What is Dengue?
Dengue fever is the most common insect borne viral illness. It is estimated that over 100 million cases of Dengue Fever occur annually on a worldwide basis. It is a condition that occurs in tropical countries of Asia, Africa, Central America and South America. Unfortunately it is also a widespread problem in Singapore. Countries in South East Asia including Indonesia, Thailand, Cambodia, Northern Australia and Vietnam have very high rates of Dengue.
The illness
Dengue is characterised by an abrupt onset of high fever, severe headache (usually located behind the eyes), and severe back, muscle and joint ache, and abdominal pain. Vomiting is common in the early stages. This stage will last 2-7 days. This may be associated with a fine skin rash after 3-5 days. The condition is usually self limiting and the patient will recover quite quickly. Some patients may continue to feel tired for a few weeks but have no other symptoms.
In some cases, a severe form of the disease may occur called Dengue Haemorrhagic Fever (DHF). The critical stage of the illness is around day 4 to 5, when the fever resolves, and the patient feels better, however bleeding may occur at this time as the platelets in the blood drops. This can also lead to another more severe form called Dengue Shock Syndrome (DSS) in which the blood pressure drops. These can be fatal and hence the need for early medical diagnosis and management. DHF and DSS is more common if you have had Dengue at least once before. Symptoms include bleeding (gums/nose/skin/gastrointestinal tract). This happens when the platelets (factors in the blood that help in clotting) fall to dangerously low levels.
Most young children do not have symptoms or have very mild symptoms only when infected with dengue.
How is Dengue spread?
Dengue is spread most commonly by the mosquito Aedes Aegypti. This mosquito thrives in densely populated urban areas. They tend to be most active during the daytime and can be present indoors.
The breeding sites for the mosquitoes can be stagnant collections of water such as household pails, flower pots, unused toilets and cisterns, water tanks, an empty can, motor car tyres, the base of a potted plant, a blocked roof gutter or in a natural reservoir (e.g. pooling water resting on vegetation).
The symptoms of the illness usually begin 4-6 days after the Aedes mosquito bite.
If a household member is diagnosed with dengue, it is important that good measures are taken to eliminate mosquitoes within the house and to use insect repellent liberally, as the same mosquito biting the infected person could easily bite other people in the household whilst they are infectious and spread dengue.
Management
- There is no specific treatment for dengue
- Maintaining hydration is important
- Paracetamol is given for fever
- Avoid using aspirin and related anti-inflammatory drugs such as Ibuprofen due to the risk of bleeding
- Regular monitoring of the level of platelets in the blood until they are normal
- Serious cases need to be hospitalised for intravenous fluids and monitoring. Look out for unexplained bleeding, bleeding spots under the skin, dizziness, severe weakness, cold extremities, and severe abdominal pain. These could be signs of the development of dengue haemorrhagic fever or dengue shock.
Prevention
A Dengue vaccine is now available but it can only be given to those who have had a previous bout of the disease. It is therefore important in the first instance to undertake insect avoidance measures to decrease your risk.
Please refer to our brochure on insect avoidance measures or discuss this with your doctor. Also, it is important to prevent mosquitoes from breeding in your home. More details on how to do this can be found at the National Environment Agency website www.nea.gov.sg. If you are diagnosed with dengue, the NEA may conduct an inspection of your home to see if mosquitoes are breeding there so be sure to carefully check your home for breeding sites and eliminate them or you may be fined.
