Dengue Fever- An Overview

Dengue fever is a mosquito-borne infection found in tropical and sub-tropical places around the world.
In the recent years, transmission of dengue has increased predominantly in urban and semi-urban areas and has become a major cause for ill health globally.
Severe dengue (known as Dengue Hemorrhagic Fever) was first identified in 1950's during dengue epidemics in the Philippines and Thailand.
In the present days, severe dengue affects most of the Asian and Latin American countries and has become a leading cause for hospitalization and deaths
among children in these countries
There are four distinct types of the virus that cause dengue which are closely related,they are :

• DEN-1
• DEN-2 
• DEN-3
• DEN-4.

Aedes aegypti (DENGUE CAUSING MOSQUITO) 

How Dengue Fever is Transmitted?

The Aedes aegypti (A type of mosquito)is the primary vector of dengue. 

The virus is transmitted to humans through the bites of infected female mosquitoes. 

After the virus incubation for 4-10 days, an infected mosquito is capable of transmitting the virus for the rest of its life. The Infected humans are the main carriers and multipliers of the virus, serving as a potential source for the virus for uninfected mosquitoes. 

Patients who are already infected with the dengue virus can transmit the infection (for 4-5 days to upto a maximum 12 days) via Aedes mosquitoes after their first symptoms appear. The Aedes aegypti mosquito lives in urban habitats and breeds mostly in man-made containers. Unlike other mosquitoes Aedes aegypti is a daytime feeder; and its peak biting time periods includes  are early in the morning and in the evening before sun set.  Female Aedes aegypti bites multiple people during each feeding time

Aedes albopictus, a secondary dengue vector in Asia, has spread to North America and Europe mainly due to the international trade using tyres (a breeding habitat) and other goods (e.g. lucky bamboo).

Characteristics of Dengue:

• Dengue fever is a severe, flu-like illness that affects all individuals irrespective of age and gender, and seldom causes death.
• Dengue fever can be suspected when a high fever (40°C/ 104°F) is accompanied with following major symptoms: severe headache, pain behind the eyes, muscle and joint pains, nausea, vomiting, swollen glands or rashes.
• The Symptoms usually last for 2-7 days, after an incubation period of 4-10 days after the bite from an infected mosquito.

Treatment for Dengue:

There is no specific treatment for dengue fever. However for severe dengue, medical care by the physicians and nurses who are experienced with the effects and progression of the disease can save lives of the patients.

Above all the maintenance of the patient's body fluid volume is critical to severe dengue care.

Consumption of fruit juices will considerably increase the fluid content in the body. Also intravenous administration of normal saline will drastically provide strength and also maintains the fuid volume in the body.

Prevention and Control of Dengue:
The only method for preventing or controlling the dengue fever is by combating the vector mosquitoes.
The following are to be adopted to prevent or combat the mosquitoes:

• Preventing the mosquitoes from accessing egg-laying habitats by environmental management and modification.
• Disposing the solid waste properly and removing artificial man-made habitats.
• Adapting the appropriate usage of insecticides to water storage outdoor containers.
• Covering, emptying and cleaning of the domestic water storage containers regularly.
• Using of personal household protections such as window screens, long-sleeved clothes, insecticide treated materials, coils and vaporizers.

Spraying the insecticide in the pots at home for killing the vector mosquitoes. 

For Complete information on the GUIDELINES FOR DIAGNOSIS,TREATMENT, PREVENTION AND CONTROL OF DENGUE, visit  the following link http://whqlibdoc.who.int/publications/2009/9789241547871_eng.pdf