A 32-year-old woman from Mumbai presents with fever, myalgia, and rash on day 5 of illness. Dengue serology is positive. Which is the most common vector responsible for dengue transmission in urban India?

Explanation

## Dengue Vectors in India **Key Point:** *Aedes aegypti* is the primary and most common vector of dengue in urban India, responsible for the majority of human-to-human transmission in cities and towns. ### Vector Characteristics and Distribution | Vector | Habitat | Biting Behavior | Urban/Rural | Dengue Transmission | |--------|---------|-----------------|-------------|--------------------| | *Aedes aegypti* | Artificial containers, urban areas | Diurnal, anthropophilic | Urban (primary) | Most common, efficient | | *Aedes albopictus* | Natural breeding sites, peridomestic | Diurnal, opportunistic | Periurban, rural | Secondary, less efficient | | *Culex quinquefasciatus* | Polluted water, drains | Nocturnal | Urban and rural | Not a dengue vector | | *Anopheles stephensi* | Larval habitats in water | Nocturnal | Urban and rural | Not a dengue vector | **High-Yield:** *Aedes aegypti* is the **primary urban dengue vector** in India. It breeds in clean, stagnant water in artificial containers (flower pots, coolers, discarded tires, water tanks) within and around human habitations. ### Epidemiological Significance 1. **Anthropophilic preference:** Feeds almost exclusively on humans, making human-to-human transmission highly efficient. 2. **Peridomestic breeding:** Thrives in urban and periurban environments with high human density. 3. **Daytime activity:** Bites during daylight hours (early morning and late afternoon), increasing contact with humans. 4. **Geographic distribution:** Established in most urban centers of India, particularly coastal and metropolitan areas (Delhi, Mumbai, Bangalore, Chennai). **Clinical Pearl:** The presence of *Aedes aegypti* in a locality is the strongest epidemiological predictor of dengue outbreaks. Larval surveys and Breteau Index (BI) are used to assess dengue risk in communities. **Mnemonic:** **AEDES = Artificial containers, Early morning/afternoon biting, Diurnal, Efficient dengue vector, Domestic (peridomestic), Stagnant water** ### Role of *Aedes albopictus* *Aedes albopictus* (Asian tiger mosquito) is a secondary vector in India, found in periurban and rural areas with natural breeding sites. It is less anthropophilic and less efficient at dengue transmission compared to *Aedes aegypti*, but can amplify transmission in areas where *Aedes aegypti* is absent. [cite:Park 26e Ch 8]