SINGAPORE — The number of dengue cases spiked sharply last week to 492 cases, surpassing the high of 406 cases in the previous week and setting a new record for the year.

As of 3pm yesterday, another 91 cases were recorded. The number of cases recorded this year so far stands at 4,334, compared to 4,632 in the whole of last year.

As was the case in the previous week, the most active clusters were in Tampines. A dengue cluster is formed when two or more dengue cases occur within 14 days and the homes of the dengue victims are within the distance of 150 metres.

The cluster of Tampines Street 12, 21 and 22 had 116 cases, followed by the cluster of Yishun Industrial Street 1 and Yishun Street 23 with 59 cases. The cluster of Tampines Avenue 8, Street 71, 82, 83, 84 and Tampines Central had 58 cases. There are 50 clusters in total.

The National Environment Agency (NEA) said the increase in the number of dengue cases could be associated with a possible increase in the less common Dengue Serotype 1 (DEN-1) virus, which the community has lower immunity against.

It has advised residents to step up dengue prevention measures by checking for stagnant water in their homes at least once a week, and it will deploy more manpower to target areas where DEN-1 has been circulating, install Gravitraps to monitor and trap the adult mosquito population, and step up on community outreach. It will also be rolling out a publicity campaign to spread the message on the need for vigilance.