza viruses is important for clinical management and epidemiology. In this assay, a cost-effective chemiluminescence (CL) detection oligonucleotide microarray was developed to genotype and detect avian influenza A (H7N9), avian influenza A (H5N1), 2009 influenza A (H1N1), seasonal influenza A (H1N1), and seasonal influenza A (H3N2). Influenza A viruses and influenza B viruses were also generally detected using this microarray. The results of detection of 40 cultivated influenza virus strains showed that the microarray was able to distinguish the subtypes of these influenza viruses very well. The microarray possessed similar or 10 fold higher limit of detection than the real-time RT-PCR method. Sixty-six clinical swab samples were detected using this microarray and verified with real time RT-PCR to evaluate the efficiency of this microarray for clinical testing. A reliable CL detection oligonucleotide microarray had been developed to genotype and detected these influenza viruses.

  8. 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.

  9. 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.

  10. 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

  11. Genetic correlation between current circulating H1N1 swine and human influenza viruses.

    PubMed

    Lu, Lu; Yin, Yanbo; Sun, Zhongsheng; Gao, Lei; Gao, George F; Liu, Sidang; Sun, Lei; Liu, Wenjun

    2010-11-01

    H1N1 is the main subtype influenza A virus circulating in human and swine population, and has long been a threat to economy and public health. To explore the genetic correlation between current circulating H1N1 swine and human influenza viruses. Three new H1N1 swine influenza viruses (SIVs) were isolated and genomes sequencing were conducted followed by phylogenetic and molecular analysis of all swine and human H1N1 influenza viruses isolated in China in the past five years. Homology and phylogenetic analysis revealed that the three isolates possessed different characteristics: the genome of A/Swine/Shandong/1112/2008 was closely related to that of classical H1N1 SIV, while A/Swine/Shandong/1123/2008 was a reassortant with NS gene from the human-like H3N2 influenza virus and other genes from the classical H1N1 SIV, and A/Swine/Fujian/0325/2008 fell into a lineage of seasonal human H1N1 influenza viruses. Genetically, 2009 H1N1 influenza A viruses (2009 H1N1) in China were contiguous to the SIV lineages rather than the seasonal H1N1 human influenza virus's lineage. Furthermore, molecular analysis among human and swine influenza viruses provided more detail information for understanding their genetic correlation. These results suggested that in China in the past five years, the classical, avian-like and human-like H1N1 SIV existed in swine herds and the reassortment between H1N1 swine and H3N2 human influenza viruses was identified. In addition, the present data showed no evidence to support a strong correlation between the 2009 H1N1 and the swine influenza virus circulating in China. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. The pig as a mixing vessel for influenza viruses: Human and veterinary implications

    PubMed Central

    Ma, Wenjun; Kahn, Robert E; Richt, Juergen A

    2009-01-01

    Influenza A viruses are highly infectious respiratory pathogens that can infect many species. Birds are the reservoir for all known influenza A subtypes; and novel influenza viruses can emerge from birds and infect mammalian species including humans. Because swine are susceptible to infection with both avian and human influenza viruses, novel reassortant influenza viruses can be generated in this mammalian species by reassortment of influenza viral segments leading to the “mixing vessel” theory. There is no direct evidence that the reassortment events culminating in the 1918, 1957 or 1968 pandemic influenza viruses originated from pigs. Genetic reassortment among avian, human and/or swine influenza virus gene segments has occurred in pigs and some novel reassortant swine viruses have been transmitted to humans. Notably, novel reassortant H2N3 influenza viruses isolated from the US pigs, most likely infected with avian influenza viruses through surface water collected in ponds for cleaning barns and watering animals, had a similar genetic make-up to early isolates (1957) of the H2N2 human pandemic. These novel H2N3 swine viruses were able to cause disease in swine and mice and were infectious and highly transmissible in swine and ferrets without prior adaptation. The preceding example shows that pigs could transmit novel viruses from an avian reservoir to other mammalian species. Importantly, H2 viruses pose a substantial risk to humans because they have been absent from mammalian species since 1968 and people born after 1968 have little preexisting immunity to the H2 subtype. It is difficult to predict which virus will cause the next human pandemic and when that pandemic might begin. Importantly, the establishment and spread of a reassorted mammalian-adapted virus from pigs to humans could happen anywhere in the world. Therefore, both human and veterinary research needs to give more attention to potential cross-species transmission capacity of influenza A

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

    MedlinePlus

    ... operations Diseases Biorisk reduction Human infection with avian influenza A(H7N9) virus – China Disease outbreak news 18 ... of a laboratory-confirmed human infection with avian influenza A(H7N9) virus and on 12 January 2017, ...

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

    PubMed Central

    Nelson, Martha I.; Vincent, Amy L.

    2015-01-01

    The origins of the influenza A (H1N1) pandemic of 2009 in swine are unknown, highlighting gaps in our understanding of influenza A virus ecology and evolution. Here 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. PMID:25564096

  15. 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. Published by Elsevier Ltd.

  16. Antibody-Dependent Cell-Mediated Cytotoxicity to Hemagglutinin of Influenza A Viruses After Influenza Vaccination in Humans

    PubMed Central

    Zhong, Weimin; Liu, Feng; Wilson, Jason R.; Holiday, Crystal; Li, Zhu-Nan; Bai, Yaohui; Tzeng, Wen-Pin; Stevens, James; York, Ian A.; Levine, Min Z.

    2016-01-01

    Background. Detection of neutralizing antibodies (nAbs) to influenza A virus hemagglutinin (HA) antigens by conventional serological assays is currently the main immune correlate of protection for influenza vaccines However, current prepandemic avian influenza vaccines are poorly immunogenic in inducing nAbs despite considerable protection conferred. Recent studies show that Ab-dependent cell-mediated cytotoxicity (ADCC) to HA antigens are readily detectable in the sera of healthy individuals and patients with influenza infection. Methods. Virus neutralization and ADCC activities of serum samples from individuals who received either seasonal or a stock-piled H5N1 avian influenza vaccine were evaluated by hemagglutination inhibition assay, microneutralization assay, and an improved ADCC natural killer (NK) cell activation assay. Results. Immunization with inactivated seasonal influenza vaccine led to strong expansion of both nAbs and ADCC-mediating antibodies (adccAbs) to H3 antigen of the vaccine virus in 24 postvaccination human sera. In sharp contrast, 18 individuals vaccinated with the adjuvanted H5N1 avian influenza vaccine mounted H5-specific antibodies with strong ADCC activities despite moderate virus neutralization capacity. Strength of HA-specific ADCC activities is largely associated with the titers of HA-binding antibodies and not with the fine antigenic specificity of anti-HA nAbs. Conclusions. Detection of both nAbs and adccAbs may better reflect protective capacity of HA-specific antibodies induced by avian influenza vaccines. PMID:27419174

  17. Host genetics of severe influenza: from mouse Mx1 to human IRF7

    PubMed Central

    Ciancanelli, Michael J.; Abel, Laurent; Zhang, Shen-Ying; Casanova, Jean-Laurent

    2016-01-01

    Influenza viruses cause mild to moderate respiratory illness in most people, and only rarely devastating or fatal infections. The virulence factors encoded by viral genes can explain seasonal or geographic differences at the population level but are unlikely to account for inter-individual clinical variability. Inherited or acquired immunodeficiencies may thus underlie severe cases of influenza. The critical role of host genes was first demonstrated by forward genetics in inbred mice, with the identification of interferon (IFN)-α/β-inducible Mx as a canonical influenza susceptibility gene. Reverse genetics has subsequently characterized the in vivo role of other mouse genes involved in IFN-α/β and –λ immunity. A series of in vitro studies with mouse and human cells have also refined the cell-intrinsic mechanisms of protection against influenza viruses. Population-based human genetic studies have not yet uncovered variants with a significant impact. Interestingly, human primary immunodeficiencies affecting T and B cells were also not found to predispose to severe influenza. Recently however, human IRF7 was shown to be essential for IFN-α/β- and IFN-λ-dependent protective immunity against primary influenza in vivo, as inferred patient with life-threatening influenza revealed to be IRF7-deficient by whole exome sequencing. Next generation sequencing of human exomes and genomes will facilitate the analysis of the human genetic determinism of severe influenza. PMID:26761402

  18. Serologic evidence of human influenza virus infections in swine populations, Cambodia.

    PubMed

    Rith, Sareth; Netrabukkana, Punnaporn; Sorn, San; Mumford, Elizabeth; Mey, Channa; Holl, Davun; Goutard, Flavie; Y, Bunthin; Fenwick, Stan; Robertson, Ian; Roger, François; Buchy, Philippe

    2013-05-01

    This study was conducted from 2006 to 2010 and investigated the seroprevalence of influenza A viruses in Cambodian pigs, including human H1N1, H3N2, 2009 pandemic H1N1 (A(H1N1)pdm09), and highly pathogenic avian H5N1 influenza A viruses. A total of 1147 sera obtained from pigs in Cambodia were tested by haemagglutination inhibition (HI) assays for antibody to human influenza A viruses along with both HI and microneutralization (MN) tests to assess immunological responses to H5N1 virus. The results were compared by year, age, and province. Antibodies against a human influenza A virus were detected in 14·9% of samples. A(H1N1)pdm09 virus were dominant over the study period (23·1%), followed by those to human H1N1 (17·3%) and H3N2 subtypes (9·9%). No pigs were serologically positive for avian H5 influenza viruses. The seroprevalence of human H1N1 and H3N2 influenza viruses peaked in 2008, while that of A(H1N1)pdm09 reached a peak in 2010. No significant differences in seroprevalence to human influenza subtypes were observed in different age groups. Cambodian pigs were exposed to human strains of influenza A viruses either prior to or during this study. The implications of these high prevalence rates imply human-to-swine influenza virus transmission in Cambodia. Although pigs are mostly raised in small non-commercial farms, our preliminary results provide evidence of sustained human influenza virus circulation in pig populations in Cambodia. © 2012 Blackwell Publishing Ltd.

  19. 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

  20. 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. This article is copyright of The Authors, 2016.

  1. 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.

  2. IgA and Neutralizing Antibodies to Influenza A Virus in Human Milk: A Randomized Trial of Antenatal Influenza Immunization

    PubMed Central

    Schlaudecker, Elizabeth P.; Steinhoff, Mark C.; Omer, Saad B.; McNeal, Monica M.; Roy, Eliza; Arifeen, Shams E.; Dodd, Caitlin N.; Raqib, Rubhana; Breiman, Robert F.; Zaman, K.

    2013-01-01

    Background Antenatal immunization of mothers with influenza vaccine increases serum antibodies and reduces the rates of influenza illness in mothers and their infants. We report the effect of antenatal immunization on the levels of specific anti-influenza IgA levels in human breast milk. (ClinicalTrials.gov identifier NCT00142389; http://clinicaltrials.gov/ct2/show/NCT00142389). Methods and Findings The Mother's Gift study was a prospective, blinded, randomized controlled trial that assigned 340 pregnant Bangladeshi mothers to receive either trivalent inactivated influenza vaccine, or 23-valent pneumococcal polysaccharide vaccine during the third trimester. We evaluated breast milk at birth, 6 weeks, 6 months, and 12 months, and serum at 10 weeks and 12 months. Milk and serum specimens from 57 subjects were assayed for specific IgA antibody to influenza A/New Caledonia (H1N1) using an enzyme-linked immunosorbent assay (ELISA) and a virus neutralization assay, and for total IgA using ELISA. Influenza-specific IgA levels in breast milk were significantly higher in influenza vaccinees than in pneumococcal controls for at least 6 months postpartum (p = 0.04). Geometric mean concentrations ranged from 8.0 to 91.1 ELISA units/ml in vaccinees, versus 2.3 to 13.7 ELISA units/mL in controls. Virus neutralization titers in milk were 1.2 to 3 fold greater in vaccinees, and correlated with influenza-specific IgA levels (r = 0.86). Greater exclusivity of breastfeeding in the first 6 months of life significantly decreased the expected number of respiratory illness with fever episodes in infants of influenza-vaccinated mothers (p = 0.0042) but not in infants of pneumococcal-vaccinated mothers (p = 0.4154). Conclusions The sustained high levels of actively produced anti-influenza IgA in breast milk and the decreased infant episodes of respiratory illness with fever suggest that breastfeeding may provide local mucosal protection for the infant for at least 6 months

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Spatial Dynamics of Human-Origin H1 Influenza A Virus in North American Swine

    PubMed Central

    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

    2011-01-01

    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. PMID:21695237

  9. 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.

  10. Nasal IgA Provides Protection against Human Influenza Challenge in Volunteers with Low Serum Influenza Antibody Titre

    PubMed Central

    Gould, Victoria M. W.; Francis, James N.; Anderson, Katie J.; Georges, Bertrand; Cope, Alethea V.; Tregoning, John S.

    2017-01-01

    In spite of there being a number of vaccines, influenza remains a significant global cause of morbidity and mortality. Understanding more about natural and vaccine induced immune protection against influenza infection would help to develop better vaccines. Virus specific IgG is a known correlate of protection, but other factors may help to reduce viral load or disease severity, for example IgA. In the current study we measured influenza specific responses in a controlled human infection model using influenza A/California/2009 (H1N1) as the challenge agent. Volunteers were pre-selected with low haemagglutination inhibition (HAI) titres in order to ensure a higher proportion of infection; this allowed us to explore the role of other immune correlates. In spite of HAI being uniformly low, there were variable levels of H1N1 specific IgG and IgA prior to infection. There was also a range of disease severity in volunteers allowing us to compare whether differences in systemic and local H1N1 specific IgG and IgA prior to infection affected disease outcome. H1N1 specific IgG level before challenge did not correlate with protection, probably due to the pre-screening for individuals with low HAI. However, the length of time infectious virus was recovered from the nose was reduced in patients with higher pre-existing H1N1 influenza specific nasal IgA or serum IgA. Therefore, IgA contributes to protection against influenza and should be targeted in vaccines. PMID:28567036

  11. Nasal IgA Provides Protection against Human Influenza Challenge in Volunteers with Low Serum Influenza Antibody Titre.

    PubMed

    Gould, Victoria M W; Francis, James N; Anderson, Katie J; Georges, Bertrand; Cope, Alethea V; Tregoning, John S

    2017-01-01

    In spite of there being a number of vaccines, influenza remains a significant global cause of morbidity and mortality. Understanding more about natural and vaccine induced immune protection against influenza infection would help to develop better vaccines. Virus specific IgG is a known correlate of protection, but other factors may help to reduce viral load or disease severity, for example IgA. In the current study we measured influenza specific responses in a controlled human infection model using influenza A/California/2009 (H1N1) as the challenge agent. Volunteers were pre-selected with low haemagglutination inhibition (HAI) titres in order to ensure a higher proportion of infection; this allowed us to explore the role of other immune correlates. In spite of HAI being uniformly low, there were variable levels of H1N1 specific IgG and IgA prior to infection. There was also a range of disease severity in volunteers allowing us to compare whether differences in systemic and local H1N1 specific IgG and IgA prior to infection affected disease outcome. H1N1 specific IgG level before challenge did not correlate with protection, probably due to the pre-screening for individuals with low HAI. However, the length of time infectious virus was recovered from the nose was reduced in patients with higher pre-existing H1N1 influenza specific nasal IgA or serum IgA. Therefore, IgA contributes to protection against influenza and should be targeted in vaccines.

  12. 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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  14. A review on the clinical spectrum and natural history of human influenza.

    PubMed

    Punpanich, Warunee; Chotpitayasunondh, Tawee

    2012-10-01

    The objective of this review is to provide updated information on the clinical spectrum and natural history of human influenza, including risk factors for severe disease, and to identify the knowledge gap in this area. We searched the MEDLINE database of the recent literature for the period January 2009 to August 17, 2011 with regard to the abovementioned aspects of human influenza, focusing on A(H1N1)pdm09 and seasonal influenza. The clinical spectrum and outcomes of cases of A(H1N1)pdm09 influenza have been mild and rather indistinguishable from those of seasonal influenza. Sporadic cases covering a wide range of neurological complications have been reported. Underlying predisposing conditions considered to be high-risk for A(H1N1)pdm09 infections are generally similar to those of seasonal influenza, but with two additional risk groups: pregnant women and the morbidly obese. Co-infections with bacteria and D222/N variants or 225G substitution of the viral genome have also been reported to be significant factors associated with the severity of disease. The current knowledge gap includes: (1) a lack of clarification regarding the relatively greater severity of the Mexican A(H1N1)pdm09 influenza outbreak in the early phase of the pandemic; (2) insufficient data on the clinical impact, risk factors, and outcomes of human infections caused by resistant strains of influenza; and (3) insufficient data from less developed countries that would enable them to prioritize strategies for influenza prevention and control. Clinical features and risk factors of A(H1N1)pdm09 are comparable to those of seasonal influenza. Emerging risk factors for severe disease with A(H1N1)pdm09 include morbid obesity, pregnancy, bacterial co-infections, and D222/N variants or 225G substitution of the viral genome. Copyright © 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  15. 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/.

  16. 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. © The American Society of Tropical Medicine and Hygiene.

  17. 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.

  18. Dynamic patterns of avian and human influenza in east and southeast Asia.

    PubMed

    Park, Andrew W; Glass, Kathryn

    2007-08-01

    The seasonal patterns of human influenza in temperate regions have been well documented; however, much less attention has been paid to patterns of infection in the tropical and subtropical areas of east and southeast Asia. During the period 1997-2006, this region experienced several outbreaks of highly pathogenic avian influenza A (H5N1) in hosts including wild and domestic poultry, human beings, and other mammals. H5N1 is thought to be a likely source of a pandemic strain of human influenza. Incidence of both human influenza and avian influenza in human beings shows evidence of seasonality throughout east and southeast Asia, although the seasonal patterns in tropical and subtropical areas are not as simple or as pronounced as those in temperate regions around the world. The possibility of a human being becoming co-infected with both human and avian strains of influenza is not restricted to a short season, although the risks do appear to be greatest during the winter months.

  19. Avian influenza

    MedlinePlus

    Bird flu; H5N1; H5N2; H5N8; H7N9; Avian influenza A (HPAI) H5 ... The first avian influenza in humans was reported in Hong Kong in 1997. It was called avian influenza (H5N1). The outbreak was linked ...

  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. 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.

  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. Avian influenza virus directly infects human natural killer cells and inhibits cell activity.

    PubMed

    Mao, Huawei; Liu, Yinping; Sia, Sin Fun; Peiris, J S Malik; Lau, Yu-Lung; Tu, Wenwei

    2017-04-01

    Natural killer (NK) cell is a key component of innate immunity and plays an important role in host defense against virus infection by directly destroying infected cells. Influenza is a respiratory disease transmitted in the early phase of virus infection. Evasion of host innate immunity including NK cells is critical for the virus to expand and establish a successful acute infection. Previously, we showed that human influenza H1N1 virus infects NK cells and induces cell apoptosis, as well as inhibits NK cell activity. In this study, we further demonstrated that avian influenza virus also directly targeted NK cells as an immunoevasion strategy. The avian virus infected human NK cells and induced cell apoptosis. In addition, avian influenza virion and HA protein inhibited NK cell cytotoxicity. This novel strategy has obvious advantages for avian influenza virus, allowing the virus sufficient time to expand and subsequent spread before the onset of the specific immune response. Our findings provide an important clue for the immunopathogenesis of avian influenza, and also suggest that direct targeting NK cells may be a common strategy used by both human and avian influenza viruses to evade NK cell immunity.

  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. An Amphibian Host Defense Peptide Is Virucidal for Human H1 Hemagglutinin-Bearing Influenza Viruses.

    PubMed

    Holthausen, David J; Lee, Song Hee; Kumar, Vineeth Tv; Bouvier, Nicole M; Krammer, Florian; Ellebedy, Ali H; Wrammert, Jens; Lowen, Anice C; George, Sanil; Pillai, Madhavan Radhakrishna; Jacob, Joshy

    2017-04-18

    Although vaccines confer protection against influenza A viruses, antiviral treatment becomes the first line of defense during pandemics because there is insufficient time to produce vaccines. Current antiviral drugs are susceptible to drug resistance, and developing new antivirals is essential. We studied host defense peptides from the skin of the South Indian frog and demonstrated that one of these, which we named "urumin," is virucidal for H1 hemagglutinin-bearing human influenza A viruses. This peptide specifically targeted the conserved stalk region of H1 hemagglutinin and was effective against drug-resistant H1 influenza viruses. Using electron microscopy, we showed that this peptide physically destroyed influenza virions. It also protected naive mice from lethal influenza infection. Urumin represents a unique class of anti-influenza virucide that specifically targets the hemagglutinin stalk region, similar to targeting of antibodies induced by universal influenza vaccines. Urumin therefore has the potential to contribute to first-line anti-viral treatments during influenza outbreaks. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. 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

  8. Animal and human health implications of avian influenza infections.

    PubMed

    Capua, Ilaria; Alexander, Dennis J

    2007-12-01

    Avian influenza (AI) is a listed disease of the World Organisation for Animal Health (OIE) that has become a disease of great importance both for animal and human health. Until recent times, AI was considered a disease of birds with zoonotic implications of limited significance. The emergence and spread of the Asian lineage highly pathogenic AI (HPAI) H5N1 virus has dramatically changed this perspective; not only has it been responsible of the death or culling of millions of birds, but this virus has also been able to infect a variety of non-avian hosts including human beings. The implications of such a panzootic reflect themselves in animal health issues, notably in the reduction of a protein source for developing countries and in the management of the pandemic potential. Retrospective studies have shown that avian progenitors play an important role in the generation of pandemic viruses for humans, and therefore these infections in the avian reservoir should be subjected to control measures aiming at eradication of the Asian H5N1 virus from all sectors rather than just eliminating or reducing the impact of the disease in poultry.

  9. 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.

  10. Development of an immunochromatographic kit for rapid detection of human influenza B virus infection.

    PubMed

    Zhang, Peirui; Duan, Yueqiang; Zhang, Dexi; Zhang, Shaogeng; Li, Zhiwei; Wang, Xiliang; Yang, Penghui

    2014-01-01

    Type B influenza virus is a major epidemic strain responsible for considerable mortality and morbidity. A colloidal gold immunochromatographic strip for the rapid detection of human influenza B virus was developed. This test is based on membrane chromatography and uses colloidal gold conjugated with influenza B virus anti-NP monoclonal antibody as the tracer. The assembled test strip was housed in a plastic case. The colloid gold strip (CGS) specifically detected all influenza B viruses tested and did not react with other respiratory viruses. Compared with SYBR Green real-time PCR, the sensitivity and specificity of the CGS test was 89.76% and 99.56%, respectively, and the consistency ratio between CGS and real-time PCR was 96.06% in detecting influenza B virus in 710 nasopharyngeal swabs from patients with influenza-like illness in the hospital. The CGS array developed in this study enabled typing of influenza B viruses in human clinical specimens. Thus, together with the advantages of rapid detection and easy operation without requiring specialized personnel and equipment, this technique is a convenient and relatively inexpensive diagnostic tool for large-scale screening of clinical samples.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  12. Haemophilus influenzae: using comparative genomics to accurately identify a highly recombinogenic human pathogen.

    PubMed

    Price, Erin P; Sarovich, Derek S; Nosworthy, Elizabeth; Beissbarth, Jemima; Marsh, Robyn L; Pickering, Janessa; Kirkham, Lea-Ann S; Keil, Anthony D; Chang, Anne B; Smith-Vaughan, Heidi C

    2015-08-27

    Haemophilus influenzae is an opportunistic bacterial pathogen that exclusively colonises humans and is associated with both acute and chronic disease. Despite its clinical significance, accurate identification of H. influenzae is a non-trivial endeavour. H. haemolyticus can be misidentified as H. influenzae from clinical specimens using selective culturing methods, reflecting both the shared environmental niche and phenotypic similarities of these species. On the molecular level, frequent genetic exchange amongst Haemophilus spp. has confounded accurate identification of H. influenzae, leading to both false-positive and false-negative results with existing speciation assays. Whole-genome single-nucleotide polymorphism data from 246 closely related global Haemophilus isolates, including 107 Australian isolate genomes generated in this study, were used to construct a whole-genome phylogeny. Based on this phylogeny, H. influenzae could be differentiated from closely related species. Next, a H. influenzae-specific locus, fucP, was identified, and a novel TaqMan real-time PCR assay targeting fucP was designed. PCR specificity screening across a panel of clinically relevant species, coupled with in silico analysis of all species within the order Pasteurellales, demonstrated that the fucP assay was 100 % specific for H. influenzae; all other examined species failed to amplify. This study is the first of its kind to use large-scale comparative genomic analysis of Haemophilus spp. to accurately delineate H. influenzae and to identify a species-specific molecular signature for this species. The fucP assay outperforms existing H. influenzae targets, most of which were identified prior to the next-generation genomics era and thus lack validation across a large number of Haemophilus spp. We recommend use of the fucP assay in clinical and research laboratories for the most accurate detection and diagnosis of H. influenzae infection and colonisation.

  13. 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.

  14. 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

  15. 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.

  16. Relationship of the quaternary structure of human secretory IgA to neutralization of influenza virus

    PubMed Central

    Suzuki, Tadaki; Kawaguchi, Akira; Ainai, Akira; Tamura, Shin-ichi; Ito, Ryo; Multihartina, Pretty; Setiawaty, Vivi; Pangesti, Krisna Nur Andriana; Odagiri, Takato; Tashiro, Masato; Hasegawa, Hideki

    2015-01-01

    Secretory IgA (S-IgA) antibodies, the major contributors to humoral mucosal immunity to influenza virus infection, are polymeric Igs present in many external secretions. In the present study, the quaternary structures of human S-IgA induced in nasal mucosa after administration of intranasal inactivated influenza vaccines were characterized in relation to neutralization potency against influenza A viruses. Human nasal IgA antibodies have been shown to contain at least five quaternary structures. Direct and real-time visualization of S-IgA using high-speed atomic force microscopy (AFM) demonstrated that trimeric and tetrameric S-IgA had six and eight antigen-binding sites, respectively, and that these structures exhibited large-scale asynchronous conformational changes while capturing influenza HA antigens in solution. Furthermore, trimeric, tetrameric, and larger polymeric structures, which are minor fractions in human nasal IgA, displayed increased neutralizing potency against influenza A viruses compared with dimeric S-IgA, suggesting that the larger polymeric than dimeric forms of S-IgA play some important roles in protection against influenza A virus infection in the human upper respiratory tract. PMID:26056267

  17. 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

  18. Introductions and evolution of human-origin seasonal influenza a viruses in multinational swine populations.

    PubMed

    Nelson, Martha I; Wentworth, David E; Culhane, Marie R; Vincent, Amy L; Viboud, Cecile; LaPointe, Matthew P; Lin, Xudong; Holmes, Edward C; Detmer, Susan E

    2014-09-01

    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 influenza viruses collected from North American swine during 2002 to 2011 and identified a swine virus that possessed all eight genome segments of human seasonal A/H3N2 virus origin. A molecular clock analysis indicates that this virus--A/sw/Saskatchewan/02903/2009(H3N2)--has likely circulated undetected in swine for at least 7 years. For historical context, we performed a comprehensive phylogenetic analysis of an additional 1,404 whole-genome sequences from swine influenza A viruses collected globally during 1931 to 2013. Human-to-swine transmission occurred frequently over this time period, with 20 discrete introductions of human seasonal influenza A viruses showing sustained onward transmission in swine for at least 1 year since 1965. Notably, human-origin hemagglutinin (H1 and H3) and neuraminidase (particularly N2) segments were detected in swine at a much higher rate than the six internal gene segments, suggesting an association between the acquisition of swine-origin internal genes via reassortment and the adaptation of human influenza viruses to new swine hosts. Further understanding of the fitness constraints on the adaptation of human viruses to swine, and vice versa, at a genomic level is central to understanding the complex multihost ecology of influenza and the disease threats that swine and humans pose to each other. The swine origin of the 2009 A/H1N1 pandemic virus underscored the importance of understanding how influenza A virus evolves in these animals hosts. While the importance of reassortment in generating genetically diverse influenza viruses in swine is well documented, the role of human-to-swine transmission has not been as intensively studied. Through a

  19. Introductions and Evolution of Human-Origin Seasonal Influenza A Viruses in Multinational Swine Populations

    PubMed Central

    Wentworth, David E.; Culhane, Marie R.; Vincent, Amy L.; Viboud, Cecile; LaPointe, Matthew P.; Lin, Xudong; Holmes, Edward C.; Detmer, Susan E.

    2014-01-01

    ABSTRACT 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 influenza viruses collected from North American swine during 2002 to 2011 and identified a swine virus that possessed all eight genome segments of human seasonal A/H3N2 virus origin. A molecular clock analysis indicates that this virus—A/sw/Saskatchewan/02903/2009(H3N2)—has likely circulated undetected in swine for at least 7 years. For historical context, we performed a comprehensive phylogenetic analysis of an additional 1,404 whole-genome sequences from swine influenza A viruses collected globally during 1931 to 2013. Human-to-swine transmission occurred frequently over this time period, with 20 discrete introductions of human seasonal influenza A viruses showing sustained onward transmission in swine for at least 1 year since 1965. Notably, human-origin hemagglutinin (H1 and H3) and neuraminidase (particularly N2) segments were detected in swine at a much higher rate than the six internal gene segments, suggesting an association between the acquisition of swine-origin internal genes via reassortment and the adaptation of human influenza viruses to new swine hosts. Further understanding of the fitness constraints on the adaptation of human viruses to swine, and vice versa, at a genomic level is central to understanding the complex multihost ecology of influenza and the disease threats that swine and humans pose to each other. IMPORTANCE The swine origin of the 2009 A/H1N1 pandemic virus underscored the importance of understanding how influenza A virus evolves in these animals hosts. While the importance of reassortment in generating genetically diverse influenza viruses in swine is well documented, the role of human-to-swine transmission has not been as

  20. 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.

  1. 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

  2. The role of influenza and parainfluenza infections in nasopharyngeal pneumococcal acquisition among young children.

    PubMed

    Grijalva, Carlos G; Griffin, Marie R; Edwards, Kathryn M; Williams, John V; Gil, Ana I; Verastegui, Hector; Hartinger, Stella M; Vidal, Jorge E; Klugman, Keith P; Lanata, Claudio F

    2014-05-01

    Animal models suggest that influenza infection favors nasopharyngeal acquisition of pneumococci. We assessed this relationship with influenza and other respiratory viruses in young children. A case-control study was nested within a prospective cohort study of acute respiratory illness (ARI) in Andean children <3 years of age (RESPIRA-PERU study). Weekly household visits were made to identify ARI and obtain nasal swabs for viral detection using real-time reverse-transcription polymerase chain reaction. Monthly nasopharyngeal (NP) samples were obtained to assess pneumococcal colonization. We determined whether specific respiratory viral ARI episodes occurring within the interval between NP samples increased the risk of NP acquisition of new pneumococcal serotypes. A total of 729 children contributed 2128 episodes of observation, including 681 pneumococcal acquisition episodes (new serotype, not detected in prior sample), 1029 nonacquisition episodes (no colonization or persistent colonization with the same serotype as the prior sample), and 418 indeterminate episodes. The risk of pneumococcal acquisition increased following influenza-ARI (adjusted odds ratio [AOR], 2.19; 95% confidence interval [CI], 1.02-4.69) and parainfluenza-ARI (AOR, 1.86; 95% CI, 1.15-3.01), when compared with episodes without ARI. Other viral infections (respiratory syncytial virus, human metapneumovirus, human rhinovirus, and adenovirus) were not associated with acquisition. Influenza and parainfluenza ARIs appeared to facilitate pneumococcal acquisition among young children. As acquisition increases the risk of pneumococcal diseases, these observations are pivotal in our attempts to prevent pneumococcal disease.

