Aug. 29 (Bloomberg) -- Singapore reported more than 100 new cases of chikungunya fever this month, 10 times last year's total, as outbreaks elsewhere in Asia spread to the city-state through travelers and migrant workers.
The disease, which can trigger debilitating joint pain lasting months, probably caused sporadic infections at 18 separate sites this year, the Ministry of Health said in an Aug. 25 statement. The cases highlight the equatorial island's struggle to control virus-carrying mosquitoes and the threat of exotic diseases posed by international travel.
``In this day of rapid cross-border travel, Singapore, just like other countries, is at risk from the importation of viruses,'' said Ng Lee Ching, head of the nation's Environmental Health Institute. ``With the recent surge in importations, our risk of local transmission has increased significantly.''
Chikungunya is a reminder of globalization's role in the international spread of SARS, the deadly respiratory virus that probably infected more than 8,000 people worldwide in 2002 and 2003, including 238 in Singapore. The disease, first reported in southern China, cost Asian businesses an estimated $60 billion.
Until this year, Singapore found cases of chikungunya only in travelers who had caught the bug overseas. Since January, 70 ``imported'' and 80 locally acquired infections have been officially reported, almost two-thirds of which were in non- Singaporeans, according to ministry data.
Chikungunya, which means to become contorted in the Makonde language of southeastern Tanzania, was first recorded in Africa in 1953, and has infected people in 35 countries. There's no vaccine or specific treatment for the fever, rash and joint- swelling, which are usually nonfatal.
Ng says genetic analysis shows the viruses in Singapore are similar to strains from India, Sri Lanka and Malaysia.
A Passage From India
Fifteen Indian states and territories had a total of 1.39 million confirmed or suspected chikungunya cases in 2006, according to health authorities in New Delhi. Kerala and Karnataka have had cases as recently as this month.
Malaysia, linked to Singapore by a causeway, has had more than 1,500 infections since late July, according to the country's health ministry. Of Singapore's imported cases, 56 patients had been in the adjacent Malaysian state of Johor Bahru before their illness, Health Minister Khaw Boon Wan told Parliament on Aug. 27.
An outbreak in Italy last year, the first in Europe, provided an example of how chikungunya can take hold when an infected person enters an area and is bitten by a mosquito capable of transmitting the virus, and the insect then feeds on the blood of people who aren't immune to the pathogen.
The World Health Organization says 2.5 billion people globally live in areas where epidemics of chikungunya, and the potentially lethal diseases dengue and yellow fever, can occur.
Tiger Mosquito
A chikungunya epidemic hasn't erupted in Singapore, even though most of its 4.6 million inhabitants are susceptible to it.
That may be because one of the main transmitters of the disease here -- the Asian tiger mosquito, or Aedes albopictus -- is less inclined to hover inside homes, and also feeds on other mammals that don't catch the virus, said Duane Gubler, director of the emerging infectious diseases program at the Duke-National University of Singapore Graduate Medical School.
``The fact that you have got such widespread transmission but it's still sporadic is a good indication that it's not going to blow up into a big epidemic,'' Gubler said in an interview.
Public Health Cost
Chikungunya's persistence in Singapore may reveal a hidden public-health cost of lower-paid, unskilled laborers -- many of whom come from Malaysia and Indonesia, where the disease is endemic -- to work in the city's booming construction and shipping industries.
Singapore had about 757,000 unskilled and semiskilled foreign workers as of Dec. 31, according to the Ministry of Manpower. Laborers working in construction or manufacturing were paid a median gross monthly wage of S$800 ($564) last year, according to ministry data.
Many laborers are put up in ``unhygienic, very cramped'' dormitories by their employers at a monthly cost of S$150-S$200 per bed, said Jolovan Wham, executive director of the Humanitarian Organization for Migration Economics, a charity that supports foreign workers.
By comparison, the average daily room rate at a Singapore hotel was S$238 in July.
``You can imagine what kinds of conditions they would be living in if it's going to be so cheap,'' Wham said. ``Many companies are willing to cut corners.''
More Beds
Land for 11 dormitory sites was released during the past 18 months to provide about 65,000 more ``housing spaces,'' Acting Minister for Manpower Gan Kim Yong said this month. Efforts to improve housing must be supported by dormitory operators and employers by ``maintaining and enhancing standards of current housing facilities,'' Gan said.
At a three-story, corrugated-iron dormitory in northwestern Singapore, laundry, buckets and cooking paraphernalia clutter 54 bunk-bed-lined rooms, each ventilated by a single window lacking insect screens.
``Anytime you're importing a large number of laborers from a highly endemic area, and these laborers are housed in a communal area that is unscreened, you're at a high risk of creating a focal outbreak that can spread,'' said Scott A. Ritchie, a medical entomologist with the Tropical Public Health Unit Network in Cairns, Australia.
The National Environment Agency says foreign workers are an important target for its education and outreach programs. In response to the chikungunya cases, the agency produced more pamphlets in English, Mandarin, Malay and Tamil detailing ways foreign workers can protect themselves and prevent mosquito breeding, and is preparing versions in Bengali, Burmese, Tagalog and Thai. It also holds mandatory safety courses and seminars.
