West Nile Virus kills horse in Loulé. “Risk of human infection is low”

A horse has died in Loulé after becoming infected with the mosquito-borne West Nile Virus (WNV). Though on alert, authorities say the risk of people becoming infected is “low”.

The animal died on August 26 from “encephalitis caused by the infection”.

Loulé council and regional water company Águas do Algarve acted fast to destroy existing mosquito nests in the borough, the Algarve’s health delegate Ana Cristina Guerreiro told Lusa news agency, and further infections are unlikely.

Guerreiro suggested this was an “isolated case” that may have been caused by a “mosquito that was contaminated by a passing bird” and which then passed the virus onto the horse.

Nonetheless, doctors have been warned to be on the lookout for any symptoms of the virus.

The regional veterinary authority is also warning people to use insect repellents and anti-mosquito electrical devices and stay away from “stagnant waters” like sewage water treatment plants.

The last case of a human infected with WNV in the Algarve was detected last year, when a Faro resident had to be admitted to hospital (click here).

Other cases date back to 2004, when two birdwatchers developed symptoms after an Algarve holiday, said Guerreiro.

West Nile Virus is mosquito-borne and does not transmit from human to human.

In most cases (around 80%) it causes few or no symptoms, but in 20% of cases people can suffer headaches, body aches, joint pains, vomiting, diarrhoea, and/ or a rash.

Most people affected recover completely, but fatigue and weakness can affect them for some time afterwards.

In less than 1% of cases, serious neurologic illness such as encephalitis or meningitis occur, according to USA’s Centre for Disease Control and Prevention.