Examine the environmental and occupational determinants of zoonotic disease outbreaks in flood-prone agrarian states, with reference to leptospirosis in Kerala.

Q. Examine the environmental and occupational determinants of zoonotic disease outbreaks in flood-prone agrarian states, with reference to leptospirosis in Kerala. (15 marks, 250-350 words)

Leptospirosis, a bacterial zoonosis spread through the urine of rodents and livestock contaminating soil and water [3], is endemic in Kerala and carries the highest mortality among the State's communicable diseases [4]. Its recurrence shows that outbreaks in flood-prone agrarian States are driven less by pathogen novelty than by ecology and livelihood exposure.

Environmental determinants - Flood amplification: leptospirosis hotspots in Kerala rose sharply after the heavy 2018 floods compared with the non-flood year 2017, establishing a clear flood-severity–incidence link [1]. - Pathogen persistence: Leptospira survives for weeks in freshwater and moist soil, so humid, high-rainfall terrain sustains transmission beyond the flood event itself [3]. - Dense human–animal interface: high population density, paddy wetlands and peri-domestic rodent reservoirs place carrier animals next to homes [3]. - Post-flood breakdown of drainage and waste disposal turns stagnant water into a shared exposure medium.

Occupational determinants - Wet-work occupations dominate case profiles — paddy cultivators, plantation workers, canal- and well-cleaning labourers — as skin abrasions and mucosa allow entry during prolonged water contact [4]. - Relief and clean-up work after floods extends exposure to volunteers and sanitation staff. - Equity dimension: the burden falls on low-income manual workers in productive age groups, converting a health shock into a livelihood shock [4].

Governance and surveillance dimension - Kerala's aggressive case-logging and diagnostic depth partly explain its high reported numbers; the disease is officially endemic across a dozen States and two UTs under the Programme for Prevention and Control of Leptospirosis (PPCL), launched in the 12th Five Year Plan [2], implying under-detection elsewhere. - Weak inter-sectoral coordination between health, animal husbandry and local bodies delays chemoprophylaxis.

Leptospirosis is therefore a disease of environment and occupation acting together, not of monsoon alone. Strengthening PPCL's surveillance and diagnostic pillars [2], pre-monsoon rodent control, and assured doxycycline prophylaxis for at-risk workers can break this cycle. Embedding such measures within a One Health framework aligns disaster resilience with SDG-3, ensuring the burden of floods does not settle on those who work the land.

(~320 words)

Sources: 1. Analysing the outbreaks of leptospirosis after floods in Kerala, India — International Journal of Health Geographics (2024) — flood severity linked to spike in cases and hotspots (2017/2018/2019) 2. Programme for Prevention and Control of Leptospirosis — National Centre for Disease Control, MoHFW — 12th Five Year Plan launch, endemic States/UTs covered, surveillance-diagnostics strategy 3. Leptospirosis — PAHO/WHO — zoonotic transmission via animal urine, environmental survival, epidemic potential after heavy rainfall 4. Outbreak of Leptospirosis in Kerala — Indian Journal of Community Medicine (PMC) — Kerala endemicity, highest communicable-disease mortality, occupational exposure groups