A 16-year-old boy in Hunan province is seriously ill after contracting the H5N1 strain of the bird flu virus, the Ministry of Health said yesterday.

The teenager, surnamed Wu, is the fourth confirmed case this year, it said on its website.

A native of Guizhou province, Wu fell ill at home on Jan 8. On Friday, he was admitted to hospital in Huaihua, Hunan, after his condition worsened, the ministry said.