Sep 13, 2010 (CIDRAP News) – Reversing a trend that began in 2007, the number of countries affected by H5N1 avian influenza and the number of reported H5N1 outbreaks in birds have increased this year, the United Nations Food and Agriculture Organization (FAO) says.
Sixteen countries (plus Hong Kong) had H5N1 outbreaks this year through August, compared with about 11 in all of 2009, according to charts in the Sep 2 issue of FAO AIDE News, a bulletin that reports periodically on avian flu.
In the first 6 months of this year, 390 H5N1 outbreaks were reported, versus 297 for all of 2009, the FAO said. However, those numbers do not include Indonesia, which reports the majority of H5N1 poultry outbreaks worldwide, because Indonesia, unlike other countries, counts outbreaks at the village level rather than the household level, the report says.
The FAO cautioned that the number of outbreaks is more subjective than the number of affected countries, because it is strongly influenced by such variables as the case definition, awareness level, and effectiveness of surveillance.
In particular, the report says a big increase in reported H5N1 outbreaks in Egypt this year "is most likely the result of improved surveillance through the effectiveness of the CAHO [Community Animal Health Outreach] programme." (It says Egypt has had 264 poultry outbreaks this year, compared with 71 for the same period last year, but does not specify which months those numbers cover.)
The peak month for outbreaks this year was February, with close to 150, which was well above last year's 1-month peak of about 70 outbreaks, also in February, according to the FAO report. The report cites Egypt's increased surveillance as the main explanation for the increase. In 2008 the monthly peak occurred in January at slightly over 150 outbreaks.
The FAO also reports that H5N1 outbreaks have occurred this year in several countries where the disease was thought to have been eliminated: Cambodia, Israel, Laos, Myanmar, Nepal, and Romania. The only country newly affected by the virus so far this year is Bhutan.
As for H5N1 outbreaks in Indonesia, the FAO does not list specific numbers of outbreaks reported, but a chart shows that Indonesia has had the majority of reported outbreaks every month since April 2009.
"The high number of reports each month is partially explained by the implementation of the Participatory Disease Surveillance and Response (PDSR) 1 programme that targets village poultry production systems (mainly backyard) and reports evidence of virus circulation in the village," the report states. PDSR officers visited 1,780 Indonesian villages in June and found H5N1 in 45 of them (2.5%), the FAO says.
Sixty-three countries and territories have had outbreaks since 2003, the report notes.
Sep 2 FAO AIDE News
Jul 23 CIDRAP News story "Experts say H5N1 picture not greatly improved since 2003"