Dengue hemorrhagic fever is caused by ?
Infection with more virulent dengue virus
Infection with same dengue virus repeatedly
Infection with dengue virus in immunocompromized host
Infection with more than one dengue virus
Ans. is `d' i.e., Infection with more than one dengue virus DENGUE FEVER Dengue fever is caused by arboviruses (at least 4 serotypes have been recognized) It is transmitted by Aedes (Aedes aegypti is the main vector). The reservoir of infection is both man and mosquito. The transmission cycle is Man-mosquito-man Dengue fever occurs both epidemically and endemically. Epidemics stas in rainy season and are usually explosive. Aedes mosquito becomes infective by feeding on a patient from the day before onset to the 5th day of illness.