The tiger mosquito, established in the Ile-de-France region, is capable of transmitting 5 arboviruses including West Nile, chikungunya, and dengue fever… within periods ranging from 3 to 21 days.
Arboviruses include viral diseases caused by a virus transmitted by the bites of infected mosquitoes (arbovirus), in particular tiger mosquito. We know of around a hundred arboviruses that are pathogenic to humans, for example those of yellow fever, Japanese encephalitis, Rift Valley fever, West Nile viruses, Chikungunya… But especially dengue fever, which is on the rise in the Ile-de-France region in 2024. Between 1er January and April 19, 2024, 1,679 imported cases of dengue fever were recorded in mainland France, 13 times more than last year over the same period, according to the Pasteur Institute. At an outside temperature of 28°C, the West Nile virus needs 3 days before being retransmitted by the mosquito; this period is between 3 and 7 days for the chikungunya and Usutu viruses; and it is between 14 and 21 days for dengue fever and Zika. In this context of Olympic Gamessynonymous with additional flows of people from countries endemic for other arboviruses, vigilance is necessary.
What is the definition of an arbovirosis?
Arboviruses are viral diseases transmitted by an arbovirusa vector of type mosquito (tiger mosquito for example) or tick, to animal or human hosts, defines Public Health France. These conditions are mainly tropical. There are approximately 130 known pathogenic arboviruseshome to a dozen different families of hematophages (blood eaters).
What is the list of the main arboviruses?
The main arboviruses are:
- Yellow fever
- Zika infection
- The dengue
- Chikungunya
- Japanese encephalitis
- Tick-borne encephalitis
- Crimean-Congo hemorrhagic fever…
Is malaria an arbovirus?
Malaria is a zoonosis, an infectious disease transmitted from animals to humans. The disease is caused by parasites of the genus Plasmodium, not arboviruses.
Are they present in France? How many cases?
The tiger mosquito (Aedes albopictus) can cause arboviruses such as dengue, zika or chikungunya.
According to Public Health France, from 1er as of May 26, 2023, the following have been identified in metropolitan France:
- 46 imported cases of dengue fever diagnosed in departments with documented implantation of Aedes albopictus
- albopictus (tiger mosquito)
- 1 case imported from chikungunya
- No imported cases of Zika
THE tiger mosquito (Aedes albopictus) can cause arboviruses such as dengue, zika or chikungunya. The presence of the tiger mosquito has spread throughout France since 2004. In 2023, 71 of the 96 departments metropolitan were colonized.
What is the incubation time for arbovirus?
It is an acute febrile infection with an incubation period of 2 to 12 days.
What are the symptoms of arbovirosis?
Arbovirosis manifests itself by:*
- A high fever which occurs suddenly
- Of the chills
- Of the headache
- Retro-orbital pain (pain behind the eyes)
- Nausea
- Vomitings
- Joint and muscle pain
- Sometimes a rash
After 2 to 4 daysa brief remission occurs and then the state phase occurs during which three clinical pictures can be schematically observed depending on the virus in question:
► Dengue-like syndrome: fever, severe pain, fatigue, rash, lasting 8 to 10 days and healing spontaneously without after-effects,
► Viral hemorrhagic fever syndromeranging from a few minor hemorrhagic manifestations to multiple and abundant hemorrhages linked to disseminated intravascular coagulation, which can lead to death,
► Encephalitic syndromeranging from a few benign meningeal signs to a picture of very serious acute meningoencephalomyelitis, leading to death or recovery with, sometimes, significant neurological sequelae.
Arboviruses are diseases that mainly tropical which may be caused by several viruses (are listed approximately 130 known pathogenic arbovirusesbelonging to a dozen different families). The arbovirus are viruses transmitted to humans by blood-sucking arthropods (mainly insects (flies and mosquitoes, including the tiger mosquito) and arachnids (ticks)) from an animal reservoir or an infected individual.The infection is transmitted by the infected vector picking up the virus from the blood of an infected person and can, through another bite, transmit the virus to a new person. An infected person is “contaminating for mosquitoes” when the virus is present in his blood“, explains Public Health France.
How is arbovirosis diagnosed?
Different arboviruses can be responsible for identical clinical pictures. Similarly, the same virus can cause several types of infections, hence the importance of laboratory diagnosis. This diagnosis is based on thevirus isolation, viral cultures, PCRelectron microscopy and detection of antigens and antibodies when available.
What does arbovirus surveillance consist of?
Every year between May 1 and November 30, Santé publique France launches its seasonal monitoring. Epidemiological surveillance makes it possible to slow down mosquito colonization in departments that have not yet been invaded and to limit contamination. To detect transmission risks, surveillance is based on mandatory reporting with notification of any caseimported or indigenous, biologically documented. Each report is made by doctors and laboratories and triggers an epidemiological and entomological investigation immediately. It is possible to report the presence of the tiger mosquito on the official portal of the health authorities: signalement-moustique.anses.fr
What is the treatment for arbovirosis?
No specific treatment is available. Treatment is only symptomatic. Prophylaxis is based on vector control and vaccination : yellow fever, tick-borne encephalitis, Japanese encephalitis.
To protect yourself and avoid being bitten by mosquitoes in regions where cases of chikungunya, dengue fever or zika have been reported, here are the right actions to take:
- Wear some loose and covering clothing
- Use of mosquito repellents
- Sleeping under a mosquito net
- Connecting electric diffusers
- Using coils outdoors
- Air conditioning the interiors
Upon returning from areas where cases have been reported, it is recommended:
- to consult a doctor if symptoms occur (joint pain, muscle pain, headache, rash with or without fever, conjunctivitis, etc.)
- to avoid being bitten by a mosquito and thus infecting new mosquitoes of the type Aedes which could contaminate another person
- to stay vigilant
- Medical Dictionary of the Academy of Medicine – 2023 version
- Chikungunya, dengue and zika: launch of the 2023 seasonal monitoring, Public Health France, May 25, 2022
- General information on arboviruses and arboviroses, EM Consulte.