Yesterday Hong Kong reported the finding of a dead red-whiskered bulbul - a passerine (aka `perching') bird commonly found in Asia - on Argyle street near a playground in the Kowloon district of Hong Kong. Preliminary testing suggested and H5 infection.
Today, we've confirmation that this dead bird was infected with avian H5N6.
This is not first detection of the H5N6 virus in Hong Kong (see last December's Hong Kong Reports Another Environmental Sample Positive For H5N6 and Jan 2016's Hong Kong: H5N6 Detected In Dead Egret).
But this serves as a reminder that this emerging avian virus continues to spread across Asia via migratory birds, and that - as we've seen in Japan, South Korea, and Taiwan this winter - the potential for spread to local poultry flocks is very real.
The Agriculture, Fisheries and Conservation Department (AFCD) said today (April 12) that a dead red-whiskered bulbul found in Argyle Street, Kowloon City, was confirmed to be H5N6 positive after laboratory testing.
The dead red-whiskered bulbul was found and collected near a planter in Argyle Street Playground last Friday (April 7), and was suspected to be H5 positive after initial laboratory testing this Monday (April 10).
The red-whiskered bulbul is a common resident of Hong Kong.
The spokesman said cleaning and disinfection have been stepped up at the venue, adding that there are no poultry farms within 3 kilometres of where the dead bird was found.
In view of the case, the AFCD has phoned poultry farmers to remind them to strengthen precautionary and biosecurity measures against avian influenza. Letters have been issued to farmers, pet bird shop owners and licence holders of pet poultry and racing pigeons reminding them that proper precautions must be taken.
The spokesman said the department would conduct frequent inspections of poultry farms and the wholesale market to ensure that proper precautions against avian influenza have been implemented. The department will continue its wild bird monitoring and surveillance.
"People should avoid contact with wild birds and live poultry and their droppings. They should clean their hands thoroughly after coming into contact with them. The public can call 1823 for follow-up if they come across suspicious, sick or dead birds, including the carcasses of wild birds and poultry," the spokesman said.
The Food and Environmental Hygiene Department (FEHD) will continue to be vigilant over imported live poultry as well as live poultry stalls. It will also remind stall operators to maintain good hygiene.
The Department of Health will keep up with its health education to remind the public to maintain strict personal and environmental hygiene to prevent avian influenza.
The AFCD, the FEHD, the Customs and Excise Department and the Police will strive to deter the illegal import of poultry and birds into Hong Kong to minimise the risk of avian influenza outbreaks caused by imported poultry and birds that have not gone through inspection and quarantine.
All relevant government departments will continue to be highly vigilant and strictly enforce preventive measures against avian influenza. Health advice is available from the "H5N1 Health Advice" page on the AFCD website at www.afcd.gov.hk .Ends/Wednesday, April 12, 2017Issued at HKT 20:55
Although waterfowl (ducks & geese) and gallinaceous birds (turkeys, grouse, chickens & quail) are most often associated with carriage of HPAI H5 viruses, terrestrial birds such as crows, starlings, pigeons, and sparrows are also known to carry, and shed, these viruses as well.
For many of these non-aquatic birds, however, HPAI infection can produce serious (or fatal) injury - sometimes resulting in large die offs (see OIE: H5N1 In Dead Crows - Bangladesh).
Admittedly, the incidence of terrestrial bird carriage of HPAI viruses is poorly understood and its significance remains hotly debated, but recent studies and surveillance suggests their role may be greater than previously believed.
- The Survey of H5N1 Flu Virus in Wild Birds in 14 Provinces of China from 2004 to 2007, published in 2009, found 26 positive samples distributed across 9 species from among 7320 passerine samples tested, providing a very low incidence of 0.36%. However, among tree sparrows tested, the prevalence was three times higher at 1.09%.
- The 2012 PLoS One Study A Survey of Avian Influenza in Tree Sparrows in China in 2011, found serological evidence of prior H5 subtype HPAI infection in 94 of 800 (11.75%) of sparrows tested, showing that HPAI H5 infection need not always prove fatal in that species.
- In 2013, in Pathogenesis in Eurasian tree sparrows inoculated with H5N1 highly pathogenic avian influenza virus and experimental virus transmission from tree sparrows to chickens by Yamamoto Y, Nakamura K, Yamada M, Mase M., the authors found that inoculated birds lived up to 11 days and shed copious amounts of the virus during that time, and suggested that Eurasian tree sparrows could be potential vectors to housed poultry.
- And a 2015 study - Avian Path: Susceptibility of Wild Passerine Birds To HPAI H5N1 - examined the susceptibility of three passerine bird species (reed buntings, brown-eared bulbuls and pale thrushes) to HPAI H5N1, and finds that 2 out of 3 (buntings & bulbuls) sickened and died, while pale thrushes seroconverted exhibited no clinical signs of infection.