The World Health Organization (WHO) said Wednesday that both Thailand and Vietnam have confirmed one additional human case of H5N1 infection.

The case in Thailand, which was fatal, was a four-year-old boy from Khon Kaen Province. The boy died on Feb. 3.

The case in Vietnam was also fatal, but further details about the case are pending.

To date, Thailand has reported nine cases of human H5N1 infection, of which seven were fatal, while Vietnam has reported 22 cases of human H5N1 infection, of which 15 were fatal.