Five more cases of bird flu reported in Viet Nam, UN health agency says

Five more human cases of bird flu have been reported in Viet Nam, the United Nations health agency said today, bringing the total since mid-December to 33, 15 of them fatal, in the latest outbreak of a disease that in a worst-case scenario could kill tens of millions people worldwide.

All five cases of the H5N1 virus are in a family from the northern port city of Haiphong – the 35-year-old father, the 33-year-old mother, and their three daughters, aged 13 years, 10 years and 4 months, the World Health Organization (WHO) added.

Last week WHO reported that there was currently no evidence that the virus was spreading easily from person to person. The agency added that it had become increasingly important for scientists to share the viruses from recent clusters of cases.

"Thorough investigation of all such clusters is essential to determine possible changes in the behaviour of the virus and thus support assessment of the risk of an influenza pandemic," it said of the H5N1 virus. The so-called Spanish flu pandemic of 1918-20, unrelated to the present virus, is estimated to have killed between 20 million and 40 million people worldwide.

Overall there have been more some 80 reported infections, nearly 50 of them fatal, since the first human case linked to widespread poultry outbreaks in Viet Nam and Thailand was reported in January last year.

Since then WHO has repeatedly warned that H5N1 could mutate into a new human virus with pandemic potential.

Nearly 140 million domestic birds have died or been culled over the past year in southeast Asia in an effort to curb the spread of the disease. The agency is concerned that continuing transmission to humans might give avian and human influenza viruses an opportunity to exchange genes, facilitating a pandemic.