Tropical viruses in Occitania: Usutu and West Nile would now be endemic

–Original article by Mathilde Debry from Fréquence Médicale

Transmitted by mosquitoes, the tropical viruses Usutu and West Nile have become endemic in Occitania.

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A study reported in the Midi Libre shows that two new tropical viruses are establishing themselves permanently in Occitania: the West Nile virus and the Usutu virus.

Arrived from Africa, through migratory birds, they have established themselves in the Camargue and are spread through the bites of common mosquitoes. They are found in urban and peri-urban areas of Montpellier.

"Watch carefully"

Concerning the Usutu virus, "it must be monitored carefully. There is no outbreak to fear, no need to be alarmist but there is a quiet circulation both in birds, but also in animals. Man and animals such as dogs or horses. It is probably becoming "endemic" in our region", explains to Midi Libre the scientist Yannick Simonin, lecturer at the University of Montpellier.

During the summer of 2018, "we had nearly 2,000 West Nile cases in Europe, including nearly 400 deaths (mainly related to neurological damage) and probably also cases in Occitania, but this circulation went largely unnoticed in our region", continues the specialist.

These two viruses are transmitted via mosquitoes, and their development would be favored by global warming. To protect yourself as much as possible, you must therefore put in place strategies to avoid being bitten.

Symptoms of tropical viruses

In the majority of cases (80%), West Nile virus infection is asymptomatic. "The symptomatic forms of the disease are characterized by the sudden appearance of a high fever after 3 to 6 days of incubation", explains the Pasteur Institute. This fever is accompanied by headache and back pain, muscle aches, cough, swollen glands in the neck, rash, nausea, abdominal pain, diarrhea and respiratory symptoms. "Neurological complications (meningitis, encephalitis) occur in less than 1% of cases. Even more rarely, other complications (hepatitis, pancreatitis or myocarditis) may appear", continues the research center. Generally, the patient recovers spontaneously, sometimes with sequelae. But the viral infection can prove fatal, mainly in older adults.

Also sometimes asymptomatic and deadly, the Usutu virus can cause meningitis, meningoencephalitis or paralysis. It mainly affects people who are immunocompromised or have chronic pathologies.