Why in News?
- A study in Proceedings of the National Academy of Sciences (PNAS, Sept 2025) links climate change directly to rising dengue cases.
- Found 4.6 million additional annual cases (1995–2014) across 21 countries in Asia & Americas due to higher temperatures.
- By 2050, cases may more than double in cooler regions, impacting 260+ million people.
Relevance:
- GS II (Governance & Health): Public health preparedness, disease surveillance, role of community health workers.
- GS III (Environment & Science): Climate change impact, vector-borne diseases, One Health approach, use of vaccines and Wolbachia.
Basics
- Dengue virus: Transmitted by Aedes aegypti mosquito.
- Symptoms: Fever, body pain; severe cases → bleeding, organ failure.
- Habitat drivers: Warm temperatures, erratic rainfall, urban waterlogging.
- “Goldilocks Zone” → Dengue peaks at ~27.8°C; rises as cooler regions warm, drops slightly if too hot.
Overview
- Current Trends
- Climate change caused ~18% of cases across study regions (1995–2014).
- 1.4 million observations analysed; first robust causal evidence linking warming to disease burden.
- Net global effect: Sharp rise in dengue incidence despite some declines in hottest areas.
- Future Risks
- Projected 25% spread increase by 2050 (esp. SE Asia, Sub-Saharan Africa, S. America).
- 49–76% spike possible under higher emission scenarios.
- Dengue range expanding: Local cases now in US (California, Texas, Hawaii, Florida) & Europe.
- Urbanisation, migration, and viral evolution add to risks.
- Public Health Concerns
- Data gaps: India & Africa excluded due to underreporting → actual burden underestimated.
- Health system strain: Dengue already among fastest-rising global vector-borne diseases.
- Pandemic angle: Mosquito-borne outbreaks linked to climate instability → part of One Health challenge.
- Mitigation & Adaptation
- Climate action: Aggressive emission cuts reduce long-term risk.
- Vector control: Beyond fogging → community clean-ups, Wolbachia-infected mosquitoes, spatial repellents.
- Vaccines: Under trial; potential game-changer but limited by strain diversity.
- Health system strengthening: Surveillance, rapid diagnostics, ASHA-led awareness campaigns.
Conclusion
- Dengue surge exemplifies climate-health nexus: rising temperatures → shifting disease geography.
- Calls for integrating climate mitigation + One Health approach + resilient urban planning into public health strategies.
- India, with endemic dengue and climate vulnerabilities, must act as a leader in vector-borne disease preparedness.
