Is co-infection with other viruses, such as influenza or respiratory syncytial virus (RSV), possible in COVID-19 (Coronavirus Disease 2019)?

Co-infection with Other Viruses in COVID-19 Patients

Yes, co-infection with other viruses is possible in COVID-19 patients, with viral co-infections occurring in approximately 6.6% of COVID-19 cases. 1

Prevalence and Types of Viral Co-infections

• Viral co-infections in COVID-19 patients are less common than those seen in influenza patients, where co-infection rates range from 11% to 35% 1
• The most common viral co-pathogens identified in COVID-19 patients include:
  • Epstein-Barr virus (most common) 1
  • Human herpesvirus 6 (HHV-6) 1
  • Influenza viruses 1
  • Respiratory syncytial virus (RSV) 2
  • Rhinovirus/enterovirus 2
  • Parainfluenza 2
  • Metapneumovirus 2

Clinical Significance and Detection

• Co-infections with other respiratory viruses can complicate diagnosis as they may present with similar clinical manifestations 2
• Laboratory and imaging findings alone cannot reliably distinguish between COVID-19 infection and co-infection with other respiratory viruses 2
• Multiple studies have reported co-infection cases between SARS-CoV-2 and influenza viruses:
  • In one study, 0.54% of COVID-19 patients were co-infected with influenza 3
  • Another study found five co-infections with influenza among 115 COVID-19 patients 1
  • A third study reported six co-infections with other common respiratory viruses among 92 COVID-19 patients 1

Impact on Patient Outcomes

• Co-pathogen identification is associated with:
  • Longer hospital stays 4
  • Greater patient complexity 4
  • Adverse outcomes 4
• The severity of co-infections can range from mild to severe, with some cases resulting in death or requiring mechanical ventilation 3

Diagnostic Considerations

• Newly developed syndromic multiplex panels that incorporate SARS-CoV-2 testing can facilitate early detection of co-infections 2
• Clinicians cannot rule out SARS-CoV-2 infection by identifying other respiratory pathogens, nor can they rule out co-infections by diagnosing COVID-19 2
• Influenza A has been reported as one of the most common co-infective viruses and may cause initial false-negative results for SARS-CoV-2 testing 2

Management Implications

• A high index of suspicion for co-infection is necessary among COVID-19 patients 2
• Empirical antiviral therapy (such as oseltamivir) should be rapidly de-escalated based on microbiology test results and clinical response 1
• Comprehensive microbiologic workup is recommended before administration of empirical antimicrobials in COVID-19 patients 1

Prevention Strategies

• Influenza vaccination for larger population groups is recommended to simplify clinical management and reduce the risk of co-infection 3
• This is particularly important during influenza season when both viruses may be circulating simultaneously 3

Understanding the possibility and implications of viral co-infections in COVID-19 patients is crucial for appropriate diagnosis, treatment decisions, and ultimately improving patient outcomes.