Travelers to tropics, beware chikungunya fever

NEW YORK (Reuters Health) - People who've visited tropical areas -- particularly India and islands in the Indian Ocean -- and are suffering from fever and joint pain could have chikungunya virus infection, public health officials warn.

Chikungunya virus is transmitted to humans by the bite of infected mosquitoes. Starting in May 2004, a large outbreak of chikungunya fever has occurred on islands in the Indian Ocean. Other affected areas include Kenya, continental India, and areas in southeast Asia.

Europe has reported 340 cases of imported chikungunya fever this year, and several cases have been seen in Canada, Martinique and French Guyana. However, there has been no known local transmission of chikungunya virus by mosquitoes.

In the Morbidity and Mortality Weekly Report published by the U.S. Centers for Disease Control and Prevention, Dr. E. Warner in Denver and associates describe four cases that occurred in returning travelers, one each in Minnesota, Louisiana, Maryland, and Colorado.

Symptoms included fever, chills, headache, malaise, muscle pain, joint pain, and rash. Joint pain resolved within several weeks in two cases, but persisted for months in the two others.

All four cases were confirmed as chikungunya virus infection based on blood samples submitted to the CDC.

The CDC warns travelers to chikungunya-endemic areas to avoid mosquitoes by staying in screened areas, wearing barrier clothing and using mosquito repellents.

They also caution that "some risk exists that chikungunya virus might be introduced into previously nonendemic areas by travelers ... in tropical or subtropical areas of the US," including the Gulf Coast, Hawaii, and territories in Guam, Puerto Rico and the Virgin Islands.

Chikungunya fever usually resolves on its own within 3 to 7 days, except for the joint pain, which can persist for months or even years. There is no specific therapy for the infection or vaccine against chikungunya.

SOURCE: Morbidity and Mortality Weekly Report, September 28, 2006.