Work

An updated systematic review on antimicrobial resistance among Salmonella Typhi worldwide

Year: 2026

Type: review

Abstract: BACKGROUND: Updated evidence on antimicrobial resistance (AMR) among Salmonella Typhi is needed to inform empiric treatment and typhoid prevention, including vaccine introduction. OBJECTIVES: 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 were isolated from 1972 through 2024 across 54 countries, of which 114 907 (86.9%) were from Southern Asia. Of 1289 estimates, 1172 (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 2086 (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, 1 (16.7%) of 6 from China Hong Kong Special Administrative Region, 10 (0.5%) of 1880 from India, and 3 (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.

Source: Clinical Microbiology and Infection

DOI: 10.1016/j.cmi.2026.08.007