Oropharyngeal yeast colonization in HIV-infected outpatients in southern Taiwan: CD4 count, efavirenz therapy and intravenous drug use matter

Abstract

To understand the status of oropharyngeal yeast colonization in human immunodeficiency virus (HIV) -infected outpatients in the era of highly active antiretroviral therapy (HAART), we conducted a prospective, cross-sectional study from October 2009 to January 2010 at a medical centre in southern Taiwan. Fungal cultures of the oropharyngeal swabs were performed on 327 enrolled patients. At enrolment, 258 (79%) patients had been receiving HAART, and 42 (12.8%), 73 (22.3%) and 212 (64.8%) patients had CD4 cell counts =200, 201350, and >350 cells/mm3, respectively. Oral yeast colonization was detected in 193 (59%) patients, among whom 157 (81.3%), 25 (13.0%), and 11 (5.7%) were colonized by a single, two and more than two species, respectively. Multivariate analysis showed that receipt of efavirenz-containing regiments and CD4 cell counts >200 cells/mm3 were associated with lower risks of oral yeast colonization, while intravenous drug users were at a higher risk. Among the 241 isolates recovered, Candida albicans accounted for 69.7%, followed by C.similar to dubliniensis (9.5%), C.similar to glabrata (8.3%), C similar to tropicalis (3.3%), C.similar to intermedia (2.1%), C.similar to parapsilosis (1.7%), and 11 other species (5.4%). Overall, 230 (95.4%), 236 (97.9%) and 240 (99.6%) isolates were susceptible to fluconazole, voriconazole and amphotericin B, respectively. In conclusion, colonization by C.similar to dubliniensis has emerged in recent years. In addition to a CD4 cell count =200 cells/mm3, which is a known risk factor for oropharyngeal yeast colonization in HIV-infected patients that was identified in our previous studies, two risk factors, non-receipt of efavirenz-based combinations and intravenous drug use, were first identified in the present study. Fluconazole remained effective in vitro against the yeasts colonizing the oropharynx in this population.