Highly pathogenic H5N1 is endemic in much of Southeast Asia and finding a crow infected with the virus is not a surprise, nor probably especially newsworthy, but the news this morning is interesting for its possible implications.
The International Herald Tribune:
Hong Kong finds bird flu virus in crow
Reuters
Monday, October 20, 2008
HONG KONG: A house crow found dead in a crowded district in Hong Kong last week has tested positive for the highly pathogenic H5N1 bird flu virus, a government spokeswoman said on Monday.
The appearance of the virus in Hong Kong, more active in the cooler months between October and March, is closely watched as it may indicate the level of activity of the virus in mainland China, which has a poultry population of 13 billion.
The virus is endemic in poultry in parts of Asia but experts fear it will mutate into a form that is easily passed from human to human, sparking a pandemic which could kill millions of people.
“House crows are common in Hong Kong. We have no idea if it came from elsewhere, how it was infected,” the spokeswoman for the Agriculture, Fisheries and Conservation Department said.
The crow was found dead in a public refuse bin on Wednesday.
Crows are highly intelligent omnivores. The Asian house crow has evolved to coexist with humans and is not found in areas where humans do not live. House crows will eat carrion and as such eyed as not only a harbinger of H5N1 but also a potential spreader of the pathogen.
Flublogia has long decried the dangers presented by improper disposal of poultry with confirmed or suspected infection of highly pathogenic H5N1, an issue that is manifestly more dangerous when an infected flock is not known or suspected to be so when biosecurity measures may not be a priority.
Tossing dead birds or the entrails of slaughtered poultry onto the local rubbish heap is a common practice around the world, even at a time when the world is watchful for H5N1. Old habits and customs are not easily overturned.
Some snips on the Bernard Matthews outbreak in Britain in early 2007 that highlight suspicions of vectors not traditionally assumed may have been causative…
OUTBREAK OF HIGHLY PATHOGENIC H5N1 AVIAN INFLUENZA IN SUFFOLK IN JANUARY 2007
A REPORT OF THE EPIDEMIOLOGICAL FINDINGS BY THE NATIONAL EMERGENCY EPIDEMIOLOGY GROUP, Defra
5 APRIL 2007
9. The disease was confined to a single turkey house (house 10) on the site (of the 22 sheds that contained turkeys), at the time of detection. This shed was unusual compared to others on the site in that it was in a poor state of maintenance. There were holes in the woodwork (probably rodent damage), the ventilation vents were not covered in mesh, side vents were close to the ground and the roof leaked. These features would allow access for either small wild birds, rats or mice that could mechanically carry virus into the house, or ingress of water contaminated by birds outside.
11. Rodent control was practised routinely on the turkey farm and was in evidence; however reports of visits from pest controllers show that despite the control efforts, rodents were an ongoing problem on the site and particularly in House 10.
19. There was clear evidence that gulls loafed on the roofs of the turkey houses, and also flew regularly between the farm and the factory where they scavenged waste. There was also a clear route by which pests such as rats and mice can travel between the factory and the farm.
Hong Kong, being hyper-vigilant, is at little risk of a local outbreak going undiscovered, but the dead crow begs the question of where a bird that has an infection severe enough for a fatal outcome managed to pick up the infection. In other words, the old “too sick to fly” controversy comes to mind.
Of course, I am making a rather large assumption that the bird died as a direct result of its infection. An assumption, not based on anything, because, for all I know the bird could have been the victim of poisoning. Admitting the assumption: it is probably safer to assume H5N1 was the cause, at least until proved otherwise.
SZ
{ 0 comments… add one now }