A 6-year-old Indonesia boy has died of bird flu, bringing the death toll from avian influenza in the country to 81, the World Health Organization reported.

Officials said the boy, from the Banten province, had no apparent contact with infected poultry and they were investigating how the youngster contracted the H5N1 virus. He died Sunday.

Most bird flu victims have had contact with infected birds. Health officials fear that the virus could mutate into a form easily passed from person to person, which could set off a global pandemic killing millions.

Since 2003, when the disease reemerged, there have been 318 confirmed cases of bird flu resulting in 192 deaths. Indonesia has reported 102 cases with 81 fatalities, the highest in the world. Vietnam has reported 42 deaths followed by Thailand with 17, China with 16 and Egypt with 15. A total of 12 countries have reported cases of bird flu.