Update On Chikungunya Fever Situation(2)

05 Sep 2008

Current overall situation

Since January 2008, Singapore has been experiencing outbreaks of both imported and local cases of Chikungunya fever. There have been additional 28 cases (including 16 imported) since the last update. As of 4 September 2008, a total of 178 cases have been notified this year. Of these, 86 were imported cases with history of travel to Johor (69 cases) and other states of Malaysia (eight cases), Indonesia (four cases), Sri Lanka (two cases), India (two cases) and the Maldives (one case). The rest were locally acquired infections which probably occurred at 19 separate locations, including 39 cases in Kranji Way, 13 from Little India, 14 from Sungei Kadut, 5 from Pasir Panjang Wholesale market, and 6 from Lim Chu Kang Lane 2.

New imported cases

Of the 16 imported cases, 8 were Singapore residents. 7 of them had history of travel to Malaysia [Johor(5), Malacca(2)] prior to their onset of illness, while the remaining one travelled to Maldives. The remaining 8 imported cases comprised of 7 Malaysians and one Indonesian. 4 of the 7 Malaysians live in Johor and travel daily to Singapore to work. The other 3 had history of travel to Malaysia prior to their onset of illness. The Indonesian came here for medical treatment.

Update on new local cases

Of the 12 local cases, 11 are linked to existing clusters.

Kranji Way -  For the 4 new cases of chikungunya fever, all of them developed symptoms between the period of 14 Jul and 23 Aug and were subsequently admitted to hospital. All four had visited, worked and/or lived in the area. They do not have recent travel histories prior to onset of illness. This brings the total number of cases in the Kranji Way cluster to 39.

Lim Chu Kang  -  For the one new case, the patient has  delivered goods to Lim Chu Kang Lane 5A,  developed symptoms on 29 Aug and was subsequently admitted to NUH. He has no recent travel history prior to the onset of his illness. This brings the total number of cases in the Lim Chu Kang cluster to six.

Sungei Kadut - The 6 more cases of chikungunya fever developed symptoms between the period of 21 Aug and 27 Aug. Four of them were subsequently admitted to hospital. All six had worked or lived in the area. This brings the total number of cases in the Sungei Kadut cluster to 14.

An additional sporadic case is a 28-year-old general worker who stays at Mandai Estate and has no fixed work sites. He developed symptoms on 23 Aug 08 and sought outpatient treatment on the same day. He has no recent overseas travel history. All his colleagues are well.

Updates on vector control operations by the National Environment Agency (NEA)

Mosquito control remains the primary measure to prevent the spread of chikungunya fever. Upon notification by the Ministry of Health (MOH), the NEA has been carrying out vector control operations including source reduction and fogging in and around the cases’ residential premises, including their work places and places that they normally frequent, in a bid to prevent further transmission of the chikungunya virus. 

Mosquito breedings that are detected during our inspections are destroyed immediately and enforcement action has been taken against owners/occupiers of premises found with mosquito breedings to ensure they take the necessary measures to keep their premises free of further mosquito breedings. 

The NEA has also deployed 13 officers to carry out mosquito control operations in the Mandai Estate area. Mosquito breedings have been detected and destroyed in 10 out of more than 85 premises inspected. The NEA officers are continuing with their checks.

All owners are urged to check their premises daily to remove any stagnant water that may breed mosquitoes.  Orders were also served on premises owners to render their premises non-conducive for breeding.  Under the law, non-compliance with such orders can result in a fine up to a maximum amount of $50,000.

Ministry’s Advice to the Public

In the absence of a vaccine, and the presence of the Aedes mosquito vector, Singapore remains vulnerable and receptive to the introduction of Chikungunya outbreaks. It is likely that cases will continue to occur as long as situations in neighbouring countries do not improve. The full support and cooperation of the community and every stakeholder is needed to minimise the likelihood of the disease becoming endemic in Singapore.

The Ministry advises persons who develop symptoms of chikungunya which include fever, joint pain and rashes to consult their doctors immediately.

Chikungunya fever, like dengue fever, is a mosquito-borne disease and the best way to prevent chikungunya fever is to take precautionary measures against mosquitoes and prevent their breeding. Persons visiting areas where outbreaks are reported  should take the necessary precautions while persons infected with chikungunya fever should be isolated from further mosquito bites so as to reduce the risk of further transmission of the virus.

Ministry of Health

National Environment Agency

5 September 2008