Prioritising intervention areas for antimicrobial resistance in Nigeria's human and animal health sectors using a mixed-methods approach

A One Health approach is essential to prioritise intervention areas to tackle antimicrobial resistance (AMR). This study aimed to identify and evaluate critical drivers and antimicrobial stewardship (AMS) challenges within Nigeria's human and animal health sectors. Human (22) and animal (33) health professionals in Nigeria were asked via an online questionnaire to rank priority pathogens, AMS challenges, and AMR drivers identified by subject matter experts. Descriptive statistics and the Fisher's exact test were used to evaluate differences in rankings between sectors. Subsequently, a scoping literature review of peer-reviewed research and grey literature was conducted to evaluate the evidence supporting the rankings. <i>Salmonella</i> spp. (28.5 %) and <i>Escherichia coli</i> (28.2 %) were selected as the top-ranked priority pathogens for AMR. The Fisher's exact test showed a significant association (<i>p</i> = 0.049) between profession and ranking of <i>Salmonella</i>, which was ranked higher by animal health professionals than their human health counterparts. Priority AMS challenges in both human and animal health sectors were "ease of access to over-the-counter antimicrobials" (14.9 % and 20.1 %, respectively) and "lack of awareness of AMR/AMS" (14.1 % and 20.4 %, respectively). "Lack of infection prevention and control (IPC)" (24.5 %) was the highest-ranked AMR driver across sectors. Differences were observed between the rankings human and animal health professionals gave to the challenge of access to veterinary expertise (<i>p</i> = 0.011), as medical doctors ranked this component higher than veterinarians. "Lack of IPC" (<i>p</i> = 0.022) and "environmental degradation" (<i>p</i> = 0.048) were ranked higher by medical doctors than veterinarians. Conversely, "unsanitary processes in the abattoir(s)" was ranked higher among veterinarians (<i>p</i> = 0.032). Of the 84 articles reviewed, 62 supported the rankings of AMS challenges in both sectors, while 24 captured relevant AMR drivers. Our findings underscore the need for a One Health approach in Nigeria to improve AMS and curb AMR.