The rise and spread of Dengue and its vectors in India: A Review

The dengue as an illness has been recognized for more than 200 years and the role of Aedes aegypti as the vector of this arbovirus has been known for the last 90 years. About half of the world's population is now infected with an estimated 100–400 million new infections occurring each year. Dengue is found in tropical and sub-tropical climates worldwide, mostly in urban, semi-urban and rural regions. The first reference of dengue was mentioned in Mumbai, Pune and Kolkata in 1871 and after that reported from Ganges valley as far as Ludhiana , Kerala coast and from Calicut to Quilon. The dengue vector Aedes aegypti was also distributed all over India in 1934s in a faunistic survey done by Barraud. . The vector species was even reported from all over India and even from Lahaul and Spiti in Himachal Pradesh. The species was also confirmed by the following surveys. In India dengue was first reported and documented in 1956 from Vellore. Thereafter, there was an outbreak in Kolkata during 1960s. During this period, reports of Chikungunya spread was also seen in different parts of the country, potentially because both viruses were circulating in the same place at the same time. Following that, an epidemic of haemorrhagic fever was reported in Kolkata in 1963 and febrile illness in Nagpur city in Maharashtra during 1965. 50% of the infected population were affected by severe joint and body pain. Now dengue is endemic in the country and reported in 36 states/UTs . The cases of dengue increased from 101,192 in 2018 to ,233,251 in 2022. Similarly dengue deaths also increased from 172 (2018) to 303 (2022).