Clinical Scorecard: Reduction in Test Positivity for Common Cold Coronaviruses Following Widespread SARS-CoV-2 Infections

At a Glance

Key Highlights

• Test positivity for common cold coronaviruses significantly decreased (~60% lower odds) after widespread SARS-CoV-2 Omicron infections and COVID-19 vaccination.
• No significant change in test positivity was observed for respiratory syncytial virus (RSV) or influenza virus (IV) in the same periods.
• Potential mechanisms include cross-reactive immunity among related coronaviruses and changes in behavioral and healthcare practices.

Guideline-Based Recommendations

Diagnosis

• Use comprehensive respiratory panel PCR and antigen-based molecular tests with >95% sensitivity and specificity to detect ccCoVs, RSV, and IV.
• Testing decisions should be guided by clinical algorithms and healthcare provider discretion.

Management

• Recognize that most mild respiratory infections resolve without intervention; specific microbiologic diagnosis may not always be necessary.
• Consider the impact of prior SARS-CoV-2 infection and vaccination on ccCoV disease incidence.

Monitoring & Follow-up

• Surveillance of respiratory virus test positivity rates over respiratory seasons to detect epidemiologic changes.
• Monitor for changes in ccCoV incidence in the context of SARS-CoV-2 immunity at the population level.

Risks

• Potential underdiagnosis due to home testing and omitted diagnostic testing post-Omicron surge.
• Limited therapeutics for most mild respiratory viral infections.

Patient & Prescribing Data

Individuals tested for respiratory viruses at Boston Medical Center, including pre- and post-SARS-CoV-2 Omicron surge periods

Prior SARS-CoV-2 infection associates with decreased ccCoV disease incidence; COVID-19 vaccination alone does not show the same association.

Clinical Best Practices

• Employ molecular diagnostic testing for accurate identification of respiratory viruses when clinically indicated.
• Interpret respiratory virus test positivity trends in the context of population-level SARS-CoV-2 immunity and vaccination status.
• Consider heterotypic immunity among coronaviruses when evaluating respiratory infection epidemiology.
• Maintain awareness of changing healthcare and behavioral practices that may influence respiratory virus transmission.

References

• Boston Medical Center Respiratory Virus Testing Data
• Biofire Diagnostics Respiratory Panel
• COVID-19 Vaccination Coverage in Boston