Mortality of Salmonella infections in low- and middle-income countries: a systematic review and meta-analysis

Salmonella infections remain a persistent global health burden, with rising incidence and substantial mortality. This study estimated the pooled case fatality rate (CFR) of Salmonella infections in low- and middle-income countries (LMICs) and delineated CFRs of typhoidal and non-typhoidal infections across regions and populations to inform targeted interventions. PubMed, Scopus, Web of Science and ScienceDirect were searched for primary studies without language or time restrictions. Eligible studies reported typhoidal or non-typhoidal Salmonella cases and deaths. Random-effects meta-analysis with a 95% CI was conducted in R Studio, alongside subgroup, meta-analyses, heterogeneity (I2, Egger's test) and sensitivity analyses. Study quality was assessed using STROBE and Cochrane RoB 2 tools, following PRISMA guidelines, with registration in the Open Science Framework registries. Of 1914 records, 104 studies from 35 countries were included, mostly from Africa and Asia (86%). Hospitalised patients formed the largest group (56%). Typhoidal cases predominated (70%), with culture as the main diagnostic (79%). Overall, 365 922 Salmonella infections were reported, with a pooled CFR of 5.72%. Non-typhoidal infections had a higher CFR (13.85%) than typhoidal (2.99%). Mortality was greatest in patients with typhoid intestinal perforation (15.29%) and older people (40.91%). Addressing Salmonella mortality disparities requires urgent investment in LMIC diagnostic and surveillance infrastructure.