Major health alert after suspected case of West Nile virus detected in Faro

A suspected case of mosquito-borne West Nile Virus – which can cause viral meningitis – has been detected in Faro, sparking a major health alert.

With tests still ongoing to confirm the diagnosis, medical experts, including those with responsibilities for blood storage and transplants, met on Monday to “evaluate the risks”.

Francisco George, director general of health, has confirmed that the case – involving a Portuguese man living in the Algarve – appears to have been contracted here.

The man has already been discharged from Faro Hospital with “a favourable evolution” of his symptoms, but he is still being monitored.

As international authorities have been advised of the situation, the message nationally is for a general tightening-up of anti-mosquito “mechanisms”.

Councils are to be encouraged to step-up mosquito control, while people generally are advised to use repellents, sprays and mosquito nets.

WNV used to be considered a minor risk for humans until outbreaks in Algeria (1994) and Romania (1996) which caused a high number of cases with neuroinvasive disease.

There is no vaccine available, thus prevention is the only way to prevent contagion.

General advice involves eliminating standing pools of water where mosquitoes breed, “such as old tyres, buckets, and unused swimming pools”, as well as avoiding areas where mosquitoes are more prone to congregate “such as near marshes, and areas with heavy vegetation”.

In this case, authorities will be looking into likely areas where the man may have been bitten.

For now, Francisco George has said it will take “some days” for the diagnosis of WNV to be confirmed.

Veterinary authorities also are on the alert, as “infected mosquitoes can transmit the virus to animals, particularly horses”, writes Público.

The authorities stress that this is a mosquito-born virus which does not transmit from human to human.

In 80% of cases it causes little or no symptoms, but in 20% fever, vomiting, joint-pain and skin eruptions can occur seven to 10 days after people are bitten.

Neuroinvasive disease occurs in less than 1% of cases, writes Wikipedia.

This is not the first case of suspected WNV in the Algarve. In 2004, two cases were confirmed in Ria Formosa, but the virus ended up being “contained to mosquitoes”.

Público adds that investigations back in the 60s already confirmed “some activity” of the virus in Portugal.

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