New outbreaks of avian influenza reported to the World Organisation for Animal Health (OIE) have tailed off, as might be expected from the seasonal pattern of the disease, but new cases were reported during August 2015 in Africa, Asia, the Americas and Europe.
The first outbreaks of highly pathogenic avian influenza were reported by Nigeria in January this year, all caused by an H5N1 variant of the virus. During August, the veterinary authority reported 9 outbreaks affecting more than 56,000 birds. Five of the farms were in the state of Lagos, two were in Rivers and one each was reported in Oyo and Gombe.
Ghana has reported 5 new outbreaks in August – 4 in Greater Accra and 1 in Upper East state, affecting more than 3,200 birds.
Neighbouring Cote d’Ivoire has informed OIE of 3 outbreaks of highly pathogenic H5N1 avian influenza that occurred earlier in 2015. A farm with more than 27,000 birds in Aboisso was affected in early July, while the virus was detected in a backyard flock in Bouake and a poultry market in the capital, Abidjan, in May.
Ostrich farmers in Western Cape province of South Africa have been reporting the detection of the low-pathogenic H5N2 virus in their flocks over the long term. Four more flocks tested positive for the virus during June and July.
Since January 2015, Taiwan has been hit by numerous outbreaks of highly pathogenic avian influenza. Announcements of new cases have slowed down in recent months but four outbreaks caused by the H5N2 subtype in July and a further two in August have been reported to the OIE this month. More than 117,000 birds – native chickens, geese and ducks – in the counties of Yunlin, Changhua and Nantou died or were destroyed. Also reported was one outbreak caused by the H5N8 variant of the virus, which affected more than 11,000 ducks in Yunlin County in July.
In Guangdong province in China, more than 2,000 birds died or were destroyed in an outbreak of highly pathogenic H5N6 avian influenza, the first cases since March. More than 53,000 birds were affected in an outbreak caused by the H5N2 variant of the virus in Jiangsu province.
Vietnam has reported new cases of highly pathogenic avian influenza in the last month. There have been two outbreaks in village flocks caused by the H5N6 subtype in Lao Cai in the northwest part of the country and in the central province of Quang Nai. The H5N1 variant of the virus was detected following outbreaks of the disease in two backyard flocks in the southern provinces of Tra Vinh and Soc Trang.
Following previous outbreaks earlier in 2015 caused by the highly pathogenic H5N1 virus, Turkey and Israel reported the disease issues to be resolved. A highly pathogenic H5 variant of the virus affected 6 flocks of almost 43,000 poultry in a single cluster in Palestine in April, the authority there reported to the OIE in August.
USDA has reported neither outbreaks of avian influenza not detection of any viruses in the United States during the month of August. A number of states are now officially free of the disease. Highly pathogenic H5N2 and H5N8 forms of the virus caused huge losses to the industry earlier this year, and a low-pathogenic H7N3 virus hit one farm in California in March.
The authorities in Canada lifted all restrictions in Ontario after earlier outbreaks of H5N2 highly pathogenic avian influenza there, while heightened surveillance is set to continue.
In early August, Mexico reported a sub-clinical infection of low-pathogenic avian influenza, which had started at the end of July in a layer flock of 433,000 birds in the state of Sinaloa. The virus was later identified as the H5N2 variant.
Belize has reported no new outbreaks caused by the low-pathogenic H5N2 virus since February 2015.
The situation regarding low-pathogenic H7N7 avian influenza in The Netherlands is now described as “resolved” following a single outbreak in Friesland in March. All measures have been lifted after an outbreak of low-pathogenic H5N2 avian influenza in North Brabant in May.
In the United Kingdom, surveillance has revealed no further cases since the original outbreak of highly pathogenic H7N7 affecting 180,000 birds near Preston in July. All restrictions have been lifted with the exception of the infected site, which is undergoing final cleaning and disinfection.
The veterinary authority in Russia reported detecting the highly pathogenic H5N1 form of the virus in wild birds in three locations in Novosibirsk Oblast (southwestern Siberia) and a wild swan in Zabaykalsky Krai during routine surveillance during May.