Overview
Anopheles stephensi is a species of mosquito that acts as a primary vector of malaria, particularly in urban and peri-urban areas. It is distinct from many other malaria vectors because of its strong adaptation to human-made water storage systems.
Classification
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Insecta
- Order: Diptera
- Family: Culicidae
- Genus: Anopheles
- Species: Anopheles stephensi
Geographic Distribution
- Originally native to South Asia and the Middle East
- Widely prevalent in India, Pakistan, Iran, and Gulf countries
- Recently spread to parts of Africa, raising global public health concern
Habitat and Breeding Behaviour
- Prefers urban environments, unlike many rural malaria vectors
- Breeds in clean water stored in overhead tanks, construction sites, wells, barrels, and containers
- Can survive and reproduce in artificial water bodies, making urban malaria control difficult
Disease Transmission
- Major vector of Plasmodium falciparum and Plasmodium vivax, the parasites responsible for malaria
- Efficient transmitter due to close association with human settlements
- Bites mostly during night-time, with peak activity around dusk and dawn
Public Health Significance
- Responsible for urban malaria outbreaks, especially in rapidly growing cities
- Its spread to Africa threatens malaria control gains in regions where urban malaria was previously limited
- Recognised by global health agencies as a high-risk invasive vector species
Challenges in Control
- Conventional rural-focused malaria strategies are less effective
- Resistance to some insecticides has been reported
- Difficulty in eliminating breeding sites due to widespread household water storage
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Control and Prevention Measures
- Source reduction by covering and managing water storage containers
- Use of larvivorous fish and larvicides in water bodies
- Indoor residual spraying and insecticide-treated bed nets
- Urban vector surveillance and community participation
- Integrated vector management combining environmental, chemical, and biological methods
Anopheles stephensi is a highly adaptable urban malaria vector whose spread poses a serious challenge to malaria elimination efforts, especially in cities. Effective control requires urban-specific, community-driven, and integrated vector management strategies.
