Chikungunya reemerging in Thailand

Chikungunya virus is reemerging in Thailand, according to data presented at the American Society of Tropical Medicine and Hygiene’s 58th Annual Meeting in Washington, D.C.

Thai researchers presented the data and said the reemergence represented "a serious public health concern in Southeast Asia."

Chikungunya was first reported in Thailand in 1958. By the mid-1990s, eradication efforts in Thailand were proving successful and the last cases in the country were reported in 1996. But in October 2008, Thai health officials confirmed cases of Chikungunya in patients living near the border between Thailand and Malaysia. By the end of 2008, 2,494 suspected cases of Chikungunya were reported in Thailand. So far in 2009, 41,546 suspected cases have been reported in the country. There have been no reported deaths among the patients with suspected Chikungunya and more than 90% of cases have been treated as outpatients.

The researchers said the majority of cases of Chikungunya have been reported in the four southernmost Thai provinces that border Malaysia. However, data indicate that the virus is spreading. In 2008, 99.7% of the reported cases were in these four provinces. In 2009, this number had decreased to 60%. The researchers said cases of Chikungunya have now been reported in all other southern Thai provinces, as well as some western and eastern provinces.

In both 2008 and 2009, more than 80% of cases were in adults, according to the researchers. But the median age of patients decreased from 38 years in 2008 to 33 years in 2009. The percentage of cases among patients aged 15 years or younger increased from 12.1% in 2008 to 17.3% in 2009.