The first cases of the West Nile virus in either the Republic or Britain have been confirmed in two Irish tourists who returned from the Algarve, Portugal, this month. Fiona Tyrrell reports.
The presence of the infection has prompted the National Disease Surveillance Centre (NDSC) to issue a travel advisory to people going to areas where mosquitoes are common.
Lab tests confirmed the presence of the virus yesterday, according to the NDSC, which says it is "monitoring the situation very closely".
Travellers have been urged to be vigilant and to take preventative measures against mosquito bites. The Irish Blood Transfusion Service is refusing donations from people returning from holidays in the Algarve starting from tomorrow. People will not be eligible to donate blood for 28 days after they return from the Algarve. A similar deferral policy is in place regarding people returning from the US, Canada and New Mexico.
Although the West Nile Virus infection is normally a very mild illness, it is important that the public is aware of the small potential risk when visiting any area where mosquitoes are common, according to Dr Paul McKeown, a specialist in public health medicine with the NDSC.
"The most severe disease is seen in those aged over 80; severe disease is virtually unknown in children.
" In this instance, neither traveller required hospitalisation. One individual has fully recovered while the other is getting better."
The disease was first identified in the 1930s in Africa. It travelled to Europe and in 1999 there was an outbreak in the United States. Last year in the US, 10,000 people were infected with the virus, almost 3,000 were seriously affected and some 260 people have died.
In 2003, there were three confirmed cases in Europe; one in the Netherlands was imported, and the other two cases were in the south of France (acquired locally or in Spain). While the two Irish travellers may be just an example of an "odd case" of the disease appearing, Dr McKeown said it could also be the "vanguard for more cases of the disease".
Dr Muiris Houston writes:
West Nile Virus (WNV) belongs to a group of viruses that are transmitted by insects. It is common in Africa, Australia and the Middle East and appeared in north America in 1999. The virus normally lives in birds and is spread by the bite of an infected mosquito.
West Nile Virus cannot spread from person to person.Most cases of WNV do not cause a serious infection, with 80 per cent of people experiencing no symptoms at all.
Others will develop a flu-like illness for three to five days and will require nothing more than rest, fluids and paracaetamol.
In a tiny proportion of those infected the virus spreads to the brain and the spinal cord.
It can be fatal, with people over the age of 50 especially at risk.
Treatment involves hospitalisation and supportive care. There are no specific drugs for West Nile Virus.