Representational Image | illustration by Syalima M Das
Dengue is a mosquito-borne viral disease, transmitted by the bite of an infected Aedes species of a female mosquito. While there are four variants of the Aedes mosquito that infect human, Aedes-aegypti and albopictus are the most prevalent.
These mosquitoes usually bite in the morning and evening, in shady areas or when the weather is cloudy, but can spread infection any time and all year long. The disease outbreak usually occurs in tropical and sub-tropical regions and can infect anyone irrespective of age and gender.
Dengue is more common in the rainy season and these mosquitoes are often found in still water such as in wells, storage tanks, old car tyres, leftover water in coolers or small containers. This leftover water provides favourable conditions for the breeding of these mosquitoes.
The symptoms of dengue are typical noticed after three days to two weeks from getting infected. This is called the incubation period of the dengue virus in the human body. Symptoms can include:
- High-grade fever with chills and shivering
- Severe headache, typically behind the eyes
- Muscle and joint pain
- Weakness and fatigue
- Nausea and vomiting
- Rashes all over the body
- Loss of appetite
- Sore throat
- Enlarged liver or spleen
Dengue cannot spread from one infected person to another but human-to-human transmission is possible via mosquito bites. If an infected human is bitten by a female mosquito and this mosquito then bites another healthy human, the infection can spread and the cycle of contagion continues.
Dengue is diagnosed using a series of physical and lab tests. These include:
- A physical examination diagnosing the typical signs and symptoms of dengue
- Using dengue antigen tests, either NS1 or NS2
- Low white blood cell and platelet count in blood
- Nucleic acid detection test to detect the virus about five days after onset of symptoms
- Detection of dengue virus antibodies using an ELISA test
There is no specific therapy or vaccine available to treat dengue. The treatment of symptoms is the only known approach to manage the infection. These include paracetamol to control body temperature, appetite enhancers and liver protectives – and these approaches are largely focused on reducing the days of infection.
Dos and don’ts
- Drain stagnant water from tanks and other containers at least once a week
- Use mosquito repellents and nets while sleeping
- Wear clothes that cover arms and legs in order to protect yourself from mosquito bites
- Use aerosols to kill the mosquitoes during transmission/breeding seasons
- Spraying pesticides and fogging agents in the surrounding garden areas