Saturday, February 10, 2007

Hey Mac is Yer Canary Sick?

Just as miners once used canaries to indicate dangerous conditions down below, the scientific community is keeping tabs on the avian population in order to guage the possibility of what they consider to be the next 'pandemic' flu. Avian Virus H5N1 is considered to be a threat to humans, it is already a threat to birds.

This is bird flu season as migrating birds carry the disease into the northern hemisphere. It's been bird flu season in the southern hemisphere. This winter only a couple of outbreaks were reported in Indonesia, VietNam and Japan. Does that mean there's less disease, I doubt it. It just means some countries can't afford, or can't be bothered, to track and report it. This should be evident if the disease is more widespread this year in the north.

So far three outbreaks are reported, a minor one in Turkey, what had appeared to be a minor one in Hungary and a more concerning one in an English Turkey farm.

The disease, it is claimed, spreads from wild birds to domestic fowl through infected feces. That shouldn't be a problem unless domestic birds are exposed to wild ones, i.e. they're the 'free range' variety which spend a lot of time loose, outdoors. From domestic birds the disease has spread to humans and, in a few cases, from human to human, (through the respiratory tract - it is believed). The domestic cat is being pegged as a possible vector in spreading the infection through respiration and saliva. The new strain bird flu has fairly high mortality rate in infected humans.

In many parts of the world domestic birds run loose. In Europe and North America, market conditions make the factory farm approach more efficient economically. Outbreaks of avian illness can be devastating to these operations where the genetic background all the birds in a lot are similar. But because of the nature of these operations the disease is usually transmitted by human activity - i.e. bringing in infected birds, feed or disease organisms on apparel. Avian disease, including flu, has been an on-going problem, the new strain adds another risk element. It is now believed that the English outbreak may be related to the earlier Hungarian one because the corporation owning the farm, is reputed to have processed imported Hungarian poultry at its plant adjoining the farm earlier this year. In North America the risk, as in other diseases, seems to come more directly from human economic activity thus far.

In Canada - the summer home of a large number of migrating fowl, Avian flu virus has yet to appear in significant distribution. Maybe the South American birds are not yet well-infected as few outbreaks have been reported there, or in Central America. The odds are that situation will change - due to the cross-migration that occurs naturally - one day a sick bird will show up. An outbreak on a BC chicken farm some years back was blamed on wild birds, but retrospectively it might have been because of some human activity. If it does appear, Seagulls, Canada Geese, songbirds and other wild fowl which live in closer proximity to urban centres my have to be culled. Domestic cats will have to be restrained.

Canada maintains a testing watch on the disease, sampling wildfowl. So far this year no evidence of infection has been detected. But like BSE, Canada needs to be more proactive in ensuring that economic, or other human activity, is not exposing the country to infection. No airport screening or preventative measures are apparent to minimize the risk of the disease being brought home on someone's shoes or clothing. The current customs and immigration set-up is just a clearing house for cross contamination of large numbers of travellers. That is true of other diseases as well. A sick individual could, possibly, infect a significant number of others around them in line for customs clearance. Airports aren't designed to screen for illness, or disease transmission, but if they screen for terrorists they should be.

The Plague was spread from India to Asia by trade routes, the same way it was brought to Europe by ship. Travel and commerce to-day are far more timely and efficient, and so are the possibilities of importing and exporting disease. At the time of the Spanish Flu - travel between continents was still measured in days and weeks, and still it spread around the world. Today travel is measured in hours and millions are on the move daily. The next pandemic will spread like wildfire if only because of this. A canary might not be enough warning.

No comments: