Could aspergillus be hiding out in your critically ill patient?

 

An issue from the American Journal of respiratory and Critical Care Medicine contains two articles and a related an editorial addressing this subject.

This study looked for evidence of aspergillus infection in patients diagnosed with VAP:

Rationale: Aspergillus infection in patients with suspected ventilator-associated pneumonia remains uncharacterized because of the absence of a disease definition and limited access to sensitive diagnostic tests.

Objectives: To estimate the prevalence and outcomes of Aspergillus infection in adults with suspected ventilator-associated pneumonia.

Methods: Two prospective UK studies recruited 360 critically ill adults with new or worsening alveolar shadowing on chest X-ray and clinical/hematological parameters supporting suspected ventilator-associated pneumonia. Stored serum and BAL fluid were available from 194 nonneutropenic patients and underwent mycological testing. Patients were categorized as having probable Aspergillus infection using a definition comprising clinical, radiological, and mycological criteria. Mycological criteria included positive histology or microscopy, positive BAL fluid culture, galactomannan optical index of 1 or more in BAL fluid or 0.5 or more in serum.

Measurements and Main Results: Of 194 patients evaluated, 24 met the definition of probable Aspergillus infection, giving an estimated prevalence of 12.4% (95% confidence interval, 8.1–17.8). All 24 patients had positive galactomannan in serum (n = 4), BAL fluid (n = 16), or both (n = 4); three patients cultured Aspergillus sp. in BAL fluid. Patients with probable Aspergillus infection had a significantly longer median duration of critical care stay (25.5 vs. 15.5 d, P = 0.02). ICU mortality was numerically higher in this group, although this was not statistically significant (33.3% vs. 22.8%; P = 0.23).

Conclusions: The estimated prevalence for probable Aspergillus infection in this geographically dispersed multicenter UK cohort indicates that this condition should be considered when investigating patients with suspected ventilator-associated pneumonia, including patient groups not previously recognized to be at high risk of aspergillosis.

Another study in the same issue looked at the prevalence of aspergillus in patients on mechanical ventilation with covid-19. They found it in over 20% of patients.

The accompanying editorial cited additional evidence all of which suggests that aspergillus infection is under-diagnosed in critically ill patients.

Patients need not be immunosuppressed in the traditional sense although the use of corticosteroids, even short-term, is a major risk factor. The main use of corticosteroids  was for treatment of COPD exacerbations.