Prevalence and antimicrobial resistance patterns of Campylobacter spp. Causing human gastroenteritis in Iran (2000-2025): a systematic review and meta-analysis.

aimCampylobacteriosis is a major cause of gastroenteritis globally, but comprehensive data on its prevalence and antimicrobial resistance (AMR) patterns in Iran are limited. This study aimed to estimate the national prevalence of Campylobacter-associated gastroenteritis in Iran, analyze temporal trends in infection rates, and characterize antibiotic resistance patterns among circulating Campylobacter spp. over the past two decades.

methodsIn accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search was performed across the Web of Science, PubMed, Scopus, Embase, Islamic World Science Citation Center (ISC), Scientific Information Database (SID), and Magiran databases for studies published from 2000 to 2025. Eligible studies were assessed based on predefined inclusion criteria, followed by both qualitative and quantitative analyses of the selected studies. The quality of the studies was evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist, and data analysis was conducted utilizing the R statistical programming language along with the 'meta' package. A random-effects model was applied to calculate the pooled prevalence, while heterogeneity was measured using the I² statistic and a prediction interval.

resultsA total of 46 studies met the inclusion criteria. Meta-analysis using a random-effects model revealed an overall pooled prevalence of 8.0% (95% CI: 6.0-10.0%), with substantial heterogeneity among studies (I² = 97.0%, p < 0.0001), likely due to variability in diagnostic methods, populations, and study designs. Subgroup analysis showed a higher prevalence for C. jejuni (35.0%, 95% CI: 22.0-49.0%, I² = 98.5%) compared to C. coli (16.0%, 95% CI: 11.0-22.0%, I² = 75.5%), while C. lari was excluded due to rarity. A temporal assessment revealed a peak prevalence of 11.0% (95% CI, 7.0-15.0%, I² = 94.2%) during the period 2013-2020, indicating a general upward trend over time. In patients ≤ 10 years, prevalence was 6.0% (95% CI, 3.0-9.0%, I² = 92.1%), with C. jejuni and C. coli responsible for 45.0% (95% CI, 13.0-80.0%) and 14.0% (95% CI, 7.0-23.0%) of cases, respectively. Among those ˃ 10 years, prevalence was 8.0% (95% CI, 6.0-11.0%, I² = 97.6%), with 32.0% (95% CI, 18.0-47.0%) for C. jejuni and 16.0% (95% CI, 10.0-24.0%) for C. coli. Resistance to ciprofloxacin (65%; higher in C. coli) and nalidixic acid (98%; higher in C. jejuni) - both quinolones-has shown a consistent and sharp increase, reaching the highest resistance levels in recent years. Similarly, tetracycline (79%; higher in C. coli) resistance has followed a rising trend, particularly in C. coli and overall Campylobacter spp., making these antibiotics increasingly ineffective for empirical treatment.

conclusionThis systematic review and meta-analysis highlight a moderate but rising prevalence of gastroenteric Campylobacter infections in Iran, with C. jejuni being the predominant species. Increasing resistance to quinolones, tetracyclines, and macrolides poses a serious threat to treatment, especially in C. coli. While gentamicin shows sustained low resistance, its parenteral administration restricts routine use, limiting its role to severe cases. Strengthened national surveillance, standardized diagnostics, and robust antimicrobial stewardship, particularly in poultry-the main source of human disease-are urgently needed. CLINICAL TRIAL NUMBER: Not applicable.