RABIES TREATMENT CASCADE, SURVEILLANCE GAPS, POST-EXPOSURE PROPHYLAXIS ADHERENCE AND HEALTH-SYSTEM BARRIERS IN THE NIGER DELTA REGION OF NIGERIA: A SCOPING REVIEW

Abstract

Rabies remains a fatal yet vaccine-preventable zoonosis, with Nigeria accounting for an estimated 1,600-10,000 human deaths annually. Despite effective vaccines, weak surveillance systems, inadequate laboratory confirmation, and poor health-seeking behaviour obscure the true disease burden, particularly in southern states such as Akwa Ibom. Rabies remains an almost entirely preventable but near-uniformly fatal zoonosis, and dog-mediated transmission continues to impose a disproportionate burden on low-resource settings, with Nigeria ranked among the countries with the highest absolute rabies mortality worldwide Within Nigeria, the Niger Delta region presents a distinct combination of riverine geographic fragmentation, documented veterinary and surveillance capacity gaps, and health-system constraints that may shape a treatment cascade different from that described elsewhere in the country, yet no prior review has systematically synthesized this evidence.  This scoping review, incorporating systematic elements, sought to consolidate and critically appraise available evidence on the rabies treatment cascade, surveillance gaps, post-exposure prophylaxis (PEP) adherence, and health-system barriers within the Niger Delta region of Nigeria. The review followed the Arksey and O'Malley framework and reported in accordance with the PRISMA Extension for Scoping Reviews (PRISMA-ScR). The evidence was charted across the population-concept-context (PCC) domains of rabies-exposed individuals, treatment-cascade and surveillance outcomes, and the Niger Delta setting, drawing on peer-reviewed literature, WHO and NCDC programmatic sources, and comparator studies from analogous Nigerian states. The results as evidenced, indicates a treatment cascade that leaks at multiple points rather than at a single stage: unprovoked bites disproportionately affecting children, inconsistent formal care-seeking, and highly variable PEP completion, including a documented instance in which no sampled Cross River victims completed a full regimen. Surveillance in the region has historically been passive and fragmented, with systematic real-time tracking only introduced in Cross River State in 2022. Recurrent barriers included PEP cost, facility distance, and workforce and community knowledge gaps.  The Niger Delta's rabies burden appears sustained less by any single point of failure than by the absence of coordinated human-animal-environmental surveillance and financing structures. Emerging One Health coordination mechanisms piloted elsewhere in Nigeria offer a transferable, though yet unproven, template for the region.