Brazil began a 28-day bird flu observation period on Thursday which it hopes will show the country's chicken farms are free of the disease after local authorities said a farm where its first outbreak was detected had been fully disinfected.

Brazil, one of the world’s largest producers and exporters of poultry, has confirmed the country’s first bird flu outbreak on a commercial farm.

The Brazilian government on Thursday said that Russia, Belarus, Armenia and Kyrgyzstan have banned chicken imports from the Brazilian state where the country's first bird flu outbreak occurred on a commercial farm, reported Reuters .