Risk factors for pulmonary Aspergillus terreus infection in patients with positive culture for filamentous fungi.

BACKGROUND

Invasive aspergillosis (IA) is a common fungal infection in immunocompromised patients and has a high mortality rate. Among patients with IA, Aspergillus terreus infections have become a growing concern in the past few years.

OBJECTIVE

To determine the clinical risk factors for isolation of and respiratory infection by A terreus in patients with culture findings positive for filamentous fungi.

METHODS

Cohort study of 505 consecutive isolates of filamentous fungi in 332 patients from one center. A terreus was present in 46 isolates from 40 patients (9.1%). Clinical histories were reviewed to identify the risk factors related to isolation of and infection by A terreus, which were grouped into three categories (ie, host factors, factors related to immunosuppression, and factors related to hospitalization), and were analyzed using a multiple logistic regression model.

RESULTS

A total of 192 of 505 isolates studied (38%) were due to invasive respiratory infection. A total of 27 of 46 cultures (58.7%) that were positive for A terreus were due to invasive infection (odds ratio [OR], 2.53; 95% confidence interval [CI], 1.37 to 4.69; p = 0.034). The factors associated with invasive A terreus infection were prophylactic use of amphotericin B aerosols (OR, 27.8; 95% CI, 6.7 to 109.7; p = 0.001) and mechanical ventilation (OR, 3.3; 95% CI, 1.02 to 10.9; p = 0.04). Transplantation was associated with a lower risk of A terreus infection (OR, 0.2; 95% CI, 0.046 to 0.789; p = 0.02).

CONCLUSIONS

In patients with culture findings positive for filamentous fungi, the prophylactic use of amphotericin B aerosols and mechanical ventilation are associated with a higher risk of A terreus infections. In these patients, transplantation is associated with a lower risk of isolation and respiratory infection by A terreus.