Thailand ? A 5-year-old boy became Thailand’s second bird flu fatality in two months.

Thai health authorities said Friday that lab tests showed the boy died from the H5N1 strain of bird flu, which international experts fear could trigger a human pandemic if it mutates into a form easily passed between people.

The boy fell ill with fever, stomach pains and vomiting on Nov. 25 at his home in a district of Nakhon Nayok province, about 45 miles northeast of Bangkok, Public Health Minister Phinij Jarusombat said. He was hospitalized nine days later and died Wednesday.

Health officials believe the boy had contact with the feces of chickens belonging to an uncle living next door.

The cause of death was not yet confirmed by the World Health Organization.