Underreporting of Respiratory Viral Infections in Winter Mortality

Overview

A Spanish population-based study found that over one-third of individuals who died during winter tested positive for respiratory viruses postmortem, yet most infections were not diagnosed before death. This discrepancy highlights significant underrecognition of respiratory viral infections in mortality data and clinical practice.

Background

Respiratory viral infections are common during winter months and can contribute to mortality, especially in vulnerable populations. Accurate diagnosis before death is crucial for appropriate clinical management and public health surveillance. However, current testing and reporting systems may fail to capture the true burden of these infections. Molecular diagnostic tools like multiplex PCR offer enhanced detection capabilities but are underutilized in many settings.

Data Highlights

Key Findings

• 36% of deceased individuals tested positive for at least one respiratory virus via postmortem PCR.
• Rhinovirus and influenza were the most frequently detected viruses, each found in 11% of cases.
• Only 1.4% of deaths had influenza recorded as the cause, indicating underreporting.
• Just 17% of those with influenza detected postmortem had been diagnosed with influenza prior to death.
• Only 11% of individuals underwent respiratory virus testing in the 30 days before death.
• Co-infections with multiple respiratory viruses were identified, especially in older or vulnerable patients.

Clinical Implications

Clinicians should maintain a high index of suspicion for respiratory viral infections in vulnerable patients during winter months and consider broader use of molecular diagnostic testing. Improved and more consistent testing, including in community and long-term care settings, may enhance detection and management. Surveillance systems should integrate molecular diagnostics to better capture the true impact of respiratory viruses on mortality.

Conclusion

This study reveals a substantial underrecognition of respiratory viral infections in mortality data, underscoring the need for enhanced diagnostic strategies and surveillance to better understand and address the role of these infections in winter deaths.

References

1. Spanish Population-Based Study 2016–2020 -- Are Respiratory Deaths Underreported?