Albopictus, mosquito that caused dengue surges in 1950s, back in Kolkata
Times of India | 3 August 2024
Representative image KOLKATA: A mosquito species that used to cause dengue surges in Kolkata in the 1950s and 1960s has returned.
Larvae of Aedes albopictus, a dengue virus carrier, is being found in increasing numbers in the city this year and is responsible for many of the cases. The dominant dengue mosquito in Kolkata for several years has been the Aedes aegypti. The return of albopictus, therefore, has entomologists and doctors puzzled and worried.
Both mosquito types are vectors of dengue as well as zika and chikungunya viruses. But, while aegypti prefers breeding in close proximity to humans and their homes, albopictus prefers bushes and rural areas. To a lay person, both would look the same with white stripes on their legs and backs.
"During our vector control drives, we found albopictus in some locations, particularly the city's added areas, where we have been struggling to clean up garbage from vacant land and abandoned buildings," a KMC health department official said.
According to KMC entomologists, during the 1950s, albopictus used to be found in bushes and abandoned land. But KMC has found their breeding grounds in unusual spots like abandoned tyres along roads.
KMC chief entomologist Debasish Biswas said the worry was the change in its breeding pattern. “Long ago, when Kolkata was a growing city, albopictus used to breed in areas that were away from heart of the city and less populated. These areas had plenty of greenery and the albopictus would breed in tree trunks. This was the dominant strain of dengue till late 50s and early 60s. Later, aedes aegypti replaced it as major strain. Now, we are not only worried about return of albopictus but its changing nature that is making them breed in container-like substances,” said Biswas.
Infections diseases specialist Yogiraj Ray, associate professor at IPGMER Kolkata, said: “Both mosquitoes are vectors of dengue virus and will cause the same type of infection as far as the disease is concerned. The worry could be any alteration in pattern, degree of spread.”