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.

SAO PAULO (Reuters) -Brazil, the world's largest chicken exporter, on Friday reported its first case of highly pathogenic avian influenza - also known as bird flu - on a commercial farm, triggering fears over global poultry supply chains.

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.