Climate Change, Ecosystem Loss, and Emerging Infectious Diseases in Nigeria

Abstract

Climate change and ecosystem degradation can affect infectious-disease hazards, human exposure and the recognition of outbreaks, but the direction and strength of those influences differ among pathogens. Nigeria provides a pertinent setting because reservoir-associated infections, mosquito-borne diseases, waterborne outbreaks and climatically sensitive respiratory infections occur across contrasting ecological zones and unequal healthcare environments. This critical narrative review evaluates literature on climatic variability, land-use change, biodiversity, transmission ecology and disease surveillance, giving priority to Nigerian empirical work and using regional or global studies to clarify mechanisms rather than substitute for local evidence. The strongest environment-linked Nigerian analyses concern Lassa fever, whose geographical incidence correlates with climate, land use and socioeconomic factors, although retrospective prediction does not establish prospective forecast utility. Rodent field studies show that seasonal host abundance and viral detection do not necessarily move together. Dengue investigations identify under-recognised febrile illness and competent mosquito habitats, but antibody, vector and molecular results have different inferential meanings. Yellow fever patterns are inseparable from immunity and surveillance selection. For cholera, floods and climatic anomalies interact with water-system failures, displacement and sanitation disadvantage; direct attribution to ecosystem loss remains limited. Meningitis and mpox further illustrate the danger of extending one ecological mechanism across fundamentally different transmission systems. Persistent limitations include spatial aggregation, incomplete diagnostic denominators, heterogeneous environmental measurements and scarce longitudinal linkage of ecosystem disturbance, infected hosts and confirmed human infection. The synthesis argues for pathogen-specific One Health monitoring, prospective ecological–clinical cohorts, out-of-sample validation of warnings and controlled evaluation of water, vector and household interventions. Climate adaptation and ecosystem protection offer important opportunities, but infectious-disease benefits should be demonstrated rather than presumed.