Dengue is a viral disease, transmitted by the infective bite of a particular mosquito known as Aedes Aegypti. Human being develops disease after 5 – 6 days of being bitten by an infective mosquito. It occurs in two forms: Classical Dengue fever also known as “break bone” fever and Dengue Haemorrhagic Fever (DHF) which is life threatening. It is very common after rainy season. It is highly contagious and spreads from one person to another through mosquito bites. It is widespread in tropical and sub-tropical regions.
It is a very common disease in India since last two decades. Dengue can affect everybody, irrespective of their age and gender. However, deaths are common amongst children during DHF outbreak.
The disease is endemic in more than 100 countries in the WHO regions of Africa, the Americas, the Eastern Mediterranean, South-East Asia and the Western Pacific. The America, South-East Asia and Western Pacific regions are the most seriously affected.
In the year 2015, According to National Vector Borne Disease Control Programme (NVBDCP) maximum numbers of cases were reported from Delhi followed by Punjab, Haryana, West Bengal, Gujarat , Karnataka, Maharashtra, Kerala, Tamil Nadu, Rajasthan, Andhra Pradesh, Uttar Pradesh, Orissa, Madhya Pradesh, Arunachal Pradesh, Bihar, Uttarakhand, Telangana and other states.
Symptoms usually develop within 3-14 days after being exposed to the dengue virus (also known as incubation period). The average incubation period is around 4-7 days.
Symptoms of dengue are:
Dengue virus is an RNA virus. Transmission of this virus occurs in a cycle. An infected human is bitten by a female mosquito. The infected mosquito then bites another human, and the cycle continues.
Aedes aegypti mosquitoes most commonly bite at dusk and dawn, indoors, in shady areas, or when the weather is cloudy. They can bite and spread infection at any time of day and all year long.
The mosquitoes prefer to breed in areas of stagnant water, such as flower vases, uncovered barrels, buckets, water coolers and discarded tires. Some of the dangerous areas are wet floors and toilet tanks, as they allow the mosquitoes to breed in the residence.
Although the lifespan of an adult A. aegypti is two to four weeks depending on conditions, the eggs can be viable for over a year in dry state. This allows the mosquito to reappear after a cold winter or dry spell.
There are four serotypes of the virus that cause dengue (DEN-1, DEN-2, DEN-3 and DEN-4)
Some facts about Ades mosquito-
A person with dengue may develop a severe and life threatening form of dengue known as dengue shock syndrome. This may be accompanied by a sudden and severe drop in blood pressure. Other symptoms of dengue shock syndrome are as follows:
The patients may seek medical advice immediately.