Vietnam-Bird Flu.

VIETNAM-BIRD FLU.

HANOI , Vietnam — Health officials say a Vietnamese woman has died of bird flu, the country’s fourth human case this year.

The 23-year-old woman died Wednesday in Thanh Hoa province, some 94 miles south of Hanoi .

A health official said Friday test results confirmed she was infected with the H5N1 strain of the bird flu virus.

The woman became ill early this month and was hospitalized Wednesday.

Bird flu has killed 56 people in Vietnam .