JAKARTA, Oct. 8 (Xinhua) -- A 44-year-old Indonesian woman who died on Saturday in Riau province of Sumatra Island was positively infected by avian influenza, health ministry said here Monday.

    The confirmation put the death toll to 87 out of 108 cases in the hardest-hit country, an official of anti-bird-flu center of the ministry Joko Suyono said.

    "Two laboratory tests of the woman who died on Saturday were positive," he told Xinhua.

    The official said that it was not clear yet whether the woman, who began having the germ of the disease on last Monday, had historical contact with fowl, as officials from animal husbandry are heading to the woman's residential area for testing.

    But, contact with chicken is the most cause of bird flu death in Indonesia.

    So far, the viruses have killed globally 197 out of 325 infected people, most of them in Indonesia.

    Suyono said that the woman went to a health clinic soon after she felt the germ and one day later she was admitted to a hospital in Pekanbaru the capital of the province.

    Three days later she was shifted to a designed-bird flu hospital in the capital and died on Saturday, he said.

    Indonesia has struggled to fight with highly pathogenic H5N1 viruses, which have slowly and persistently spread on human.

    The country already completed a clinical test for anti-bird-flu vaccine for human that it made in cooperating with the U.S. drug maker Baxter in September and now ready to use them.

    Experts fear that the highly pathogenic H5N1 virus could mutate in a certain level that can make them transmittable among humans that can cause a pandemic where million people can be killed.

    Huge territory, traditional way of rising chickens on back yard and lack of obedience of provincial administration in implementing the Jakarta decision to stop the virus spread, are among the obstacles in fighting the bird flu in the country.