Tropism and innate host responses of influenza A/H5N6 virus: an analysis of and cultures of the human respiratory tract.

Since their first isolation in 2013, influenza A/H5N6 viruses have spread amongst poultry across multiple provinces in China and to Laos, Vietnam and Myanmar. So far, there have been 14 human H5N6 infections with 10 fatalities.We investigated the tropism, replication competence and cytokine induction of one human and two avian H5N6 isolates in and cultures derived from the human respiratory tract.

Transmission of H7N9 Influenza Viruses with a Polymorphism at PB2 Residue 627 in Chickens and Ferrets.

Unlabelled: Poultry exposure is a major risk factor for human H7N9 zoonotic infections, for which the mode of transmission remains unclear. We studied the transmission of genetically related poultry and human H7N9 influenza viruses differing by four amino acids, including the host determinant PB2 residue 627. A/Silkie chicken/HK/1772/2014 (SCk1772) and A/HK/3263/14 (HK3263) replicated to comparable titers in chickens, with superior oropharyngeal over cloacal shedding; both viruses transmitted efficiently among chickens via direct contact but inefficiently via the airborne route.

Experimental challenge of chicken vaccinated with commercially available H5 vaccines reveals loss of protection to some highly pathogenic avian influenza H5N1 strains circulating in Hong Kong/China.

Highly pathogenic avian influenza (HPAI) H5N1 virus continues to circulate in poultry in Asia and Africa posing a threat to both public and animal health. Vaccination, used as an adjunct to improved bio-security and stamping-out policies, contributed to protecting poultry in Hong Kong from HPAI H5N1 infection in 2004-2008 although the virus was repeatedly detected in dead wild birds. The detection of clade 2.

Southeast Asian foot-and-mouth disease viruses in Eastern Asia.

Foot-and-mouth disease (FMD) outbreaks recently affected 2 countries (Japan and South Korea) in eastern Asia that were free of FMD without vaccination. Analysis of viral protein 1 nucleotide sequences indicated that FMD serotype A and O viruses that caused these outbreaks originated in mainland Southeast Asia to which these viruses are endemic.

Comparative analysis of six genome sequences of three novel picornaviruses, turdiviruses 1, 2 and 3, in dead wild birds, and proposal of two novel genera, Orthoturdivirus and Paraturdivirus, in the family Picornaviridae.

In this territory-wide molecular epidemiology study of picornaviruses, involving 6765 dead wild birds from 201 species in 50 families over a 12 month period, three novel picornaviruses, turdiviruses 1, 2 and 3 (TV1, TV2 and TV3), were identified from birds of different genera in the family Turdidae. In contrast to many other viruses in birds of the family Turdidae or viruses of the family Picornaviridae, TV1, TV2 and TV3 were found exclusively in the autumn and winter months. Two genomes each of TV1, TV2 and TV3 were sequenced.

Characterization of avian influenza viruses A (H5N1) from wild birds, Hong Kong, 2004-2008.

From January 2004 through June 2008, surveillance of dead wild birds in Hong Kong, People's Republic of China, periodically detected highly pathogenic avian influenza (HPAI) viruses (H5N1) in individual birds from different species. During this period, no viruses of subtype H5N1 were detected in poultry on farms and in markets in Hong Kong despite intensive surveillance. Thus, these findings in wild birds demonstrate the potential for wild birds to disseminate HPAI viruses (H5N1) to areas otherwise free from the viruses.

Comparative analysis of complete genome sequences of three avian coronaviruses reveals a novel group 3c coronavirus.

In this territory-wide molecular epidemiology study of coronaviruses (CoVs) in Hong Kong involving 1,541 dead wild birds, three novel CoVs were identified in three different bird families (bulbul CoV HKU11 [BuCoV HKU11], thrush CoV HKU12 [ThCoV HKU12], and munia CoV HKU13 [MuCoV HKU13]). Four complete genomes of the three novel CoVs were sequenced. Their genomes (26,396 to 26,552 bases) represent the smallest known CoV genomes.

Investigation of outbreaks of highly pathogenic H5N1 avian influenza in waterfowl and wild birds in Hong Kong in late 2002.

Outbreaks of highly pathogenic H5N1 avian influenza have occurred in Hong Kong in chickens and other gallinaceous poultry in 1997, 2001, twice in 2002 and 2003. High mortality rates were seen in gallinaceous birds but not in domestic or wild waterfowl or other wild birds until late 2002 when highly pathogenic H5N1 avian influenza occurred in waterfowl (geese, ducks and swans), captive Greater Flamingo (Phoenicopterus ruber) and other wild birds (Little Egret Egretta garzetta) at two waterfowl parks and from two dead wild Grey Heron (Ardea cinerea) and a Black-headed Gull (Larus ridibundus) in Hong Kong. H5N1 avian influenza virus was also isolated from a dead feral pigeon (Columba livia) and a dead tree sparrow (Passer montanus) during the second outbreak.