Chikungunya

17 March 2008

According to ProMED mail, Chikungunya is rapidly spreading in Sri Lanka.

Chikungunya virus is a togavirus in the alphavirus genus. The infection is spread by mosquitos, mainly Aedes aegypti. The viral disease has been known for more than 50 years in the tropics and savannahs of developing countries of Asia and Africa, but never has been a problem of the developed countries in Europe. The disease is uncomfortable (rashes, joint pains), but not fatal. In the last five years, this once third-world viral disease has come into the forefront of public concern.

In 2004, outbreaks of Chikungunya disease spread from Kenya to islands in the Indian Ocean and then to India, where it had not been reported in over 30 years. In 2007, there was an outbreak in Italy, the first ever in Europe. In some of the Indian Ocean islands, more than 40% of the population fell ill.

The reason for the recent spread of Chikungunya disease is that the virus has acquired a new vector, the Asian tiger mosquito Aedes albopictus. A point mutation in the viral genome appears to be the cause for this vector switch. Aedes albopictus is spreading across the globe from eastern Asia and is now found in mainland Europe and the US.