This brings the year's total to 178 cases.

Four new cases cropped up in Kranji Way, bringing the toll there to 29 cases; six were reported in Sungei Kadut, which has had 14 to date. An isolated case was found in Mandai, where a 28-year-old general worker was affected.

The National Environment Agency has deployed 13 officers in Mandai estate to check for mosquito breeding. Mosquitoes were found breeding in 10 of the 85 houses checked.

Owners who do not comply with orders to take steps to prevent this can be fined up to $50,000.

The remaining 16 new infections are 'imported cases', among those who travelled to and from mainly Malaysia.

Looking at the year's total of 178 cases, 86 have been imported ones. Locally acquired infections surfaced in 19 locations here.

Symptoms of chikungunya, which is caused by a mosquito-borne virus, include fever, rashes and joint pain.

The Ministry of Health advises people who develop these symptoms to consult their doctors immediately.