Screening for Cryptococcal Antigenemia in Anti-Retroviral Naïve 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 naïve (ART-naïve) 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-naïve 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/µl 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-naïve AIDS patients with CD4 counts ≤200 cells/µL; 19 (12.7%) were positive for serum Cryptococcal antigen. ART-naïve AIDS patients with CD4 count ≤50 cells/µl 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- naïve AIDS patients in Benin City. The prevalence of crag was higher in ART-naïve AIDS patients with lower CD4 counts. There is an urgent need to introduce routine screening for crag in ART- naïve 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.