Epidemiology and Risk of Invasive Pulmonary Aspergillosis in Ventilated COVID-19 Patients

Overview

A prospective multicenter US study found a 7% incidence of COVID-19–associated pulmonary aspergillosis (CAPA) in mechanically ventilated patients. The study highlights that single positive mycologic tests are insufficient for diagnosing invasive pulmonary aspergillosis (IPA), with an overall median estimated IPA likelihood of 30% among CAPA cases.

Background

COVID-19–associated pulmonary aspergillosis (CAPA) is a complication in critically ill COVID-19 patients, especially those mechanically ventilated. Diagnosing CAPA is challenging due to overlapping clinical and imaging features with severe COVID-19 and the lack of definitive histopathologic confirmation. Existing CAPA definitions do not clearly distinguish invasive aspergillosis from colonization, and false-positive mycologic test results are common. Understanding CAPA incidence, risk factors, and the true contribution of IPA to mortality remains uncertain.

Data Highlights

Key Findings

• CAPA incidence in mechanically ventilated COVID-19 patients was 7% using MSGERC criteria.
• Independent risk factors for CAPA included EORTC/MSGERC host factors and presence of cavitary lung lesions.
• Among CAPA cases, 7% had proven IPA, 79% putative IPA, and 14% unlikely IPA, with median IPA likelihood estimated at 30%.
• Single positive bronchoalveolar lavage galactomannan tests without corroborating evidence were common in CAPA-unlikely IPA cases.
• CAPA mortality was high (71%) but was not significantly affected by antifungal treatment and was similar to mortality in patients without CAPA.
• CAPA incidence varied by diagnostic definitions, with higher rates using European Confederation of Medical Mycology and Public Health Wales criteria, which had lower specificity for IPA.

Clinical Implications

Clinicians should be cautious in diagnosing invasive pulmonary aspergillosis in COVID-19 patients based on single positive mycologic tests, as these may represent colonization rather than true infection. A combination of clinical, radiologic, and multiple mycologic test results improves IPA likelihood estimation. Given the high mortality associated with CAPA but unclear contribution of IPA, antifungal treatment decisions should consider the overall clinical context and diagnostic certainty.

Conclusion

CAPA occurs in a minority of mechanically ventilated COVID-19 patients and is associated with high mortality, though the role of invasive aspergillosis remains uncertain. Accurate diagnosis requires integrating multiple diagnostic modalities rather than relying on single positive tests.

References

1. Bartoletti et al. 2022 -- Epidemiology and Estimated Risk of Invasive Pulmonary Aspergillosis in Mechanically Ventilated COVID-19 Patients: Findings from the Prospective MSG-017 Study Across Seven US Hospitals