Environmental Engineering Reference
In-Depth Information
damage from another outbreak was set at US$50 billion to US$60 billion (wHo
2005, 54). Yet the worst was by no means over: the evolution of the virus suggested a
deepening threat (5). the H5n1 strain had become endemic in southeast asia, having
found a permanent ecological niche in domestic poultry and asymptomatic ducks.
Despite individual control measures, avian influenza continues to spread, creating
further economic, ecological, and human devastation. russian authorities warned
that 'the infection cannot be contained, and it is impossible to isolate' and that the
avian influenza 'will have serious consequences for the environment, the economy,
and primarily for human health', making it imperative to legislate comprehensive
anti-epidemic, sanitary, and veterinary measures ('Bird Flu Confirmed in 45 Russian
Settlements: chief veterinary Inspector' 2005).
Highly Pathogenic Avian Influenza Strikes Canada
In canada, a slightly higher number of dead chickens (8-16 per day) was reported
in one barn in Fraser valley, british columbia, on 6 February 2004. low-pathogenic
avian influenza (LPAI) was confirmed on 16 February (Tweed
et al. 2004). although
the flock was quickly quarantined and depopulated by the canadian Food Inspection
agency (cFIa), within three weeks a highly pathogenic strain (H7n3) was detected
in another flock on the same premise, killing 2000 birds in two days. With this started
the largest outbreak of highly pathogenic avian influenza (HPAI) in Canada—the first
since 1960 (chicken Farmers of canada 2004, 6). Despite the containment efforts,
the virus continued to spread, infecting more than 50 commercial and backyard
farms. More drastic measures, including the destruction of 17 million chickens,
turkeys, and ducks, stopped the viral progress by 4 June. but it took another two
months of disinfection for all the remaining restrictions to be lifted (5).
Those six months of the HPAI scare had a significant negative impact on the
province of british columbia chicken industry in terms of farm sales, cleaning
and disinfecting costs, increased bio-security, and industry coordination. as trade
partners banned various poultry imports—from all of canada—the total losses for
the chicken industry were estimated at CA$100 million in the first year of recovery
(chicken Farmers of canada 2004, 7). the Fraser valley outbreaks also represented
the first known case of human H7n3 infections.
6
Lessons Relearned
british columbia's frightening episode was not without precedent: SarS should
have been an eye opener for the whole world. SarS had jumped to humans from
infected animals that were sold and slaughtered in unsanitary and crowded markets
in china's Guangdong province, from where it travelled to five countries within
24 hours and across six continents in several months, causing 8000 infections
worldwide, with a 10 percent mortality rate (osterholm 2005). the crisis demonstrated
that a lack of proper agricultural practices and sanitary standards in one corner of the