  3. Caveolin-1 influences human influenza A virus (H1N1) multiplication in cell culture

    PubMed Central

    2010-01-01

    Background The threat of recurring influenza pandemics caused by new viral strains and the occurrence of escape mutants necessitate the search for potent therapeutic targets. The dependence of viruses on cellular factors provides a weak-spot in the viral multiplication strategy and a means to interfere with viral multiplication. Results Using a motif-based search strategy for antiviral targets we identified caveolin-1 (Cav-1) as a putative cellular interaction partner of human influenza A viruses, including the pandemic influenza A virus (H1N1) strains of swine origin circulating from spring 2009 on. The influence of Cav-1 on human influenza A/PR/8/34 (H1N1) virus replication was determined in inhibition and competition experiments. RNAi-mediated Cav-1 knock-down as well as transfection of a dominant-negative Cav-1 mutant results in a decrease in virus titre in infected Madin-Darby canine kidney cells (MDCK), a cell line commonly used in basic influenza research as well as in virus vaccine production. To understand the molecular basis of the phenomenon we focussed on the putative caveolin-1 binding domain (CBD) located in the lumenal, juxtamembranal portion of the M2 matrix protein which has been identified in the motif-based search. Pull-down assays and co-immunoprecipitation experiments showed that caveolin-1 binds to M2. The data suggest, that Cav-1 modulates influenza virus A replication presumably based on M2/Cav-1 interaction. Conclusion As Cav-1 is involved in the human influenza A virus life cycle, the multifunctional protein and its interaction with M2 protein of human influenza A viruses represent a promising starting point for the search for antiviral agents. PMID:20504340

  4. 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

  5. Clinical characterization of influenza A and human respiratory syncytial virus among patients with influenza like illness.

    PubMed

    Saxena, Swati; Singh, Dharamveer; Zia, Amreen; Umrao, Jyoti; Srivastava, Naveen; Pandey, Ankita; Singh, Sushma; Bhattacharya, Piyali; Kumari, Reema; Kushwaha, Ramawadh; Dhole, T N

    2017-01-01

    Influenza A and Respiratory Syncytial Virus (RSV) has been recognized as a major cause of acute respiratory tract infection. H1N1 is one of the subtypes of influenza A, pandemic worldwide in July 2009, causing 18,449 deaths globally. To investigate the prevalence and clinical manifestation of the influenza A, H1N1pdm09, and RSV. Throat/nasal swab collected from the patients of all age group either outpatients/inpatients having respiratory illness from 2 to 5 days. The clinical data were recorded in a predesigned questionnaire. RNA was extracted and analyzed by real time PCR at a tertiary care center, 2009-2014. Total 4,352 samples tested for influenza A and H1N1. Out of 4,352, 32.2% (median positivity 21%; range 16-41% during 6 years) were positive for influenza A and 19% were H1N1 (median positivity 16.7%; range 8.7-23% during 6 years). Total 1653 samples were analyzed for RSV from 2011 to 2014, 12% were RSV positive (median positivity 11.35%; range 10-16.3% during 4 years). Pharyngitis, dyspnea were frequent symptoms in influenza A and H1N1 (P < 0.005) whereas bronchiolitis and pneumonia were commonly present in RSV (P < 0.005). The positivity of influenza A and H1N1 was higher in age-group 21-30, whereas RSV in infant and children. H1N1 and RSV were co-circulated and have common clinical symptoms particularly in lower age group. Therefore, laboratory confirmation is necessary for further disease prognosis. Age was an important risk factor that affects the positivity of influenza A, H1N1, and RSV. Different clinical manifestation of H1N1 and RSV will be helpful for early and accurate diagnosis. J. Med. Virol. 89:49-54, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  6. 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.

  7. [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.

  8. 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.

  9. 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

  10. Prevalence of non-influenza respiratory viruses in acute respiratory infection cases in Mexico

    PubMed Central

    Fernandes-Matano, Larissa; Monroy-Muñoz, Irma Eloísa; Angeles-Martínez, Javier; Sarquiz-Martinez, Brenda; Palomec-Nava, Iliana Donají; Pardavé-Alejandre, Hector Daniel; Santos Coy-Arechavaleta, Andrea; Santacruz-Tinoco, Clara Esperanza; González-Ibarra, Joaquín; González-Bonilla, Cesar Raúl

    2017-01-01

    Background Acute respiratory infections are the leading cause of morbidity and mortality worldwide. Although a viral aetiological agent is estimated to be involved in up to 80% of cases, the majority of these agents have never been specifically identified. Since 2009, diagnostic and surveillance efforts for influenza virus have been applied worldwide. However, insufficient epidemiological information is available for the many other respiratory viruses that can cause Acute respiratory infections. Methods This study evaluated the presence of 14 non-influenza respiratory viruses in 872 pharyngeal exudate samples using RT-qPCR. All samples met the operational definition of a probable case of an influenza-like illness or severe acute respiratory infection and had a previous negative result for influenza by RT-qPCR. Results The presence of at least one non-influenza virus was observed in 312 samples (35.8%). The most frequent viruses were rhinovirus (RV; 33.0%), human respiratory syncytial virus (HRSV; 30.8%) and human metapneumovirus (HMPV; 10.6%). A total of 56 cases of co-infection (17.9%) caused by 2, 3, or 4 viruses were identified. Approximately 62.5% of all positive cases were in children under 9 years of age. Conclusion In this study, we identified 13 non-influenza respiratory viruses that could occur in any season of the year. This study provides evidence for the prevalence and seasonality of a wide range of respiratory viruses that circulate in Mexico and constitute a risk for the population. Additionally, our data suggest that including these tests more widely in the diagnostic algorithm for influenza may reduce the use of unnecessary antibiotics, reduce the hospitalisation time, and enrich national epidemiological data with respect to the infections caused by these viruses. PMID:28467515

  11. Prevalence of non-influenza respiratory viruses in acute respiratory infection cases in Mexico.

    PubMed

    Fernandes-Matano, Larissa; Monroy-Muñoz, Irma Eloísa; Angeles-Martínez, Javier; Sarquiz-Martinez, Brenda; Palomec-Nava, Iliana Donají; Pardavé-Alejandre, Hector Daniel; Santos Coy-Arechavaleta, Andrea; Santacruz-Tinoco, Clara Esperanza; González-Ibarra, Joaquín; González-Bonilla, Cesar Raúl; Muñoz-Medina, José Esteban

    2017-01-01

    Acute respiratory infections are the leading cause of morbidity and mortality worldwide. Although a viral aetiological agent is estimated to be involved in up to 80% of cases, the majority of these agents have never been specifically identified. Since 2009, diagnostic and surveillance efforts for influenza virus have been applied worldwide. However, insufficient epidemiological information is available for the many other respiratory viruses that can cause Acute respiratory infections. This study evaluated the presence of 14 non-influenza respiratory viruses in 872 pharyngeal exudate samples using RT-qPCR. All samples met the operational definition of a probable case of an influenza-like illness or severe acute respiratory infection and had a previous negative result for influenza by RT-qPCR. The presence of at least one non-influenza virus was observed in 312 samples (35.8%). The most frequent viruses were rhinovirus (RV; 33.0%), human respiratory syncytial virus (HRSV; 30.8%) and human metapneumovirus (HMPV; 10.6%). A total of 56 cases of co-infection (17.9%) caused by 2, 3, or 4 viruses were identified. Approximately 62.5% of all positive cases were in children under 9 years of age. In this study, we identified 13 non-influenza respiratory viruses that could occur in any season of the year. This study provides evidence for the prevalence and seasonality of a wide range of respiratory viruses that circulate in Mexico and constitute a risk for the population. Additionally, our data suggest that including these tests more widely in the diagnostic algorithm for influenza may reduce the use of unnecessary antibiotics, reduce the hospitalisation time, and enrich national epidemiological data with respect to the infections caused by these viruses.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. Demographic and ecological risk factors for human influenza A virus infections in rural Indonesia.

    PubMed

    Root, Elisabeth Dowling; Agustian, Dwi; Kartasasmita, Cissy; Uyeki, Timothy M; Simões, Eric A F

    2017-09-01

    Indonesia has the world's highest reported mortality for human infections with highly pathogenic avian influenza (HPAI) A(H5N1) virus. Indonesia is an agriculturally driven country where human-animal mixing is common and provides a unique environment for zoonotic influenza A virus transmission. To identify potential demographic and ecological risk factors for human infection with seasonal influenza A viruses in rural Indonesia, a population-based study was conducted in Cileunyi and Soreang subdistricts near Bandung in western Java from 2008 to 2011. Passive influenza surveillance with RT-PCR confirmation of influenza A viral RNA in respiratory specimens was utilized for case ascertainment. A population census and mapping were utilized for population data collection. The presence of influenza A(H3N2) and A(H1N1)pdm09 virus infections in a household was modeled using Generalized Estimating Equations. Each additional child aged <5 years in a household increased the odds of H3N2 approximately 5 times (OR=4.59, 95%CI: 3.30-6.24) and H1N1pdm09 by 3.5 times (OR=3.53, 95%CI: 2.51-4.96). In addition, the presence of 16-30 birds in the house was associated with an increased odds of H3N2 (OR=5.08, 95%CI: 2.00-12.92) and H1N1pdm09 (OR=12.51 95%CI: 6.23-25.13). Our findings suggest an increase in influenza A virus infections in rural Indonesian households with young children and poultry. © 2017 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  17. 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.

  18. Isolation of influenza virus in human lung embryonated fibroblast cells (MRC-5) from clinical samples.

    PubMed Central

    de Oña, M; Melón, S; de la Iglesia, P; Hidalgo, F; Verdugo, A F

    1995-01-01

    Ninety-four pharyngeal swab samples corresponding to 94 patients with suspected influenza virus infection were inoculated in Madin-Darby canine kidney (MDCK) cells, the conventional cell system for the isolation of influenza virus, and in fibroblastic human embryo lung (MRC-5) cells, a cell system less commonly used for this purpose but one frequently used in clinical virology laboratories. Both cell preparations were treated with trypsin. Influenza virus was recovered from 15% of the samples inoculated in MDCK cells and from 18% of those inoculated in MRC-5 cells. The use of MRC-5 cells can simplify the search for respiratory viruses and would assist in the rapid detection of influenza virus during new epidemics. PMID:7665680

  19. 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.

  20. 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.

  1. 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.

  2. Epidemiology of human influenza A(H7N9) infection in Hong Kong.

    PubMed

    Leung, Yiu-Hong; To, May-Kei; Lam, Tsz-Sum; Yau, Shui-Wah; Leung, Oi-Shan; Chuang, Shuk-Kwan

    2017-04-01

    We conducted a case series study to review the epidemiology of human influenza A(H7N9) infection reported in Hong Kong. We reviewed case records of confirmed human cases of influenza A(H7N9) infection reported in Hong Kong in the 2013-2014 winter season. We compared the median viral shedding duration and interval from illness onset to initiation of oseltamivir treatment between severe and mild cases. We estimated the incubation period of influenza A(H7N9) virus from cases with a single known date of poultry exposure. A total of 10 cases were reported and all were imported infection from Mainland China. Four patients died and the cause of death was related to influenza A(H7N9) infection in two patients. The median interval from illness onset to initiation of oseltamivir treatment for the severe cases (4.5 days) was significantly longer than the mild cases (2 days; p = 0.025). Severe cases had a significantly longer viral shedding duration than mild cases (p = 0.028). The median incubation period for cases with a single known exposure date was 4 days. Nasopharyngeal aspirate taken from the 88 close contacts of the 10 patients all tested negative for influenza A virus using reverse transcription polymerase chain reaction. Delayed administration of antiviral treatment may be associated with a more severe illness for influenza A(H7N9) infection. Despite our aggressive contact tracing policy with laboratory testing of all close contacts, no secondary case was identified which implied that the potential of human-to-human transmission of the circulating influenza A(H7N9) virus remains low. Copyright © 2015. Published by Elsevier B.V.

  3. 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

  4. Randomized controlled trials for influenza drugs and vaccines: a review of controlled human infection studies.

    PubMed

    Balasingam, Shobana; Wilder-Smith, Annelies

    2016-08-01

    Controlled human infection, the intentional infection of healthy volunteers, allows disease pathogenesis to be studied and vaccines and therapeutic interventions to be evaluated in a controlled setting. A systematic review of randomized controlled trials of countermeasures for influenza that used the experimental human infection platform was performed. The primary objective was to document the scope of trials performed to date and the main efficacy outcome in the trials. The secondary objective was to assess safety and identify serious adverse events. The PubMed database was searched for randomized controlled influenza human challenge studies with predetermined search terms. Review papers, papers without outcomes, community-acquired infections, duplicated data, pathogenesis studies, and observational studies were excluded. Twenty-six randomized controlled trials published between 1947 and 2014 fit the study inclusion criteria. Two-thirds of these trials investigated antivirals and one-third investigated influenza vaccines. Among 2462 subjects inoculated with influenza virus, the incidence of serious adverse events was low (0.04%). These challenge studies helped to down-select three antivirals and one vaccine that were subsequently approved by the US Food and Drug Administration (FDA). Controlled human infection studies are an important research tool in assessing promising influenza vaccines and antivirals. These studies are performed quickly and are cost-effective and safe, with a low incidence of serious adverse events. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26412348

  6. 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.

  7. 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.

  8. 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.

  9. Detection of Human Influenza A Viruses by Loop-Mediated Isothermal Amplification

    PubMed Central

    Poon, Leo L. M.; Leung, Cynthia S. W.; Chan, Kwok H.; Lee, Jack H. C.; Yuen, Kwok Y.; Guan, Yi; Peiris, Joseph S. M.

    2005-01-01

    Here we describe the use of the loop-mediated isothermal amplification (LAMP) method to detect human influenza viruses (H1 to H3). Our results were correlated 100% with results deduced from routine clinical diagnostic tests. In addition, we also developed a LAMP assay specific for human β-actin cDNA as a quality control test. PMID:15635005

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

    USDA-ARS?s Scientific Manuscript database

    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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Timing of Influenza A(H5N1) in Poultry and Humans and Seasonal Influenza Activity Worldwide, 2004–2013

    PubMed Central

    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

    2015-01-01

    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. PMID:25625302

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  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. 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

  4. 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.

