Abstract
Background: Updated evidence on antimicrobial resistance (AMR) among Salmonella Typhi is needed to inform empiric treatment and typhoid prevention including vaccine introduction.
Objective: To update our 2020 systematic review on prevalence and trends of AMR among Salmonella Typhi.
Methods: DATA SOURCES: PubMed, Web of Science, and preprint repositories from database inception through 30 November 2025, citation searching, and contacting authors of new reports.
Study eligibility criteria: We included studies reporting antimicrobial susceptibility testing results of Salmonella Typhi isolated from a normally sterile site in a person.
Risk of bias assessment: We adapted the Joanna Briggs Institute guidance for critical appraisal on prevalence studies.
Data synthesis methods: We calculated the proportion of resistant isolates for each antimicrobial tested by dividing the number of resistant isolates by the total number of isolates tested. We computed by decade the median proportions of isolates resistant by United Nations region and performed chi-squared test for trend in proportions.
Results: Of 411 included reports tested 132,174 Salmonella Typhi isolated from 1972-2024 across 54 countries, of which 114,907 (87.0%) were from Southern Asia. Of 1,289 estimates, 1,172 (90.9%) were facility-based. Of Salmonella Typhi isolates assessed, 22,320 (30.7%) of 72,731 were multidrug-resistant (MDR), 41,225 (42.4%) of 97,269 resistant to ciprofloxacin, and 2,086 (3.4%) of 62,186 resistant to azithromycin. From 1990, by decade, the median proportion of MDR Salmonella Typhi increased by consecutive decade for Africa and decreased for Asia. Of isolates in countries reporting extensively drug-resistant (XDR) Salmonella Typhi, 20,954 (58.0%) of 36,153 were from Pakistan, one (16.7%) of six from China Hong Kong Special Administrative Region, 10 (0.5%) of 1,880 from India and three (0.4%) of 736 from Laos.
Conclusion: The expansion of MDR Salmonella Typhi in Africa and regional emergence of XDR Salmonella Typhi in Asia compromise typhoid treatment and support typhoid prevention including by vaccination.