Clinical Outcomes of Campylobacter Bacteremia: A Systematic Review with Meta-Analysis

Purpose: Campylobacter spp. are a common cause of acute enteric infections. In immunocompromised or elderly patients, they can lead to extraintestinal infections, including bacteremia. The clinical significance of Campylobacter bacteremia is not fully understood. Methods: We conducted a systematic review and meta-analysis on Campylobacter spp. bacteremia, including studies published up to June 2024. Results: Twenty-five retrospective observational studies, published between 1978 and 2024, were included. The studies involved a total of 2480 patients, with a mean age range across studies from 1 to 70 years; 62.45% were male. The pooled prevalence of Campylobacter species was: C. jejuni 60% [95% CI 0.45-0.73], C. coli 8% [95% CI 0.04-0.13], C. fetus 7% [95% CI 0.03-0.15], and other species 9% [95% CI 0.04-0.16]. Mortality was the primary outcome in 22 studies, with a pooled case-fatality risk of 5% [95% CI 0.03-0.09]. Univariate meta-regression showed higher mortality associated with C. fetus (beta = 3.217, [95% CI 0.632-5.802], p = 0.017), immunocompromised status (beta = 2.749, [95% CI 0.316-5.184], p = 0.029), and chronic liver disease (beta = 5.072, [95% CI 0.424-9.720], p = 0.034). Regarding complications, secondary localizations (e.g., endovascular infections) showed a pooled prevalence of 9% [95% CI: 0.04-0.18]; relapses, 3% [95% CI 0.02-0.04]; endocarditis, 2% [95% CI 0.01-0.03]; and persistent bacteremia, 1% [95% CI 0.001-0.27]. Conclusion: Campylobacter spp. bacteremia shows a considerable risk of mortality and complications.