The Aedes mosquito – responsible for spreading dengue – also transmits the Zika virus. By Audrey Tan
Photo: macmackyky / www.123rf.com
The weather may be hot nowadays, but it is likely to get worse from next month, all the way until October. This period marks the warmer months of the year – and the traditional peak dengue season in Singapore, said the National Environment Agency (NEA).
Even though Singapore only registered 13,000 dengue cases last year – half the projected 30,000 – NEA on Sunday (May 14) urged people to remain vigilant, by launching this year’s edition of the National Dengue Prevention Campaign. The campaign urged people to do the mozzie wipe-out at home to reduce breeding places for mosquitoes.
The Aedes aegypti mosquito, the main vector of dengue, also transmits the Zika virus. “Since the start of 2017, there have been five Zika clusters, all of which are located in the same vicinity, indicating that transmission is ongoing in the area,” NEA said.
A cluster is formed when at least two cases have onset within 14 days and are located within 150m of each other. Four of them have since closed, and only one cluster remains in the Highland Road/ Jansen Close/ Jalan Sahabat/ Kovan Road and Upper Serangoon Road (D’Pavilion) area.
Vector control operations are ongoing in that area, NEA said. As of March 31, NEA has conducted 290,000 inspections and uncovered 2,700 instances of mosquito breeding habitats. On top of inspections, NEA is also trying out a small-scale field study involving the release of male mosquitoes carrying the naturally-occurring Wolbachia bacteria at three selected sites at Braddell Heights, Tampines West and Nee Soon East. Male mosquitoes do not bite humans.
When the male Wolbachia-carrying mosquitoes mate with female mosquitoes, the bacteria causes the females to produce eggs that do not hatch. This helps to reduce the population of mosquitoes that can spread diseases to humans.
NEA said on Sunday that the study, first launched last October, will conclude by the end of this month (May 2017). Data collected will be analysed to plan for a larger-scale suppression trial.
In February, NEA said the number of viable Aedes mosquito eggs collected from the Tampines West site was reduced by about half. This means about half of the eggs did not hatch. This suggests that the released male Wolbachia-Aedes mosquitoes successfully mated with the urban Aedes aegypti females, NEA said then.
But Minister for the Environment and Water Resources Masagos Zulkifli, speaking at a Do the Mozzie Wipeout campaign launch in Tampines, urged residents not to be complacent, saying the Wolbachia technology was not a silver bullet, and that it would take years before it can be deployed on a large-scale.
“It is therefore important that all of us must continue with our efforts to prevent mosquito breeding. This is the impetus for the Do the Mozzie Wipeout campaign that we are launching today… Collectively, we can keep Zika and dengue at bay, and protect not just ourselves, but also protect our family and friends,” said Mr Masagos.
A version of this article originally appeared in the online version of The Straits Times at www.straitstimes.com.