Prevalence and Sequelae of Cryptococcal Antigenemia in Antiretroviral Therapy-experienced Populations: An Evaluation of Reflex Cryptococcal Antigen Screening in Botswana.

BACKGROUND: Evidence to inform cryptococcal antigen (CrAg)-screening guidelines among antiretroviral therapy (ART)-experienced populations are lacking. We performed a study evaluating the utility of reflex CrAg-screening in Gaborone, Botswana. METHODS: CD4 count data were collected from samples tested at the HIV reference laboratory from 2014-2016. CrAg screening was performed on samples with CD4 /=1:80 provided the best discrimination for 6-month survival. CONCLUSIONS: CrAg-positivity rates in an ART-experienced population were comparable to those seen in ART-naive populations. Repeat screening identified individuals who seroconverted to CrAg-positivity and were at risk of cryptococcal disease. CrAg titers >/=1:80 can help identify the individuals at highest risk of death for more intensive management.