Misdiagnosis raises questions about extent of avian flu epidemic

The illness of a Vietnamese boy who died from the H5N1 strain of avian influenza last year was not correctly diagnosed at the time because he had not developed the severe respiratory symptoms normally associated with the disease.

That the actual cause of his death was not identified at the time suggests that the prevalence of avian flu in South East Asia was underestimated, experts from the World Health Organization say.

The 4 year old boy was admitted to hospital on 12 February 2004 with severe diarrhoea. An x ray film of his chest was normal. Three days later he became drowsy …