SINGAPORE, May 21 — After the number of dengue cases hit a 16-year low last year, the authorities have called on the public not to let their guard down, amid a spike in the Aedes aegypti mosquito population between January and March.
Recently, three dengue-related deaths were reported in as many weeks in a Jurong West cluster. There were no such fatalities for the whole of last year.
At the launch of the National Dengue Prevention Campaign at Punggol West yesterday, Minister for the Environment and Water Resources Masagos Zulkifli said the Jurong West cluster was a "sobering reminder" of how deadly the virus is.
As Singapore approaches the traditional peak season for dengue, from June to October, Mr Masagos urged Singaporeans to stay vigilant as the National Environment Agency (NEA) keeps up with its inspection and outreach efforts.
There is usually a higher transmission of the dengue virus during this warmer season due to the accelerated breeding and maturation cycles of the Aedes mosquitoes and the shorter incubation periods for the virus.
The NEA's Gravitrap surveillance system has detected 22 per cent more Aedes aegypti mosquitoes in the first three months of this year, compared to the fourth quarter of last year. Gravitraps are black cylindrical containers with sticky surfaces which trap female Aedes mosquitoes looking for water surfaces to lay their eggs.
Speaking to reporters on the sidelines of the event, Mr Masagos said the increase in mosquito population was a concern.
"It shows that as much as we do to bring down the breeding, there is a role for everyone to not allow the breeding to happen, particularly at home. We have discovered that every time there is a cluster, many of the breeding spots are found within the homes, or just outside the homes," he added.
In the Jurong West cluster for instance, 70 per cent of the breeding sites were found in residential premises in flower bowls, vases, fountain, pails and dish-drying trays. Some of these breeding spots contained up to 200 larvae each.
As of May 12, there have been 930 dengue cases this year. The Jurong West cluster as well as another one in Bedok North Street 3 are currently classified as high-risk areas with 10 or more dengue cases.
There were 2,772 dengue cases in Singapore last year, the lowest since 2001, partly due to the local population's built-up immunity after a high number of cases in the last few years when there were dengue outbreaks, among other factors.
Since the authorities were notified of the Jurong West cluster on Apr 3, the minister said 140 NEA officers were deployed on the ground to step up inspections and outreach efforts.
The Ministry of Health and NEA are investigating the reasons that may have contributed to the severe cases in the cluster.
While new cases are still being reported in that cluster, they are coming in at a slower pace, Mr Masagos said.
All homes found to be breeding mosquitoes face a S$200 (RM591) fine.
While there are no plans to increase these penalties, Mr Masagos pointed out a misconception among some that mosquitoes will not breed in clean water. "That is not true...any stagnant water can attract mosquitoes to breed," he added.
Punggol West resident Lim Jun Wei, 33, said the recent deaths made his family more aware of the dengue situation and prompted them to take preventive steps, such as emptying their pails after using them on the same day.
From January to March, the NEA has conducted about 265,000 inspections, including 2,400 that were carried out at construction sites which tend to have a higher potential for dengue transmission. About 4,200 instances of mosquito breeding habitats have been found.
The NEA also issued about 100 notices to attend court and six stop work orders during this period. Nine court prosecutions were taken against contractors for repeat offences.
In recent years, fewer construction sites have been found to be breeding mosquitoes, with the proportion falling from 11 per cent of the breeding spots discovered in 2013 to six per cent last year. — TODAY
