Friday, September 4, 1998 Published at 11:54 GMT 12:54 UK
Experts warn of brain fever epidemic
West Nile fever is spread by mosquitoes
A mosquito-borne brain infection found in Africa, Asia and the Middle East has winged its way to Europe and could lead to future epidemics.
Scientists, writing in this week's Lancet, are warning of the risks of outbreaks of West Nile fever in Europe following an epidemic in Romania.
The virus had previously been almost non-existent in Europe.
Symptoms include fever, rash, severe aches, eye irritation and swollen lymph glands.
It can also lead to meningitis and encephalitis (swelling of the brain). In some cases, these can be fatal conditions.
In August 1996, doctors in two infectious disease hospitals in the Romanian capital Bucharest noticed a rise in the number of central nervous disorders.
By September, when the outbreak peaked, they were able to confirm that the patients had been infected with West Nile fever.
After laboratory tests of blood and spinal fluid samples, 393 patients were confirmed as having the infection in addition to meningitis and encephalitis.
Thirteen per cent of patients went into come and 3% - 17 patients, all over 50 years old - died, although experts believe the true number of deaths and infection may have been higher than recorded because of a delay in setting up a national surveillance programme.
In Africa, the virus is normally transmitted by the Culex univittatus mosquito.
After the first cases of West Nile fever were identified, the Romanian Ministry of Health asked the US Centers for Disease Control and Prevention to look into the outbreak, see if local laboratories were capable of diagnosing new cases and recommend control measures.
They found that the virus was carried by the Culex pipiens mosquito.
They think birds from Africa may have carried the virus to Europe and passed it on to mosquitos there.
Apartment blocks in urban areas, particularly those which had experienced flooding, were heavily infested and provided a good breeding ground for the mosquito.
The mosquito is known to feed regularly on humans, particularly in rural areas. Forty-one per cent of domestic fowl were infected.
Writing in The Lancet, Dr Ted Tsai and colleagues say the outbreak was "the first important outbreak" of West Nile fever in Europe.
And they warn: "In some areas of Europe, urban conditions are suitable for the introduction and amplification of West Nile virus, with the risk of future epidemics."