  5. 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

  6. Global epidemiology of non-influenza RNA respiratory viruses: data gaps and a growing need for surveillance.

    PubMed

    Tang, Julian W; Lam, Tommy T; Zaraket, Hassan; Lipkin, W Ian; Drews, Steven J; Hatchette, Todd F; Heraud, Jean-Michel; Koopmans, Marion P

    2017-04-28

    Together with influenza, the non-influenza RNA respiratory viruses (NIRVs), which include respiratory syncytial virus, parainfluenza viruses, coronavirus, rhinovirus, and human metapneumovirus, represent a considerable global health burden, as recognised by WHO's Battle against Respiratory Viruses initiative. By contrast with influenza viruses, little is known about the contemporaneous global diversity of these viruses, and the relevance of such for development of pharmaceutical interventions. Although far less advanced than for influenza, antiviral drugs and vaccines are in different stages of development for several of these viruses, but no interventions have been licensed. This scarcity of global genetic data represents a substantial knowledge gap and impediment to the eventual licensing of new antiviral drugs and vaccines for NIRVs. Enhanced genetic surveillance will assist and boost research and development into new antiviral drugs and vaccines for these viruses. Additionally, understanding the global diversity of respiratory viruses is also part of emerging disease preparedness, because non-human coronaviruses and paramyxoviruses have been listed as priority concerns in a recent WHO research and development blueprint initiative for emerging infectious diseases. In this Personal View, we explain further the rationale for expanding the genetic database of NIRVs and emphasise the need for greater investment in this area of research. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Human Dendritic Cell Response Signatures Distinguish 1918, Pandemic, and Seasonal H1N1 Influenza Viruses.

    PubMed

    Hartmann, Boris M; Thakar, Juilee; Albrecht, Randy A; Avey, Stefan; Zaslavsky, Elena; Marjanovic, Nada; Chikina, Maria; Fribourg, Miguel; Hayot, Fernand; Schmolke, Mirco; Meng, Hailong; Wetmur, James; García-Sastre, Adolfo; Kleinstein, Steven H; Sealfon, Stuart C

    2015-10-01

    Influenza viruses continue to present global threats to human health. Antigenic drift and shift, genetic reassortment, and cross-species transmission generate new strains with differences in epidemiology and clinical severity. We compared the temporal transcriptional responses of human dendritic cells (DC) to infection with two pandemic (A/Brevig Mission/1/1918, A/California/4/2009) and two seasonal (A/New Caledonia/20/1999, A/Texas/36/1991) H1N1 influenza viruses. Strain-specific response differences included stronger activation of NF-κB following infection with A/New Caledonia/20/1999 and a unique cluster of genes expressed following infection with A/Brevig Mission/1/1918. A common antiviral program showing strain-specific timing was identified in the early DC response and found to correspond with reported transcript changes in blood during symptomatic human influenza virus infection. Comparison of the global responses to the seasonal and pandemic strains showed that a dramatic divergence occurred after 4 h, with only the seasonal strains inducing widespread mRNA loss. Continuously evolving influenza viruses present a global threat to human health; however, these host responses display strain-dependent differences that are incompletely understood. Thus, we conducted a detailed comparative study assessing the immune responses of human DC to infection with two pandemic and two seasonal H1N1 influenza strains. We identified in the immune response to viral infection both common and strain-specific features. Among the stain-specific elements were a time shift of the interferon-stimulated gene response, selective induction of NF-κB signaling by one of the seasonal strains, and massive RNA degradation as early as 4 h postinfection by the seasonal, but not the pandemic, viruses. These findings illuminate new aspects of the distinct differences in the immune responses to pandemic and seasonal influenza viruses. Copyright © 2015, American Society for Microbiology. All

  8. Human Dendritic Cell Response Signatures Distinguish 1918, Pandemic, and Seasonal H1N1 Influenza Viruses

    PubMed Central

    Hartmann, Boris M.; Thakar, Juilee; Albrecht, Randy A.; Avey, Stefan; Zaslavsky, Elena; Marjanovic, Nada; Chikina, Maria; Fribourg, Miguel; Hayot, Fernand; Schmolke, Mirco; Meng, Hailong; Wetmur, James; García-Sastre, Adolfo

    2015-01-01

    ABSTRACT Influenza viruses continue to present global threats to human health. Antigenic drift and shift, genetic reassortment, and cross-species transmission generate new strains with differences in epidemiology and clinical severity. We compared the temporal transcriptional responses of human dendritic cells (DC) to infection with two pandemic (A/Brevig Mission/1/1918, A/California/4/2009) and two seasonal (A/New Caledonia/20/1999, A/Texas/36/1991) H1N1 influenza viruses. Strain-specific response differences included stronger activation of NF-κB following infection with A/New Caledonia/20/1999 and a unique cluster of genes expressed following infection with A/Brevig Mission/1/1918. A common antiviral program showing strain-specific timing was identified in the early DC response and found to correspond with reported transcript changes in blood during symptomatic human influenza virus infection. Comparison of the global responses to the seasonal and pandemic strains showed that a dramatic divergence occurred after 4 h, with only the seasonal strains inducing widespread mRNA loss. IMPORTANCE Continuously evolving influenza viruses present a global threat to human health; however, these host responses display strain-dependent differences that are incompletely understood. Thus, we conducted a detailed comparative study assessing the immune responses of human DC to infection with two pandemic and two seasonal H1N1 influenza strains. We identified in the immune response to viral infection both common and strain-specific features. Among the stain-specific elements were a time shift of the interferon-stimulated gene response, selective induction of NF-κB signaling by one of the seasonal strains, and massive RNA degradation as early as 4 h postinfection by the seasonal, but not the pandemic, viruses. These findings illuminate new aspects of the distinct differences in the immune responses to pandemic and seasonal influenza viruses. PMID:26223639

  9. 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.

  10. 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.

  11. [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.

  12. 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. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. 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.

  14. 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.

  15. Haemophilus influenzae uses the surface protein E to acquire human plasminogen and to evade innate immunity.

    PubMed

    Barthel, Diana; Singh, Birendra; Riesbeck, Kristian; Zipfel, Peter F

    2012-01-01

    Pathogenic microbes acquire the human plasma protein plasminogen to their surface. In this article, we characterize binding of this important coagulation regulator to the respiratory pathogen nontypeable Haemophilus influenzae and identify the Haemophilus surface protein E (PE) as a new plasminogen-binding protein. Plasminogen binds dose dependently to intact bacteria and to purified PE. The plasminogen-PE interaction is mediated by lysine residues and is also affected by ionic strength. The H. influenzae PE knockout strain (nontypeable H. influenzae 3655Δpe) bound plasminogen with ∼65% lower intensity as compared with the wild-type, PE-expressing strain. In addition, PE expressed ectopically on the surface of Escherichia coli also bound plasminogen. Plasminogen, either attached to intact H. influenzae or bound to PE, was accessible for urokinase plasminogen activator. The converted active plasmin cleaved the synthetic substrate S-2251, and the natural substrates fibrinogen and C3b. Using synthetic peptides that cover the complete sequence of the PE protein, the major plasminogen-binding region was localized to a linear 28-aa-long N-terminal peptide, which represents aa 41-68. PE binds plasminogen and also vitronectin, and the two human plasma proteins compete for PE binding. Thus, PE is a major plasminogen-binding protein of the Gram-negative bacterium H. influenzae, and when converted to plasmin, PE-bound plasmin aids in immune evasion and contributes to bacterial virulence.

  16. Preexisting human antibodies neutralize recently emerged H7N9 influenza strains

    PubMed Central

    Henry Dunand, Carole J.; Leon, Paul E.; Kaur, Kaval; Tan, Gene S.; Zheng, Nai-Ying; Andrews, Sarah; Huang, Min; Qu, Xinyan; Huang, Yunping; Salgado-Ferrer, Marlene; Ho, Irvin Y.; Taylor, William; Hai, Rong; Wrammert, Jens; Ahmed, Rafi; García-Sastre, Adolfo; Palese, Peter; Krammer, Florian; Wilson, Patrick C.

    2015-01-01

    The emergence and seasonal persistence of pathogenic H7N9 influenza viruses in China have raised concerns about the pandemic potential of this strain, which, if realized, would have a substantial effect on global health and economies. H7N9 viruses are able to bind to human sialic acid receptors and are also able to develop resistance to neuraminidase inhibitors without a loss in fitness. It is not clear whether prior exposure to circulating human influenza viruses or influenza vaccination confers immunity to H7N9 strains. Here, we demonstrate that 3 of 83 H3 HA-reactive monoclonal antibodies generated by individuals that had previously undergone influenza A virus vaccination were able to neutralize H7N9 viruses and protect mice against homologous challenge. The H7N9-neutralizing antibodies bound to the HA stalk domain but exhibited a difference in their breadth of reactivity to different H7 influenza subtypes. Mapping viral escape mutations suggested that these antibodies bind at least two different epitopes on the stalk region. Together, these results indicate that these broadly neutralizing antibodies may contribute to the development of therapies against H7N9 strains and may also be effective against pathogenic H7 strains that emerge in the future. PMID:25689254

  17. 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.

  18. 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

  19. Profiles of cytokine and chemokine gene expression in human pulmonary epithelial cells induced by human and avian influenza viruses

    PubMed Central

    2010-01-01

    Influenza pandemic remains a serious threat to human health. In this study, the repertoire of host cellular cytokine and chemokine responses to infections with highly pathogenic avian influenza H5N1, low pathogenicity avian influenza H9N2 and seasonal human influenza H1N1 were compared using an in vitro system based on human pulmonary epithelial cells. The results showed that H5N1 was more potent than H9N2 and H1N1 in inducing CXCL-10/IP-10, TNF-alpha and CCL-5/RANTES. The cytokine/chemokine profiles for H9N2, in general, resembled those of H1N1. Of interest, only H1N1, but none of the avian subtypes examined could induce a persistent elevation of the immune-regulatory cytokine - TGF-β2. The differential expression of cytokines/chemokines following infection with different influenza viruses could be a key determinant for clinical outcome. The potential of using these cytokines/chemokines as prognostic markers or targets of therapy is worth exploring. PMID:21108843

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  1. 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.

  2. Three mutations switch H7N9 influenza to human-type receptor specificity.

    PubMed

    de Vries, Robert P; Peng, Wenjie; Grant, Oliver C; Thompson, Andrew J; Zhu, Xueyong; Bouwman, Kim M; de la Pena, Alba T Torrents; van Breemen, Marielle J; Ambepitiya Wickramasinghe, Iresha N; de Haan, Cornelis A M; Yu, Wenli; McBride, Ryan; Sanders, Rogier W; Woods, Robert J; Verheije, Monique H; Wilson, Ian A; Paulson, James C

    2017-06-01

    The avian H7N9 influenza outbreak in 2013 resulted from an unprecedented incidence of influenza transmission to humans from infected poultry. The majority of human H7N9 isolates contained a hemagglutinin (HA) mutation (Q226L) that has previously been associated with a switch in receptor specificity from avian-type (NeuAcα2-3Gal) to human-type (NeuAcα2-6Gal), as documented for the avian progenitors of the 1957 (H2N2) and 1968 (H3N2) human influenza pandemic viruses. While this raised concern that the H7N9 virus was adapting to humans, the mutation was not sufficient to switch the receptor specificity of H7N9, and has not resulted in sustained transmission in humans. To determine if the H7 HA was capable of acquiring human-type receptor specificity, we conducted mutation analyses. Remarkably, three amino acid mutations conferred a switch in specificity for human-type receptors that resembled the specificity of the 2009 human H1 pandemic virus, and promoted binding to human trachea epithelial cells.

  3. Infection and Pathogenesis of Canine, Equine, and Human Influenza Viruses in Canine Tracheas

    PubMed Central

    Gonzalez, Gaelle; Marshall, John F.; Morrell, Joanna; Robb, David; McCauley, John W.; Perez, Daniel R.; Parrish, Colin R.

    2014-01-01

    ABSTRACT Influenza A viruses (IAVs) can jump species barriers and occasionally cause epidemics, epizootics, pandemics, and panzootics. Characterizing the infection dynamics at the target tissues of natural hosts is central to understanding the mechanisms that control host range, tropism, and virulence. Canine influenza virus (CIV; H3N8) originated after the transfer of an equine influenza virus (EIV) into dogs. Thus, comparing CIV and EIV isolates provides an opportunity to study the determinants of influenza virus emergence. Here we characterize the replication of canine, equine, and human IAVs in the trachea of the dog, a species to which humans are heavily exposed. We define a phenotype of infection for CIV, which is characterized by high levels of virus replication and extensive tissue damage. CIV was compared to evolutionarily distinct EIVs, and the early EIV isolates showed an impaired ability to infect dog tracheas, while EIVs that circulated near the time of CIV emergence exhibited a CIV-like infection phenotype. Inoculating dog tracheas with various human IAVs (hIAVs) showed that they infected the tracheal epithelium with various efficiencies depending on the virus tested. Finally, we show that reassortant viruses carrying gene segments of CIV and hIAV are viable and that addition of the hemagglutinin (HA) and neuraminidase (NA) of CIV to the 2009 human pandemic virus results in a virus that replicates at high levels and causes significant lesions. This provides important insights into the role of evolution on viral emergence and on the role of HA and NA as determinants of pathogenicity. IMPORTANCE Influenza A viruses (IAVs) have entered new host species in recent history, sometimes with devastating consequences. Canine influenza virus (CIV) H3N8 originated from a direct transfer of an equine influenza virus (EIV) in the early 2000s. We studied the infection patterns of IAVs that circulate in dogs or to which dogs are commonly exposed and showed that CIV

  4. Infection and pathogenesis of canine, equine, and human influenza viruses in canine tracheas.

    PubMed

    Gonzalez, Gaelle; Marshall, John F; Morrell, Joanna; Robb, David; McCauley, John W; Perez, Daniel R; Parrish, Colin R; Murcia, Pablo R

    2014-08-01

    Influenza A viruses (IAVs) can jump species barriers and occasionally cause epidemics, epizootics, pandemics, and panzootics. Characterizing the infection dynamics at the target tissues of natural hosts is central to understanding the mechanisms that control host range, tropism, and virulence. Canine influenza virus (CIV; H3N8) originated after the transfer of an equine influenza virus (EIV) into dogs. Thus, comparing CIV and EIV isolates provides an opportunity to study the determinants of influenza virus emergence. Here we characterize the replication of canine, equine, and human IAVs in the trachea of the dog, a species to which humans are heavily exposed. We define a phenotype of infection for CIV, which is characterized by high levels of virus replication and extensive tissue damage. CIV was compared to evolutionarily distinct EIVs, and the early EIV isolates showed an impaired ability to infect dog tracheas, while EIVs that circulated near the time of CIV emergence exhibited a CIV-like infection phenotype. Inoculating dog tracheas with various human IAVs (hIAVs) showed that they infected the tracheal epithelium with various efficiencies depending on the virus tested. Finally, we show that reassortant viruses carrying gene segments of CIV and hIAV are viable and that addition of the hemagglutinin (HA) and neuraminidase (NA) of CIV to the 2009 human pandemic virus results in a virus that replicates at high levels and causes significant lesions. This provides important insights into the role of evolution on viral emergence and on the role of HA and NA as determinants of pathogenicity. Influenza A viruses (IAVs) have entered new host species in recent history, sometimes with devastating consequences. Canine influenza virus (CIV) H3N8 originated from a direct transfer of an equine influenza virus (EIV) in the early 2000s. We studied the infection patterns of IAVs that circulate in dogs or to which dogs are commonly exposed and showed that CIV emergence was likely

  5. Avian Influenza in Birds

    MedlinePlus

    ... during outbreaks of highly pathogenic avian influenza the economic impact and trade restrictions from a highly pathogenic avian influenza outbreak the possibility that avian influenza A viruses could be transmitted to humans When H5 or H7 avian influenza outbreaks occur ...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  7. 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.

  8. Human respiratory syncytial virus in children with lower respiratory tract infections or influenza-like illness and its co-infection characteristics with viruses and atypical bacteria in Hangzhou, China.

