Clearing the fog:strategies against Aedes mosquitoes

India needs a revised strategy to combat Aedes mosquitoes—the carriers of dengue, Zika, and chikungunya—since traditional methods like fogging are ineffective.

Key points:

Ineffectiveness of fumigation: Aedes mosquitoes bite indoors during the day/night, making outdoor fumigation, vaporizers, and bed nets largely useless.
Top-down strategies: Wolbachia mosquitoes and dengue vaccine trials show promise but face challenges like high costs and limited scope (don’t cover Zika/chikungunya).
Best current defences: Personal protection and community mobilisation to eliminate larval breeding sites.
Repellents:
- Highly effective & recommended: DEET (20%), picaridin, IR3535, 2-undecanone, PMD (except for kids <3 yrs).
- Ineffective: citronella and other “natural” oils (short-lived, cause skin irritation).
Community action: Studies (e.g., Camino Verde in Latin America, Chennai RCT) show significant reduction in dengue cases when communities remove stagnant water from pots, containers, plastics, tyres, etc.
Challenges: Resistance to larvicides like temephos, plastic pollution creating breeding grounds, poor awareness of safe repellents.
Successful models:
- Delhi’s “10 Weeks, 10 AM, 10 Minutes” campaign for larval source reduction.
- Peru’s use of transfluthrin-coated spatial emanators that reduced ABVD risk by 34%.
Way forward:
- Use fogging only in outbreaks.
- Scale up personal protection, community awareness, and larval control.
- Introduce safe repellents (DEET, picaridin, PMD) in Indian markets.
- Adopt innovative top-down strategies like Wolbachia, delayed-release repellents.
- Combine top-down innovation with bottom-up community action for maximum impact.

Note on Aedes-borne Viral Diseases (ABVD) in India

Major diseases: Dengue, chikungunya, Zika.
Public health impact: Seasonal outbreaks lead to huge loss in productivity, burden on healthcare, and rising urban vulnerability.
Breeding habits: Aedes aegypti thrives in urban settings, especially stagnant water in containers, discarded plastics, and coolers.
Current challenges:
- Over-reliance on fogging and larvicides.
- Low public awareness of effective repellents.
- Weak waste management and urban planning.
Effective strategies:
- Community mobilisation: Regular water container cleaning, covering water storage, waste removal.
- Personal protection: Long clothing, WHO-approved repellents (DEET, picaridin, PMD, IR3535).
- Policy action: Nationwide campaigns (like Delhi’s 10-10-10 model), ASHA worker mobilisation, better urban waste/plastic management.
- Innovation adoption: Wolbachia mosquito releases, spatial emanators, cost-effective repellents, improved vaccines.