Screening for cryptococcal antigenemia in anti-retroviral naive AIDS patients in Benin City, Nigeria

ABSTRACT

Cryptococcus neoformans is the most incriminated fungal pathogen causing meningitis in acquired immune deficiency syndrome [AIDS] patients, and is known to constitute a major cause of deaths in AIDS patients. This study thus aimed to determine the baseline sero-prevalence of Cryptococcus neoformans infection in anti-retroviral naive [ART-naive] AIDS patients using the serum Cryptococcal antigen [crag] detection method. Baseline effect of variation in CD4 counts, as well as sex and age with sero-positivity for crag were also determined. This descriptive cross-sectional study included 150 [61 males and 89 females] ART-naive AIDS patients attending the Human Immunodeficiency Virus clinic [HIV] at the University of Benin Teaching hospital, Benin City, Nigeria, within the period from February 2011- July 2011. Forty [18 males and 22 females] HIV positive outpatients with CD4 counts >200 cells/microl who were ART-naive were recruited and used as controls. The sero-prevalence of crag in the patients and the control group was measured using the cryptococcal antigen latex agglutination system [CALAS] [Meridian Bioscience, Europe] and CD4 counts were measured using flow cytometry [Partec flow cytometer, Germany]. Of the 150 ART-naive AIDS patients with CD4 counts cells/microL; 19 [12.7%] were positive for serum Cryptococcal antigen. ART-naive AIDS patients with CD4 count cells/microl had the highest prevalence of serum crag. Lower CD4 counts were significantly associated with positivity for serum crag [p<0.001]. Age and sex had no significant effect on the sero-positivity for serum crag. One [2.5%] of the controls was sero-positive for crag. Thus, serum crag was significantly associated with AIDS but not with HIV [p<0.001]. This study uncovers a high prevalence of crag in ART- naive AIDS patients in Benin City. The prevalence of crag was higher in ART-naive AIDS patients with lower CD4 counts. There is an urgent need to introduce routine screening for crag in ART- naive AIDS patients in our locality to reduce the rapid mortality from Cryptococcal meningitis which accounts for a majority of the morbidity factor if undiagnosed during ART therapy