Survey of Aspergillus species associated with the human respiratory tract.

Abstract

A comprehensive survey has been carried out on the occurrence ofAspergillus species in the respiratory tract of patients of bronchopulmonary diseases in Delhi. In all, 1238 clinical specimens, which included 1082 sputa, 143 bronchial aspirates and 13 throat swabs obtained from 812 patients, were examined. Of these 61.7 per cent patients were culturally positive yielding 29 different species ofAspergillus. The prevalence of aspergilli in sputa was significantly higher than in the bronchial aspirates.Aspergillus niger was the commonest species isolated showing a prevalence of 36.7 per cent. It was followed byA. flavus, A. nidulans, A. terreus, A. versicolor, A. sydowi, A. japonicus andA. oryzae. None of theAspergillus species showed a significant correlation with any of the diseases, or the type of treatment the patients had received. Of the 8 broad occupational groups investigated farmers and labourers showed higher prevalence ofA. niger andA. flavus. The prevalence ofAspergillus species in the throats of healthy persons was 16 per cent withA. versicolor being the commonest species followed byA. flavus, A. amstelodami, A. sydowi andA. terreus. A comparison of the prevalence ofAspergillus species in the patients, healthy individuals and atmosphere of Delhi appears to support the view that the aspergilli are transient residents in the human respiratory tract following their inhalation from the environment.