18 new cases of chikungunya infection reported in Singapore

Hasnita A Majid, Channel NewsAsia 6 Aug 08;

SINGAPORE : 18 new cases of chikungunya infection have been reported in Singapore, bringing the total number of cases to 54 this year.

One of them - a 25-year-old Chinese national - was infected locally. It is believed that the technician, who resides at Miltonia Close in Yishun, caught the virus around the area or at his workplace.

Authorities said a mosquito breeding spot was found near his home, while another was found near his workplace in a factory at the Marsiling Industrial Estate.

The man developed symptoms on July 18 and was admitted to a hospital from July 19-23. Fortunately, none of his 10 housemates caught the virus.

Separately, 17 others have tested positive for chikungunya. They are believed to be linked to the Kranji Way cluster where three cases were reported earlier, on August 2.

These 17 cases have been admitted for isolation and treatment in the Communicable Diseases Centre at Tan Tock Seng Hospital.

The total number of cases linked to Kranji Way currently stands at 20. Preliminary investigations indicate that the Kranji Way cluster is due to local transmission.

Since the notification of the first three cases, NEA officers have been conducting intensive mosquito control operations within the vicinity of the victims' workplace and residences, and the areas that they frequent.

More than 23 premises have been inspected in the Kranji Way area and a total of 15 premises were found breeding the Aedes mosquito.

Outdoor and indoor fogging of insecticide is also being carried out at all the checked premises. Intensive operations to seek out and remove any mosquito breeding habitats will continue.

Residents and owners of premises in the vicinity of Kranji Way have all been advised to check their premises daily to remove any stagnant water that may breed mosquitoes.

Besides the cluster in Kranji Way, to date, the Ministry of Health (MOH) has been notified of a total of 54 confirmed cases of chikungunya fever. 19 were local cases and 35 were imported cases.

The MOH advises anyone who has travelled to Kranji Way recently and developed symptoms of chikungunya - which include fever, joint pain and rashes - to consult their doctors.

Singapore's Communicable Disease Centre said it is not surprised that more cases of chikungunya infection have surfaced, given the conducive environment for the disease to flourish here.

This includes the presence of the mosquito vector, low immunity to the virus, and mobility of the population, who may have ventured into areas where the disease is endemic.

However, there is one consolation - unlike the dengue which comes in four strains, chikungunya has only one.

"Having one dengue infection cannot protect the individual from the other three. Chikungunya has one serotype so you are likely to have the infection just once," said Associate Professor Leo Yee Sin, Clinical Director of the Communicable Disease Centre at Tan Tock Seng Hospital.

Prof Leo said so far there has been no case of death in Singapore linked to chikungunya, possibly because most patients are still young and healthy. However, she cautioned that fatalities may happen if the elderly catch the virus.

She appealed to those who are infected to cooperate with the hospitals and be isolated to prevent further transmission.

Patients admitted to the Tan Tock Seng Hospital with the chikungunya virus will be placed at the Communicable Disease Centre, where they will be treated until their infective period is over.

Meanwhile, Mount Alvernia Hospital, where two patients with chikungunya were treated, said both patients are recovering well and will be discharged soon.

Prof Leo added that researchers are also looking out for people with dual infection - both dengue and chikungunya. There are concerns that the Aedes mosquito, which is the host of both viruses, may be able to spread both viruses at the same time.

There have been reports of chikungunya outbreaks in the region such as India, Indonesia, and Malaysia. Persons travelling overseas are advised to remain vigilant and seek prompt medical treatment if they are unwell and develop symptoms of chikungunya. - CNA /ls

Biggest cluster in Kranji
17 cases in industrial area; local transmission possible
Leong Wee Keat, Today Online 7 Aug 08;

SEVENTEEN more people have fallen victim to chikungunya fever in Kranji Way, making the area the largest cluster of cases so far.

The affected area is next to Kranji Reservoir, and is largely an industrial area comprising of factories and sawmills. Punters who frequent the Singapore Turf Club can breathe somewhat easy as the outbreak area is about 3km away.

