Respiratory viral and bacterial pathogen dynamics among healthcare workers and community members in Ethiopia: A prospective cohort study.

Abstract

Objectives: Respiratory infections cause substantial morbidity, with high burden in low-resource settings where surveillance is limited. We characterized symptomatic respiratory event burden and etiologic patterns in Ethiopia.

Methods: A prospective cohort of urban community members and healthcare workers (HCWs) at Jimma University Medical Center, Ethiopia, was followed from November 2022-December 2024. Nasopharyngeal swabs from symptomatic episodes were tested for viral and bacterial pathogens using multiplex and quantitative PCR. Person-period logistic regression assessed factors for symptomatic episodes; generalized linear mixed models identified factors for pathogen detection.

Results: Among 500 participants, 163 (32.6%) experienced 237 symptomatic episodes (2.08 per 100 person-months; 95% CI: 1.81-2.34). The Tsedey (September-November) season (aOR: 1.98; p<0.001) and HIV positivity (aOR: 1.62; p=0.044) were independently associated with symptomatic episodes. Viral pathogens were detected in 50.4% (116/230), mainly HRV, adenovirus, and SARS-CoV-2, while bacterial nucleic acid, predominantly S. pneumoniae and H. influenzae, was detected by nasopharyngeal PCR in 60.5% (135/223) of tested episodes. The Tsedey season was associated with viral (aOR: 3.58; p=0.004) and bacterial detection (aOR: 3.96; p=0.002). HCWs had higher odds of viral detection (aOR: 2.29; p=0.023).

Conclusions: Pathogens were frequently detected in symptomatic individuals. Seasonality drove respiratory episodes and viral/bacterial detection. HIV increased symptom risk; HCW status increased viral but not bacterial detection. Findings support seasonal surveillance and targeted interventions.