Understand Dengue: Dengue fever is most often transmitted to humans by the Aedes aegypti mosquito. Dengue fever can be caused by any of four related dengue viruses (DENV-1 to DENV-4). Fever is common in several parts of India. It has been known to occur in India for a long time. However the first case of dengue hemorrhagic fever was reported from Calcutta in 1963. After that outbreaks of dengue fever from India have been reported several times. This section helps you to understand dengue facts and aims at improving your knowledge too.