A World Health Organization laboratory test has confirmed a five-year-old Indonesian boy who died last month was infected with bird flu.
His death takes the total number of confirmed bird flu deaths in the country to 40.
The latest victim died on June 16th in Tulungagung in East Java province after being admitted to hospital on June 8th.
The infection was confirmed to be from the H5N1 avian virus by a WHO laboratory in Hong Kong. An official said a dead chicken was found near the boy's house.
Indonesia has seen a steady rise in human bird flu infections and deaths since its first known outbreak of H5N1 in poultry in late 2003, and the country has registered more deaths this year than any other country.
Indonesia has 220 million people and an estimated 1.2 billion chickens, some 30 per cent of them in the yards of homes in both rural and urban areas.
The bird flu virus is endemic in poultry in nearly all of the 33 provinces in Indonesia, a country of 17,000 islands sprawling across some 5,000 km (3,100 miles).
Despite the climbing death toll, the government has resisted mass culling of birds, saying it is too costly and impractical.
Vaccination has been preferred to culling, which has been done only sporadically at selective farms and their immediate surroundings.
Bird flu remains essentially an animal disease but many countries around the world are on alert over fears it may mutate into a disease that could pass easily among people and trigger a pandemic, killing millions.