26 October 2012
Chikungunya virus activity – Asia
This update reports on current and recent chikungunya (CHIKV) outbreaks; it is not a comprehensive listing. Further information on confirmed and suspected CHIKV outbreaks can be accessed via the NaTHNaC Outbreak Surveillance Database.
A map of areas of risk is available from the US Centers for Disease Control and Prevention.
On 30 July 2012, the Ministry of Health officially declared the first outbreak of chikungunya fever in Bhutan. As of 31 August 2012, the Public Health Laboratory had tested a total 215 samples, of which 64 were laboratory confirmed CHIKV cases from Samtse, Gomtu (Chukha) districts . There were three likely index cases: two from Samtse and Gomtu districts had travel history to neighbouring border towns of Birpara and Chamarchi, in West Bengal (where outbreaks had also been recently reported) and a further index case from Phuentsholing town in Chujka district, however, this case had no travel history to the border towns of West Bengal prior to onset of illness .
On 7 March 2012, several cases of rash with fever were reported among village residents of Trapeang Roka in Kampong Speu Province, Cambodia. Four of six blood samples from affected persons were positive for CHIKV. During enhanced surveillance, 425 febrile village residents were surveyed in the area, of which 188 (44.2 %) tested positive for CHIKV. A temporal association was noted between an unusually large rainfall on 13–14 February 2012 and this subsequent outbreak of cases of CHIKV. Sporadic cases of chikungunya were identified in Cambodia in 2011 .
As of 26 September 2012, a total of 11,076 suspected cases of CHIKV have been reported by the Ministry of Health and Family Welfare of India during 2012. The state of Tamil Nadu has reported the highest number of cases (4,630), followed by Karnataka (1,810), Andhra Pradesh (1,022) and West Bengal (1012). The total number of CHIKV cases has been higher in 2011, affecting 20,402 persons .
In 2012, media sources have reported outbreaks in West Java, Greater Jakarta and Central Java. Details on these unverified outbreaks can be found on the Outbreak Surveillance Database.
CHIKV has been reported in several parts of the country, including Batan Island, Albay, the regions of Ilocos, Cagayan Valley, Metro Manila, Calabarzon, Western Visayas, Northern Mindanao, Davao and Caraga. To date, 600 cases have been reported in 2012; more than 1,000 cases were reported in 2011 [4, 5].
Papua New Guinea
The health authorities of Papua New Guinea have reported confirmed cases of chikungunya virus infection in the province of Sandaun (West Sepik) for the first time. Since June 2012, 633 suspected cases have been reported, of which 14 have been laboratory-confirmed [6-7].
As of 24 October 2012, 13 confirmed cases of CHIKV have been reported in Singapore. One case had no history of travel outside of Singapore and is the first autochthonous (locally-acquired) case documented in 2012. Eleven other cases were imported and one case is still under investigation. A total of 13 cases were reported in 2011 (including nine imported cases) [8-9].
As of 24 October 2012, a total of 27,431 cases have been reported in 76 provinces of Thailand in 2012. The highest incidence rates have been reported from Central provinces, followed by North-East, North and Southern provinces .
Advice for travellers
CHIKV is a viral infection of humans and non-human primates transmitted by Aedes spp. mosquitoes. It is endemic in parts of sub-Saharan Africa, the islands of the Indian Ocean, and South and South East Asia. In symptomatic illness there is sudden onset of fever, headache, myalgia and arthralgia. After 2 to 3 days a generalised maculopapular rash can develop. Most cases recover in 3 to 5 days, however, 5-10 percent of cases can have chronic joint pain, arthritis and fatigue. Treatment is supportive.
There is no vaccine to prevent CHIKV. Travellers to endemic areas can reduce their risk of infection by practising insect bite avoidance measures. Aedes spp. mosquitoes responsible for transmitting CHIKV, are most active during daylight hours. Particular vigilance with bite avoidance should be taken around dawn and dusk.
1. Public Health Laboratory, Department of Public Health in Bhutan. Report on Chikungunya fever outbreak in Bhutan. August 2012. [Accessed 26 October 2012]. Available at: http://www.phls.gov.bt/recent_reports/REPORT%20ON%20
2. U.S Centers for Disease Control and Prevention. Chikungunya Outbreak — Cambodia, February–March 2012. [Accessed 26 October 2012]. Available at: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6137a2.htm
3. Government of India. National Vector Borne Disease Control Programme. State-wise clinically suspected chikungunya cases in the country. 26 September 2012. [Accessed 26 October]. Available at: http://nvbdcp.gov.in/chik-cd.html
4. Republic of the Philippines, Department of Health. Chikungunya disease
originated from OCD? 23 October 2012. [Accessed 26 October 2012]. Available at: http://www.doh.gov.ph/sites/default/files/102312-0008.pdf
5. Philippine Information Agency. Albay medical team validates Chikungunya fever cases in Rapu-rapu. 2 October 2012. [Accessed 26 October 2012], Available at:
6. Insitute de Veille Sanitaire. Bulletin Hebdomadaire International No. 368. 3-9 octobre, 2012. In French. [Accessed 26 October 2012]. Available at: http://www.invs.sante.fr/content/download/47413/206694/versio
7. European Centre for Disease Prevention and Control. Communicable Disease threats Report, 7-13 October 2012, 12. [Accessed 26 October 2012]. Available at: http://ecdc.europa.eu/en/publications/Publications/ECDC
8. Ministry of Health, Singapore. Weekly Infectious Disease Bulletin. Epidemiological week 42, 2012 [Accessed 26 October 2012]. Available at: http://www.moh.gov.sg/content/dam/moh_web/Statistics/
9. Ministry of Health, Singapore. Weekly Infectious Disease Bulletin. Epidemiological week 52, 2011 [Accessed 26 October 2012]. Available at: http://www.moh.gov.sg/content/dam/moh_web/Statistics/
10. Bureau of Epidemiology, Department of Disease Control Ministry of Public Health of Thailand. 24 October 2012 [in Thai] [Accessed 26 October 2012]. Available at: http://www.boe.moph.go.th/boedb/surdata/506wk/y5