TWO more people have come down with the mosquito-borne, dengue-like illness called chikungunya. They were hospitalised on Thursday.

This brings the total number of those who were infected to eight, of whom four have been admitted to the Communicable Disease Centre (CDC).

All the eight were staying within the same row of shophouses on Clive Street.As they do not have a history of recent travel, it is highly likely that they acquired the infection locally, said the Ministry of Health in statement on Friday.

This is the first outbreak of chikungunya in Singapore.

Since the disease first surfaced here in 2006, all 13 previous cases had been imported ones. Patients have symptoms similar to dengue, such as such as fever, joint pains, chills and nausea, which usually last three to 10 days.

There is no cure for the illness, but it usually goes away on its own, and rarely results in death.

The Health Ministry is still investigating how the outbreak began. But it was most probably sparked off by an imported case - someone who was infected while overseas, and fell sick here, said Dr Lyn James, director of MOH's communicable diseases division.

The disease is spread by the Aedes mosquito, and not from human to human.

So it was likely that the first person who contracted the virus overseas was bitten by mosquitoes here, which in turn became infected, and then spread the virus by biting other people, she said.

Since Jan 14, the Health Ministry, together with National Environment Agency (NEA)'s Environmental Health Institute, has screened close to 500 people living or working in the Clive Street area. Epidemiological investigations are still ongoing and screening efforts will continue over the next few days.

NEA has inspected a total of 1,879 premises in the Clive Street area. A total of 25 indoor breeding and 10 outdoor breeding sites were detected and destroyed.

Residents and premise owners are advised to check their premises daily to remove any stagnant water that may breed mosquitoes.

Persons who have been in the Clive Street area recently and have developed a fever are advised to consult their doctors.

Persons infected with chikungunya fever should be isolated from further mosquitoes bites (by staying indoors and sleeping under a mosquito net during the first few days of illness) to reduce the risk of further transmission of the virus.

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