JAKARTA, Sept 3 (Reuters) - Indonesia rejected on Monday a study by U.S. researchers that concluded that the H5N1 bird flu virus had spread from person to person during an outbreak last year, saying it was misleading.

A mathematical analysis published last week in the U.S. journal of Emerging Infectious Diseases said it found statistical evidence of human-to-human transmission in a cluster of cases on Sumatra island, where eight family members died in May 2006. Indonesia"e;s Health Minister Siti Fadillah Supari said the research findings had "misled the public".

"It"e;s pure logic... If there had been human-to-human transmission, it would have already swept the country and killed thousands," Supari told a news conference.

"Our scientists have already determined that the 2006 outbreak on North Sumatra was not a case of human-to-human transmission." Researcher Ira Longini and colleagues at the Ferd Hutchinson Cancer Research Center in Seattle, who examined two clusters of bird flu cases, said they had developed a tool to run quick tests on disease outbreaks to see if dangerous epidemics or pandemics may be developing.

"We find statistical evidence of human-to-human transmission in Sumatra, but not in Turkey," they wrote in a report published in the journal Emerging Infectious Diseases on the two clusters studied.

Bird flu is endemic in bird populations in most parts of Indonesia, where millions of backyard chickens live in close proximity to people.

While it is largely an animal disease, experts fear the virus could mutate and spread from human to human, turning into pandemic that could kill millions.

Contact with sick fowl is the most common way for humans to contract the disease.

Indonesia has had 105 confirmed human cases from bird flu, out of which 84 have been fatal, the highest for any country in the world.

The popular resort island of Bali, the centre of Indonesia"e;s tourism industry, recently saw its first confirmed human fatalities from the disease.

Supari said tests done in WHO laboratories in Atlanta on virus samples from Bali showed the virus had jumped from animal to humans.

"There is nothing to worry about, so far Atlanta has not issued any alarm," she said after the news conference.

Bali regularly hosts large international conventions and is due to hold an important U.N. climate change conference in December with about 10,000 people expected to attend.

Globally there have been 327 cases and 199 human deaths from bird flu, World Health organisation data shows.