Protective efficacy of poultry vaccines against recently circulating Highly Pathogenic Avian Influenza (HPAI) H5N1 virus isolater from markets and farms in Hong Kong 2008

Parallel Session 2 - Emerging/Infectious Diseases: no. S7Theme: Translating Health Research into Policy and Practice for Health of the PopulationINTRODUCTION: Highly pathogenic avian influenza (HPAI) H5N1 remains a major threat to animal and public health. Since 2003, Hong Kong has successfully used poultry vaccination as part of its strategy to minimise this threat within Hong Kong. In mid-2008, an HPAI H5N1 outbreak occurred in a vaccinated poultry farm in Hong Kong. AIMS: a) to compare protective efficacy of different poultry vaccines against the 2008 farm outbreak strain; and b) to assess whether there needs to be a change in the poultry vaccine used in Hong Kong. METHODS: White leghorn chickens were raised in a clean laboratory environment and …published_or_final_versio

Proinflammatory cytokine response and viral replication in mouse bone marrow derived macrophages infected with influenza H1N1 and H5N1 viruses

The pathogenesis of human influenza H5N1 virus infection remains poorly understood and controversial. Cytokine dysregulation in human infection has been hypothesized to contribute to disease severity. We developed in vitro cultures of mouse bone marrow derived macrophages (BMDMΦ) from C57BL/6N mouse to compare influenza A (H5N1 and H1N1) virus replication and pro-inflammatory cytokine and chemokine responses. While both H1N1 and H5N1 viruses infected the mouse bone marrow derived macrophages, only the H1N1 virus had showed evidence of productive viral replication from the infected cells. In comparison with human seasonal influenza H1N1 (A/HK/54/98) and mouse adapted influenza H1N1 (A/WSN/33) viruses, the highly pathogenic influenza H5N1 virus (A/HK/483/97) was a more potent inducer of the chemokine, CXCL 10 (IP-10), while there was not a clear differential TNF-α protein expression pattern. Although human influenza viruses rarely cause infection in mice without prior adaption, the use of in vitro cell cultures of primary mouse cells is of interest, especially given the availability of gene-defective (knock-out) mice for specific genes.published_or_final_versio

Influenza viruses in healthy wild birds in Hong Kong

Poster Presentations: Animal Influenza EcologyWild waterfowl are considered the natural reservoir of influenza A viruses. The recent outbreak of highly pathogenic avian influenza (HPAI) H5N1 in Asia which has now spread as far as Africa highlights the importance of defining the influenza virus gene pool in these birds and understanding the potential role played by migratory waterfowl in such HPAI outbreaks. Seventy-three influenza viruses were isolated from 16,724 samples collected from feral waterfowls or their fecal droppings during 2003-7 at Mai Po Marshes and Lok Ma Chau in Hong Kong. A diversity of influenza viruses representing hemagglutinin subtypes of H1, H2, H4, H5, H6, H7, H8, H9, H10 and H11; neuramidinase subtypes of N1, N2, N3, N4, N6, N7, N8 and N9, were isolated. Seventy-two of these 73 positive isolates were collected during the winter period coinciding with the southern migration of waterfowl along the East Asian flyway. No HPAI H5N1 viruses were isolated from healthy birds sampled in this study, though H5N1 viruses have been isolated from dead wild birds found in Hong Kong. Phylogenetic analyses of the HA gene of the H5 viruses isolated in the study showed that they clustered with other LP H5 viruses isolated from Hokkaido, Mongolia and Siberia but they seemed not to be very closely related to the HP H5N1. Six of 150 blood sample collected from wild ducks and one of 43 from shorebirds were tested to have antibody by neutralization tests for H5 subtype hemagglutinin.postprin

Highly Pathogenic Avian Influenza Virus among Wild Birds in Mongolia

Mongolia combines a near absence of domestic poultry, with an abundance of migratory waterbirds, to create an ideal location to study the epidemiology of highly pathogenic avian influenza virus (HPAIV) in a purely wild bird system. Here we present the findings of active and passive surveillance for HPAIV subtype H5N1 in Mongolia from 2005-2011, together with the results of five outbreak investigations. In total eight HPAIV outbreaks were confirmed in Mongolia during this period. Of these, one was detected during active surveillance employed by this project, three by active surveillance performed by Mongolian government agencies, and four through passive surveillance. A further three outbreaks were recorded in the neighbouring Tyva Republic of Russia on a lake that bisects the international border. No HPAIV was isolated (cultured) from 7,855 environmental fecal samples (primarily from ducks), or from 2,765 live, clinically healthy birds captured during active surveillance (primarily shelducks, geese and swans), while four HPAIVs were isolated from 141 clinically ill or dead birds located through active surveillance. Two low pathogenic avian influenza viruses (LPAIV) were cultured from ill or dead birds during active surveillance, while environmental feces and live healthy birds yielded 56 and 1 LPAIV respectively. All Mongolian outbreaks occurred in 2005 and 2006 (clade 2.2), or 2009 and 2010 (clade 2.3.2.1); all years in which spring HPAIV outbreaks were reported in Tibet and/or Qinghai provinces in China. The occurrence of outbreaks in areas deficient in domestic poultry is strong evidence that wild birds can carry HPAIV over at least moderate distances. However, failure to detect further outbreaks of clade 2.2 after June 2006, and clade 2.3.2.1 after June 2010 suggests that wild birds migrating to and from Mongolia may not be competent as indefinite reservoirs of HPAIV, or that HPAIV did not reach susceptible populations during our study.published_or_final_versio

The role of drinking water as a transmission route of influenza (H9N2) in live poultry market

Poster Presentation: P2.17The 2nd International Conference on Infectious Diseases Dynamics (Epidemics 2), Athens, Greece, 2-4 December 2009

Innate immune responses to influenza A H5N1: friend or foe?

Avian influenza A H5N1 remains unusual in its virulence for humans. Although infection of humans remains inefficient, many of those with H5N1 disease have a rapidly progressing viral pneumonia that leads to acute respiratory distress syndrome and death, but its pathogenesis remains an enigma. Comparison of the virology and pathogenesis of human seasonal influenza viruses (H3N2 and H1N1) and H5N1 in patients, animal models and relevant primary human cell cultures is instructive. Although the direct effects of viral replication and differences in the tropism of the virus for cells in the lower respiratory tract clearly contribute to pathogenesis, we focus here on the possible contribution of the host innate immune response in the pathogenesis of this disease. © 2009 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

Droplet detachment behavior from a rough hydrophilic surface

202207 bckwAccepted ManuscriptPublishe

Minimizing risk of avian influenza: The effect of interventions on H9N2 influenza isolation in live poultry markets, 1999-2005 (abstract)

Free Paper

Reliable universal RT-PCR assays for studying influenza polymerase subunit gene sequences from all 16 haemagglutinin subtypes

Realizable one-step RT-PCR assays specific for influenza PB2, PB1 and PA segments are described in this report. The designs of the consensus primers were based on more than five thousands polymerase genes derived from avian or mammalian viral strains. All the viral RNA tested in this study could be consistently amplified by the assays. The reaction products were specific and could be used for direct DNA sequencing. These assays might be useful tools to study the sequences of these genes. © 2007 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex