Rates of infection with other pathogens after a positive COVID-19 test versus a negative test in US veterans (November, 2021, to December, 2023): a retrospective cohort study.

Summary

In 836,913 US veterans, a positive COVID-19 test (vs negative) was associated with higher 12-month rates of multiple infections and hospitalizations for infectious illnesses, including sepsis. Non-hospitalized positives had increased outpatient infections (RR 1.17), respiratory infections (RR 1.46), and infection-related hospitalizations (RR 1.41); risks were greater among those hospitalized for COVID-19. Compared with seasonal influenza admissions, COVID-19 admissions had higher sepsis hospitalizations (RR 1.35).

Key Findings

• Compared with test-negative controls, non-hospitalized COVID-19 positives had increased outpatient infectious diagnoses (RR 1.17, 95% CI 1.15–1.19) and respiratory infections (RR 1.46, 95% CI 1.43–1.50).
• Hospitalizations for infectious illnesses, including sepsis and respiratory infections, were higher after COVID-19 (RR 1.41, 95% CI 1.37–1.45).
• Those hospitalized for acute COVID-19 had generally higher risks than non-hospitalized positives.
• Versus seasonal influenza admissions, COVID-19 admissions had higher hospitalizations for infectious illnesses (RR 1.24), sepsis (RR 1.35), and in-hospital antimicrobial use (RR 1.23).

Clinical Implications

Post-COVID patients warrant targeted infection prevention, vaccination optimization, and vigilance for sepsis; risk stratification may guide follow-up and early intervention.

Limitations

• Residual confounding and misclassification cannot be fully excluded in retrospective EHR-based analyses.
• Generalizability may be limited to US veterans; health-seeking behaviors could differ between groups.

Future Directions

Elucidate immunologic mechanisms underlying post-COVID susceptibility; test targeted prevention and surveillance strategies to reduce sepsis and infection burden.