West Nile virus alert

A Europe-wide health alert has been issued about the West Nile virus, leading the Portuguese health authorities to step up vigilance against this rare but sometimes fatal illness. The virus infects humans via mosquitoes, but cannot be transmitted from person to person.

In around 80 per cent of cases, the infection does not present any symptoms at all and, in the remaining 20 per cent of cases, the symptoms are similar to the flu. The best way to avoid the virus is to avoid being bitten by mosquitoes. Last year, the virus killed more than 100 people in the United States and thousands of people were infected.

A spokesman from the Director-General of Health (Direcção-Geral de Saúde) has indicated that the department has taken “appropriate measures” in Portugal, following a recent confirmation that two ill foreigners contracted the West Nile virus after a visit to the Algarve.

The DGS stressed that in Portugal, as in remaining countries in Southern Europe, “the risk of contracting the virus is very low”, although it has appeared in the South of France. Apparently, the onset of the illness is “normally benign and serious infections are less than one per cent”.

But studies conducted in Portugal since the 1960s have revealed some evidence that the virus has circulated around the country in the past. And, in spite of the official low risk of the illness spreading, the Director-General of Health, the Institute of Hygiene and Tropical Medicine, the Veterinary Director-General and the National Institute of Health have taken extra measures. These include increased vigilance of illness in humans and animals bitten by mosquitoes.

Deputy Director-General at the Director General of Health, Francisco George, refused to divulge many details about the two suspected cases, but he did agree to speak to The Resident: “What I can tell you is that they were treated in England – but they are not British.” (They are believed to be Irish) “Both the patients are now at home and recovering well.”

Doctor George explained more about the transmission of the virus: “The mosquito bites infected birds and then becomes infected itself. But the risk of cases in Portugal is very, very low and certainly no higher than in other Mediterranean countries. So far, the tests performed on mosquitoes in labs are all negative. But we will increase the number of tests.

“The first ever case of the virus was identified in Uganda in the 1930s, hence the name of the virus, but the infected birds can be anywhere. One of the biggest epidemics in recent years was in America in 1999. But people in countries like Portugal have more resistance in the form of antibodies so they will be more resilient to the virus,” he told us.