Dengue is acute viral infection caused by four types of viruses that are distinct yet closely related. Clinical observations reveal that infection with one virus generally bestows immunity against that particular virus and partial protection against the others. Epidemics are often endemic especially during monsoons and rainy season.
The most important vector is the female mosquito of the urban species Aedes aegyptii commonly known as ‘tiger mosquito’ owing to the white stripes on its body. With the explosion of the urban global population, larger groups of people are being exposed to this mosquito. Tiger mosquitoes thrive where household water is stored and quite commonly breeds and lays eggs in stagnant water. These mosquitoes bite exclusively during daytime.