Chikungunya fighters in Singapore breathe easy after 6 weeks

Lee Hui Chieh, Straits Times 22 Feb 08;

SINGAPORE'S first outbreak of the mosquito-borne disease chikungunya is over, health officials have declared.

Yesterday was the 24th day since the last person to catch the virus fell sick - a milestone that means the disease has likely been beaten.

Overall, 13 who lived or worked in Little India got the virus, which causes fever and joint pain but is rarely fatal.

The all-clear caps six frenzied weeks for health and environment officers, who targeted the centre of the outbreak, destroyed mosquito breeding grounds, took blood samples and handed out fines.

A spokesman for the National Environment Agency (NEA) said: 'We believe that through our close coordination, we were able to avert a potentially larger outbreak.'

The 24th day had been marked as the finish line because that is twice the disease's incubation period. Any new cases of the virus would have surfaced within that time.

While the battle against chikungunya has been won, the authorities cautioned yesterday that the disease could return.

The Health Ministry and the NEA said Singapore remains at risk as it is a popular stop with travellers from places where the disease has a foothold.

In fact, it was probably an infected traveller who sparked the outbreak, although health officers have not been able to identify this 'patient zero'.

Still, the end was met with relief from the health and environment officers who have been battling the outbreak.

One of them was Dr Tan Li Kiang, 34, a research scientist with the NEA's Environmental Health Institute (EHI). She said: 'We have been feeling 'jetlag'. I've been praying that there won't be any more new cases.'

The outbreak was uncovered when a 27-year-old Bangladeshi man turned up at a clinic at Upper Weld Road, off Clive Street, complaining of a high fever and body aches. A doctor sent the man's blood sample for testing and the result was positive for chikungunya.

Over the next three weeks, the Health Ministry sent 15 public health officers out to Clive Street to find others who might be infected. That was double the number of officers sent out on a regular day.

Doctors who usually did policy work helped collect blood samples from people who lived or worked in the area.

Officers, though, had trouble keeping tabs on people in Little India, which hosts many foreign workers and tourists.

Public health officer Han Hwi Kwang, 36, said: 'One day you took blood from people, but when you went back to the same place the next day, you realised, there's a whole new group.'

In the three weeks till Feb 4, they sent samples from 2,626 people to the EHI for testing.

There, seven research officers tested 400 to 500 blood samples daily. Seven others helped with labelling and paperwork.

They burned the midnight oil so the results could be out before the next morning in a bid to get those infected to hospital as soon as possible.

Dr Tan, who oversaw the testing, often worked from 9am to 2am daily in the first two weeks of the outbreak. The mother of a 20-month-old boy said: 'I didn't get to see my son awake for four days in a row.'

NEA sent 55 officers and 40 pest control operators to wipe out mosquitoes and breeding grounds in Little India.

In the last six weeks, they checked more than 5,500 properties, destroyed 78 breeding sites, and meted out fines of $100 to $200 to 43 people for allowing mosquitoes to breed.

The agency also issued 532 orders for the removal of roof gutters that had fallen into disrepair in Little India, of which 322 have been taken down.

Nine people have been fined $2,000 each for refusing to comply, while the rest have asked for more time to do so.

The EHI's head, Dr Ng Lee Ching said: 'I'm happy that everyone was prompt in their response to the outbreak.'

An official from the International Society for Infectious Diseases praised Singapore's effort as 'an outstanding example of detecting and then responding to the appearance of a disease new to an area'.