The Nosocomial-Environmental Nexus of Acinetobacter Species in Nigeria: A Narrative Review of Prevalence, Resistance, and Public Health Implications

Abstract

Background: Acinetobacter, a World Health Organization critical-priority pathogen, exemplifies the challenge of antimicrobial resistance (AMR), particularly in healthcare settings. The ‘One Health’ framework emphasizes that hospital ecosystems are closely linked to the external environment, a critical yet understudied interface in low- and middle-income countries like Nigeria, where limited infrastructure may accelerate environmental dissemination of antimicrobial-resistant pathogens. Objective: This narrative review synthesizes and critically appraises the existing literature on the prevalence, antibiotic resistance profiles, and genetic mechanisms of Acinetobacter species circulating between Nigerian clinical and environmental settings, and discusses the public health implications. Methods: A systematic search of Scopus, PubMed, and Web of Science databases was conducted for literature published between 2010 and 2024. The narrative synthesis focused on studies from Nigeria, contextualized with key global and regional evidence. Results: Evidence confirms that multidrug-resistant (MDR) Acinetobacter species, particularly A. baumannii, are endemic in Nigerian hospitals. High rates of resistance to carbapenems, aminoglycosides, and fluoroquinolones are reported, driven by genes such as blaOXA-23, blaOXA-51, and blaNDM-1. Critically, these high-risk clones and their resistance genes are increasingly detected in hospital wastewater, municipal sewage, and adjacent river systems, demonstrating a continuous transmission cycle facilitated by inadequate infection prevention and control (IPC) and poor sanitation infrastructure. Conclusion: The nosocomial-environmental nexus of Acinetobacter in Nigeria represents a significant and growing public health threat. Breaking this cycle requires an integrated ‘One Health’ approach that combines strengthened hospital IPC, enhanced antimicrobial stewardship, and robust environmental waste management policies.