Dengue fever is a mosquito born tropical disease caused by dengue virus.The virus has five different types. This is a disease that has troubled the world for generations and has no vaccination.
Transmission of Dengue:
Dengue is spread by several species of mosquito of Aedes type, particularly A.aegypti. These mosquitoes usually live between latitudes of 35 degree north and 35 degree south and below 1000 meters height.
They typically bite during early morning and evening but may bite during any time of day and can spread infection. Humans are the primarily hosts of the virus but this virus can also circulate in non human primates.An infection can be acquired by a single bite. The virus have no detrimental effect on the mosquito and they can remain infected for life. It prefers to lay eggs in artificial water containers particularly fresh water. It also prefers to live in close proximity to humans and feed on people rather than other vertebrates.
Dengue can be transmitted via infected blood products or through organ donations.Vertical transmission is also reported.Other person to person mode of transmission is unusual.
Favorite spots of bite are below elbows and below knee.which is also most exposed part of the body.
They are generally active between August and October – this is the peak period. Dengue mosquito cannot breed in temperatures below 16 degrees Celsius. Transmission rarely occurs in winters.
Prevention depends on protection from bite of mosquito that transmits it.
WHO recomends integrated vector control. The same consists of:
- Social mobilization and legislation to strengthen public health bodies and community.
- Collaboration between health and private and public sector.
- Integrated approach for disease control to maximise use of resources.
- Evidence based intervention targeted appropriately.
- Capacity building for adequate response to local situation.
How to Control the Breeding of Dengue Mosquito?
- aegypti is elimination of its habitats. Elimination of open source of stagnant water or if not possible add insecticides or biological control agents .
- Generalized spraying of organophosphats or pyrethroids insecticides.
- Reducing open collection of water.
- People should wear full sleeve clothing that covers skin .
- Use mosquito repellent during rest.
- Applications of mosquito repellent on exposed skin.
There is no commercially available vaccine for dengue . One vaccine that is partially effective is likely to become available soon in Mexico,Philippines and Brazil. It is based on weakened combination of yellow fever vaccine and each of the four dengue serotype. The same is yet to be introduced in India.