Avian influenza (H5N1) virus is possibly spreading among humans in Vietnam, the World Health Organization (WHO) said in a document made public on its Web site on Thursday (May 19).
Reporting on an international meeting held in the Philippines last week, WHO officials said worrying changes in the epidemiology of the virus had been seen between January and April this year in the north of Vietnam. "Investigators were not able to prove that human-to-human transmission had occurred, [but] they expressed concerns, which were shared by local clinicians," they said.
The document notes concerns that the latest H5N1 strains could be resistant to the antiviral oseltamivir, previously thought effective in fighting infection. It also discusses changes to the hemagglutinin (HA) protein that have been noted in 2005 H5N1 isolates, but had not been seen in 2004 sequence data. "The changes are consistent with the possibility that recently emerging H5N1 viruses may ...
