Impact of respiratory viruses detection on outcomes in ventilated nosocomial pneumonia: an exposed/unexposed study.

INTRODUCTION

Ventilator-associated pneumonia (VAP) and ventilated hospital-acquired pneumonia (vHAP) are major causes of morbidity and mortality in intensive care unit (ICU) patients. The role of viral co-infections in these conditions is an emerging area of interest; however, their impact on clinical outcomes remains poorly understood. This study aimed to assess the effect of viral detection on mortality and other clinical outcomes in patients with bacterial vHAP/VAP.

MATERIALS AND

METHODS

We conducted a retrospective analysis of patients diagnosed with bacterial vHAP or VAP in a tertiary ICU between 2020 and 2024. All patients underwent distal respiratory sampling with quantitative culture and multiplex PCR (mPCR) testing for respiratory viruses (Biofire FilmArray Pneumonia Panel). Patients with SARS-CoV-2 infection were excluded. Those with bacterial and viral co-infections were matched 1:1 with patients having bacterial-only vHAP/VAP based on age, sex, SAPS II score, ICU admission cause, and causative bacteria. We compared clinical outcomes, including ICU mortality, 3-month mortality, ICU length of stay, and duration of mechanical ventilation between the two groups.

RESULTS

Eighty patients were included, 40 with bacterial and viral detection and 40 with bacterial-only vHAP/VAP. The median age was 63 years, and 92% of the cohort were male. Common comorbidities included diabetes (25%), heart failure (20%), chronic renal failure (20%), and chronic lung disease (32%). Nineteen percent of patients were immunocompromised. The viral pathogens identified in the co-infection group were rhinovirus/enterovirus 33% (13/40), endemic coronaviruses 30% (12/40), influenza viruses 10% (4/40), parainfluenza viruses 8% (3/10), adenovirus 8% (3/10), metapneumovirus 5% (2/40), and respiratory syncytial virus 5% (2/40). Respiratory viruses were detected in a nasopharyngeal swab in 30% (12/30). The 3-month mortality rate was 36%, ICU mortality was 32%, the median duration of mechanical ventilation was 21 days [IQR 12-31.5], and the median ICU length of stay was 24 days [IQR 13-39.5]. There were no significant differences in these outcomes between the bacterial and viral group and the bacterial-only group.

CONCLUSIONS

In this cohort of patients with bacterial vHAP/VAP, the detection of respiratory viruses did not significantly impact ICU mortality, 3-month mortality, or ICU length of stay. These findings may suggest that bacterial infections are the primary determinants of clinical outcomes in vHAP/VAP.