Global frequency of Campylobacter-associated hospitalisations: A systematic review and meta-analyses

Abstract

A minority of Campylobacter infections cause severe morbidity, yet admission rates for patients requiring hospital-based treatment are poorly understood. Our study aimed to quantify the percentage of Campylobacter infections requiring hospitalisation and determine variation by patient subgroups. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we performed a systematic review and meta-analyses of globally reported hospitalisation frequencies for Campylobacter infections. We performed a risk of bias assessment, followed by meta-analyses under the assumption of common parameters. Results were interpreted from the Quality Effects (QE) models in MetaXL and the heterogeneity of included studies assessed using chi-square tests. In addition to the primary meta-analysis for Campylobacter infections overall, we conducted subgroup analyses by Campylobacter species, demographic group, clinical group, antimicrobial resistance (AMR) status, start decade of cases and event type (sporadic or outbreak-associated). The study was registered with PROSPERO (CRD42023493466). A total of 137 articles (containing 235 studies) published from 1979 to 2025 were eligible for meta-analysis. These publications contained 1,377,770 Campylobacter infections for 946 patient groups (data points), primarily from North America, Europe and Oceania. In the pooled analysis of hospitalisation frequencies for Campylobacter infections, 13.8% (95% CI 9.6-18.6) of individuals were hospitalised. Steady increases in hospitalisation frequency were observed over time. In a pooled analysis of data from three studies, species other than C. jejuni or C. coli were associated with a higher frequency of hospitalisation (27.3%; 95% CI 11.0-47.2). Pooled hospitalisation frequencies of males (6.4%; 95% CI 1.4-14.1) and females (6.8%; 95% CI 1.5-15.0) were similar, and patients aged ≥65 years (27.9%; 95% CI 13.5-45.0) and children <1 year old (15.6%; 95% CI 9.8-22.4) were hospitalised more often compared to other age groups. Patients with pre-existing conditions were at higher risk of hospitalisation (37.1%; 95% CI 13.4-64.2). Older age, comorbidities and infection with C. fetus were often associated with bacteraemia. Where bacteraemia was identified, most patients were hospitalised (89.5%; 95% CI 79.6-96.5). Hospitalisations were overrepresented amongst tetracycline-resistant Campylobacter infections (24.4% hospitalised; 95% CI 21.4-27.5). Cases associated with outbreaks were much less likely (4.2%; 95% CI 1.7-7.6) to be hospitalised compared to sporadic cases (16.1%; 95% CI 8.1-26.1). While most patients with Campylobacter infections are not hospitalised, vulnerable groups such as the very young, older adults and those with comorbidities are more likely to be hospitalised. The increase in hospitalisation frequency over time reinforces the urgent need to address this burden by prioritising research and interventions targeting Campylobacter exposure in vulnerable populations.