Dengue trends and risks in Singapore

In 2020, reported cases of dengue fever in the first five weeks of the year was 60 per cent higher than the diagnosed over the same period for the previous year. In addition, there has been an increase in infections of dengue strain DENV-3. However, the Singapore population has lower immunity to DENV-3 as it has not been dominant for the past 30 years.

Your burning questions answered. What is a dengue strain? How has dengue trends evolved in Singapore and what are the preventive steps we can take? Read on to learn more about how to protect yourself against dengue fever in Singapore.

What are the risks and signs of dengue fever?

Dengue fever is a disease transmitted through the bite of an infected female aedes mosquito. Symptoms include high fever, skin rash, muscle and joint pains. Not to mention, in severe cases, it may lead to serious bleeding of internal organs, plasma leakage and even death.

Dengue serotypes (DENV 1-4)

The 4 dengue serotypes, DENV 1, 2, 3 and 4 are closely related viruses with different interactions with the antibodies in human blood serum.

• DENV-1 was a dominant serotype during the 2013 dengue outbreak in Singapore
• DENV-2 has been a dominant strain in Singapore since 2016
• DENV-3 has not been dominant in Singapore for the past 30 years. However, in 2020, there is an increase in DENV-3 cases
• DENV-4 cases have generally been sporadic in Singapore

5 Reasons why Singapore is an ideal mosquito breeding ground

Meanwhile, let us take a look at the factors that influence the development of dengue fever in Singapore.

• High temperature: Our sunny shores are a magnet for Aedes mosquitoes that thrive in warm environments.
• Humidity: Mosquitoes love the humidity in Singapore. On the contrary, research suggests that low humidity decreases the lifespan of mosquitoes.
• Steady rainfall: Mosquitoes need water to breed. The abundance of rainfall in Singapore creates an ideal environment for Aedes mosquitoes.
• Densely populated: The chances of getting infected with dengue fever increases with urbanisation because the dengue virus has adapted to the transmission cycle in an urban environment.
• Global warming is a global concern: Increased average temperatures caused by climate change enable higher transmission rates for dengue. As a matter of fact, the top 10 hottest years in Singapore since 1950 all occurred within the last 22 years!

Wet weather can promote stagnant water collection that causes mosquito breeding

5 Dengue trends in Singapore

Do you know? Dengue has been around in Singapore for over 100 years!

• Dengue was first reported in 1901 in Singapore
• In the 1960s and 1970s, it became a public health problem that affected many children
• In 1966, a pilot project was launched to control the Aedes mosquitoes in Singapore
• After decades of low incidence, dengue has remerged in Singapore in the 1990s and early 2000s. In addition, lowered herd immunity and transmission outside the home has led to a higher number of adults infections
• 2005 saw a significant rise in the number of dengue fever cases – 14,209 cases and 27 deaths

5 Dengue initiatives in Singapore

Project Wolbachia: The dengue vector control research study program was launched in Singapore in December 2019. Project Wolbachia involves the release of male Aedes mosquitoes infected with the Wolbachia bacterium to mate with females, causing them to lay eggs that do not hatch.

Dengue vaccine:  Dengvaxia is the world’s first dengue vaccine. The Health Sciences Authority (HSA) in Singapore approved dengvaxia for use only for those who had prior infection with dengue. Clinical trial data suggests that Dengvaxia could worsen symptoms for those not previously infected with dengue. Additionally, it is approved for use only in patients aged between 12 and 45 and requires three doses to be administered over 12 months by injections.

National Environment Agency (NEA) 5 steps mozzie wipeout: Launched in April 2013, the annual NEA Mozzie Wipeout campaign gathers support from the community to take the necessary precautions to reduce the spread of dengue. Outreach efforts includes the distribution of educational materials, roadshows, house visits and posters display.

5 Steps in the Mozzie Wipeout campaign:

• Turn over water storage containers
• Change water in vases
• Remove water from flowerpot plates
• Loosen hardened soil
• Clear blockages and put insecticide in roof gutters

Dengue community alert system:  In 2018, NEA launched the Dengue Community Alert System to provide residents with the latest update on the severity of the dengue situation in their precinct. For instance, banners indicating the colour codes (yellow, red or green banners) are displayed in dengue cluster areas. Red presents more than 10 dengue cases in the area while yellow represents less than 10 cases. On the other hand, green represents no new cases, under surveillance for the next 21 days.

Dengue Inter-Agency Task Force (IATF): Formed in September 2005, IATF enhances the communication and coordination on dengue control efforts among multiple Government agencies.

5 Facts about Aedes mosquitoes

How well do you know the Aedes mosquito?

• Have a flight range of up to 400 metres
• Able to travel through high-rise buildings
• Have distinctive black and white markings on their bodies and legs
• Active during the day
• Usually remains close to human habitation

Mosquitoes can enter high rise buildings as well

5 steps: How to prevent dengue

Additionally, here are 5 preventive steps you can adopt to reduce your risks of mosquito bites.

• Apply mosquito repellent, preferably one containing DEET, an active ingredient that repels insects
• Sleep under mosquito nets
• Wear long sleeve and long pants
• Keep air circulated with the use of fans
• Wear light coloured clothes as mosquitoes are attracted to dark colours like black and navy blue

Why use a professional mosquito control?

Do you need a sustainable pest control strategy? Here are the top reasons why a professional pest control solution can give you a winning edge.

• Professionals know how to identify the early warning signs of a mosquito infestation
• Beyond the treatment, a professional pest control technician will be able to identify the cause of infestation and recommend the preventive steps to ensure a consistent control in mosquito breeding
• Reduces both adult mosquitoes. In addition, it controls new larvae population for long-term effectiveness
• Environmentally-friendly options are available
• Licensed pest technicians are trained to carry out treatments according to the industry’s highest standards. In summary, ensuring risks to the environment and its occupants are minimised

6 reasons why pest control for mosquitoes is essential

In2Care Mosquito Trap: An innovation that leverages on mosquito behaviour

Rentokil’s In2Care Mosquito Trap is an innovative solution that significantly reduces both the adult mosquito and larvae population. It features a trap with water treated with In2Mix larvicide to attract adult mosquitoes and larvae.

Firstly, once a mosquito enters the trap, it will breed and release larvae inside the trap. Secondly, the larvicide in the water will kill the larvae. Thirdly, the infected adult female mosquito will spread the larvicide powder to the other breeding sites that it visits. Finally, it prevents the emergence of new mosquitoes from breeding sites and therefore helps to continuously and consistently control mosquitoes around your premise.

Let the mosquito do the job for you with In2care Mosquito trap

Get in touch with a Rentokil pest control specialist to find a mosquito control solution that works for you. Call (65) 6347 8138 to learn more.