Project description:New reassortant H5N6 highly pathogenic avian influenza viruses (AIVs) were isolated from apparently healthy domestic ducks in Southern China in 2014. Our results show that the viruses grew efficiently in eggs and replicated systemically in chickens. They were completely lethal in chicken (100% mortality), and the mean death time was 6 to 7 days post-inoculation. The viruses could transmit in chickens by naïve contact. BLAST analysis revealed that their HA gene was most closely related to A/wild duck/Shangdong/628/2011 (H5N1), and their NA genes were most closely related to A/swine/Guangdong/K6/2010 (H6N6). The other genes had the highest identity with A/wild duck/Fujian/1/2011(H5N1). The results of phylogenetic analysis showed that their HA genes clustered into clade 2.3.4.4 of the H5N1 viruses and all genes derived from H5 were Mix-like or H6-like viruses. Thus, the new H5N6 viruses were reassortmented of H5N1 and H6N6 virus. Therefore, the circulation of the new H5N6 AIVs may become a threat to poultry and human health.
Project description:Although reports of human infection with influenza A(H5N6) increased in 2021, reports of similar H5N6 virus infection in poultry are few. We detected 10 avian influenza A(H5N6) clade 2.3.4.4b viruses in poultry from 4 provinces in China. The viruses showed strong immune-escape capacity and complex genetic reassortment, suggesting further transmission risk.
Project description:In March 2014, avian influenza in poultry in Laos was caused by an emergent influenza A(H5N6) virus. Genetic analysis indicated that the virus had originated from reassortment of influenza A(H5N1) clade 2.3.2.1b, variant clade 2.3.4, and influenza A(H6N6) viruses that circulate broadly in duck populations in southern and eastern China.
Project description:Since 2013, highly pathogenic (HP) H5N6 influenza A viruses (IAVs) have emerged in poultry in Asia, especially Southeast Asia. These viruses have also caused sporadic infections in humans within the same geographic areas. Active IAV surveillance in wild birds sampled in Guangdong province, China from August 2014 through February 2015 resulted in the recovery of three H5N6 IAVs. These H5N6 IAV isolates possess the basic amino acid motif at the HA1-HA2 cleavage site that is associated with highly pathogenic IAVs infecting chickens. Noteworthy findings include: (1) the HP H5N6 IAV isolates were recovered from three species of apparently healthy wild birds (most other isolates of HP H5N6 IAV in Asia are recovered from dead wild birds or fecal samples in the environment) and (2) these isolates were apparently the first recoveries of HP H5N6 IAV for two of the three species thus expanding the demonstrated natural host range for these lineages of virus. This investigation provides additional insight into the natural history of HP H5N6 IAVs and identifies the occurrence of non-lethal, HP H5N6 IAV infections in wild birds thereby demonstrating the value of active IAV surveillance in wild birds.
Project description:First identified in May 2014 in China's Sichuan Province, initial cases of H5N6 avian influenza virus (AIV) infection in humans raised great concerns about the virus's prevalence, origin, and development. To evaluate both AIV contamination in live poultry markets (LPMs) and the risk of AIV infection in humans, we have conducted surveillance of LPMs in Guangdong Province since 2013 as part of environmental sampling programs. With environmental samples associated with these LPMs, we performed genetic and phylogenetic analyses of 10 H5N6 AIVs isolated from different cities of Guangdong Province from different years. Results revealed that the H5N6 viruses were reassortants with hemagglutinin (HA) genes derived from clade 2.3.4.4 of H5-subtype AIV, yet neuraminidase (NA) genes derived from H6N6 AIV. Unlike the other seven H5N6 viruses isolated in first 7 months of 2014, all of which shared remarkable sequence similarity with the H5N1 AIV in all internal genes, the PB2 genes of GZ693, GZ670, and ZS558 more closely related to H6N6 AIV and the PB1 gene of GZ693 to the H3-subtype AIV. Phylogenetic analyses revealed that the environmental H5N6 AIV related closely to human H5N6 AIVs isolated in Guangdong. These results thus suggest that continued reassortment has enabled the emergence of a novel H5N6 virus in Guangdong, as well as highlight the potential risk of highly pathogenic H5N6 AIVs in the province.
Project description:New reassortant H5N8 highly pathogenic avian influenza viruses were isolated from waterfowl in Southern China. Blast analysis demonstrated that the PB2 gene in these viruses were most closely related to A/wild duck/Shangdong/628/2011 (H5N1), while their NP genes were both more closely related to A/wild duck/Shandong/1/2011 (H5N1) and A/duck/Jiangsu/k1203/2010 (H5N8). However, the HA, NA, PB1, PA, M, and NS genes had the highest identity with A/duck/Jiangsu/k1203/2010 (H5N8). Phylogenetic analysis revealed that their HA genes belonged to the same GsGd H5 clade 2.3.4.4 detected in China in 2010. Therefore, we supposed that these H5N8 viruses might be novel reassortant viruses that have a H5N8 backbone while acquiring PB2 and NP genes from H5N1 viruses. This study is useful for better understanding the genetic and antigenic evolution of H5 avian influenza viruses in Southern China.
Project description:The distribution and prevalence of H3 subtype influenza viruses in avian and mammalian hosts constitutes a potential threat to both human and avian health. We report a complete genome sequence of a novel reassortant H3N2 avian influenza virus. Phylogenetic analysis showed that HA and NA showed the highest sequence homologies with those of A/white-backed munia/Hong Kong/4519/2009 (H3N2). However, the internal genes had the highest sequence homologies with those of H6 and H7 subtypes. The data provide further evidence of the existence of a natural reassortant H3N2 strain in southern China.
Project description:A novel highly pathogenic avian influenza A(H5N6) clade 2.3.4.4b virus was isolated from a poultry market in China that a person with a confirmed case had visited. Most genes of the avian and human H5N6 isolates were closely related. The virus also exhibited distinct antigenicity to the Re-11 vaccine strain.