BEIJING - H7N9 avian influenza, which was first reported in humans in China this year, has a lower fatality risk than H5N1-type bird flu that emerged in 2003, researchers said on Monday.

A study by researchers from the Chinese Center for Disease Control and Prevention in Beijing and the University of Hong Kong found that the H7N9 proved fatal in 36 percent of hospitalized patients on the Chinese mainland.

Writing in a paper in the online publication of the Lancet medical journal on Monday, the researchers estimated that the fatality risk for a symptomatic case of H7N9 flu could be 0.16 percent to 2.8 percent.

That meant the influenza was much less deadly than the H5N1 that has killed 375 of the 630 infected people around the world in the past decade, according to the paper.

"Human infections with avian influenza H7N9 virus seem to be less serious than has been previously reported," researchers wrote in the paper. However, they added that continued vigilance and sustained intensive control efforts are needed to minimize the risks of human infection.

Official statistics showed that from the end of March when the first H7N9 infection case in the world was reported to May 27, the Chinese mainland recorded a total of 130 laboratory-confirmed cases of H7N9, among whom 37 died and 76 recovered. Seventeen patients remain in hospital.