    PubMed

    Yu, Xinfen; Kou, Yu; Xia, Daozong; Li, Jun; Yang, Xuhui; Zhou, Yinyan; He, Xiaoyan

    2015-08-01

    Human respiratory syncytial virus (RSV) is the most important viral pathogen in children. However, its epidemic patterns and co-infection characteristics are not fully understood. We attempted to determine the level of genetic variation of RSV, and describe the prevalence and co-infection characteristics of RSV in Hangzhou during two epidemic seasons. Single respiratory samples from 1820 pediatric patients were screened for RSV and genotyped by RT-PCR and sequencing. In all RSV positive specimens, we screened for viruses and atypical bacteria. Demographic and clinical information was recorded and analyzed. A total of 34.5% and 3.8% of samples from acute lower respiratory tract infections (ALRI) and influenza-like illness (ILI) were positive for RSV, respectively. Phylogenetic analysis revealed that 61.1% of the selected 167 RSV strains were NA1, 31.1% were BA, 3.6% were ON1, 2.4% were CB1, and 1.8% were NA3. A new genotype, BA11 was identified, which comprised 98.1% of BA strains in this study, while the rest were BA10. A total of 36.4% and 9.1% of RSV-positive children with ALRI and ILI respectively were found to be co-infected. Rhinovirus was the most common additional respiratory virus, followed by human metapneumovirus. Except for fever, no significant differences in other clinical presentation between the RSV mono-infection and co-infection groups were observed. The circulating RSV strains had high genetic variability with RSV-B showing a more local pattern. In ALRI cases, co-infection of RSV with other viruses or atypical bacteria has no significant effect on the clinical presentation except fever. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. 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

  10. 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.

  11. 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.

  12. 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...

  13. 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...

  14. Influenza and other respiratory viruses in three Central American countries

    PubMed Central

    Laguna‐Torres, Victor A.; Sánchez‐Largaespada, José F.; Lorenzana, Ivette; Forshey, Brett; Aguilar, Patricia; Jimenez, Mirna; Parrales, Eduardo; Rodriguez, Francisco; García, Josefina; Jimenez, Ileana; Rivera, Maribel; Perez, Juan; Sovero, Merly; Rios, Jane; Gamero, María E.; Halsey, Eric S.; Kochel, Tadeusz J.

    2010-01-01

    Please cite this paper as: Laguna‐Torres et al. (2011) Influenza and other respiratory viruses in three Central American countries. Influenza and Other Respiratory Viruses 5(2), 123–134. Background  Despite the disease burden imposed by respiratory diseases on children in Central America, there is a paucity of data describing the etiologic agents of the disease. Aims  To analyze viral etiologic agents associated with influenza‐like illness (ILI) in participants reporting to one outpatient health center, one pediatric hospital, and three general hospitals in El Salvador, Honduras, and Nicaragua Material & Methods  Between August 2006 and April 2009, pharyngeal swabs were collected from outpatients and inpatients. Patient specimens were inoculated onto cultured cell monolayers, and viral antigens were detected by indirect and direct immunofluorescence staining. Results  A total of 1,756 patients were enrolled, of whom 1,195 (68.3%) were under the age of 5; and 183 (10.4%) required hospitalization. One or more viral agents were identified in 434 (24.7%) cases, of which 17 (3.9%) were dual infections. The most common viruses isolated were influenza A virus (130; 7.4% of cases), respiratory syncytial virus (122; 6.9%), adenoviruses (63; 3.6%), 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 enteroviruses (coxsackie and echovirus) were isolated from patient specimens. Discussion  When compared to the rest of the population, viruses were isolated from a significantly higher percentage of patients age 5 or younger. The prevalence of influenza A virus or influenza B virus infections was similar between the younger and older age groups. RSV was the most commonly detected pathogen in infants age 5 and younger and was significantly associated with pneumonia (p < 0.0001) and hospitalization (p < 0.0001). Conclusion  Genetic analysis of influenza

  15. 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

  16. Global Migration Dynamics Underlie Evolution and Persistence of Human Influenza A (H3N2)

    PubMed Central

    Bedford, Trevor; Cobey, Sarah; Beerli, Peter; Pascual, Mercedes

    2010-01-01

    The global migration patterns of influenza viruses have profound implications for the evolutionary and epidemiological dynamics of the disease. We developed a novel approach to reconstruct the genetic history of human influenza A (H3N2) collected worldwide over 1998 to 2009 and used it to infer the global network of influenza transmission. Consistent with previous models, we find that China and Southeast Asia lie at the center of this global network. However, we also find that strains of influenza circulate outside of Asia for multiple seasons, persisting through dynamic migration between northern and southern regions. The USA acts as the primary hub of temperate transmission and, together with China and Southeast Asia, forms the trunk of influenza's evolutionary tree. These findings suggest that antiviral use outside of China and Southeast Asia may lead to the evolution of long-term local and potentially global antiviral resistance. Our results might also aid the design of surveillance efforts and of vaccines better tailored to different geographic regions. PMID:20523898

  17. 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

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

    PubMed

    Neher, Richard A; Bedford, Trevor

    2015-11-01

    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. Python and Javascript source code is freely available from https://github.com/blab/nextflu, while the web-application is live at http://nextflu.org. tbedford@fredhutch.org. © The Author 2015. Published by Oxford University Press.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. Effect of influenza-induced fever on human bioimpedance values.

    PubMed

    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

    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. 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. 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). 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.

  4. Quantifying influenza virus diversity and transmission in humans.

    PubMed

    Poon, Leo L M; Song, Timothy; Rosenfeld, Roni; Lin, Xudong; Rogers, Matthew B; Zhou, Bin; Sebra, Robert; Halpin, Rebecca A; Guan, Yi; Twaddle, Alan; DePasse, Jay V; Stockwell, Timothy B; Wentworth, David E; Holmes, Edward C; Greenbaum, Benjamin; Peiris, Joseph S M; Cowling, Benjamin J; Ghedin, Elodie

    2016-02-01

    Influenza A virus is characterized by high genetic diversity. However, most of what is known about influenza evolution has come from consensus sequences sampled at the epidemiological scale that only represent the dominant virus lineage within each infected host. Less is known about the extent of within-host virus diversity and what proportion of this diversity is transmitted between individuals. To characterize virus variants that achieve sustainable transmission in new hosts, we examined within-host virus genetic diversity in household donor-recipient pairs from the first wave of the 2009 H1N1 pandemic when seasonal H3N2 was co-circulating. Although the same variants were found in multiple members of the community, the relative frequencies of variants fluctuated, with patterns of genetic variation more similar within than between households. We estimated the effective population size of influenza A virus across donor-recipient pairs to be approximately 100-200 contributing members, which enabled the transmission of multiple lineages, including antigenic variants.

  5. [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.

  6. 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.

  7. 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

  8. 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

  9. 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

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

    PubMed

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

    2015-01-01

    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. 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. 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. NN-DNJ inhibits influenza A virus replication in a strain-specific manner that is dependent on the HA. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

  11. 6SLN-lipo PGA specifically catches (coats) human influenza virus and synergizes neuraminidase-targeting drugs for human influenza therapeutic potential.

    PubMed

    Sriwilaijaroen, Nongluk; Suzuki, Katsuhiko; Takashita, Emi; Hiramatsu, Hiroaki; Kanie, Osamu; Suzuki, Yasuo

    2015-10-01

    The purpose of this study was to develop a new compound to overcome influenza epidemics and pandemics as well as drug resistance. We synthesized a new compound carrying: (i) Neu5Acα2-6Galβ1-4GlcNAc (6SLN) for targeting immutable haemagglutinins (HAs) unless switched from human-type receptor preference; (ii) an acyl chain (lipo) for locking the compound with the viral HA via hydrophobic interactions; and (iii) a flexible poly-α-L-glutamic acid (PGA) for enhancing the compound solubility and for coating the viral surface, precluding accessibility of the PGA-coated virus to the negatively charged sialic acid on the host cell surface. 6SLN-lipo PGA appears to subvert binding of pandemic H1 and seasonal H3 HAs to receptors, as assessed by using guinea pig erythrocytes, which is critical for virus entry into host cells for multiplication. It shows high potency with IC50 values in the range of 300-500 nM against multiplication of both influenza pandemic H1N1/2009 and seasonal H3N2/2004 viruses in cell culture. It acts in synergism with either of the two FDA-approved neuraminidase inhibitor (NAI) clinical drugs, zanamivir (Relenza(®)) and oseltamivir carboxylate (active form of Tamiflu(®)), and it has the potential to aid NAI drugs to achieve complete clearance of the virus from the culture. 6SLN-lipo PGA is a new potential candidate drug for influenza control and is an attractive candidate for use in combination with an NAI drug for minimized toxicity, delayed development of resistance, prevention and treatment with the potential for eradication of human influenza. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. Localization of a Region in the Fusion Protein of Avian Metapneumovirus That Modulates Cell-Cell Fusion

    PubMed Central

    Wei, Yongwei; Feng, Kurtis; Yao, Xiangjie; Cai, Hui; Li, Junan; Mirza, Anne M.; Iorio, Ronald M.

    2012-01-01

    The genus Metapneumovirus within the subfamily Pneumovirinae of the family Paramyxoviridae includes two members, human metapneumovirus (hMPV) and avian metapneumovirus (aMPV), causing respiratory tract infections in humans and birds, respectively. Paramyxoviruses enter host cells by fusing the viral envelope with a host cell membrane. Membrane fusion of hMPV appears to be unique, in that fusion of some hMPV strains requires low pH. Here, we show that the fusion (F) proteins of aMPV promote fusion in the absence of the attachment protein and low pH is not required. Furthermore, there are notable differences in cell-cell fusion among aMPV subtypes. Trypsin was required for cell-cell fusion induced by subtype B but not subtypes A and C. The F protein of aMPV subtype A was highly fusogenic, whereas those from subtypes B and C were not. By construction and evaluation of chimeric F proteins composed of domains from the F proteins of subtypes A and B, we localized a region composed of amino acid residues 170 to 338 in the F protein that is responsible for the hyperfusogenic phenotype of the F from subtype A. Further mutagenesis analysis revealed that residues R295, G297, and K323 in this region collectively contributed to the hyperfusogenicity. Taken together, we have identified a region in the aMPV F protein that modulates the extent of membrane fusion. A model for fusion consistent with these data is presented. PMID:22915815

  13. 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. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  14. [Pulmonary pathology in fatal human influenza A (H1N1) infection].

    PubMed

    Duan, Xue-jing; Li, Yong; Gong, En-cong; Wang, Jue; Lü, Fu-dong; Zhang, He-qiu; Sun, Lin; Yue, Zhu-jun; Song, Chen-chao; Zhang, Shi-Jie; Li, Ning; Dai, Jie

    2011-12-01

    To study the pulmonary pathology in patients died of fatal human influenza A(H1N1) infection. Eight cases of fatal human influenza A (H1N1) infection, including 2 autopsy cases and 6 paramortem needle puncture biopsies, were enrolled into the study. Histologic examination, immunohistochemitry, flow cytometry and Western blotting were carried out. The major pathologic changes included necrotizing bronchiolitis with surrounding inflammation, diffuse alveolar damage and pulmonary hemorrhage. Influenza viral antigen expression was detected in the lung tissue by Western blotting. Immunohistochemical study demonstrated the presence of nuclear protein and hemagglutinin virus antigens in parts of trachea, bronchial epithelium and glands, alveolar epithelium, macrophages and endothelium. Flow cytometry showed that the apoptotic rate of type II pneumocytes (32.15%, 78.15%) was significantly higher than that of the controls (1.93%, 3.77%). Necrotizing bronchiolitis, diffuse alveolar damage and pulmonary hemorrhage followed by pulmonary fibrosis in late stage are the major pathologic changes in fatal human influenza A (H1N1) infection.

  15. Application of three duplex real-time PCR assays for simultaneous detection of human seasonal and avian influenza viruses.

    PubMed

    Stefańska, Ilona; Dzieciatkowski, Tomasz; Brydak, Lidia B; Romanowska, Magdalena

    2013-08-01

    This study was performed to develop real-time PCR (qPCR) for detection of human seasonal and avian influenza viruses in duplex format. First duplex qPCR detects haemagglutinin (HA) gene of influenza virus A(H1N1)pdm09 and HA gene of influenza virus A(H3N2), the second reaction detects neuraminidase (NA) gene of influenza virus A(H3N2) and NA gene of influenza virus A(H1N1)pdm09 and A(H5N1), and the third reaction detects HA gene of influenza A(H5N1) and nonstructural protein gene of influenza B virus. Primers and probes were designed using multiple alignments of target gene sequences of different reference strains. Assays were optimised for identical thermocycling conditions. Their specificity was confirmed by conventional PCR and monoplex qPCR with nucleic acids isolated from different influenza viruses and other respiratory pathogens. Plasmid constructs with a fragment of specific gene were used to assess sensitivity of the assay. The limit of detection ranged from 27 to 96 cDNA copies/reaction. Clinical specimens (n = 107) have been tested using new assays, immunofluorescence and monoplex qRT-PCR. It has been shown that developed assays have been capable of rapid and accurate simultaneous detection and differentiation of influenza viruses. They are more sensitive than immunofluorescence and at least as sensitive as monoplex qRT-PCR.

  16. 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

  17. 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.

  18. 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.

  19. [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.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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.

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

    PubMed Central

    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. PMID:20663475

  6. Structure and Receptor Binding of the Hemagglutinin from a Human H6N1 Influenza Virus

    DOE PAGES

    Tzarum, Netanel; de Vries, Robert P.; Zhu, Xueyong; ...

    2015-03-11

    Avian influenza viruses that cause infection and are transmissible in humans involve changes in the receptor binding site (RBS) of the viral hemagglutinin (HA) that alter receptor preference from α2-3-linked (avian-like) to α2-6-linked (human-like) sialosides. A human case of avian-origin H6N1 influenza virus was recently reported, but the molecular mechanisms contributing to it crossing the species barrier are unknown. We find that, although the H6 HA RBS contains D190V and G228S substitutions that potentially promote human receptor binding, recombinant H6 HA preferentially binds α2-3-linked sialosides, indicating no adaptation to human receptors. Crystal structures of H6 HA with avian and humanmore » receptor analogs reveal that H6 HA preferentially interacts with avian receptor analogs. Lastly, this binding mechanism differs from other HA subtypes due to a unique combination of RBS residues, highlighting additional variation in HA-receptor interactions and the challenges in predicting which influenza strains and subtypes can infect humans and cause pandemics.« less

  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. 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.

  10. 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.

  11. 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

  12. The aminobisphosphonate pamidronate controls influenza pathogenesis by expanding a γδ T cell population in humanized mice

    PubMed Central

    Zheng, Jian; Liu, Yinping; Sia, Sin Fun; Liu, Ming; Qin, Gang; Xiang, Zheng; Lam, Kwok-Tai

    2011-01-01

    There are few antiviral drugs for treating influenza, and the emergence of antiviral resistance has further limited the available therapeutic options. Furthermore, antivirals are not invariably effective in severe influenza, such as that caused by H5N1 viruses. Thus, there is an urgent need to develop alternative therapeutic strategies. Here, we show that human Vγ9Vδ2 T cells expanded by the aminobisphosphonate pamidronate (PAM) kill influenza virus–infected cells and inhibit viral replication in vitro. In Rag2−/−γc−/− immunodeficient mice reconstituted with human peripheral mononuclear cells (huPBMCs), PAM reduces disease severity and mortality caused by human seasonal H1N1 and avian H5N1 influenza virus, and controls the lung inflammation and viral replication. PAM has no such effects in influenza virus–infected Rag2−/−γc−/− mice reconstituted with Vγ9Vδ2 T cell–depleted huPBMCs. Our study provides proof-of-concept of a novel therapeutic strategy for treating influenza by targeting the host rather than the virus, thereby reducing the opportunity for the emergence of drug-resistant viruses. As PAM has been commonly used to treat osteoporosis and Paget’s disease, this new application of an old drug potentially offers a safe and readily available option for treating influenza. PMID:21708931

  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. Published sequences do not support transfer of oseltamivir resistance mutations from avian to human influenza A virus strains.

