Implementation of point-of-care testing and prevalence of cryptococcal antigenaemia among patients with advanced HIV disease in Mumbai, India

ObjectivesTo describe the implementation of screening for cryptococcal antigenaemia by point-of-care (POC) serum cryptococcal antigen (CrAg) lateral flow assay, measure the prevalence and factors associated with serum cryptococcal antigenaemia in the routine programmatic setting. DesignCross-sectional study. SettingSeventeen publicly funded antiretroviral therapy (ART) centres in Mumbai, India. ParticipantsSerum CrAg screening was offered to all adolescents (>10 years of age) and adults with advanced HIV disease (AHD) (CD4 <200 cells/mm(3) or with WHO clinical stage III/IV) regardless of symptoms of cryptococcal meningitis. Primary and secondary outcome measuresThe primary outcome was to describe the implementation of serum CrAg screening and secondary outcome was to measure the prevalence of serum cryptococcal antigenaemia and its risk factors. ResultsA total of 2715 patients with AHD were tested for serum CrAg by POC assay. Of these, 25 (0.9%) had a CrAg positive result. Among CrAg-positive patients, only one had symptoms. Serum CrAg positivity was 3.6% (6/169) and 1.6% (6/520) among those presenting with CD4 <100 cells/mm(3) in the treatment naive and treatment experienced group, respectively. On multivariable analysis, CD4 count <100 cells/mm(3) (OR: 2.3, 95% CI 1.01 to 5.3; p=0.05) and people living with HIV who were treatment naive (OR: 2.5, 95% CI 1.04 to 6.0; p=0.04) were significantly associated with a positive serum CrAg result. Lumbar puncture was obtained in 20/25 patients within 4 days (range: 1-4 days) of positive serum CrAg result and one person was confirmed to have meningitis. All serum CrAg-positive patients who had a negative cerebrospinal fluid CrAg were offered pre-emptive therapy. ConclusionsImplementation of a POC CrAg assay was possible with existing ART centre staff. Initiation of pre-emptive therapy and management of cryptococcal antigenaemia are operationally feasible at ART centres. The Indian National AIDS Control Programme may consider reflexive CrAg screening of all AHD patients with CD4 <100 cells/mm(3).

Automated summary

This study describes the implementation of screening for serum cryptococcal antigenaemia in Mumbai, India and measures its prevalence and associated factors in routine programmatic setting. The results show a low prevalence of serum cryptococcal antigenaemia, which is significantly associated with CD4 count <100 cells/mm(3) and treatment-naive individuals.