The epidemiology of invasive pulmonary aspergillosis at a large teaching hospital.

OBJECTIVE

To characterize the epidemiology of invasive pulmonary aspergillosis (IPA).

DESIGN

A retrospective case series.

SETTING

An 850-bed, academic, tertiary-care medical center.

PARTICIPANTS

Adult inpatients, between January 1, 1990, and December 31, 1998, with either a histopathology report consistent with IPA or a discharge diagnosis of aspergillosis.

METHODS

We reviewed medical records and categorized case-patients as definitive or probable and acquisition of IPA as nosocomial, indeterminate, or community using standard definitions. To determine the rate of aspergillus respiratory colonization, we identified all inpatients who had a respiratory culture positive for Aspergillus species without a histopathology report consistent with IPA or a discharge diagnosis of aspergillosis. Three study intervals were defined: interval 1, 1990 to 1992; interval 2, 1993 to 1995; and interval 3, 1996 to 1998. Carpeting in rooms for patients following heart-lung and liver transplant was removed and ceiling tiles were replaced during interval 1; a major earthquake occurred during interval 2.

RESULTS

72 case-patients and 433 patients with respiratory colonization were identified. Acquisition was nosocomial for 18 (25.0%), indeterminate for 9 (12.5%), and community-acquired for 45 (62.5%) case-patients. Seventeen (23.6%) of the 72 case-patients had prior transplants, including 15 solid organ and 2 bone marrow. The IPA rate per 100 solid organ transplants (SOTs) decreased from 2.45 during interval 1 to 0.93 during interval 2 and to 0.52 during interval 3 (chi-square for trend, 5.44; P<.05). The hospitalwide IPA rate remained stable at 0.03 per 1,000 patient days.

CONCLUSIONS

The SOT IPA rate decreased after intervals 1 and 2, although the hospitalwide IPA rate remained stable during the study period. Post-earthquake hospital demolition and construction occurring after interval 2 was not associated with an increase in the rate of IPA at our institution.