    PubMed

    Norberg, Peter; Lindh, Magnus; Olofsson, Sigvard

    2015-03-28

    Tamiflu (oseltamivir phosphate ester, OE) is a widely used antiviral active against influenza A virus. Its active metabolite, oseltamivir carboxylate (OC), is chemically stable and secreted into wastewater treatment plants. OC contamination of natural habitats of waterfowl might induce OC resistance in influenza viruses persistently infecting waterfowl, and lead to transfer of OC-resistance from avian to human influenza. The aim of this study was to evaluate whether such has occurred. A genomics approach including phylogenetic analysis and probability calculations for homologous recombination was applied on altogether 19,755 neuraminidase (N1 and N2) genes from virus sampled in humans and birds, with and without resistance mutations. No evidence for transfer of OE resistance mutations from avian to human N genes was obtained, and events suggesting recombination between human and avian influenza virus variants could not be traced in the sequence material studied. The results indicate that resistance in influenza viruses infecting humans is due to the selection pressure posed by the global OE administration in humans rather than transfer from avian influenza A virus strains carrying mutations induced by environmental exposure to OC.

  15. 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.

  16. The frequency and seasonality of influenza and other respiratory viruses in Tennessee: two influenza seasons of surveillance data, 2010-2012.

    PubMed

    Landes, Michelle B; Neil, R Brock; McCool, Susan S; Mason, Bryan P; Woron, Amy M; Garman, Robb L; Smalley, David L

    2013-11-01

    In 2010, the Tennessee Department of Health, in collaboration with the Centers for Disease Control and Prevention (CDC), expanded influenza surveillance in Tennessee to include other respiratory viruses. To determine the prevalence and seasonality of influenza and other respiratory viruses during the influenza seasons of 2010-2012. Nasal and nasopharangeal swabs/washings from persons with influenza-like illness were collected across Tennessee. Influenza and other respiratory viruses were identified using a molecular-based respiratory virus panel. Influenza A positives were subtyped using real-time PCR according to the CDC protocol. Data were analyzed to describe frequency and seasonality of circulating strains. Of the 933 positive specimens, 60·3% were identified as influenza viruses, 19·8% rhinovirus/enterovirus, 8·6% respiratory syncytial virus (RSV), 5·8% metapneumovirus, 3·0% adenovirus, and 2·5% parainfluenza viruses. In the 2010-2011 season, influenza B was prominent during weeks 48-3, while influenza A(H1N1) was most frequently identified during weeks 4-10. Influenza A(H3N2) was present at lower levels during weeks 48-17. However, in the 2011-2012 season, overall numbers of influenza cases were reduced and influenza A (H3N2) was the most abundant influenza strain. The expanded surveillance for other respiratory viruses noted an increase in identified specimens from the first to the second season for adenovirus, metapneumovirus, RSV, and rhinovirus/enterovirus. This study provides data of the influenza strains in circulation in Tennessee. It also establishes a baseline and time of year to expect other respiratory viruses that will aid in detecting outbreaks of non-influenza respiratory viruses in Tennessee. © 2013 John Wiley & Sons Ltd.

  17. Human Alveolar Macrophages May Not Be Susceptible to Direct Infection by a Human Influenza Virus.

    PubMed

    Ettensohn, David B; Frampton, Mark W; Nichols, Joan E; Roberts, Norbert J

    2016-12-01

    The current studies were undertaken to determine the susceptibility of human alveolar macrophages (AMs) to influenza A virus (IAV) infection in comparison with autologous peripheral blood-derived monocytes-macrophages (PBMs). AMs and PBMs were exposed to IAV in vitro and examined for their ability to bind and internalize IAV, and synthesize viral proteins and RNA. PBMs but not AMs demonstrated binding and internalization of the virus, synthesizing viral proteins and RNA. Exposure of AMs in the presence of a sialidase inhibitor or anti-IAV antibody resulted in viral protein synthesis by the cells. Exposure of AMs to fluorescein isothiocyanate-labeled IAV in the presence of anti-fluorescein isothiocyanate antibody also resulted in viral protein synthesis. Thus, human AMs are apparently not susceptible to direct infection by a human IAV but are likely to be infected indirectly in the setting of exposure in the presence of antibody that binds the challenging strain of IAV. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  18. Estimating the Lineage Dynamics of Human Influenza B Viruses

    PubMed Central

    Tessmer, Heidi L.; Arimura, Hiroki; Ito, Kimihito

    2016-01-01

    The prediction of the lineage dynamics of influenza B viruses for the next season is one of the largest obstacles for constructing an appropriate influenza trivalent vaccine. Seasonal fluctuation of transmissibility and epidemiological interference between the two major influenza B lineages make the lineage dynamics complicated. Here we construct a parsimonious model describing the lineage dynamics while taking into account seasonal fluctuation of transmissibility and epidemiological interference. Using this model we estimated the epidemiological and evolutional parameters with the time-series data of the lineage specific isolates in Japan from the 2010–2011 season to the 2014–2015 season. The basic reproduction number is similar between Victoria and Yamagata, with a minimum value during one year as 0.82 (95% highest posterior density (HPD): 0.77–0.87) for the Yamagata and 0.83 (95% HPD: 0.74–0.92) for Victoria, the amplitude of seasonal variation of the basic reproduction number is 0.77 (95% HPD:0.66–0.87) for Yamagata and 1.05 (95% HPD: 0.89–1.02) for Victoria. The duration for which the acquired immunity is effective against infection by the Yamagata lineage is shorter than the acquired immunity for Victoria, 424.1days (95% HPD:317.4–561.5days). The reduction rate of susceptibility due to immune cross-reaction is 0.51 (95% HPD: 0.084–0.92) for the immunity obtained from the infection with Yamagata against the infection with Victoria and 0.62 (95% HPD: 0.42–0.80) for the immunity obtained from the infection with Victoria against the infection with Yamagata. Using estimated parameters, we predicted the dominant lineage in 2015–2016 season. The accuracy of this prediction is 68.8% if the emergence timings of the two lineages are known and 61.4% if the emergence timings are unknown. Estimated seasonal variation of the lineage specific reproduction number can narrow down the range of emergence timing, with an accuracy of 64.6% if the emergence

  19. Estimating the Lineage Dynamics of Human Influenza B Viruses.

    PubMed

    Nyirenda, Mayumbo; Omori, Ryosuke; Tessmer, Heidi L; Arimura, Hiroki; Ito, Kimihito

    2016-01-01

    The prediction of the lineage dynamics of influenza B viruses for the next season is one of the largest obstacles for constructing an appropriate influenza trivalent vaccine. Seasonal fluctuation of transmissibility and epidemiological interference between the two major influenza B lineages make the lineage dynamics complicated. Here we construct a parsimonious model describing the lineage dynamics while taking into account seasonal fluctuation of transmissibility and epidemiological interference. Using this model we estimated the epidemiological and evolutional parameters with the time-series data of the lineage specific isolates in Japan from the 2010-2011 season to the 2014-2015 season. The basic reproduction number is similar between Victoria and Yamagata, with a minimum value during one year as 0.82 (95% highest posterior density (HPD): 0.77-0.87) for the Yamagata and 0.83 (95% HPD: 0.74-0.92) for Victoria, the amplitude of seasonal variation of the basic reproduction number is 0.77 (95% HPD:0.66-0.87) for Yamagata and 1.05 (95% HPD: 0.89-1.02) for Victoria. The duration for which the acquired immunity is effective against infection by the Yamagata lineage is shorter than the acquired immunity for Victoria, 424.1days (95% HPD:317.4-561.5days). The reduction rate of susceptibility due to immune cross-reaction is 0.51 (95% HPD: 0.084-0.92) for the immunity obtained from the infection with Yamagata against the infection with Victoria and 0.62 (95% HPD: 0.42-0.80) for the immunity obtained from the infection with Victoria against the infection with Yamagata. Using estimated parameters, we predicted the dominant lineage in 2015-2016 season. The accuracy of this prediction is 68.8% if the emergence timings of the two lineages are known and 61.4% if the emergence timings are unknown. Estimated seasonal variation of the lineage specific reproduction number can narrow down the range of emergence timing, with an accuracy of 64.6% if the emergence times are assumed to be

  20. 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

  1. [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.

  2. 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.

  3. 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.

  4. Contemporary North American influenza H7 viruses possess human receptor specificity: Implications for virus transmissibility.

    PubMed

    Belser, Jessica A; Blixt, Ola; Chen, Li-Mei; Pappas, Claudia; Maines, Taronna R; Van Hoeven, Neal; Donis, Ruben; Busch, Julia; McBride, Ryan; Paulson, James C; Katz, Jacqueline M; Tumpey, Terrence M

    2008-05-27

    Avian H7 influenza viruses from both the Eurasian and North American lineage have caused outbreaks in poultry since 2002, with confirmed human infection occurring during outbreaks in The Netherlands, British Columbia, and the United Kingdom. The majority of H7 infections have resulted in self-limiting conjunctivitis, whereas probable human-to-human transmission has been rare. Here, we used glycan microarray technology to determine the receptor-binding preference of Eurasian and North American lineage H7 influenza viruses and their transmissibility in the ferret model. We found that highly pathogenic H7N7 viruses from The Netherlands in 2003 maintained the classic avian-binding preference for alpha2-3-linked sialic acids (SA) and are not readily transmissible in ferrets, as observed previously for highly pathogenic H5N1 viruses. However, H7N3 viruses isolated from Canada in 2004 and H7N2 viruses from the northeastern United States isolated in 2002-2003 possessed an HA with increased affinity toward alpha2-6-linked SA, the linkage type found prominently on human tracheal epithelial cells. We identified a low pathogenic H7N2 virus isolated from a man in New York in 2003, A/NY/107/03, which replicated efficiently in the upper respiratory tract of ferrets and was capable of transmission in this species by direct contact. These results indicate that H7 influenza viruses from the North American lineage have acquired sialic acid-binding properties that more closely resemble those of human influenza viruses and have the potential to spread to naïve animals.

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

    PubMed Central

    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

    2013-01-01

    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. PMID:26038484

  6. 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.

  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

    ... Isolated From Human Cells for Vaccine and Therapeutic Evaluation and Development (U01) AGENCY: Food and... processed and presented on soluble HLA (human leucocyte antigen) expressed by human cells. Initial studies... produced from influenza infected human lung cell lines. There is a growing interest in developing universal...

  8. 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

  9. 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

  10. 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.

  11. The C-Terminal Tail of TRIM56 Dictates Antiviral Restriction of Influenza A and B Viruses by Impeding Viral RNA Synthesis

    PubMed Central

    Liu, Baoming; Li, Nan L.; Shen, Yang; Bao, Xiaoyong; Elbahesh, Husni; Webby, Richard J.

    2016-01-01

    ABSTRACT Accumulating data suggest that tripartite-motif-containing (TRIM) proteins participate in host responses to viral infections, either by acting as direct antiviral restriction factors or through regulating innate immune signaling of the host. Of >70 TRIMs, TRIM56 is a restriction factor of several positive-strand RNA viruses, including three members of the family Flaviviridae (yellow fever virus, dengue virus, and bovine viral diarrhea virus) and a human coronavirus (OC43), and this ability invariably depends upon the E3 ligase activity of TRIM56. However, the impact of TRIM56 on negative-strand RNA viruses remains unclear. Here, we show that TRIM56 puts a check on replication of influenza A and B viruses in cell culture but does not inhibit Sendai virus or human metapneumovirus, two paramyxoviruses. Interestingly, the anti-influenza virus activity was independent of the E3 ligase activity, B-box, or coiled-coil domain. Rather, deletion of a 63-residue-long C-terminal-tail portion of TRIM56 abrogated the antiviral function. Moreover, expression of this short C-terminal segment curtailed the replication of influenza viruses as effectively as that of full-length TRIM56. Mechanistically, TRIM56 was found to specifically impede intracellular influenza virus RNA synthesis. Together, these data reveal a novel antiviral activity of TRIM56 against influenza A and B viruses and provide insights into the mechanism by which TRIM56 restricts these medically important orthomyxoviruses. IMPORTANCE Options to treat influenza are limited, and drug-resistant influenza virus strains can emerge through minor genetic changes. Understanding novel virus-host interactions that alter influenza virus fitness may reveal new targets/approaches for therapeutic interventions. We show here that TRIM56, a tripartite-motif protein, is an intrinsic host restriction factor of influenza A and B viruses. Unlike its antiviral actions against positive-strand RNA viruses, the anti-influenza

  12. Differential Susceptibilities of Human Lung Primary Cells to H1N1 Influenza Viruses

    PubMed Central

    Travanty, Emily; Zhou, Bin; Zhang, Hongbo; Di, Y. Peter; Alcorn, John F.; Wentworth, David E.; Mason, Robert

    2015-01-01

    ABSTRACT Human alveolar epithelial cells (AECs) and alveolar macrophages (AMs) are the first lines of lung defense. Here, we report that AECs are the direct targets for H1N1 viruses that have circulated since the 2009 pandemic (H1N1pdm09). AMs are less susceptible to H1N1pdm09 virus, but they produce significantly more inflammatory cytokines than AECs from the same donor. AECs form an intact epithelial barrier that is destroyed by H1N1pdm09 infection. However, there is significant variation in the cellular permissiveness to H1N1pdm09 infection among different donors. AECs from obese donors appear to be more susceptible to H1N1pdm09 infection, whereas gender, smoking history, and age do not appear to affect AEC susceptibility. There is also a difference in response to different strains of H1N1pdm09 viruses. Compared to A/California04/09 (CA04), A/New York/1682/09 (NY1682) is more infectious and causes more epithelial barrier injury, although it stimulates less cytokine production. We further determined that a single amino acid residue substitution in NY1682 hemagglutinin is responsible for the difference in infectivity. In conclusion, this is the first study of host susceptibility of human lung primary cells and the integrity of the alveolar epithelial barrier to influenza. Further elucidation of the mechanism of increased susceptibility of AECs from obese subjects may facilitate the development of novel protection strategies against influenza virus infection. IMPORTANCE Disease susceptibility of influenza is determined by host and viral factors. Human alveolar epithelial cells (AECs) form the key line of lung defenses against pathogens. Using primary AECs from different donors, we provided cellular level evidence that obesity might be a risk factor for increased susceptibility to influenza. We also compared the infections of two closely related 2009 pandemic H1N1 strains in AECs from the same donor and identified a key viral factor that affected host susceptibility

  13. 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.

