Officials and chicken farmers in Brazil have stepped up sanitary controls close to where the country's first case of avian influenza was found on a commercial farm, while racing to track the virus to stop its spread.

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.

A devastating U.S. bird flu outbreak and wider trade tensions with Washington have limited Chinese appetite for American poultry. China now blocks poultry from more than 40 U.S. states over bird flu, according to U.S. government data.