GLOBAL - The last week has brought news of a surge in outbreaks of avian influenza across the United States as well as a first outbreak in Canada since the turn of the year. Outbreaks in poultry have also been reported in Palestine, Viet Nam, China, Taiwan and the Netherlands, with new human cases in China and Egypt.
Following a brief lull during February 2015, there have been 15 outbreaks in the US across 10 states, mainly in commercial turkeys, and centred on the state on Minnesota.
The great majority of the outbreaks have been caused by the H5N2 subtype of the highly pathogenic virus, which has been identified as having mixed Eurasian and North American origin. With nearly all the outbreaks being in the Mississippi flyway, wild birds are thought the most likely to be spreading the virus to domestic poultry.
Two outbreaks appear to be different from the rest; they occurred in backyard flocks of mixed poultry, one in Kansas and one in Montana, which are in the Central flyway although the virus is apparently the same H5N2 variant.
Direct losses from the outbreaks are mounting up, with mortalities and destruction of 810,000 turkeys since the beginning of March alone, as well as restrictions placed by a number of countries on imports of US poultry and poultry products.
In the last week, Canada has reported its first high-path avian flu outbreak this year – also the H5N2 subtype and on a commercial turkey farm in Ontario. Eight nearby farms are currently in quarantine. The outbreak occurred as the Canadian Food Inspection Agency increased the restrictions on poultry products from its northern neighbour.
Meanwhile, in Asia, there has been an outbreak of high-path bird flu in a village poultry flock in Viet Nam and the virus has also been detected for the first time in the border area between China and Myanmar. There have also been new outbreaks in Taiwan and China.
Palestine has reported a new outbreak and in Europe, the Netherlands has reported a new outbreak of low-pathogenic avian flu in North Brabant in the east of the country, affecting a free-range laying hen flock.
Further cases of flu of avian origin have been reported in people in Egypt and China over the last week.