Nigeria is the first African country to have a confirmed outbreak of the deadly H5N1 bird flu virus, according to international animal health agencies.

The UN Food and Agriculture Organization (FAO) and the World Organisation for Animal Health (OIE) announced today (8 February) that laboratory tests had confirmed the presence of H5N1 in samples taken from an industrial chicken farm in the northern Kaduna state.

Laboratory tests are underway to determine which known strains of H5N1 the virus found in Nigeria most resembles. This could help authorities determine how the virus reached Nigeria.

Authorities suspected an outbreak of bird flu in Nigeria earlier this month but preliminary tests led them to announce this week that H5N1 was not to blame.

The OIE and the FAO will coordinate an immediate response to the outbreak.

"A team of experts will be sent to the affected area in order to assess the situation and provide technical advice to the national authorities," says a statement from the OIE.

Although it will be difficult to prove the source of the virus, scientists have long feared that wild birds migrating to Africa would carry the virus from Europe or Asia and spread it quickly across the continent, which lacks a robust public health and monitoring infrastructure.