Chikungunya patients here were hit by a strain of the virus circulating in Malaysia
Lee Hui Chieh, Straits Times 19 Aug 08;
IF YOU are heading across the Causeway, stay well covered up and have insect repellent handy, as the record number of chikungunya cases in Malaysia is having a spillover effect here.
At least 82 of this year's 117 chikungunya patients were hit by a strain of the virus that has been circulating in Malaysia.
Of these 82, 43 caught the mosquito- borne disease that causes fever and joint pains in Johor while three others fell ill after visiting Malacca.
The remaining 36 contracted the disease in Singapore after being bitten by Aedes mosquitoes here, which had probably become infected after feeding on patients who returned from Malaysia, or one of the 36 after they fell ill.
Malaysia has reported a record high of 136 chikungunya patients this year, up from last year's tally of fewer than 100.
Tests by the National Environment Agency's (NEA) Environmental Health Institute showed that the strain of the virus in the 46 travellers' blood was identical to that found in the 36 infected here.
They include 32 workers from the largest cluster in Kranji Way, and four others living in Teachers' Estate off Upper Thomson Road, Jalan Jelita off Holland Road, and Miltonia Close off Yishun Avenue 1.
The institute's scientists mapped the genetic code, or DNA, of the viruses in patients' blood samples, and compared them against one another and against those from overseas. They found that the virus that caused the Little India outbreak resembled viruses found in India, while the one behind the Farrer Road cluster was similar to viruses in Sri Lanka.
This means that the two incidents were not linked, said the institute's head, Dr Ng Lee Ching. Each time, someone had probably picked up the virus overseas and passed it on to mosquitoes here that went on to infect other people.
But the viruses from patients at Teachers' Estate, Jalan Jelita, Kranji Way and Miltonia Close, were the same as that from patients infected in Malaysia.
So it is no longer possible to tell if each of these incidents was sparked off by a different infected traveller, or if the virus has gone into the community and is spreading from area to area, Dr Ng said.
But in any case, efforts to stop the disease from spreading further should not be relaxed, she said.
'So far, our clusters have mostly been small. It's better to have patients popping up one by one, than have many Kranji Way clusters. So every single case is still worth the effort of fighting,' she added.
The scientists have yet to test viruses from the latest incidents in areas such as Woodlands, Sungei Kadut and the Pasir Panjang Wholesale Centre, but will do so.
The Woodlands episode may have resulted from the virus being spread from an imported case to a local one.
Dr Charity Low, who runs a clinic in Woodlands Street 83, diagnosed her first chikungunya patient on July 22.
The 59-year-old teacher, who lives on that street, developed a fever, joint pains, rashes and throat ulcers, three days after returning from Johor. He had visited two friends there who had fever and joint pains.
Dr Low had his blood tested for both dengue and chikungunya, which cause similar symptoms, and was surprised when the results were positive for chikungunya.
Less than two weeks later, she received a second surprise. A 27-year-old housewife living in Woodlands Street 81 showed up with fever, joint pains and rashes. Tests showed that she too had chikungunya.
Dr Low said: 'She had no travel history, so most probably she caught it from my first patient or others in the area.'
Woodlands has had three other imported cases from Malaysia since July.
This year, 63 people here have been infected locally, and a further 54 overseas. Apart from those who caught the virus in Malaysia, four were infected in Indonesia, two in India and two in Sri Lanka.
The Health Ministry and NEA advise travellers to wear long-sleeved shirts and long pants, apply insect repellent and use mosquito coils while in chikungunya outbreak areas such as the Malaysian states of Johor, Malacca, Negri Sembilan and Perak; Indonesia and India.
Chikungunya patients should also protect themselves from being bitten again when they are ill, to prevent the disease from spreading further.
Business hurt by Chikungunya cluster at Pasir Panjang Wholesale Centre
Teoh Kheng Siong & Hoe Yeen NIe, Channel NewsAsia 18 Aug 08;
SINGAPORE : Some stall owners at Pasir Panjang Wholesale Centre saw business drop by as much as 30 per cent, after three cases of Chikungunya fever were reported there last week.
Two of the victims - a 61-year-old man and his daughter - have recovered, and the daughter has since returned to work at the market.
Still, customers are shying away from the market, raising concerns among some stall owners, who said it will take about a month for business to recover.
Officers from the National Environment Agency (NEA) have been making thorough checks at the premises, and so far they have discovered four mosquito-breeding sites.
NEA officers are also distributing posters warning of the dangers of the disease. - CNA /ls
