Frequency of clinical isolation and winter prevalence of different Aspergillus species at a large southwestern army medical center.

The frequent occurrence of aspergillosis caused by species other than Aspergillus fumigatus at Brooke Army Medical Center prompted the authors to study the prevalence of the different Aspergillus species at Brooke Army Medical Center and at two other hospitals in San Antonio, Texas. Two parameters were analyzed: (1) frequency of isolation from clinical specimens over a five-year period and (2) relative prevalence in the atmosphere during the late fall and early winter using volumetric air-sampling. A fumigatus was infrequently recovered from clinical specimens and was one of the least prevalent species of Aspergillus in the air. A. terreus, a rare species in prevalence studies performed elsewhere, was frequently recovered from patients; it was the second most prevalent organism in the air after A. niger. Climatic conditions in the authors' area probably favor the growth of A. terreus over A. fumigatus. Since A. terreus has been shown to be a potential pathogen, an increased frequency of disease caused by this organism may be expected in this environment.