Critically discuss how ecological degradation accelerates zoonotic spillover of vector-borne pathogens. Explain why India needs a robust One Health framework to mitigate this risk.

Ecological degradation is now a direct driver of infectious disease risk. When forests are cleared, wetlands altered and climates destabilised, the buffers between wildlife, livestock and humans weaken, enabling vector-borne pathogens to spill over.

How degradation raises spillover

• Habitat loss pushes wildlife into farms, villages and peri-urban spaces, increasing contact with people and domestic animals.
• Biodiversity loss weakens the dilution effect, allowing competent hosts and vectors to sustain transmission.
• Changed microclimates after deforestation and urbanisation create warmer, wetter breeding sites for mosquitoes and ticks.
• Climate change speeds vector breeding and pathogen replication; floods and cyclones expand mosquito habitats.
• Land-use change and irrigation bring workers, livestock and vectors together, raising exposure to Japanese encephalitis, Kyasanur Forest disease and dengue.

Why India needs One Health

• High population density, large livestock populations, rich biodiversity and rapid land-use change make India highly vulnerable.
• Dengue, JE, KFD, scrub typhus and West Nile virus are expanding into new areas, showing changing disease ecology.
• Separate human, animal and environmental systems miss early warning signals and delay response.

India needs a robust One Health framework to integrate surveillance of humans, animals, vectors and ecosystems, enable shared data and joint response, and shift from reactive outbreak control to prevention and preparedness.