Do Enteroviruses Cause Ventilator-Associated Pneumonia?
No, enteroviruses are not recognized as a cause of ventilator-associated pneumonia (VAP) in immunocompetent patients, and nosocomial viral infections overall are uncommon causes of VAP. 1
Viral Etiology in VAP
Nosocomial virus infections are uncommon causes of HAP and VAP in immunocompetent patients. 1 The American Thoracic Society guidelines explicitly state that while outbreaks of influenza have occurred sporadically in hospital settings, these can be substantially reduced with infection control measures, vaccination, and antiviral agents. 1
The viruses that have been studied in the context of VAP are primarily:
- Influenza A and B - the only viruses with Level I evidence for causing nosocomial pneumonia, though sporadic 1
- Herpesviruses (HSV and CMV) - detected in nonimmunosuppressed ICU patients with increased morbidity and mortality, though their pathogenic role remains controversial 2
Enteroviruses are not mentioned in any major VAP guidelines or microbiology reviews as causative pathogens. 1, 3
Predominant VAP Pathogens
Bacteria cause most cases of VAP, with many infections being polymicrobial. 1 The actual causative organisms are:
- Aerobic gram-negative bacilli: Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter species 1
- Gram-positive cocci: Staphylococcus aureus (particularly MRSA) 1
- Enterobacteriaceae: E. coli, Enterobacter, Serratia 1, 3
The role of atypical bacteria, viruses, and fungi in VAP has not been studied systematically and remains unclear. 3 Even among the viruses that have been investigated, enteroviruses are conspicuously absent from the literature.
Clinical Implications
When evaluating a mechanically ventilated patient with suspected pneumonia, empiric therapy should target bacterial pathogens based on timing of onset and risk factors for multidrug-resistant organisms, not viral pathogens. 1
For early-onset VAP (<5 days): Cover Streptococcus pneumoniae, Haemophilus influenzae, and methicillin-sensitive S. aureus 1
For late-onset VAP (≥5 days) or patients with MDR risk factors: Use combination therapy covering Pseudomonas, resistant gram-negatives, and MRSA 1, 4
Antiviral therapy is only indicated for documented influenza outbreaks in the hospital setting, using neuraminidase inhibitors (oseltamivir, zanamivir) for both influenza A and B. 1