  14. Triple-reassortant swine influenza A (H1) in humans in the United States, 2005-2009.

    PubMed

    Shinde, Vivek; Bridges, Carolyn B; Uyeki, Timothy M; Shu, Bo; Balish, Amanda; Xu, Xiyan; Lindstrom, Stephen; Gubareva, Larisa V; Deyde, Varough; Garten, Rebecca J; Harris, Meghan; Gerber, Susan; Vagasky, Susan; Smith, Forrest; Pascoe, Neal; Martin, Karen; Dufficy, Deborah; Ritger, Kathy; Conover, Craig; Quinlisk, Patricia; Klimov, Alexander; Bresee, Joseph S; Finelli, Lyn

    2009-06-18

    Triple-reassortant swine influenza A (H1) viruses--containing genes from avian, human, and swine influenza viruses--emerged and became enzootic among pig herds in North America during the late 1990s. We report the clinical features of the first 11 sporadic cases of infection of humans with triple-reassortant swine influenza A (H1) viruses reported to the Centers for Disease Control and Prevention, occurring from December 2005 through February 2009, until just before the current epidemic of swine-origin influenza A (H1N1) among humans. These data were obtained from routine national influenza surveillance reports and from joint case investigations by public and animal health agencies. The median age of the 11 patients was 10 years (range, 16 months to 48 years), and 4 had underlying health conditions. Nine of the patients had had exposure to pigs, five through direct contact and four through visits to a location where pigs were present but without contact. In another patient, human-to-human transmission was suspected. The range of the incubation period, from the last known exposure to the onset of symptoms, was 3 to 9 days. Among the 10 patients with known clinical symptoms, symptoms included fever (in 90%), cough (in 100%), headache (in 60%), and diarrhea (in 30%). Complete blood counts were available for four patients, revealing leukopenia in two, lymphopenia in one, and thrombocytopenia in another. Four patients were hospitalized, two of whom underwent invasive mechanical ventilation. Four patients received oseltamivir, and all 11 recovered from their illness. From December 2005 until just before the current human epidemic of swine-origin influenza viruses, there was sporadic infection with triple-reassortant swine influenza A (H1) viruses in persons with exposure to pigs in the United States. Although all the patients recovered, severe illness of the lower respiratory tract and unusual influenza signs such as diarrhea were observed in some patients, including

  15. 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

  16. 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.

  17. 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

  18. A comparison of clinical and epidemiological characteristics of fatal human infections with H5N1 and human influenza viruses in Thailand, 2004-2006.

    PubMed

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

    2011-04-29

    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. 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). 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 both would benefit from early antiviral

  19. Characterization of a human H9N2 influenza virus isolated in Hong Kong.

    PubMed

    Saito, T; Lim, W; Suzuki, T; Suzuki, Y; Kida, H; Nishimura, S I; Tashiro, M

    2001-10-12

    Two H9N2 viruses were isolated, for the first time, from humans in Hong Kong in 1999. Isolation of influenza viruses with a novel subtype of the hemagglutinin (HA) drew attention of health care authorities worldwide from the view of pandemic preparedness. Sequence analysis of the HA genes reveals that HA of A/Hong Kong/1073/99 (H9N2) is most closely related to that of A/quail/HK/G1/97 (H9N2) that contains the internal genes similar to those of Hong Kong/97 (H5N1) viruses. Phylogenetic and antigenic analyses demonstrated the diversity among H9 HA. A/Hong Kong/1073/99 was shown to cause a respiratory infection in Syrian hamsters, suggesting that the virus can replicate efficiently in mammalian hosts. We developed a whole virion test vaccine with a formalin-inactivated egg-grown HK1073. Intraperitoneal administration of the vaccine twice to hamsters conferred a complete protection against challenge infection by the MDCK cell-grown homologous virus. Receptor specificity of HK1073 appeared different from that of other avian influenza viruses of H9 subtype which recognize preferentially alpha-2,3 linked sialic acid. Hemagglutination of HK1073 with guinea pig erythrocytes was inhibited by both alpha-2,3 and alpha-2,6 linked sialic acid containing polymers. These data suggested that HK1073 had acquired a broader host range, including humans. Together with data so far available, the present study suggested that isolation of the H9 influenza viruses from humans requires precaution against the emergence of a novel human influenza.

  20. Testing human sera for antibodies against avian influenza viruses: horse RBC hemagglutination inhibition vs. microneutralization assays.

    PubMed

    Kayali, Ghazi; Setterquist, Sharon F; Capuano, Ana W; Myers, Kendall P; Gill, James S; Gray, Gregory C

    2008-09-01

    The hemagglutination inhibition (HI) assay is a frequently used method to screen human sera for antibodies against influenza A viruses. Because HI has relatively poor sensitivity in detecting antibodies against avian influenza A strains, a more complicated microneutralization (MN) assay is often preferred. Recent research suggests that the sensitivity of the HI assay can be improved by switching from the traditionally used turkey, guinea pig, human, or chicken RBCs to horse RBCs. To evaluate the performance of the horse RBC HI when screening for human antibodies against avian influenza types H3, H4, H5, H6, H7, H9, H11, and H12. We evaluated the reproducibility of horse RBC HI and its agreement with MN results using sera from people exposed or not exposed to wild and domestic birds. The horse RBC HI assay had high reliability (90%-100%) and good agreement with MN assay results (52%-100%). The horse RBC HI assay is reliable, less expensive, less complex, and faster than the MN assay. While MN will likely remain the gold standard serologic assay for avian viruses, the horse RBC HI assay may be very useful as a screening assay in large-scale epidemiologic studies.

  1. Adaptation of influenza A (H7N9) virus in primary human airway epithelial cells.

    PubMed

    Huang, Daniel Tsung-Ning; Lu, Chun-Yi; Chi, Ya-Hui; Li, Wan-Ling; Chang, Luan-Yin; Lai, Mei-Ju; Chen, Jin-Shing; Hsu, Wen-Ming; Huang, Li-Min

    2017-09-12

    Influenza A (H7N9) is an emerging zoonotic pathogen with pandemic potential. To understand its adaptation capability, we examined the genetic changes and cellular responses following serial infections of A (H7N9) in primary human airway epithelial cells (hAECs). After 35 serial passages, six amino acid mutations were found, i.e. HA (R54G, T160A, Q226L, H3 numbering), NA (K289R, or K292R for N2 numbering), NP (V363V/I) and PB2 (L/R332R). The mutations in HA enabled A(H7N9) virus to bind with higher affinity (from 39.2% to 53.4%) to sialic acid α2,6-galactose (SAα2,6-Gal) linked receptors. A greater production of proinflammatory cytokines in hAECs was elicited at later passages together with earlier peaking at 24 hours post infection of IL-6, MIP-1α, and MCP-1 levels. Viral replication capacity in hAECs maintained at similar levels throughout the 35 passages. In conclusion, during the serial infections of hAECs by influenza A(H7N9) virus, enhanced binding of virion to cell receptors with subsequent stronger innate cell response were noted, but no enhancement of viral replication could be observed. This indicates the existence of possible evolutional hurdle for influenza A(H7N9) virus to transmit efficiently from human to human.

  2. 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. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Human genomic diversity, viral genomics and proteomics, as exemplified by human papillomaviruses and H5N1 influenza viruses

    PubMed Central

    2009-01-01

    The diversity of hosts, pathogens and host-pathogen relationships reflects the influence of selective pressures that fuel diversity through ongoing interactions with other rapidly evolving molecules in the environment. This paper discusses specific examples illustrating the phenomenon of diversity of hosts and pathogens, with special reference to human papillomaviruses and H5NI influenza viruses. We also review the influence of diverse host-pathogen interactions that determine the pathophysiology of infections, and their responses to drugs or vaccines. PMID:19706363

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

    PubMed

    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

    2011-08-23

    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.

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. Swine-to-Human Transmission of Influenza A(H3N2) Virus at Agricultural Fairs, Ohio, USA, 2012

    PubMed Central

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

    2014-01-01

    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. PMID:25148572

  20. 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.

  1. 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

  2. Detection and typing of human-infecting influenza viruses in China by using a multiplex DNA biochip assay.

    PubMed

    Wang, Yongqiang; Qu, Jiuxin; Ba, Qi; Dong, Jiuhong; Zhang, Liang; Zhang, Hong; Wu, Aiping; Wang, Dayan; Xia, Zanxian; Peng, Daxin; Shu, Yuelong; Cao, Bin; Jiang, Taijiao

    2016-08-01

    Rapid identification of the infections of specific subtypes of influenza viruses is critical for patient treatment and pandemic control. Here we report the application of multiplex reverse transcription polymerase chain reaction (RT-PCR) coupled with membrane-based DNA biochip to the detection and discrimination of the type (A and B) and subtype (human H1N1, human H3N2, avian H5N1 and avian H7N9) of influenza viruses in circulation in China. A multiplex one-step RT-PCR assay was designed to simultaneously amplify the HA and NA genes of the four subtypes of influenza A viruses and NS genes to discriminate type A and B viruses. PCR products were analyzed by a membrane-based biochip. The analytical sensitivity of the assay was determined at a range of 2-100 copies/reactions for each of the gene transcripts. Eighty one clinical samples, containing 66 positive samples with evident seasonal influenza virus infections, were tested, which gives the clinical sensitivity and specificity of 95.5% and 100% respectively. For the avian influenza samples, 3 out of 4 H5N1 samples and 2 out of 2 H7N9 avian samples were correctly identified. We argue this method could allow a rapid, reliable and inexpensive detection and differentiation of human-infecting influenza viruses. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. 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.

  4. 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.

  5. Comparison of Different Cell Substrates on the Measurement of Human Influenza Virus Neutralizing Antibodies

    PubMed Central

    Zhai, Weiguo; Zhang, Dan Ning; Mai, Cecilia; Choy, Justin; Jian, Gary; Sra, Kuldip; Galinski, Mark S

    2012-01-01

    Eight cell lines were systematically compared for their permissivity to primary infection, replication, and spread of seven human influenza viruses. Cell lines were of human origin (Caco-2, A549, HEp-2, and NCI-H292), monkey (Vero, LLC-MK2), mink (Mv1 Lu), and canine (MDCK). The influenza viruses included seasonal types and subtypes and a pandemic virus. The MDCK, Caco-2, and Mv1 Lu cells were subsequently compared for their capacity to report neutralization titers at day one, three and six post-infection. A gradient of sensitivity to primary infection across the eight cell lines was observed. Relative to MDCK cells, Mv1 Lu reported higher titers and the remaining six cell lines reported lower titers. The replication and spread of the seven influenza viruses in the eight cell substrates was determined using hemagglutinin expression, cytopathic effect, and neuraminidase activity. Virus growth was generally concordant with primary infection, with a gradient in virus replication and spread. However, Mv1 Lu cells poorly supported virus growth, despite a higher sensitivity to primary infection. Comparison of MDCK, Caco-2, and Mv1 Lu in neutralization assays using defined animal antiserum confirmed MDCK cells as the preferred cell substrate for influenza virus testing. The results observed for neutralization at one day post-infection showed MDCK cells were similar (<1 log2 lower) or superior (>1 log2 higher) for all seven viruses. Relative to Caco-2 and Mv1 Lu cells, MDCK generally reported the highest titers at three and six days post-infection for the type A viruses and lower titers for the type B viruses and the pandemic H9N2 virus. The reduction in B virus titer was attributed to the complete growth of type B viruses in MDCK cells before day three post-infection, resulting in the systematic underestimation of neutralization titers. This phenomenon was also observed with Caco-2 cells. PMID:23284988

  6. Emergence of a novel swine-origin influenza A (H1N1) virus in humans.

    PubMed

    Dawood, Fatimah S; Jain, Seema; Finelli, Lyn; Shaw, Michael W; Lindstrom, Stephen; Garten, Rebecca J; Gubareva, Larisa V; Xu, Xiyan; Bridges, Carolyn B; Uyeki, Timothy M

    2009-06-18

    On April 15 and April 17, 2009, novel swine-origin influenza A (H1N1) virus (S-OIV) was identified in specimens obtained from two epidemiologically unlinked patients in the United States. The same strain of the virus was identified in Mexico, Canada, and elsewhere. We describe 642 confirmed cases of human S-OIV infection identified from the rapidly evolving U.S. outbreak. Enhanced surveillance was implemented in the United States for human infection with influenza A viruses that could not be subtyped. Specimens were sent to the Centers for Disease Control and Prevention for real-time reverse-transcriptase-polymerase-chain-reaction confirmatory testing for S-OIV. From April 15 through May 5, a total of 642 confirmed cases of S-OIV infection were identified in 41 states. The ages of patients ranged from 3 months to 81 years; 60% of patients were 18 years of age or younger. Of patients with available data, 18% had recently traveled to Mexico, and 16% were identified from school outbreaks of S-OIV infection. The most common presenting symptoms were fever (94% of patients), cough (92%), and sore throat (66%); 25% of patients had diarrhea, and 25% had vomiting. Of the 399 patients for whom hospitalization status was known, 36 (9%) required hospitalization. Of 22 hospitalized patients with available data, 12 had characteristics that conferred an increased risk of severe seasonal influenza, 11 had pneumonia, 8 required admission to an intensive care unit, 4 had respiratory failure, and 2 died. The S-OIV was determined to have a unique genome composition that had not been identified previously. A novel swine-origin influenza A virus was identified as the cause of outbreaks of febrile respiratory infection ranging from self-limited to severe illness. It is likely that the number of confirmed cases underestimates the number of cases that have occurred. 2009 Massachusetts Medical Society

  7. 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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. 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

  9. The 150-Loop Restricts the Host Specificity of Human H10N8 Influenza Virus.

    PubMed

    Tzarum, Netanel; de Vries, Robert P; Peng, Wenjie; Thompson, Andrew J; Bouwman, Kim M; McBride, Ryan; Yu, Wenli; Zhu, Xueyong; Verheije, Monique H; Paulson, James C; Wilson, Ian A

    2017-04-11

    Adaptation of influenza A viruses to new hosts are rare events but are the basis for emergence of new influenza pandemics in the human population. Thus, understanding the processes involved in such events is critical for anticipating potential pandemic threats. In 2013, the first case of human infection by an avian H10N8 virus was reported, yet the H10 hemagglutinin (HA) maintains avian receptor specificity. However, the 150-loop of H10 HA, as well as related H7 and H15 subtypes, contains a two-residue insert that can potentially block human receptor binding. Mutation of the 150-loop on the background of Q226L and G228S mutations, which arose in the receptor-binding site of human pandemic H2 and H3 viruses, resulted in acquisition of human-type receptor specificity. Crystal structures of H10 HA mutants with human and avian receptor analogs, receptor-binding studies, and tissue staining experiments illustrate the important role of the 150-loop in H10 receptor specificity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. 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

  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. The evolution of human influenza A viruses from 1999 to 2006: A complete genome study

    PubMed Central

    Bragstad, Karoline; Nielsen, Lars P; Fomsgaard, Anders

    2008-01-01

    Background Knowledge about the complete genome constellation of seasonal influenza A viruses from different countries is valuable for monitoring and understanding of the evolution and migration of strains. Few complete genome sequences of influenza A viruses from Europe are publicly available at the present time and there have been few longitudinal genome studies of human influenza A viruses. We have studied the evolution of circulating human H3N2, H1N1 and H1N2 influenza A viruses from 1999 to 2006, we analysed 234 Danish human influenza A viruses and characterised 24 complete genomes. Results H3N2 was the prevalent strain in Denmark during the study period, but H1N1 dominated the 2000–2001 season. H1N2 viruses were first observed in Denmark in 2002–2003. After years of little genetic change in the H1N1 viruses the 2005–2006 season presented H1N1 of greater variability than before. This indicates that H1N1 viruses are evolving and that H1N1 soon is likely to be the prevalent strain again. Generally, the influenza A haemagglutinin (HA) of H3N2 viruses formed seasonal phylogenetic clusters. Different lineages co-circulating within the same season were also observed. The evolution has been stochastic, influenced by small "jumps" in genetic distance rather than constant drift, especially with the introduction of the Fujian-like viruses in 2002–2003. Also evolutionary stasis-periods were observed which might indicate well fit viruses. The evolution of H3N2 viruses have also been influenced by gene reassortments between lineages from different seasons. None of the influenza genes were influenced by strong positive selection pressure. The antigenic site B in H3N2 HA was the preferred site for genetic change during the study period probably because the site A has been masked by glycosylations. Substitutions at CTL-epitopes in the genes coding for the neuraminidase (NA), polymerase acidic protein (PA), matrix protein 1 (M1), non-structural protein 1 (NS1) and

  13. 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

  14. 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

  15. 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

    2017-07-01

    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.

