Dengue fever cases have peaked unexpectedly in the first quarter of 2019.

Alarming rise in dengue fever cases in S'pore

According to the National Environment Agency (NEA), there are at least 2,224 cases of dengue fever reported in the three months of the year.

Compared to 2018, the number of reported cases is at least three times more within the same period, with 600 dengue cases reported in the first quarter of 2018.

Three elderly people have died from dengue fever this year.

This includes a 71-year-old woman from Ang Mo Kio and another two men in their seventies from Bedok and Hougang.

There were a total of 2,772 dengue cases in 2017 and 3,285 cases in 2018.

Five people died from dengue fever last year.

Although the number of Aedes aegypti mosquitoes (Aedes mosquitoes) in March 2019 is seven per cent less than in March 2018, mosquito population remains high. 

An impact of climate change

2019 is likely to be hotter than usual due to the onset of El Niño, which is a periodical warm phase in the climate pattern.

However, even without the El Niño effect, the past few months have been one of the hottest months on the record as announced by the Meteorological Singapore Service:

"March 2019, February 2019, January 2019 and December 2018 are the warmest respective months in the last 90 years that are not influenced by the El Niño."

As mosquitoes breed well in warm and wet weather, this could explain the sudden spike in the number of dengue fever cases this year.

It may also suggest that more dengue cases are expected in the warmer months ahead between June and October, as warned by NEA.

In fact, the warmer temperature and high rainfall will accelerate the development of Aedes mosquitoes, which transmit the dengue virus.

Such weather conditions also shorten the incubation period of the virus.

According to the World Health Organisation, about half of the world's population would be exposed to dengue by 2085 because of climate change. 

Places such as Japan and the United States are also seeing the reappearance of dengue cases after more than 70 years.

What can we do to fight against dengue?

Preventive measures can be taken to effectively mitigate the breeding of Aedes mosquitoes and keep dengue cases as low as possible.

The Ministry of Environment and Water Resources (MEWR) kickstarted the national dengue prevention campaign earlier this year.

Minister of MEWR, Masagos Zulkifli, urges everyone to be vigilant and watch out for common breeding spots at home and in the neighbourhood.

All it takes is a small amount of water -- the size of a 20-cent coin -- for mosquitoes to breed. 

The Aedes mosquitoes can be identified by the distinctive black and white stripes on its body. Besides the dengue virus, they can also transmit Zika.

Here are the five steps you can do to ensure that there are no mosquito breeding grounds near you:

1. Turn the pail
2. Tip the vase
3. Flip the flower pot plate
4. Loosen the hardened soil
5. Clear the roof gutter and place Bti insecticide

List of active dengue clusters

You might also want to check if you are living or working in any active dengue clusters.

Here's the most updated list as of Apr. 9, 2019:

High risk area with 10 or more cases

- Woodlands Circle (Blk 721) / Woodlands Cres / Woodlands Cres (Blk 774, 775, 776, 777, 779, 780A, 780D, 780F, 782E)

- Woodlands Dr 60 (Blk 770, 771, 772, 778, 786B, 786C, 786D, 786E, 786F)

- Woodlands Ave 4 (Blk 844) / Woodlands St 82 (Blk 817, 839, 842, 850) / Woodlands St 83 (Blk 832, 835)

- Woodlands Dr 40 (Blk 701, 702, 703, 706) / Woodlands Dr 70 (Blk 712)

- Woodlands Dr 72 (Blk 796, 798)

- Golden Walk / Tai Hwan Ave, Cres, Gr, Ter, Walk

High risk area with less than 10 cases

- Hai Sing Rd / Hougang Ave 3 (Blk 1) / Hougang St 32 (Blk 376B) / Hougang St 32 (Parc Vera)

- Choa Chu Kang Ave 1 (Blk 130, 132)

- Lor 1 Toa Payoh (Blk 148, 153A, 155) / Lor 2 Toa Payoh (Blk 147, 152, 175)

- Pending Rd (Blk 114, 117, 118, 121) / Petir Rd (Blk 150)

- Hougang Ave 6 (Blk 423) / Hougang Ave 10 (Blk 409, 463)

- Woodlands Dr 62 (Blk 681C, 682B, 684C)

- Woodlands Ave 6 (Blk 763) / Woodlands Circle (Blk 742)

- Yishun Ave 11 (Blk 349, 350, 351)

- Yishun Ring Rd (Blk 617) / Yishun St 61 (Blk 626)

- Yishun St 61 (Blk 632, 634)

- Bedok Reservoir Rd (Blk 103) / Jln Eunos (Euhabitat) / Jln Punai / Teo Kim Eng Rd

- Changi Rd / Joo Chiat Ter / Lor 101 Changi (Park Ct)

- Aljunied Rd (Avant Residences) / Geylang Rd / Lor 27 Geylang (The Centren)

- Chai Chee Rd (Blk 22, 61, 63)

- Jln Tarum

- Kaki Bt Ind Ter

- Lor 1 Toa Payoh (Blk 125) / Lor 2 Toa Payoh (Blk 122)

- Maria Ave / Taman Siglap

- Admiralty St

- Frankel Cl

- Tampines St 45 (Blk 498F, 498H)

Top photo from ProjectManhattan via Commons Wikimedia (for illustration purposes only)