Brazil, the world's largest chicken exporter, has declared an animal health emergency for 180 days, Reuters reported. The decision is in response to the first detection of a highly pathogenic bird flu virus in wild birds in that country. Based on World Organization for Animal Health guidelines, infection with the H5N1 subtype does not lead to a trade ban.

But in Brazil they know that an outbreak of disease on a farm usually results in the killing of the entire herd and can trigger trade restrictions from importing countries. So far, eight cases of the virus have been confirmed in wild birds. Most of the production is in the southern regions which are not affected, but the government is on alert.

The news also affected the shares of Brazil's BRF SA, the world's largest chicken exporter.

They rose by 3,6 percent before the government's announcement, and ended with a 0,5 percent drop a day later. Poultry vaccination would inevitably lead to trade restrictions and therefore this country does not support this preventive measure, reports "Economic Times" and reports "Agroclub". Exports would be threatened if the virus infects commercial farms.

They export poultry and poultry products to more than 130 countries, making possible negotiations for the export of vaccinated poultry and poultry products difficult. The virus is usually fatal to poultry, and entire flocks must be destroyed even when only one bird is infected or tests positive for the disease.