Hong Kong may not be prepared for future bird flu outbreaks if the virus has mutated from the known H5N1 strain which has twice jumped the species barrier, killing seven people, the agricultural chief warned yesterday.
'We are at a stage where we are quite comfortable as far as the H5N1 virus is concerned. Now there is of course the possibility there may be other forms of avian flu in Hong Kong,' said Director of Agriculture, Fisheries and Conservation Thomas Chan Chun-yuen.
But bio-security and hygiene standards had been stepped up in farms after the fourth outbreak of H5N1 flu last year, Mr Chan said after a speech at a lecture series on the control of farm animal diseases at the University of Hong Kong.
Influenza viruses are divided into subtypes based on two proteins on the surface of the virus. These proteins are called haemagglutinin (H) and neuraminidase (N) and are subject to mutations.
Trevor Ellis, a senior Agriculture, Fisheries and Conservation Department veterinary officer, said the department's study of the chicken vaccination programme, which covered 75 farms, found 'vaccinated chickens can get infected and shed virus, albeit at lower levels than unvaccinated chickens'.
'There are still concerns over the evolution of new virus strains,' he said.
