There were four new cases of Zika infection as of noon yesterday, bringing the total number to 333 since the first locally transmitted case was found last month.

The authorities provided this updated figure on the National Environment Agency's (NEA) website late last night.

The number of clusters remains unchanged at seven. Most of the cases - 269 - are in the Aljunied cluster, of which 101 emerged in the last two weeks.

The second-biggest is the Elite Terrace cluster, with seven cases, all emerging in the last two weeks.

As of Sunday, there were eight pregnant women confirmed to have contracted the mosquito-borne virus. Zika infections during pregnancy have been linked to a higher chance of babies being born with microcephaly, a severe birth defect in which the head and brain of the child are undersized.

The pregnant women's doctors are following up closely with them to provide support and counselling.

At least three outreach events were held on Sunday to raise awareness about the virus, with much of the efforts focused on preventing mosquito-breeding in homes.

Two-thirds of mosquito-breeding sites are found in homes, while the rest are in common areas and construction sites.

NEA chairman Liak Teng Lit told The Straits Times on Sunday that fogging alone has "limited use" and "cannot stop this problem".

As of yesterday, the authorities will be issuing daily Zika updates on NEA's website at www.nea.gov.sg/zika-clusters

Kok Xing Hui