Fight The Bite


They may be small, but certain insects can cause great harm to our health. Find out how to keep you and your loved ones safe from insect-borne diseases.

Did you know that there are 7,797 people occupying each square kilometre of Singapore? With a land area of just 719.2sq.km, that makes our sunny island quite densely populated. Throw in rapid urban development and we have a thriving environment for a different kind of population: insects.

According the National Environment Agency, mosquitoes, fleas, cockroaches and flies are the insects we should worry about the most. Together, they are responsible for some of the world’s most fatal diseases such as dengue haemorrhagic fever, the plague, cholera and dysentery. We may not be constantly inundated with news of such epidemics in Singapore, but this doesn’t mean that they never happen.

MOSQUITOES
Responsible for transmitting:

  • Dengue and Dengue Haemorrhagic Fever
  • Chikungunya
  • Zika

The carrier:
Of the 140 species of mosquitoes that have been identified in Singapore so far, only Aedes aegypti and Aedes albopictus have been found to transmit the diseases listed above. Both species live in flowerpots, clogged roof gutters and household water storage containers, while Aedes albopictus also likes plant-filled areas, tree holes and dry leaves. The two species are daytime biters, but will also bite at night if the area is well-lit.

The diseases:
Dengue and Dengue Haemorrhagic Fever Young adults aged between 15 and 24 years old are the most likely to get infected with dengue. Typical symptoms include:

  • a sudden onset of fever that lasts two to seven days
  • severe headache
  • pain in the muscles, bones and joints
  • rashes
  • nausea and vomiting
    In more severe cases, dengue fever can be accompanied by bleeding complications, such as in the gums and gastrointestinal tract. The patient may also have seizures or become comatose.
  • Chikungunya and Zika
    Symptoms are similar to dengue, but only dengue is fatal. Zika is the mildest of the three but can cause serious complications in a small number of unborn children. Your family doctor will do a blood test to determine if you have any of these diseases.

Taking action:

  • Repellents - The mosquito needs to fly to within 4cm from the application site before it will be repelled. While all exposed skin is at risk, take care not to apply the repellent near the nose and eyes. The product may work anywhere between 15 minutes and 10 hours depending on the climate, humidity, formulation of the product, concentration of the formulation and the species of the mosquito. Synthetic repellents that contain DEET last longer than plant-based ones.
  • Insecticide spray cans - These will kill mosquitoes and are thus a better way of preventing disease transmission. However, spraying a room with insecticide will keep it mosquito-free for a short time only.
  • Mosquito coils - One coil is usually effective in a bedroom through the night. The smoke from the coil prevents mosquitoes from entering the room, while any that are already inside are expelled or have difficulty finding their host. Lighted coils are a fire hazard, so take care not to place them near curtains and other flammable materials.
  • Clothes - Our hot and humid climate encourages us to wear less, but this only leaves our skin exposed to mosquitoes. If you are venturing out to any areas that may have mosquitoes, do try to cover yourself as much as possible. Use a repellent on exposed skin and apply some onto your clothes as well to extend the repellent’s effectiveness.
  • Air-conditioning - Besides keeping you cool, air-conditioners also help to keep flying insects out of the room. But you’ll have to use an insecticide to kill any mosquitoes that are already there with you.

FLEAS
Responsible for transmitting:
Plague

The carrier:
Fleas can’t fly but they can jump long distances, thanks to their powerful, elongated legs. Adult fleas can jump as high as 15cm.

The disease:
As fleas usually jump from pets, carpets, bedding or furnishings to feed, their bites are usually found on the feet or lower legs. In addition, infants are more likely to get bitten by fleas, particularly when they are playing on carpeted areas or on rugs. The bite is not painful but it is extremely itchy. See your family doctor if the itchiness is accompanied by any of these symptoms:

  • fever
  • malaise
  • headache
  • muscle pain
  • nausea
  • vomiting
  • abdominal pain
These are signs of bubonic plague, which could progress to the fatal and highly contagious pneumonic plague if left untreated.

Taking action:

  • Pets - They are the main source of flea infestations. Wash their bedding weekly at above 60˚C. Use a flea comb on your pets each time they return from the outdoors, where they could have picked up fleas from other animals such as birds and rats.
  • Carpets and floors - Vacuum these regularly. If you are moving into a new home, inspect the carpets and flooring carefully for signs of eggs or ‘flea dirt’. Ask if the previous owners had pets as the flea larvae might still be in the house.
  • Organic matter - Check your carpets, bedding and furnishings regularly for any food that might have been accidentally dropped. This is a potential food supply for flea larvae.

COCKROACHES
Responsible for transmitting:
Food-borne diseases

The carrier:
If you see a 10–15mm long insect with a yellowish-brown, tongue-shaped body running around a cupboard or behind the fridge, it’s most likely a German Cockroach. They are the most common type of cockroach found in residences, where they can be found in dark, secluded areas such as rotting waste material and refuse. Because of this preference, they pick up disease-carrying organisms on their bodies, which are deposited in various other places as the cockroaches travel from one location to another.

The disease:
Cholera is one example of a food-borne disease that is carried by cockroaches. Generally, the symptoms include:

a sudden onset of diarrhoea
nausea
vomiting

If left untreated, patients will get severely dehydrated and may suffer renal failure.

Taking action:

  • Food storage - Use containers with tight lids or plastic bags that can be sealed to store dry foods. Never leave food exposed.
  • Clean up - Clear all food waste and wipe up all spills as soon as possible. Throw all waste into a bin that can be tightly closed and clear it each day.
  • Get rid of clutter - Dispose of old newspapers, magazines, cardboard boxes and anything else that’s on the floor or beneath cupboards and beds that could provide a dark habitat for cockroaches.
  • Secure entry points - There are many ways cockroaches can enter your property: through cracks, crevices, vents, sewers and pipe drains. Gaps around doors are another possibility. Walk around your home and seal these areas off.

FLIES
Responsible for transmitting:
Food-borne diseases

The carrier:
Houseflies and bluebottle flies are the most common types of flies that can be found in or around homes. Like cockroaches, these flies prefer rotting waste, including faeces, which they use for feeding and breeding.

The disease:
Due to their feeding and breeding habits, flies are notorious as carriers of food-borne diseases such as typhoid, salmonellosis, dysentery and cholera. Symptoms to look out for include:

  • diarrhoea
  • fever
  • nausea and vomiting
  • severe headache
  • abdominal pain
See your family doctor if any of these symptoms persist for more than a week or if they are particularly severe.

Taking action:

  • Food storage - Store all food in airtight containers or in the fridge. Never leave anything exposed.
  • Clean up - Wipe up all spills immediately. Throw all waste into garbage bins and keep them tightly covered.
  • Get rid of odours - Wash your garbage bins regularly as flies are attracted to the odour of rotting waste.