Apr 5, 2004 (CIDRAP News) – Canadian officials said today that 19 million poultry in southwestern British Columbia's Fraser Valley would be destroyed in a vastly expanded campaign to stop highly pathogenic avian influenza.
Meanwhile, the World Health Organization reported today on cases of H7 influenza in two poultry workers who had contact with infected birds in the outbreak area. The two patients both had conjunctivitis and have recovered, the WHO said.
More aggressive approach needed
In today's announcement by the Canadian Food Inspection Agency (CFIA), Agriculture Minister Bob Speller said, "Due to the rapidly spreading nature of avian influenza, it is clear that a more aggressive approach is needed to control this highly contagious bird disease. This is not a decision I take lightly, but it is important for the long-term viability of the poultry industry."
On Mar 31 the CFIA said the H7N3 avian flu virus had been confirmed on only seven farms, six of which were in a 5-kilometer-wide "high-risk" region. At that point the agency was talking about sacrificing about 365,000 birds. But in an Apr 2 briefing, officials said 18 farms had been infected and the disease was spreading quickly.
Today the CFIA said that "a significant number" of the condemned birds may not be infected, but the culling is necessary as a "pre-emptive strike." Poultry from uninfected flocks "can be processed under full inspection in registered establishments" and sold, the agency said.
A Reuters report today said the cull would affect about 15 million chickens on 600 farms, as well as turkeys and other poultry.
Speller met with provincial, industry, and CFIA experts Apr 2 to discuss control options, according to the CFIA statement. The officials considered less radical options, but they concluded that the rapid spread of the disease demanded a very aggressive approach, the agency said.
The agency said it is now requiring poultry owners to restrict access to their farms and require all visitors to use strict biosecurity precautions, including cleaning vehicles with disinfectant and wearing protective clothing and footwear.
The British Columbia outbreak was described as low-pathogenic when it was first announced on Feb 23. But on Mar 9 the CFIA said low-pathogenic and highly pathogenic forms of the H7N3 avian flu were present on the same farm, indicating the virus had mutated.
The Reuters report said British Columbia's poultry industry is worth about 230 million US dollars annually to farmers, but the province is not a major exporter of poultry to the world market.
WHO reports on human cases
In reporting on the human cases of avian flu in British Columbia, the WHO said one worker's eyes might have been exposed to infective material when he was culling poultry Mar 13 and 14. He reported conjunctivitis and a nasal discharge Mar 16 and was treated with oseltamivir, an antiviral drug, starting Mar 18. Health Canada determined Mar 30 that his illness was caused H7 avian flu.
The second worker experienced conjunctivitis Mar 25 after close contact with infected birds, the WHO said. He was treated with oseltamivir the same day and subsequently recovered.
The WHO today raised the "global pandemic preparedness level" for the Canadian avian flu outbreak from 0.1 to 0.2, a routine step when more than one human case of a new viral subtype has been identified. Countries with a 0.2 preparedness level are advised to increase their surveillance of people exposed to affected poultry, launch studies of the virus, advise people at risk to wear protective clothing, and consider the use of antivirals and human influenza vaccine, the agency said.
The change in preparedness level also means the WHO will begin steps to obtain the virus, characterize it, and assess the needs for diagnostic tools and a vaccine, the agency said.
Apr 5 WHO statement