Epidemiology, diagnosis and prognosis of critically ill patients with positive fungal cultures

Introduction

Fungal infection in critically ill patients is an increasingly prevalent problem [1]. Candida spp cause the majority of these infections in ICU. The significance of a positive culture has been debated as it may represent local colonization or disseminated infection [2].

Objectives

This study analyzed the clinical significance of positive fungus cultures in the ICU patient.

Method

We reviewed the charts of all patients with at least one positive fungal culture who were admitted to a 13-bed general intensive care unit between 01/02/98 and 31/01/2000. We analyzed the following: age, APACHEIII score, length of stay in the ICU, diagnosis, site and species of fungal isolation, risk factors and treatment. The patients were classified according to the clinical profile, microbiological data and therapeutic interventions in five groups: probable fungal infection, empiric therapy, fungemia, confirmed fungal infection and colonization.

Results

Of the 1084 patients admitted to the ICU in the period of the study, 55 (5.0%) had at least one positive culture for fungus. These patients were older, worse and had a greater length of stay in the ICU compared to the general ICU population. One Candida species was isolated in 107 out of 109 positive fungal cultures. The urine was the site of growth in 56 cultures, tracheal secretion in 29, intravenous catheter in eight and blood in four cultures. Twenty-eight patients (50.9%) were colonized. Twenty-two patients (40.0%) were classified as probable fungal infection. Four patients had fungemia, and only one patient had confirmed fungal infection. Thirty-seven (67.2%) of the patients received at least one antifungal therapy. Of these, 15 were colonized. Fourteen (63.6%) of the 22 patients with probable fungal infection died, compared with nine out of 28 (32.1%) of the colonized patients (P < 0.05). Three out of four patients with fungemia and the patient with confirmed fungal infection survived.

Conclusion

Positive fungal cultures are associated with markedly increased mortality rates in critically ill patients. A percentage of these patients may be succumbing to unrecognized fungal infection. To identify and treat the patients with probable fungal infection could reduce the high mortality rate observed today.