A prospective study of fungal colonization and invasive fungal disease in long-term mechanically ventilated patients in a respiratory intensive care unit

Background: Long-term mechanical ventilation in an Intensive Care Unit (ICU) exposes the patient to fungal colonization and invasive fungal disease due to the presence of indwelling catheters, administration of broad-spectrum antibiotics, and intravenous corticosteroids. A study is hence required to study the risk factors and incidence of fungal infection in these patients. Methods: A prospective observational study was carried out in the respiratory ICU of a tertiary care hospital for a period of approximately 1 year in which patients on mechanical ventilation (>7 days) were enrolled. Blood, urine, and endotracheal aspirate (ETA) of these patients were sent for fungal culture on day 1 and day 7 of mechanical ventilation. Fiberoptic bronchoscopy was done on day 7 and bronchoalveolar lavage along with transbronchial lung biopsy (TBLB) were sent for fungal culture. Results: During 7 days of ventilation, there was a statistically significant increase in the proportion of culture-positive ETA and urine samples. Overall, Candida albicans emerged as the most common colonizer. Blood candidemia was seen in 10% of patients on day 7 of mechanical ventilation. Fungal invasion of the lung, as evidenced by fungal culture-positive TBLB specimens, was seen in 17% of patients. Diabetes was found to be a statistically significant risk factor for respiratory and urinary tract colonization as well as invasive fungal disease. Conclusion: Long-term mechanical ventilation (>7 days) is strongly associated with fungal colonization of the respiratory tract and urinary tract. Appropriate prophylactic antifungals may be given and infection control practices to be observed to ensure minimum colonization and therefore infection in such settings.