This virus can be transmitted after the bite of a tiger mosquito. At first, the infection looks like a influenza syndrome.
Surveillance of chikungunya is strengthening each summer in France with the proliferation of tiger mosquito. He is now present In 81 departments French, increasing the risk of disease. We asked Professor Anna-Bella Failloux, head of the research and expertise unit “arbovirus and vectors insects” at the Pasteur Institute, to explain to us what Chikungunya is and if it is necessary to worry in the event of contamination.
What is chikungunya?
Chikungunya, also called “chik” or “curved man’s disease”, is an infectious disease belonging to the family of arboviroses (diseases transmitted by an arthropod). It is transmitted to man following a bite of an infected mosquito of the genus Aedes like the tiger mosquito. The name “Chikungunya” is derived from a word of the Kimakonde language which means “distorting”. The first epidemic due to the Chikungunya virus in the world was described in Africa, precisely in Tanzania, in 1952.
What are the symptoms of chikungunya?
At the beginning, the infection looks like a influenza syndrome with:
- An intense fever
- Headache
- Joint pain mainly concerning small joint belts (wrists, fingers, ankles, feet) but also knees
- Strong muscle pain
- A rash at the trunk and members
- Abdominal pain
- Inflammation of one or more cervical lymph node (s)
- A conjunctivitis
At an advanced stage, serious neurological complications can arise, especially in newborns and the elderly. Joint pain and significant fatigue can persist several months after the initial diagnosis. Bleeding of the gums or noses have also been described, mainly in Asia.
What is the incubation time?
The symptoms of chikungunya manifest themselves after an incubation period of 2 to 12 days on average.
The virus can be detected directly in blood samples taken from the patient during the first week of the disease. Other tests can seek the presence of antibodies directed against the virus. Antibody levels are generally detectable in the first week after the appearance of the disease and can still be detected for about 2 months.
How long does the disease last?
Symptoms usually last a few days, but may persist for weeks, months or even years. Anyone who has been infected once naturally acquires sustainable immunity (several years). On the other hand, certain joint pain (arthralgia) may persist or reappear over variable periods of time. It is an independent joint reaction of a reinfection by the virus.
“The spontaneous evolution of the disease is most often favorable”
Is it deadly? What risks of consequences?
The severe or deadly cases of Chikungunya are very rare, and are almost always associated with the existence of other pathologies. “The spontaneous evolution of the disease is most often favorable, but it can evolve towards a chronic form, with for several months prolonged fatigue and/or the persistence of joint pain (in 20% of cases) for months or years sometimes very embarrassing in daily life, Observe Professor Failloux. The achievement of other organs is possible:
- Neurological damage such as Guillain-Barré syndrome (damage to peripheral nerves responsible for paralysis, muscle weaknesses or sensations disorders with for example tingling in the arms and legs). A few cases of meningo-enquphalitis were observed during the Reunion epidemic.
- Eye damage: conjunctivitis spontaneously healing, decrease in vision.
- Complications in the kidney, liver or heart are exceptional.
The treatment is above all symptomatic and aims to relieve fever and pain with the prescription of antipyretics, suitable pain relievers (paracetamol or acetaminophen), a good liquid intake and patient rest. There is no specific antiviral drug against chikungunya infection.
Is there a vaccine against chikungunya?
There is currently no approved vaccine or specific treatment for infections by the chikungunya virus. Several vaccines are under development. To protect yourself, in addition to the means of physical protection (wearing long clothing covering the arms and legs to the ankles, mosquito nets in the habitat …), it is strongly recommended to use a repulsive product while respecting the precautions for use.
What risks during pregnancy?
In the case of a pregnant woman who is infected with the virus, the baby’s contamination occurs directly during childbirth in one in two cases. It generates neurological and/or cardiac disorders in half of the infants. It is recommended to pregnant women who would go to regions affected by chikungunya, to protect themselves by all the means available against mosquito bites and especially during the last trimester of pregnancy.
Thank you to Professor Anna-Bella Failloux, head of the “Arbovirus and Vector Insect Research and Expertise Unit at the Institut Pasteur.
