Bhimanto Suwastoyo, Jakarta – The death toll in Indonesia from bird flu rose to 55 after officials confirmed that a 27-year-old woman who died last week was infected with the virus.

The death is the third to be confirmed in two days in Indonesia, which is grappling with the world's highest number of deaths from avian influenza.

"Both tests showed her to be positively infected with the bird flu virus, making her the 55th fatal casualty" in Indonesia, said Tontro, an official at the health ministry's national bird flu information centre.

Positive results from two Indonesian laboratories mean that the World Health Organization (WHO) includes the case in its records.

The woman from Central Java province, identified by the centre as Mistiyem, developed symptoms on October 8 and was hospitalised on October 12. She died a day later, according to a statement posted on the WHO website.

The WHO said the source of her exposure to the virus was currently under investigation. The vast majority of cases in the archipelago nation have been spread by contact with infected poultry, though several cases of limited human-to-human transmission have also occurred here.

More human cases of the virus – 72 have now been reported in Indonesia, the world's fourth most populous nation – increase the possibility of the H5N1 virus mutating to become easily transmissible among people.

Scientists fear that this could lead to a global flu pandemic with a potential death toll of millions.

On Monday, the health ministry confirmed the deaths of a 67-year-old woman who died in West Java's Bandung late Sunday and an 11-year-old boy, who died in Jakarta on Saturday. Both were believed to have had contact with poultry before they died, the WHO statement said.

Health officials said that the woman had been suffering from encephalitis, or inflammation of the brain, believed to be caused by the virus and the first case of its type in Indonesia.

The UN's senior bird flu official appealed to international donors last month to speed up the disbursement of promised aid to Indonesia to help it fight the spread of H5N1 among the population.

Officials here have said they need around 250 million dollars a year for the next three years to effectively combat the virus, but next to no funds have arrived since donors pledged millions at a conference in Beijing this year.

Critics have charged that the country, which was accused of initially covering up outbreaks, has been slow to fight bird flu.