Pulmonary dimorphic fungal infections among HIV/AIDS non-TB patients with chronic cough in Kampala, Uganda.

INTRODUCTION:Dimorphic fungi cause infection following the inhalation of spores into the pulmonary system. In the lower respiratory tract, the conidia transform into yeasts, which are engulfed by alveolar macrophages and may be destroyed without disease manifestation. However, in some immunocompromised individuals, they may persist and cause active fungal disease characterized by formation of granulomas in the infected tissues, which may mimic Mycobacterium tuberculosis (MTB). OBJECTIVE:To determine the prevalence of pulmonary dimorphic fungal infections among HIV/AIDS patients with non-TB chronic cough at Mulago National Referral and Teaching Hospital in Kampala, Uganda. METHODS:Sputum samples were collected from 175 consented HIV/AIDS patients attending the immuno-suppression syndrome (ISS) clinic at the hospital. Upon Xpert MTB/RIF sputum testing, 21 patients tested positive for MTB, and these were excluded from further analysis. The other 154 sputum negative samples were then subjected to PCR for dimorphic fungi at MBN Clinical Laboratories. Singleplex PCR was used to detect the target sequences in selected respective genes of each dimorphic fungal species of interest. DNA amplicons were detected based on gel electrophoresis. RESULTS:Dimorphic fungi were detected in 16.2% (25/154) of the studied population. Of these 9.1% (14/154) had Blastomyces dermatitidis and 7.1% (11/154) had Talaromyces marneffei. The remaining 84% of the studied participants had no dimorphic fungi. Histoplasma capsulatum, Coccidioides immitis and Paracoccidioides brasiliensis were not detected in any of the participants. CONCLUSION:Dimorphic fungi (B. dermatitidis and T. marneffei) were found in 16.2% of the HIV/AIDS patients with non-TB chronic cough in Kampala, Uganda. We recommend routine testing for these pathogens among HIV/AIDS patients with chronic cough.