Jan 17, 2008 (CIDRAP News) – Officials in Iran have confirmed their country"e;s first H5N1 avian influenza outbreak in domestic birds, while authorities in eastern India are working on a massive poultry cull amid worries about possible new H5N1 outbreaks.

A report that Iran filed with the World Organization for Animal Health (OIE) yesterday says the outbreak occurred in Mazandaran, a northern province that fronts on the Caspian Sea. Authorities destroyed a flock of 475 surviving free-range chickens after 14 chickens died in an outbreak that began Dec 10, the report says.

The outbreak was detected through Iran"e;s passive surveillance program for avian flu, officials reported. Samples from the birds first tested positive in the Iran Veterinary Organization"e;s central laboratory in December, and an OIE reference lab in Padova, Italy, confirmed the findings on Jan 8. The source of the outbreak is under investigation, the report says.

Iran"e;s only previous reported outbreak of H5N1 in birds occurred in February 2006 and killed 153 wild swans in Gilan province, which borders Mazandaran on the west, according to OIE records. The country has reported no human cases.

In India, meanwhile, an official in West Bengal state voiced concern that the virus may have spread to several other villages near one where a poultry outbreak was confirmed on Jan 15, according to an Agence France-Presse (AFP) report published today.

"Reports have reached [us] that hens have started dropping dead in several villages surrounding Margram," Anisur Rahaman, the state"e;s animal resources minster, told AFP. "We are worried over the situation. We have sought more help from the federal government."

In a Jan 15 report to the OIE, Indian officials said the virus had killed more than 35,000 chickens on "small and marginal farms" in three villages in Birbhum district and 261 birds in a separate outbreak in Dinajpur district. Both districts are in West Bengal. The report said control measures would include destroying all poultry within about 5 kilometers of the outbreak sites. News reports have said that about 400,000 birds would be destroyed.

An Associated Press (AP) report today quoted Rahaman as saying that hundreds of bird deaths were reported on four new districts of West Bengal yesterday. But rather than avian flu, he said the signs in those cases suggested a virus locally known as Ranikhet, which affects all bird species but not humans.

The AP story put the number of birds killed by the H5N1 virus in Birbhum and Dinajpur districts at 54,000.

The World Health Organization (WHO) expressed concern about the Indian outbreaks today, according to several news reports. "More serious risk factors are associated with this current outbreak than previously encountered, including that the affected areas are more widespread and because of proximity to extended border areas," the WHO was quoted as saying. The statement was carried by AFP and by The Statesman, a West Bengal newspaper, among other reports, but it was unclear which WHO official or office issued it.

Rahaman said about 8,000 birds were killed yesterday, the first day of culling, but officials were facing some resistance from bird owners, according to the AFP story.

West Bengal borders Bangladesh, which also has had recent avian flu outbreaks. A Reuters report today said poultry culling in Bangladesh was going smoothly after the detection of the virus in three more districts. Authorities reported Jan 13 that avian flu had killed 500 chickens in the northeastern district of Moulivabazar.

In other developments, United Kingdom officials reported today that the H5N1 virus has been found in another mute swan from the same area where three other swans recently tested positive. The area is a swan sanctuary in Dorset on England"e;s southwest coast. The latest infected bird was collected on Jan 11.

"There is currently no evidence to suggest widespread disease in the wild bird population, but enhanced surveillance is taking place and poultry keepers in the area are reminded to remain vigilant and report any signs of disease immediately," the UK Department of Environment, Food, and Rural Affairs (DEFRA) said in a statement about the new case. "There is no evidence of disease in domestic birds."