Global Burden of Bloodstream Infections in COVID-19: Updated Systematic Review on Prevalence, Antimicrobial Resistance, and Mortality

Background: Bloodstream infections (BSIs) are severe complications in hospitalized COVID-19 patients, increasing morbidity, mortality, and healthcare burdens. This up-dated systematic review and meta-analysis estimates global BSI prevalence, characterizes antimicrobial resistance (AMR) patterns, identifies risk factors, and assesses clinical outcomes in RT-PCR-confirmed COVID-19 patients, incorporating post-Omicron data up to 2025. Methods: We searched PubMed, Google Scholar, ScienceDirect, and MDPI journals (January 1, 2020–August 9, 2025) for observational studies (retrospective, prospective, cross-sectional) on BSIs in COVID-19 patients, following PRISMA guidelines. Data on prevalence, pathogens, AMR, risk factors, and outcomes were extracted. Random-effects models estimated pooled outcomes, with subgroup analyses by setting (ICU vs. non-ICU) and population (adult vs. pediatric). Heterogeneity (I²) was assessed via sensitivity analyses, accounting for diagnostic criteria variations (e.g., CDC vs. ECDC). Results: Across 38 studies from 16 countries, involving 153,778 patients and 1,058,809 blood cultures, pooled BSI prevalence was 7.1% (95% CI: 5.0–9.5, I²=92%). ICU settings showed higher rates (12.2%, 95% CI: 8.6–16.4) than non-ICU (4.7%, 95% CI: 3.1–6.7), and adults (8.0%) than pediatrics (2.9%). Gram-negative bacteria (e.g., Klebsiella pneumoniae, Acinetobacter baumannii) predominated, with AMR rates of 36.2% for MRSA and 30% for ESBL-producing Enterobacterales. Key risk factors were mechanical ventilation (OR: 2.6, 95% CI: 2.0–3.4), immunosuppression (OR: 2.2, 95% CI: 1.7–2.9), and azithromycin use (OR: 2.5, 95% CI: 1.8–3.4). BSIs increased mortality (OR: 2.8, 95% CI: 2.2–3.8) and hospital stay (MD: 7.2 days, 95% CI: 5.0–10.0). Conclusions: BSIs, driven by multidrug-resistant pathogens, remain frequent and deadly in COVID-19, particularly in ICU settings. Enhanced infection control, antimicrobial stewardship, and global surveillance are critical. Limitations include high heterogeneity (due to varying diagnostic criteria and regional differences) and retrospective study de-signs.