5 to 7 Aug 2020
SAFETY DAY 2020
• Dengue Fever is one of the most
common mosquito-borne viral diseases in the world.
• Dengue Fever is an illness caused by
infection with a virus transmitted by the Aedes mosquito.
• There are four serotypes of this virus
(DEN-1, DEN-2, DEN-3 and DEN-4) which can infect you.
How does Dengue spread?
• Dengue fever is spread though the bite of the Aedes mosquito.
• To prevent dengue fever, you must therefore prevent the breeding of the Aedes
• Aedes mosquitoes are identified by the black and white stripes on their bodies. • You can get rid of the Aedes mosquito by frequently checking and removing
How does Dengue spread?
• The Aedes mosquito prefers to breed
in clean, stagnant water easily found in our homes.
• All it takes is clean, stagnant water as
small in volume as the size of a 20-cent coin, for mosquitoes to breed.
• During the Circuit Breaker period, NEA
observed a five-fold increase in the incidence of Aedes mosquito larvae detected in homes and common corridors in residential areas.
What is Aedes mosquito?
Did you know?
• Only the female Aedes mosquito bites, as it needs the protein in
blood for its eggs to develop.
• The mosquito becomes infective approximately seven days after
it has bitten a person carrying the virus. This is the extrinsic incubation period, during which time the virus replicates in the mosquito and reaches the salivary glands.
• Peak biting is at dawn and dusk
• The average lifespan of an Aedes mosquito in nature is two
• The mosquito can lay eggs about three times in its lifetime, and
about 100 eggs are produced each time.
• The eggs can lie dormant in dry conditions for up to about nine
months, after which they can hatch if exposed to favourable conditions, such as water and food.
1 day 4 days
2 days 3 days
What are the symptoms of Dengue?
• Sudden onset of fever for two to seven days;
• Severe headache with retro-orbital (behind the eye) pain; • Joint and muscle pain;
• Skin rashes;
• Nausea and vomiting;
• Bleeding from the nose or gums; • Easy bruising of the skin
Dengue cases in 2020
• The number of dengue cases increase five-fold during the Circuit Breaker period
“The number of dengue cases in Singapore this year has
surpassed the total number of cases for the whole of 2019." - NEA, 14 Jul 2020
Dengue surveillance data
• 4,773 dengue cases (including 11 dengue
haemorrhagic fever cases) were notified in the quarter from Jan-Mar 2020.
• There were seven reported deaths due to local
dengue infection from Jan-Mar 2020. The cases were between 60 and 80 years of age. All seven cases resided or worked within dengue clusters.
• Results of positive dengue samples serotyped
between Jan and Mar 2020 indicated that
DEN-3 accounted for majority of the typed samples, followed by DEN-2, DEN-1 and DEN4 (Figure 1) *.
Dengue Community Alert System
• NEA launched the Dengue
Community Alert System to display colour-coded banners (yellow, red or green banners) in dengue cluster areas to
provide timely information to residents of the dengue
Surveillance of the Aedes aegypti Mosquito Population
• The Gravitrap, developed by NEA’s Environmental
Health Institute (EHI), is designed to attract and trap female Aedes adult mosquitoes that are looking for sites to lay their eggs in.
• Female Aedes mosquitoes attempting to lay their
eggs in the traps will be captured and prevented from biting other people.
• The Gravitrap also traps and prevents the emergence
of any mosquitoes from eggs that are laid in the trap.
• Gravitraps, when distributed across an area, help to
monitor the Aedes mosquito population in the area and its vicinity.
• From a public health point of view, dengue threats are as real as COVID-19 as it
can transmit easily from person to person
• Dengue requires the transmitting media, in this case Aedes mosquito, to transmit
• Hence, in order to break the chain of transmission, we should break the chain of
• Recap: Senoko was fined in June 2017 for mosquito breeding
• Recap: Two (2) cases were reported in hospital and NEA ‘forced’ entry into
Senoko for inspections. Only one (1) case was reported internally.
Source of information
Retrieved 13 Jul 2020: