Context:
A study conducted in Brazil’s Atlantic Forest reveals that deforestation and loss of native wildlife are forcing mosquitoes to increasingly feed on human blood, thereby heightening the risk of transmission of arboviruses and malaria-like diseases. The findings have implications for India’s malaria burden, where a large population lives in endemic zones.
Key Highlights:
- Ecological Disruption in Atlantic Forest
- Original forest area: 1.3 million sq. km; reduced to less than one-third.
- Biodiversity hotspot:
- 850 bird species
- 370 amphibians
- 200 reptiles
- 270 mammals
- 350 fish
- Shift in Mosquito Feeding Pattern
- Researchers used CO₂ light traps and DNA blood-meal analysis.
- Mosquitoes increasingly fed on humans due to reduced wildlife hosts.
- Host availability and proximity significantly influence feeding behaviour.
- Epidemiological Implications
- Increased risk of arbovirus transmission.
- Habitat alteration changes:
- Vector population density
- Feeding preferences
- Disease transmission cycles
- India’s Context
- WHO: India accounts for ~75% of malaria cases in South & Southeast Asia.
- 95% of India’s population lives in malaria-endemic regions.
Relevant Prelims Points:
- Arboviruses: Viruses transmitted by arthropods (mosquitoes, ticks, sandflies).
- Vector Control Methods:
- Insecticide-treated nets (ITNs)
- Indoor residual spraying (IRS)
- Biological control (larvivorous fish)
- Atlantic Forest (Brazil):
- One of the world’s biodiversity hotspots.
- Zoonotic Spillover: Disease transmission from animals to humans.
- Deforestation alters vector-host dynamics.
Relevant Mains Points:
- Environment-Health Nexus:
- Biodiversity loss increases human-vector contact.
- Supports “One Health Approach” linking environment, animals, and human health.
- Climate & Land-Use Change:
- Deforestation + urban expansion alter disease ecology.
- Increased urban malaria and dengue risks.
- India’s Public Health Challenge:
- High population density intensifies outbreak risks.
- Need to integrate ecological conservation with disease control policies.
- Policy Implication:
- Conservation acts as a preventive health strategy.
Way Forward:
- Strengthen forest conservation and biodiversity restoration.
- Integrate ecological indicators into vector surveillance.
- Promote One Health framework in malaria-endemic regions.
- Improve community-based vector control in peri-urban zones.
UPSC Relevance:
GS Paper 3 – Environment & Ecology; Science & Technology
GS Paper 1 – Indian Geography (Biodiversity, Forests)
Prelims Focus: Arboviruses, Vector control, Biodiversity hotspots