  16. The Role of Influenza and Parainfluenza Infections in Nasopharyngeal Pneumococcal Acquisition Among Young Children

    PubMed Central

    Grijalva, Carlos G.; Griffin, Marie R.; Edwards, Kathryn M.; Williams, John V.; Gil, Ana I.; Verastegui, Hector; Hartinger, Stella M.; Vidal, Jorge E.; Klugman, Keith P.; Lanata, Claudio F.

    2014-01-01

    Background. Animal models suggest that influenza infection favors nasopharyngeal acquisition of pneumococci. We assessed this relationship with influenza and other respiratory viruses in young children. Methods. A case-control study was nested within a prospective cohort study of acute respiratory illness (ARI) in Andean children <3 years of age (RESPIRA-PERU study). Weekly household visits were made to identify ARI and obtain nasal swabs for viral detection using real-time reverse-transcription polymerase chain reaction. Monthly nasopharyngeal (NP) samples were obtained to assess pneumococcal colonization. We determined whether specific respiratory viral ARI episodes occurring within the interval between NP samples increased the risk of NP acquisition of new pneumococcal serotypes. Results. A total of 729 children contributed 2128 episodes of observation, including 681 pneumococcal acquisition episodes (new serotype, not detected in prior sample), 1029 nonacquisition episodes (no colonization or persistent colonization with the same serotype as the prior sample), and 418 indeterminate episodes. The risk of pneumococcal acquisition increased following influenza-ARI (adjusted odds ratio [AOR], 2.19; 95% confidence interval [CI], 1.02–4.69) and parainfluenza-ARI (AOR, 1.86; 95% CI, 1.15–3.01), when compared with episodes without ARI. Other viral infections (respiratory syncytial virus, human metapneumovirus, human rhinovirus, and adenovirus) were not associated with acquisition. Conclusions. Influenza and parainfluenza ARIs appeared to facilitate pneumococcal acquisition among young children. As acquisition increases the risk of pneumococcal diseases, these observations are pivotal in our attempts to prevent pneumococcal disease. PMID:24621951

  17. 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.

  18. Kallikrein-Related Peptidase 5 Contributes to H3N2 Influenza Virus Infection in Human Lungs.

    PubMed

    Magnen, Mélia; Gueugnon, Fabien; Guillon, Antoine; Baranek, Thomas; Thibault, Virginie C; Petit-Courty, Agnès; de Veer, Simon J; Harris, Jonathan; Humbles, Alison A; Si-Tahar, Mustapha; Courty, Yves

    2017-08-15

    Hemagglutinin (HA) of influenza virus must be activated by proteolysis before the virus can become infectious. Previous studies indicated that HA cleavage is driven by membrane-bound or extracellular serine proteases in the respiratory tract. However, there is still uncertainty as to which proteases are critical for activating HAs of seasonal influenza A viruses (IAVs) in humans. This study focuses on human KLK1 and KLK5, 2 of the 15 serine proteases known as the kallikrein-related peptidases (KLKs). We find that their mRNA expression in primary human bronchial cells is stimulated by IAV infection. Both enzymes cleaved recombinant HA from several strains of the H1 and/or H3 virus subtype in vitro, but only KLK5 promoted the infectivity of A/Puerto Rico/8/34 (H1N1) and A/Scotland/20/74 (H3N2) virions in MDCK cells. We assessed the ability of treated viruses to initiate influenza in mice. The nasal instillation of only the KLK5-treated virus resulted in weight loss and lethal outcomes. The secretion of this protease in the human lower respiratory tract is enhanced during influenza. Moreover, we show that pretreatment of airway secretions with a KLK5-selective inhibitor significantly reduced the activation of influenza A/Scotland/20/74 virions, providing further evidence of its importance. Differently, increased KLK1 secretion appeared to be associated with the recruitment of inflammatory cells in human airways regardless of the origin of inflammation. Thus, our findings point to the involvement of KLK5 in the proteolytic activation and spread of seasonal influenza viruses in humans.IMPORTANCE Influenza A viruses (IAVs) cause acute infection of the respiratory tract that affects millions of people during seasonal outbreaks every year. Cleavage of the hemagglutinin precursor by host proteases is a critical step in the life cycle of these viruses. Consequently, host proteases that activate HA can be considered promising targets for the development of new antivirals

  19. Comparative Analysis of Avian Influenza Virus Diversity in Poultry and Humans during a Highly Pathogenic Avian Influenza A (H7N7) Virus Outbreak ▿ †

    PubMed Central

    Jonges, Marcel; Bataille, Arnaud; Enserink, Remko; Meijer, Adam; Fouchier, Ron A. M.; Stegeman, Arjan; Koch, Guus; Koopmans, Marion

    2011-01-01

    Although increasing data have become available that link human adaptation with specific molecular changes in nonhuman influenza viruses, the molecular changes of these viruses during a large highly pathogenic avian influenza virus (HPAI) outbreak in poultry along with avian-to-human transmission have never been documented. By comprehensive virologic analysis of combined veterinary and human samples obtained during a large HPAI A (H7N7) outbreak in the Netherlands in 2003, we mapped the acquisition of human adaptation markers to identify the public health risk associated with an HPAI outbreak in poultry. Full-length hemagglutinin (HA), neuraminidase (NA), and PB2 sequencing of A (H7N7) viruses obtained from 45 human cases showed amino acid variations at different codons in HA (n=20), NA (n=23), and PB2 (n=23). Identification of the avian sources of human virus infections based on 232 farm sequences demonstrated that for each gene about 50% of the variation was already present in poultry. Polygenic accumulation and farm-to-farm spread of known virulence and human adaptation markers in A (H7N7) virus-infected poultry occurred prior to farm-to-human transmission. These include the independent emergence of HA A143T mutants, accumulation of four NA mutations, and farm-to-farm spread of virus variants harboring mammalian host determinants D701N and S714I in PB2. This implies that HPAI viruses with pandemic potential can emerge directly from poultry. Since the public health risk of an avian influenza virus outbreak in poultry can rapidly change, we recommend virologic monitoring for human adaptation markers among poultry as well as among humans during the course of an outbreak in poultry. PMID:21849451

  20. 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.

  1. 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

  2. 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.

  3. Serological characterization of guinea pigs infected with H3N2 human influenza or immunized with hemagglutinin protein

    PubMed Central

    2010-01-01

    Background Recent and previous studies have shown that guinea pigs can be infected with, and transmit, human influenza viruses. Therefore guinea pig may be a useful animal model for better understanding influenza infection and assessing vaccine strategies. To more fully characterize the model, antibody responses following either infection/re-infection with human influenza A/Wyoming/03/2003 H3N2 or immunization with its homologous recombinant hemagglutinin (HA) protein were studied. Results Serological samples were collected and tested for anti-HA immunoglobulin by ELISA, antiviral antibodies by hemagglutination inhibition (HI), and recognition of linear epitopes by peptide scanning (PepScan). Animals inoculated with infectious virus demonstrated pronounced viral replication and subsequent serological conversion. Animals either immunized with the homologous HA antigen or infected, showed a relatively rapid rise in antibody titers to the HA glycoprotein in ELISA assays. Antiviral antibodies, measured by HI assay, were detectable after the second inoculation. PepScan data identified both previously recognized and newly defined linear epitopes. Conclusions Infection and/or recombinant HA immunization of guinea pigs with H3N2 Wyoming influenza virus resulted in a relatively rapid production of viral-specific antibody thus demonstrating the strong immunogenicity of the major viral structural proteins in this animal model for influenza infection. The sensitivity of the immune response supports the utility of the guinea pig as a useful animal model of influenza infection and immunization. PMID:20735849

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Avian and human influenza virus compatible sialic acid receptors in little brown bats.

    PubMed

    Chothe, Shubhada K; Bhushan, Gitanjali; Nissly, Ruth H; Yeh, Yin-Ting; Brown, Justin; Turner, Gregory; Fisher, Jenny; Sewall, Brent J; Reeder, DeeAnn M; Terrones, Mauricio; Jayarao, Bhushan M; Kuchipudi, Suresh V

    2017-04-06

    Influenza A viruses (IAVs) continue to threaten animal and human health globally. Bats are asymptomatic reservoirs for many zoonotic viruses. Recent reports of two novel IAVs in fruit bats and serological evidence of avian influenza virus (AIV) H9 infection in frugivorous bats raise questions about the role of bats in IAV epidemiology. IAVs bind to sialic acid (SA) receptors on host cells, and it is widely believed that hosts expressing both SA α2,3-Gal and SA α2,6-Gal receptors could facilitate genetic reassortment of avian and human IAVs. We found abundant co-expression of both avian (SA α2,3-Gal) and human (SA α2,6-Gal) type SA receptors in little brown bats (LBBs) that were compatible with avian and human IAV binding. This first ever study of IAV receptors in a bat species suggest that LBBs, a widely-distributed bat species in North America, could potentially be co-infected with avian and human IAVs, facilitating the emergence of zoonotic strains.

  9. 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

  10. 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.

  11. Lectin-affinity chromatography for downstream processing of MDCK cell culture derived human influenza A viruses.

    PubMed

    Opitz, Lars; Salaklang, Jatuporn; Büttner, Hermann; Reichl, Udo; Wolff, Michael W

    2007-01-15

    The presented study aims on the development of a capture step for the purification of cell culture derived influenza viruses using lectin affinity chromatography. Human influenza A/Puerto Rico/8/34 virus produced in Madin Darby canine kidney cells have been chosen as a model. The influenza A virus envelop possesses two viral glycoproteins: hemagglutinin and neuraminidase. Oligosaccharides of theses glycoproteins can be targeted as affinity ligands using specific lectins. First, lectins have been screened via lectin blots and spin columns. Adequate lectins have been chosen based on published glycan structures of hemagglutinin. The most specific binding was achieved via the galactose specific Erythrina cristagalli and Euonymus europaeus lectins. Second, the chromatographic separations characteristics of these lectins have been further determined via FPLC. These experiments revealed that the rate of hemagglutinin glycan binding to the ligands was higher with the E. europaeus compared to the E. cristagalli lectin. Third, viral recoveries in addition to the total protein and host cell DNA have been balanced in a series of E. europaeus lectin chromatography runs. The total protein and dsDNA content in the product fraction of the affinity chromatography was reduced from the starting conditions to 21% and 0.1%, respectively. The average viral recovery in the product fraction was 97%. SDS-PAGE analysis indicated that the majority of the eluted proteins were of viral origin. The reproducibility and column stability was confirmed in up to 25 runs applying six different virus product batches.

  12. 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

  13. 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.

  14. 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

  15. Microfluidic Chip for Molecular Amplification of Influenza A RNA in Human Respiratory Specimens

    PubMed Central

    Chang, Jessie; Carey, Brendan; Hsieh, Christopher; Stanley, Ahjegannie; Odell, Christine A.; Mitchell, Patricia; Feldman, James; Pollock, Nira R.; Klapperich, Catherine M.

    2012-01-01

    A rapid, low cost, accurate point-of-care (POC) device to detect influenza virus is needed for effective treatment and control of both seasonal and pandemic strains. We developed a single-use microfluidic chip that integrates solid phase extraction (SPE) and molecular amplification via a reverse transcription polymerase chain reaction (RT-PCR) to amplify influenza virus type A RNA. We demonstrated the ability of the chip to amplify influenza A RNA in human nasopharyngeal aspirate (NPA) and nasopharyngeal swab (NPS) specimens collected at two clinical sites from 2008–2010. The microfluidic test was dramatically more sensitive than two currently used rapid immunoassays and had high specificity that was essentially equivalent to the rapid assays and direct fluorescent antigen (DFA) testing. We report 96% (CI 89%,99%) sensitivity and 100% (CI 95%,100%) specificity compared to conventional (bench top) RT-PCR based on the testing of n = 146 specimens (positive predictive value = 100%(CI 94%,100%) and negative predictive value = 96%(CI 88%,98%)). These results compare well with DFA performed on samples taken during the same time period (98% (CI 91%,100%) sensitivity and 96%(CI 86%,99%) specificity compared to our gold standard testing). Rapid immunoassay tests on samples taken during the enrollment period were less reliable (49%(CI 38%,61%) sensitivity and 98%(CI 98%,100%) specificity). The microfluidic test extracted and amplified influenza A RNA directly from clinical specimens with viral loads down to 103 copies/ml in 3 h or less. The new test represents a major improvement over viral culture in terms of turn around time, over rapid immunoassay tests in terms of sensitivity, and over bench top RT-PCR and DFA in terms of ease of use and portability. PMID:22457740

  16. 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

  17. Human influenza A H5N1 in Indonesia: health care service-associated delays in treatment initiation.

    PubMed

    Adisasmito, Wiku; Aisyah, Dewi Nur; Aditama, Tjandra Yoga; Kusriastuti, Rita; Trihono; Suwandono, Agus; Sampurno, Ondri Dwi; Prasenohadi; Sapada, Nurshanty A; Mamahit, M J N; Swenson, Anna; Dreyer, Nancy A; Coker, Richard

    2013-06-11

    Indonesia has had more recorded human cases of influenza A H5N1 than any other country, with one of the world's highest case fatality rates. Understanding barriers to treatment may help ensure life-saving influenza-specific treatment is provided early enough to meaningfully improve clinical outcomes. Data for this observational study of humans infected with influenza A H5N1 were obtained primarily from Ministry of Health, Provincial and District Health Office clinical records. Data included time from symptom onset to presentation for medical care, source of medical care provided, influenza virology, time to initiation of influenza-specific treatment with antiviral drugs, and survival. Data on 124 human cases of virologically confirmed avian influenza were collected between September 2005 and December 2010, representing 73% of all reported Indonesia cases. The median time from health service presentation to antiviral drug initiation was 7.0 days. Time to viral testing was highly correlated with starting antiviral treatment (p < 0.0001). We found substantial variability in the time to viral testing (p = 0.04) by type of medical care provider. Antivirals were started promptly after diagnosis (median 0 days). Delays in the delivery of appropriate care to human cases of avian influenza H5N1 in Indonesia appear related to delays in diagnosis rather than presentation to health care settings. Either cases are not suspected of being H5N1 cases until nearly one week after presenting for medical care, or viral testing and/or antiviral treatment is not available where patients are presenting for care. Health system delays have increased since 2007.

  18. 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

  19. Genetic evolution of recently emerged novel human-like swine H3 influenza A viruses (IAV) in United States swine

    USDA-ARS?s Scientific Manuscript database

    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...

  20. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. 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.

  2. Infectious Progeny of 2009 A (H1N1) Influenza Virus Replicated in and Released from Human Neutrophils.

    PubMed

    Zhang, Zhang; Huang, Tao; Yu, Feiyuan; Liu, Xingmu; Zhao, Conghui; Chen, Xueling; Kelvin, David J; Gu, Jiang

    2015-12-07

    Various reports have indicated that a number of viruses could infect neutrophils, but the multiplication of viruses in neutrophils was abortive. Based on our previous finding that avian influenza viral RNA and proteins were present in the nucleus of infected human neutrophils in vivo, we investigated the possibility of 2009 A (H1N1) influenza viral synthesis in infected neutrophils and possible release of infectious progeny from host cells. In this study we found that human neutrophils in vitro without detectable level of sialic acid expression could be infected by this virus strain. We also show that the infected neutrophils can not only synthesize 2009 A (H1N1) viral mRNA and proteins, but also produce infectious progeny. These findings suggest that infectious progeny of 2009 A (H1N1) influenza virus could be replicated in and released from human neutrophils with possible clinical implications.

  3. 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.

  4. [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.

  5. 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