Characterization of Candida Species Isolated from Cases of Lower Respiratory Tract Infection among HIV/AIDS Patients in Calabar, Nigeria

Abstract

This study was designed to identify and characterize the Candida species isolated from lower respiratory tract infections among HIV positive patients and to determine the prevalence rates of Candida infections among these subjects. Two early morning expectorate sputum samples were collected from 272 HIV positive subjects visiting the ART clinics and DOTS centre with cases of lower respiratory tract infection, over a period of 14 months from May 2009 to July 2010 in Calabar. Subjects were recruited for this study upon approval by the Ethical Research Committee of the University of Calabar Teaching Hospital and obtaining written informed consent from the patients. Samples were processed by standard methods for isolation of Candida. Speciation was done by a germ tube test, chlamydospore production on corn meal agar and sugar fermentation and assimilation tests using the Microexpress Candida identification kit (Tulip, India). Out of the 544 sputum samples collected from 272 subjects, Candida species were isolated from 40 (14.7%) and identified after confirming the growth in the second sample. The majority of Candida species among the Candida isolates were Candida albicans (80%) followed by Candida tropicalis 5 (12.5%), Candida dubliniensis 2 (5.0%) and Candida guilliermondii 1 (2.5%). The isolation rate of Candida species from sputum samples was found to be highest among subjects aged 25 - 34 years, followed by those aged 15 - 24 years. Twenty (7.3%) HIV seropositive subjects had bacterial infections, while 4 (1.5%) subjects had mixed fungal and bacterial infections. This study is the first of its kind to be carried out in Calabar and the South-South geopolitical region of Nigeria, and has shown that pulmonary candidiasis is a health problem among HIV positive patients in Calabar.