Non-typhoidal <i>Salmonella</i> prevalence and antimicrobial resistance in Nigeria: a systematic review and meta-analysis

Abstract

A systematic review and meta-analysis were conducted to estimate the prevalence of non-typhoidal Salmonella (NTS) serovar infection burden. Following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, 34 studies were identified from PubMed, Scopus, Google Scholar, ScienceDirect, African Journals Online and Web of Science between August and October 2025. The prevalence rates, serovars and antibiotic resistance were analysed using a random effects model in the DerSimonian-Laird method, with a 95% confidence interval. Of the 34 included studies, higher rates of yearly gastroenteric NTS infections (up to 100.0%) were observed compared with bloodstream infections. Salmonella enteritidis (59.1%), Salmonella Typhimurium (36.8%), Salmonella Kentucky (36.5%) and Salmonella Budapest (29.2%) were frequent. A higher pooled prevalence of NTS in food animal and food products was estimated at 12.43% (95% CI 7.32 to 20.34) compared with human (7.01% [95% CI 4.32 to 14.01]) and environmental sources (6.01% [95% CI 1.24 to 26.19]). More than 20% of reported NTS showed significant pooled resistance to nalidixic acid, ampicillin, ciprofloxacin, cefuroxime, chloramphenicol and tetracycline. Variants of bla, aph(3')-Ib, catA1, dfrA7, sul, tet(B), aph(6)-Id, qnrS, qnrA and gyrA genes were commonly reported among the serovars. The current prevalent antibiotic-resistant NTS suggest an urgent holistic implementation of One Health policies and national surveillance to mitigate the infection burden.