Chikungunya – a new threat in Bali

Chikungunya is spreading in Bali, in recent weeks we have come across numerous people who have come down with it. Chikungunya is a virus that is rather similar to Dengue fever. It is not fatal however it can lead to fever and most notably serious aches and pains. Some people develop very painful joints that can last for months.

Mosquitoes are killers

The mosquito is probably responsible for more human deaths than any other living creature.

Mosquitoes transmit some of the world’s most widespread diseases including Malaria, Dengue fever, Zika and the new rising star in the disease world – Chikungunya.

Early prevention methods

Malaria was a serious problem in India in the 19th century

We all know that malaria has been well known as a scourge of the tropics for eons of time probably from well before Adam was in short trousers. Back in the blithe filled days of the British Raj there was a lot of malaria around and it played havoc with the polo fixtures.

The incidence of malaria in India was dramatically reduced by introducing widespread use of mosquito nets and by removing standing water. They also poured oil into septic tanks and any other pools of stagnant water. Only a very small amount of low viscosity oil is needed, it spreads out in a very thin film across the surface of water and that is enough to prevent mosquitoes from laying their eggs.

Mosquitoes in Indonesia

Fortunately Bali is malaria free but not the nearby islands. I came across a man who went to Lombok where he visited a friend in a hospital, he was only there for 4 hours, the place was full of mosquitoes and he returned to Bali that same day with cerebral (that’s the most serious killer version) malaria.

Further East and malaria is a constant health risk. Sumba is noted for being particularly bad and a concerted effort by the Sumba Foundation distributing mosquito nets is considerably reducing the incidence of the disease.

These days the scourge of malaria has been joined by dengue fever and, more recently, Chikungunya both of which are, unfortunately, freely available in Bali.

In the tropics when the wet season comes we have more mosquitoes so perhaps it is a good idea to look at preventative measures we can take in and around our home.

Species of mosquito and diseases they carry

While there are probably more than 3,000 different species of mosquitoes there are only 3 that concern us. The Anopheles mosquito which carries malaria, the Aedes aegypti (Dengue Mosquito) and Aedes albopictus (Asian Tiger Mosquito) which carry the four types of Dengue fever. The Aedes mosquito also carries Chikungunya which is spreading rapidly though Indonesia.

Treatments for malaria, dengue and chikungunya

Malaria is a blood parasite and we do have treatments. Unfortunately no treatments are available for dengue fever and chikungunya.

The strategy, therefore, must be to avoid being bitten in the first place. This not only safeguards ourselves but if everyone does it the prevalence of the disease is progressively reduced.

Our concern in Bali is with the Aedes mosquitoes so let us start by understanding the enemy.

How to recognise the Aedes “Tiger” Mosquito

  • Aedes mosquitoes have striped legs but are more easily recognised by their behaviour:
  • They like to live indoors and bite people indoors.
  • They are hard to catch moving very quickly, darting back and forth.
  • They like to hide under furniture and bite people around the feet and ankles.
  • The bite is often relatively painless, so people may not notice they are being bitten or they may think they are being bitten by sandflies or biting midges.
  • The Aedes mosquito prefers to bite humans during daylight. It is very cautious when biting, flying away quickly at the slightest disturbance.
  • The Aedes mosquito does not fly very far, so if you get rid of mosquito breeding sites around your home, you will significantly reduce your risk of being bitten by dengue mosquitoes.
  • The Aedes mosquito is unusual in that it does not breed in swamps or drains, and does not often bite at night. They live 2 to 3 weeks.
  • Only females bite but trying to find a mosquito sexer can be a little difficult.
  • Carbon dioxide is the most universally recognised mosquito attractant and draws mosquitoes from up to 35 meters away.
  • They are also attracted by body odours such as lactic acid, movement and by infrared radiation (heat) of warm bodies.

How do I protect myself from mosquitoes

There are several steps you can take around your home to reduce the likelihood of being bitten by mosquitoes

  1. The most effective is to make your house mosquito proof by installing fly screens to your windows and doors. By carefully designing the flyscreens you can keep an attractive appearance on your house. Many villas have flyscreens as part of the standard window frames.

If you are adding flyscreens to existing frames take care to make sure you can still operate the door and window latches and it is advisable that they are designed so you can clean the screens and windows.

Plastic fly screen mesh has a tendency to stretch and go floppy. Metal mesh looks better, withstands the rigours of cleaning better but over time may go rusty. Aluminium mesh is available.

Fly screens avoid the need for using nasty insecticides and allow you to still enjoy cooling breezes.

  1. Do a regular inspection of your property and get rid of any standing water. Even small drops can incubate mosquito lava.
  2. Avoid living near stagnant pools and drain areas where even very small amounts of water can collect.
  3. Fish and frogs eat mosquito larva so put fish into water filled plant pots and ornamental pools. There is also a local product called “Abate” that you add to water that kills the mosquito larva without harming fish. This should be available free from your local puskesmas (health clinic).
  4. Close off access points to wells, water tanks, toilet cisterns, drains, sewers and septic tanks.
  5. Balinese people in Sanur are claiming major success in planting a mosquito repelling plant around their houses. The plant is Liligundi (Vitex Trifolia) and it is also being used to make repelling incense. It is said that since a program started to plant Liligundi dengue cases in Sanur have fallen by up to 80%.
  6. Use yellow light bulbs around the external areas of your house, yellow light does not attract mosquitoes as much as white light.
  7. Have your property fogged on a regular basis during the wet season. Beware, make sure that the fogging contractor is using the right chemicals. Diesel or kerosene makes a lot of smoke and is a lot cheaper than the proper chemicals but does not kill the mozzies. Contractors like to save a bit of money.
  8. In the house chit chats eat mosquitoes so treat them as your friends.
  9. Insect repellent can be very effective but makes you feel like someone sprayed you with hair lacquer. Local ones are Autan and Soffel but look for the fluid versions rather than the thick sticky lotions.
  10. Keep a fan going near you, mosquitoes are not the best fliers.
  11. Wear long sleeved shirts and trousers.
  12. Sleep with a sheet over you.
  13. Have a shower, the locals will tell you that sweat attracts mosquitoes. They know that a shower before dusk keeps the mosquitoes away (they go and bite the smelly bloke next door instead).

Liligundi – A Natural Mosquito Repellant

Liligundi grows as a shrub or small tree with leaves that are about 3 cms long and 1.5 cms wide. The leaves are green on the upper surface but more of a greyish green on their underside. Flowers are small and blue. Liligundi has quite a strong though not unpleasant fragrance rather like citronella. As a mosquito repellant Liligundi is a natural solution, low cost, low maintenance and (by all accounts) very effective.

Liligundi may be very useful for restaurants, hotels and villas in fact anywhere with mosquito problems.

Phil Wilson

Copyright May 2022