The 17 patients include two Singaporeans, two Malaysians, two Thai nationals, one Chinese national, three Bangladeshi, and seven Indian nationals. All but three had no history of recent travel, but health officials are investigating if the trio could still have acquired their infection locally.

Blood checks on 282 workers in the area had been conducted after three people came down with the virus last week, said the Ministry of Health (MOH) and the National Environment Agency (NEA) in a statement yesterday.

The 17 new cases picked up have since been admitted for isolation and treatment at the Communicable Diseases Centre at Tan Tock Seng Hospital. While epidemiological investigations are on-going, preliminary probes indicate the Kranji Way cluster is due to local transmission.

For companies in the area, the past few days have been business as usual, with operations continuing and workers turning up for work.

Firms have, however, become more vigilant in keeping their environment clean. For example, sawmill Kwong Man Company general manager Peter Ho said they have stepped up mosquito-fighting procedures with more frequent checks and fumigation.

Meanwhile, NEA officers have been conducting “intensive mosquito control operations”. More than 23 premises have been inspected in the Kranji Way area and 15 premises were found breeding the Aedes mosquito. Fogging is being carried out.

Heath officials have urged the public who have travelled to Kranji Way recently and developed symptoms of chikungunya — which include fever, joint pain and ­rashes — to consult their doctor.

Another new case at Yishun

Meanwhile, another new case of chikungunya fever was discovered, involving a 25-year-old Chinese national who stays at Miltonia Close, off Yishun Ave 1.

The technician developed symptoms on July 18 and was hospitalised, but has since been discharged. His movements had been largely confined to his residence and workplace at Marsiling Industrial Estate; 10 household contacts were screened and tested negative for the disease.

Chikungunya, like dengue, is a mosquito-borne disease. This year, MOH was notified of 54 confirmed cases, of which 19 were local cases and 35 were imported. The first local outbreak surfaced in January, when 13 people in Little India were infected.

18 more down with viral infection
Chikungunya strikes 17 workers in Kranji and one in Yishun
Lee Hui Chieh, Straits Times 7 Aug 08;

ANOTHER 17 workers found with chikungunya at Kranji Way have made this outbreak the largest one in Singapore.

The latest patient count includes two Singaporeans, two Malaysians, two Thais, one Chinese national, three Bangladeshis and seven Indian nationals.

They bring the total number of Kranji Way victims to 20, the Health Ministry said yesterday.

Fifteen of them worked in a company making building materials; the remaining two worked next door in a storage yard.

They were found with the mosquito-borne, dengue-like disease when health officers screened 282 workers in the area after three fell ill last month.

That trio - two foreign workers who live and work in the company, and a Singaporean who made a delivery there - have since recovered.

The rest have been isolated in the Communicable Disease Centre to treat their symptoms such as fever and joint pains, and keep them from being bitten again by mosquitoes that could further spread the disease.

Previously, the largest chikungunya outbreak here, also the nation's first, hit 13 people in Little India in January.

Separately, a technician from China, who lives in Miltonia Close, off Yishun Avenue 1, and works at Marsiling Industrial Estate, also came down with the disease. The 25-year-old fell sick on July 18, and was hospitalised the next day for five days.

None of the 10 people living with him - two co-workers, his employer's family of seven and a maid - were infected.

The National Environment Agency's (NEA) officers inspected more than 23 premises in the Kranji Way area, and found 15 breeding the chikungunya virus-transmitting Aedes mosquito.

They also checked 105 residences near Miltonia Close, and 23 factories in Marsiling Industrial Estate. A home and a factory were found to be breeding mosquitoes.

The NEA's tests on viruses from the first three incidents in Little India, Teachers' Estate and Farrer Road, showed these cases were not linked. The agency has yet to test viruses from the latest three at Jalan Jelita, Kranji Way and Miltonia Close.

The Health Ministry also said yesterday that it retrospectively detected a recovered patient who was among the earliest to have been infected by chikungunya in Singapore.

The 35-year-old man, who lives behind Hertford Road, near Little India, fell ill on Jan 18, and was hospitalised from Jan 21 to Jan 24.

This means 39 people contracted the disease here; another 35 were infected while abroad this year. Previously, 13 others were infected overseas between 2006 and last year.