These two new viruses that the tiger mosquito can transmit

The mosquito Aedes albopictus, that we call commonly the tiger mosquito is a mosquito native to Asia, which has multiplied in France since 2004 and is now present in 3/4 of the country. Essentially urban, it is a vector of diseases such as dengue fever, chikungunya or zika. But he could also transmit other diseases to humans according to‘Pastor Institute. In a press release dated June 5, 2023, the researchers announce that the tiger mosquito is now able to transmitWest Nile and Usutu viruses. These viruses are already transmitted by the Culex pipiens (which is none other than the common mosquito) and infect in particular Migrator birdswhich in the spring, make a long migration to reach their breeding grounds, passing in particular through the Great French East or the Camargue. It was within the framework of mosquito surveillance in the Grand Est that French researchers undertook to measure the capacities of five species of mosquitoes to transmit the West Nile and Usutu viruses.

“Many of our results were predictable, except for the tiger mosquito”

“Many of our results were predictable except for the tiger mosquito. Aedes albopictus. Indeed, this one proved capable of transmitting the two viruses” reports Anna-Bella Failloux, coordinator of the study. To feed, the tiger mosquito bites humans and can potentially serve as an intermediary to transmit the virus from birds to humans. “With our knowledge of the territorial distribution of the tiger mosquito, we can already establish a map of areas where both viruses are at risk of being transmitted to humans. In particular, it is possible to strengthen the monitoring of mosquitoes and birds near urban areas, where the tiger mosquito is already established”, reassures Anna-Bella Failloux.

The West Nile virus (or west nile virus) does not cause no symptoms in most cases. In 20% of cases, it causes a sudden fever, accompanied by headaches and muscle aches, sometimes associated with neurological complications (meningitis, encephalitis) potentially severe. In less than 1% of cases, other complications (hepatitis, pancreatitis or myocarditis) may occur. Generally, the patient recovers spontaneously, sometimes with sequelae. Originally from Africa, the Usutu virus was reported in 2015 for the first time in eastern France. Considered “emerging”, it can cause Japanese encephalitis which translates into central nervous disorders : disorientation, loss of motor coordination, sudden weight loss, hepatomegaly (enlargement of the liver) and splenomegaly (enlarged spleen). There is no specific treatment or vaccine. Healing involves relieving symptoms and deaths are rare even exceptional.