Prevalence and distribution of non-typhoidal Salmonella enterica serogroups and serovars isolated from normally sterile sites: A global systematic review

Epidemiol Infect. 2023 Oct 18:152:e4. doi: 10.1017/S0950268823001693.


To inform coverage by potential vaccines, we aimed to systematically review evidence on the prevalence and distribution of non-typhoidal Salmonella enterica serogroups and serovars. We searched four databases from inception through 4 June 2021. Articles were included that reported at least one non-typhoidal S. enterica strain by serogroup or serovar isolated from a normally sterile site. Of serogrouped isolates, we pooled the prevalence of serogroup O:4, serogroup O:9, and other serogroups using random-effects meta-analyses. Of serotyped isolates, we pooled the prevalence of Salmonella Typhimurium (member of serogroup O:4), Salmonella Enteritidis (member of serogroup O:9), and other serovars. Of 82 studies yielding 24,253 serogrouped isolates, the pooled prevalence (95% CI) was 44.6% (36.2%-48.2%) for serogroup O:4, 45.5% (37.0%-49.1%) for serogroup O:9, and 9.9% (6.1%-13.3%) for other serogroups. Of serotyped isolates, the pooled prevalence (95%CI) was 36.8% (29.9%-44.0%) for Salmonella Typhimurium, 37.8% (33.2%-42.4%) for Salmonella Enteritidis, and 18.4% (11.4%-22.9%) for other serovars. Of global serogrouped non-typhoidal Salmonella isolates from normally sterile sites, serogroup O:4 and O:9 together accounted for 90%, and among serotyped isolates, serovars Typhimurium and Enteritidis together accounted for 75%. Vaccine development strategies covering serogroups O:4 and O:9, or serovars Typhimurium and Enteritidis, have the potential to prevent the majority of non-typhoidal Salmonella invasive disease.

Keywords: Salmonella vaccines; meta-analysis; non-typhoidal Salmonella; prevalence; systematic review.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Animals
  • Humans
  • Prevalence
  • Salmonella Infections, Animal*
  • Salmonella enterica*
  • Salmonella enteritidis
  • Salmonella typhimurium
  • Serogroup