Dengue is a viral infection caused by four types of viruses (DENV-1, DENV-2, DENV-3, DENV-4) belonging to the Flaviviridae family. The viruses are transmitted through the bite of infected Aedes aegypti and Aedes albopictus female mosquitoes that feed both indoors and outdoors during the daytime (from dawn to dusk). These mosquitoes thrive in areas with standing water, including puddles, water tanks, containers and old tires. Lack of reliable sanitation and regular garbage collection also contribute to the spread of the mosquitoes.
In some cases, Dengue infection is asymptomatic – persons do not exhibit symptoms. Those with symptoms get ill between 4 to 7 days after the bite. The infection is characterized by flu-like symptoms which include a sudden high fever coming in separate waves, pain behind the eyes, muscle, joint, and bone pain, severe headache, and a skin rash with red spots. Treatment includes supportive care of symptoms. There is no antiviral treatment available.
The illness may progress to Dengue Hemorrhagic Fever (DHF). Symptoms include severe abdominal pain, vomiting, diarrhea, convulsions, bruising, and uncontrolled bleeding. High fever can last from 2 to 7 days. Complications can lead to circulatory system failure and shock, and can be fatal (also known as Dengue Shock Syndrome).
If you are infected with the same Dengue virus serotype you become immune to future infections. However, if you are infected subsequently with a different serotype, immunity wanes over time which increases the risk of developing Dengue Hemorrhagic Fever.
Travellers should take meticulous measures to prevent mosquito bites during the daytime.
- Use a repellent containing 20%-30% DEET or 20% Picaridin on exposed skin. Re-apply according to manufacturer’s directions.
- Wear neutral-coloured (beige, light grey) clothing. If possible, wear long-sleeved, breathable garments.
- If available, pre-soak or spray outer layer clothing and gear with permethrin.
- Get rid of water containers around dwellings and ensure that door and window screens work properly.
- Apply sunscreen first followed by the repellent (preferably 20 minutes later).
- More details on insect bite prevention.
A vaccine is available for people living in some Dengue endemic countries, but is not commercially available for travellers.
Dengue occurs nationally in Malaysia, with increased risk in urban and periurban areas. Peak transmission occurs in the late monsoon season (October through February in east peninsular Malaysia, Sabah, and Sarawak; July through August in west peninsular Malaysia).
Fogging will be carried out in the compound to give a quick knockout of adult mosquitoes. Larviciding will include breaking down the breeding cycle of mosquitoes on area with stagnant water.
1) FOGGING to control mosquitoes
2) LARVACIDING TO CONTROL MOSQUITOES (LARVA)