Number of dengue cases may surge this year: NEA

There could be a growing number of dengue cases in the coming months, the National Environment Agency (NEA) warned, based on data from its Gravitrap surveillance system.
There could be a growing number of dengue cases in the coming months, the National Environment Agency (NEA) warned, based on data from its Gravitrap surveillance system.PHOTO: AFP

The number of dengue cases is relatively low for now, but there could be an uptick in the coming months.

The National Environment Agency (NEA) warned yesterday that the increase could peak in the middle of the year.

NEA's projection is based on data from its Gravitrap surveillance system, which detected about 60 per cent more Aedes aegypti mosquitoes last month than in last October.

"If left unchecked, the high Aedes aegypti population may lead to a surge in dengue cases in 2017," the NEA said in a press statement.

Another factor which may lead to more cases is the high diversity of circulating dengue serotypes. DENV-2 was the dominant dengue serotype for much of last year, so anyone who contracted that type is immune, but the predominant serotype this year remains unclear.

"Historically, a change in predominant dengue virus serotype has been followed by a spike in dengue cases," said the NEA.

The agency also urged those spring cleaning for Chinese New Year to properly dispose of any refuse, including large items, so that they do not become unintentional mosquito breeding habitats.

It asked residents to prevent mosquito breeding by changing water in vases and turning over all water storage containers that are not in use.

Those intending to travel during the upcoming holiday period should also mosquito-proof their homes by adding insecticide in roof gutters and making sure there is no stagnant water accessible for breeding.

Madam Grace Lee, who will be travelling during the holiday weekend, said she usually covers the toilet bowls at home when her family is away.

"Our area was a dengue hot spot previously, so it is better to take precautions," said the 60-year-old cashier, who lives in Bishan.

A total of 13,115 dengue cases were reported to the Ministry of Health (MOH) from Jan 3 to Dec 31 last year.

More than 1.2 million inspections were conducted by the NEA last year, including 7,400 at construction sites.

The inspections were meant to prevent not only the transmission of dengue, but also that of the Zika virus, which mosquitoes can also carry.

The NEA discovered more than 16,000 mosquito breeding habitats. About 3,900 households were fined. More than 60 court prosecutions were taken against contractors for repeat offences, while more than 60 stop-work orders were issued to construction sites.

In February last year, the MOH and NEA warned that the number of dengue cases for that year could hit a new record high, exceeding 30,000. The NEA observed a 50 per cent increase in the number of mosquitoes caught in its Gravitraps in January last year, compared with the figure in January 2015.

"Despite an early surge in the number of cases early in 2016, the situation was brought under control," said the agency.

This was due to various factors, such as intense vector control efforts and the unusually high temperatures, which can shorten a mosquito's lifespan.

A version of this article appeared in the print edition of The Straits Times on January 20, 2017, with the headline 'Number of dengue cases may surge this year: NEA'. Print Edition | Subscribe