Madagascar has confirmed the presence in at least one person of a rare mosquito-borne disease, chikungunya fever, that has so far infected over 180,000 people in the Indian Ocean region in the last year, the World Health Organization revealed on Monday, according to media reports.
Chikungunya fever, a viral infection for which there is no known cure, is believed to have killed 93 people in the nearby French territory of Reunion.
The Madagascar infection was detected in the eastern Malagasy town of Toamasina in the midst of a general outbreak of dengue fever, Leonard Tapsoba, WHO country director for Madagascar, told Reuters. WHO estimates indicate that since March of last year 157,000 people on the island, about 20 percent of the population, may have been infected with chikungunya fever. In a single week last month, 22,000 Reunion islanders are believed to have contracted it.
Since January, thousands more cases have been reported in Mayotte, Seychelles and Mauritius, where WHO Director-General Lee Jong-wook arrived Tuesday to review efforts to control the disease.
Its symptoms include high fever, chills, headache, joint pain and rash, and it may cause vomiting, according to the US Centers for Disease Control and Prevention.
It is named after the Swahili word for “that which bends up,” describing sufferers’ arthritic posture.
No medication has yet been developed for the disease, but it is rarely fatal. Symptoms occur between four and seven days after infection and can persist for several weeks, according to the WHO.
The chikungunya virus is carried by the day-biting Tiger mosquito, which is also responsible for the spread of dengue fever, a disease present in Cambodia. An outbreak of chikungunya occurred last April in Indonesia’s West Lombok and in Malaysia’s Port Klang in 1999, but is not present in Cambodia, a health official said Wednesday.
“Never in Cambodia,” said Dr Ngan Chan Tha, director of the Health Ministry’s dengue control program. “Transmission occurs by the same mosquito but it isn’t here. Only dengue.”
He did concede that given the similarity of the symptoms caused by dengue and chikungunya, it was possible that some cases of the disease had been misdiagnosed.
Every year, blood samples from between five and 10 percent of cases where dengue fever is suspected are sent for testing to the Pasteur Institute in Phnom Penh.
The testing is to identify which of the four serotypes of dengue virus is present in a given case. This random testing from across the country would reveal the presence of the chikungunya virus, Ngan Chan Tha said, adding that so far it has not been detected.
Chikungunya “manifests itself with practically the same symptoms,” as dengue, he said, but he remained convinced that the disease was not present in Cambodia.