In 2003, 2 members of a 5 member family from Hong Kong were infected with H5N1 virus after travelling to China. The source of the infection could not be confi rmed. One of these two persons died while the other, a young boy recovered. Subsequently an outbreak of H5N1 infection in poultry and humans occurred in south East Asia. In 2003-2004, fatal and severe respiratory infection, mostly pneumonia and respiratory failure, were seen in China, Thailand and Vietnam. All of these were associated with an outbreak of H5N1 in poultry. A total of 50 cases with 36 deaths were reported with the mode of disease transmission being from sick or dead poultry to humans. Only one case of human-to-human transmission from a sick child to mother was reported in Thailand [1].