West Nile Disease is a virus which is spread through the bite of an infected mosquito.
Last year alone it killed 280 people in the States and recent tests have shown that it could be present in UK birds, although there have been no cases of the disease in the UK. West Nile virus was first discovered in the West Nile area of Uganda in 1937.
Since then it has been found in a number of other countries, including Israel, Africa, Asia and parts of Eastern Europe.
The most recent outbreaks have been in the States, where two thirds of the East Coast states have reported cases - there has even been a case of West Nile in California.
The UK has had no human cases of the disease, although researchers from Oxford University recently found West Nile antibodies in non-migratory birds in the UK, which suggest the presence of the virus.
Causes And Risk Factors
The virus is normally transmitted by mosquitoes which suck the blood of infected birds and then feed on humans.
There is no evidence to suggest that West Nile can be spread from person to person, although it may be transmitted through donor blood so potential donors are advised against donation for 28 days after leaving affected regions.
A sufferer can incubate the disease for up to a fortnight after being bitten.
Many of those who have become infected will either have no symptoms, or will have mild flu-like symptoms, which last a couple of days.
These symptoms can range from fever, headache and body aches to skin rashes on the trunk of the body and swollen lymph glands.
Less than 1% of those who become infected will get a serious form of the disease. They can suffer from West Nile encephalitis, or meningitis,typically the patient suffers a flaccid paralysis, with severe disease and even death occurring most commonly in older patients.
Out of about 1,000 people who became infected in Europe recently, there were about 40 deaths.
Treatment And Prevention
The best way to protect yourself is to avoid being bitten by a mosquito.
The mosquitoes which carry West Nile Disease bite at dawn, dusk and early evening, so if you are travelling to an area where the disease is prevalent you should either stay indoors, use insect repellent treated mosquito netting or wear long sleeved shirts and long-trousers and wear strong insect repellent such as DEET.
People travelling with young children should ensure that they use a specially prepared insect repellent, rather than the adult version.