The chikungunya outbreak appears to have taken hold in Singapore, with over 60 reported cases of infection this month alone.
This brings this year's total to 184, more than three times the 60 cases that were reported over the past three years.
The infections currently appear to be centred on the industrial area in Sungei Kadut and along Bukit Timah Road.
A Ministry of Health (MOH) spokesman said at least 37 of those identified with the disease are locals. Two were hospitalised but have been discharged.
At least 18 of the people infected in the Bukit Timah area are foreigners, she added.
A spokesman for the National Environment Agency said: "Over the past two months, NEA has been conducting intensive mosquito-control operations within the vicinity of the patients' workplace and residences, and the areas that they frequent."
It inspected 260 factories in the Sungei Kadut industrial area and fined 129 of them for breeding mosquitoes. At Namly Crescent and Fifth Avenue, it inspected 655 places and fined 29 homes where larvae was found.
Unlike dengue, this virus is not endemic here. Of the 60 cases between 2010 and last year, 48 people were infected overseas and only 12 got it here.
The picture is very different this year. Of the 184 cases, only six were infected abroad. The rest caught the virus brought in by one or more of the six.
Those with chikungunya often suffer from fever, severe joint pain, muscle pain, headache, nausea, fatigue and rash.
There is no cure and treatment consists of relieving the symptoms, many of which mirror that of dengue, another mosquito-borne virus raging here.
Infectious diseases expert Indumathi Venkatachalam from National University Hospital said: "Dengue can cause death when severe, and in that regard is more serious than chikungunya.
"But for non-fatal infections, dengue resolves with no long- term consequences. Chikungunya, however, can cause joint pains for months after resolution of the acute illness."
More than 7,500 people have already been infected by dengue this year, with about one in four needing to be hospitalised.
The infection is spreading rapidly, with about 2,000 people diagnosed with dengue this month.
The MOH spokesman said dengue patients currently make up less than 1 per cent of hospital patients.
Changi General Hospital in the east, where dengue has been on the rise for some months, has been recording occupancy rates of between 90 per cent and 95 per cent. Its spokesman said the number of dengue patients turning up at its emergency department has risen from 163 in January to 555 last month. It has already seen 460 patients this month.