Genetic analysis on the influenza A H5N1 viruses found in a 33-year-old man and his nine-year-old son, who contracted bird flu last month, show the two viruses are similar.

The Department of Health confirmed the viruses isolated are different from the 1997 strains that infected humans.

The virus genes were purely avian in origin. In the absence of human influenza gene segments in the viruses of these two cases, the risk of human to human transmission of A H5N1 virus is low. There is, therefore, no cause for panic among members of the public.

Hong Kong has a very sensitive and comprehensive surveillance system that enables it to detect suspected cases early and prevent them from spreading. 

To prevent influenza, particularly during the influenza prevailing period between January and March, the public should maintain good personal and environmental hygiene, and avoid direct contact with poultry and birds. Wash your hands thoroughly if you do come into contact with birds.