Background: Cryptococcal meningitis accounts for 15% of AIDS-related mortality. Cryptococcal antigen (CrAg) is detected in blood weeks before onset of meningitis, and CrAg positivity is an independent predictor of meningitis and death. CrAg screening for patients with advanced HIV is recommended by the World Health Organization, though implementation remains limited. Our objective was to evaluate costs and mortality reduction (lives saved) from a national CrAg screening program across Uganda.
Methods: We created a decision analytic model to evaluate CrAg screening. CrAg screening was considered for those with a CD4< 100 cells/µL per international guidelines, and in the context of a national HIV test and treatment program where CD4 testing may not be available. Costs (2016 USD) were estimated for screening, preemptive therapy, hospitalization, and maintenance therapy. Parameter assumptions are based on large prospective CrAg screening studies in Uganda, and clinical trials from sub Saharan Africa.
Results: In the base case for 1 million persons with a CD4 test annually, 128,000 with a CD4< 100 cells/µL were screened, and 8,233 were asymptomatic CrAg+ and received preemptive therapy. Compared to no screening, CrAg screening and treatment in the base case costs $3,356,724, and saves 7,320 lives, for a cost of $459 per life saved.
Within a national HIV test and treat program, of 1 million HIV-infected persons, 5,920 were incident CrAg positive (CrAg prevalence 1.5%). The total costs of a CrAg screening and treatment program was $4.12 million dollars, with 2,229 known deaths. Conversely without CrAg screening, the cost of treating meningitis was $5.45 million dollars with 6,712 deaths. Thus, despite the very low CrAg prevalence at about 1.5% in the general HIV-infected population, CrAg screening saved over $1.32 million (i.e. 13% of total costs) and averted 67% of deaths, saving $295 per death averted.
Conclusions: CrAg screening and treatment programs are cost saving and lifesaving and could be adopted and implemented by ministries of health to reduce mortality in those with advanced HIV disease. Even within HIV test and treat programs where CD4 testing is not performed, and CrAg prevalence is only 1.5%, CrAg screening is a worthy investment.


[Table 1. Input parameters for base case model]




[Figure 1: Cost of CrAg screening and preemptive treatment with differential levels of implementation. With 100% CrAg screening and treatment, 1900 lives are saved (44%) and $860,000 dollars, compared to no screening.]