Ten more cases of human bird flu in Viet Nam

Ten more cases of human bird flu in Viet Nam brings the number confirmed since mid-December to 24, 13 of these have died.

Full information is desperately needed to assess the risks of a pandemic that in a worst-case scenario could claim tens of millions of lives worldwide says the United Nations health agency.

The World Health Organization (WHO) in its latest update says immediate field investigation of each new case is essential to ensure timely detection of clusters of cases occurring in family members or health care workers- the H5N1 virus, which has caused 69 reported infections, 46 of them fatal. The first human case linked to widespread poultry outbreaks in Viet Nam and Thailand was reported in January last year.

These cases can provide the first signal that the virus is altering its behaviour in human populations and warn authorities to intervene quickly.

The agency has repeatedly cautioned that the virus could mutate into a new human virus with pandemic potential. 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.

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