Dengue Fever

Dengue is a viral febrile disease of humans, caused by a flavivirus. The main carrier of this viruses is a mosquito, known as Aedes aegypti,and is the summer season. After infection, humans are usually infective in the first three days of the illness-that is the viraemice stage of the disease. The healthy Aedes mosquitos become infective about two weeks after feeding on an infected individual and persist as carrier for the rest part of their lives.There are four antigenic serotypes (den-1,Den-2,Den-3& Den-4)of dengue virus, but all are producing a similar clinical syndrome. After infection of an individual, the immunity develops which is life-long for the same serotype of the virus infected & only a few months for the other serotypes. The usual incubation period is 7-10 days, but it can be as short as 2 days and as long as 15 days. This occurs endemically in the tropical &sub-tropical countries specially in the South-east Asia & epidemically in the other zones of the world.