A woman in a northern suburb of Bangkok has been diagnosed with bird flu (search), Thailand's 20th victim of the disease since 2003, a health official said Monday.

The 50-year-old woman is in stable condition in Bangkok's (search) Siriraj hospital, Deputy Public Health Minister Anutin Charnvirakul said.

The woman fell ill a day after helping clean a chicken coop, said Thawat Suntarajarn, director-general of Thailand's Department of Communicable Disease Control.

Of the 20 people who have gotten the virus, 13 have died.

All three of Thailand's (search) cases this year were reported in October. Besides the 50-year-old woman reported Monday, a 48-year-old man died after handling his neighbors' sick chickens. The man's 7-year-old son also contracted the disease after handling the birds.