Clues to Spread of Avian Flu

The deaths of two young children have raised the possibility that the number of cases of avian influenza has been under-estimated, new research has shown. It also suggests that, under certain conditions, humans could pass the virus to one another.

The brother and sister, who lived in a single room with their parents in southern Vietnam, were admitted to hospital suffering from gastro-enteritis and acute encephalitis, which are common ailments in the country. However neither displayed respiratory problems, which have been considered typical in cases of avian flu – H5N1.

This latest research, funded by the Wellcome Trust medical research charity and published in today’s (Feb 17th)edition of the New England Journal of Medicine, shows that the four-year-old boy had traces of the virus in his faeces, blood, nose and in the fluid around the brain, indicating that H5N1 can attack all parts of the body, not just the lungs. It is suspected his nine-year-old sister, who died two weeks earlier in February last year (04), was also suffering from the virus.

Dr Menno de Jong, virologist at the Oxford University Clinical Research Unit, based at the Hospital for Tropical Diseases in Ho Chi Minh, who led the investigation, said : “ This illustrates that when someone is suffering from any severe illness we should consider if avian flu might be the cause. It may be possible to treat but you have to act in the early stages, so awareness of the whole spectrum of symptoms in an emerging disease like avian flu is vital.

“It appears this virus is progressively adapting to an increasing range of mammals in which it can cause infection, and the range of disease in humans is wide and clearly includes encephalitis.”

Dr Jeremy Farrar, Director of the Wellcome Trust’s Vietnam unit, said: “ This latest work underlines the possibility that avian influenza can present itself in different ways. The main focus has been on patients with respiratory illnesses but clearly that’s not then only thing we should be looking for.Therefore the number of cases of H5N1 may have been under-estimated.

“The presence of virus in the faeces also highlights a potential route of human-to-human transmission, especially in crowded living conditions, which is a major cause for concern and has important implications for infection control and public health.”

It is not believed that either of the children passed the virus on but it is also not clear how they contracted it. There were no sick chickens nor ducks near their home and their parents were not affected. However the girl often swam in a nearby canal which may have been used by infected ducks and recent research has shown they can contaminate water.

ends

Notes to editors:

The Wellcome Trust is an independent research-funding charity established in 1936 under the will of tropical medicine pioneer Sir Henry Wellcome.The Trust’s mission is to promote research with the aim of improving human and animal health and it currently spends more than £400m p.a.

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