AIDS-associated cryptococcal meningitis in Rwanda (1983-1992): epidemiologic and diagnostic features

Objectives: to document the trend of AIDS-associated Cryptococcus neoformans meningitis (CM) in Kigali, Rwanda, during 1983–1992, and to highlight some diagnostic and epidemiological features of the disease.
Methods: during the study period, 3476 cerebrospinal fluid (CSF) specimens from 2824 adults (1578 men, 1246 women) were analysed in the Laboratory of Microbiology at the Centre Hospitalier de Kigali, Rwanda, Central Africa, using direct examination, culture and detection of the cryptococcal antigen (CrAg) in the CSF.
Results: CM was diagnosed among 549 (19%) patients (347 men, 202 women) and was by far the leading cause of meningitis before Neisseria meningitidis (n=115), Streptococcus pneumoniae (n=68), Mycobacterium tuberculosis (n=26), E. coli, Klebsiella pneumoniae, non-typhoid Salmonella (n=15) and streptococci (n=4). The number of CM increased from one case in 1983 to 130 new cases in 1992. All 293 tested CM patients had HIV-1 antibodies. The male/female ratio declined from 3.31 during 1983–1987 to 1.58 during 1988–1992. CM showed a seasonal fluctuation, the highest number of infections being observed during the long rainy season. The sensitivity and specificity of the latex test for diagnosing CM was 98% and 99%, respectively. Cryptococcus neoformans var. gattii was cultured from eight (1.6%) of the 499 culture positive patients.
Conclusion: CM is an important opportunistic infection among AIDS patients in Central Africa. It remains a problematic diagnosis in areas with limited diagnostic facilities.