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JAKARTA, May 30 (Reuters) - A 45-year-old Indonesian man from central Java has died of bird flu, a health ministry official said on Wednesday.

The man from Grobogan died on Monday after being hospitalised on May 17, Joko Suyono of the ministry"e;s bird flu centre said by telephone.

Authorities were still investigating, but the man was believed to have slaughtered and eaten a sick chicken, while dead fowl were found near his home, the official said.

The man"e;s death brings the number of confirmed human fatalities in Indonesia to 78, the highest in the world.

Contact with sick fowl is the most common way humans become infected with the H5N1 bird flu virus.

Indonesians keep millions of fowl in the back yards and attempts to limit contact with humans are often poorly enforced, while education campaigns often do not reach more remote areas.

For the moment, it remains largely a disease in birds but scientists are worried about the virus"e;s persistence and ability to adapt to new environments and hosts.

Scientists say H5N1 is a global threat because the virus could mutate into form that passes easily between people, triggering a pandemic in which millions could die.