Prevalence, determinants of positivity, and clinical utility of cryptococcal antigenemia in Cambodian HIV-infected patients

Abstract

OBJECTIVES: To determine the prevalence, determinants of positivity, and clinical utility of serum cryptococcal polysaccharide (CPS) antigen testing among HIV-infected patients in 2004 in Cambodia, an area highly endemic for cryptococcosis. METHODS: All HIV-infected patients with a CD4 count <200 cells/mm attending 1 of 2 Phnom Penh hospitals for the first time were systematically screened for serum CPS. Patients with positive test results were further investigated to identify those with cryptococcal meningitis (CM), pulmonary cryptococcosis, or isolated positive cryptococcal antigenemia (IPCA). RESULTS: The median (interquartile range [IQR]) CD4 count of 327 enrolled patients was 24 (IQR: 8 to 65) cells/mm. The prevalence of cryptococcal infection was 59 (18.0%) of 327 cases, of which 41 were CM and 10 were IPCA. In the absence of serum CPS detection, 17 (28.8%) of 59 cryptococcal infections would have been missed on the day of consultation. In patients with no specific symptoms of meningoencephalitis, the prevalence of positive serum CPS detection was 32 (10.8%) of 295 cases. Countryside residence (adjusted odds ratio [AOR] = 3.6), headache (AOR = 3.2), body mass index <15.4 kg/m (AOR = 3.4), CD4 count <50 cells/mm (AOR = 4.0), and male gender (marginally, AOR = 2.1) were all independently associated with a positive test result. CONCLUSION: Serum CPS screening among AIDS patients with a CD4 count <100 cells/mm is useful in areas highly endemic for cryptococcosis, allowing early diagnosis and treatment of this opportunistic infection. © 2007 Lippincott Williams & Wilkins, Inc.