Respiratory Tract Aspergillosis in the Sputum of Patients Suspected of Tuberculosis in Fako Division-Cameroon

Abstract

Respiratory tract aspergillosis refers to fungi infections of the respiratory tract caused by Aspergillus species. Respiratory tract aspergillosis has clinical and radiological characteristics which are very similar to tuberculosis thereby making the disease easily misdiagnosed and mistreated as tuberculosis. This prompted us to investigate the prevalence of respiratory tract Aspergillus sp. in the sputum of patients suspected of pulmonary tuberculosis and to study the anti-fungal susceptibility of the isolated Aspergillus strains. Two hundred sputa samples were studied for Aspergillus sp. and M. t u berculosis. Direct microscopy and fungal culture was done on two sets of Sabouraud Dextrose agar. Analysis for Acid-Fast Bacilli (AFB) was done by the Auramine-phenol fluorochrome technique. Aspergillus sp were isolated from 30(15%) patients; A. fumigatus was isolated in 10 (5%) patients while A. niger, A. flavus, and A. terreus were isolated from 9 (4.5%), 6 (3%) and 5 (2.5%) patients respectively. M. tuberculosis was found in 27(13.5%) and a co-infection of 9(4.5%) was observed.Using the broth micro dilution technique, the minimum inhibitory concentrations (MICs) for Aspergillus sp for nystatin, itraconazole and amphotericin B ranged between 0.12- >16 μg/ml, 0.06- >16 μg/ml and 0.12- 0.5 μg/ml, respectively. All the Aspergillus terreus strains were consistently sensitive to itraconazole (MIC >16 μg/ml).