Chikungunya is a tropical disease of viral cause. It contracts through mosquito bites of the genus Aedes (Aegypti and Albopictus). These mosquitoes, which are also called "tiger mosquitoes", are particularly dangerous vectors of the disease. Indeed, the arrival of infected travelers in an area where this mosquito is present can cause, by itself, a beginning of epidemic.
The causes of an epidemic are simple. Once the mosquito has stung a sick person, the infected mosquito becomes a contaminant a few days later. That's when the mosquito transmits the Chikungunya to another healthy person by pricking it.
It takes 4 to 7 days for the symptoms to appear in the person infected by the mosquito. This can, for at least 1 week after the onset of symptoms, contaminate a healthy mosquito that can then bite other people and transmit the disease. And so on...
These mosquitoes swarm in the cities and the countryside, and prevail preferentially during the rainy seasons. They bite preferably at sunrise and late afternoon.
Between the rainy seasons, mosquitoes are fewer and epidemics can calm down. The epidemics of Chikungunya are extensive because of the increase of the mosquitoes, due to several phenomena including the wild urbanization, the problems of public hygiene and the abandonment of the campaigns to disuse.
The endemic area of Chikungunya covers Africa, the Indian Ocean, India and Southeast Asia.
The tiger mosquito in pictures: