Jakarta – A nine-year-old boy has been confirmed as Indonesia's 51st human bird flu fatality, a health ministry official said.

The boy died on September 22 and test results from two laboratories confirmed he was infected with the H5N1 virus, a doctor on duty at the national bird flu center in Jakarta told AFP Sunday.

He identified the laboratories as the ministry of health's laboratory and that of the US Naval Medical Research Unit (Namru). The boy died shortly after he was admitted to the Sulianti Saroso hospital, the capital's main center for bird flu treatment, said the doctor, who declined to be named.

The latest death brought the overall toll in Indonesia from H5N1 to 51, the highest reported anywhere in the world.

Tests from two laboratories are required for the World Health Organization to count the fatality in its official toll.

The boy, who came from Pondok Pinang in South Jakarta spent two days at a police hospital before he was moved to Sulianti Saroso, the doctor said. He could not immediately provide more details, including whether the victim had come into contact with sick poultry, the usual method of transmission of the virus.

But he said the boy's family had informed doctors that the boy had already been under high fever for about a week before he was admitted to hospital.

Indonesia's death toll from bird flu has been steadily rising as the virus has marched across the archipelago nation, spreading to 29 of its 33 provinces.

While the virus does not spread easily among people, the chance of a mutation that would allow it to do so is heightened as more humans catch it from infected birds. Scientists fear that if this occurs, a global flu pandemic with a massive death toll could result.