To the Editor—We have read the commentary by Heather and Raizes on our recent publication with interest. Given that this was one of the first studies to determine cryptococcal antigen (CrAg) prevalence among individuals with suspected antiretroviral therapy (ART) with a viral load (VL) >1000 copies/mL in the public health system in Uganda, the conclusions we draw may have been overstated in relation to implementing this guidance for country programs.
We agree that we had small numbers of patients to demonstrate improvement in outcomes, however, despite the small numbers in our study, and based on prior studies in Uganda and South Africa, a CrAg prevalence of >0.6% followed by pre-emptive antifungal therapy for those with cryptococcal antigenemia is cost effective [1, 2]. We believe that a CrAg prevalence of 3% among individuals with VL >1000 copies/mL warrants the need to do larger evaluation studies, particularly in sub-Saharan Africa where cryptococcal disease remains a significant cause of AIDS-related mortality. Second, given that the proportion of HIV-infected individuals presenting with cryptococcal meningitis is increasingly skewed to those who are ART experienced, there is a need to do studies on CrAg prevalence among this population of individuals likely failing their ART regimen by using the VL test as a Crag screening entry point to define the prevalence, outcomes, and cost effectiveness in other settings.
Given the reasons above, we agree with the authors that further studies are needed to review viral load based CrAg screening in HIV patients with virologic failure in order to prevent and reduce cryptococcosis related mortality.
Note
Potential conflicts of interest. The authors: No reported conflicts of interest. Both authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest.
References
- 1.Meya DB, Manabe YC, Castelnuovo B, et al. Cost-effectiveness of serum cryptococcal antigen screening to prevent deaths among HIV-infected persons with a CD4+ cell count < or = 100 cells/microL who start HIV therapy in resource-limited settings. Clin Infect Dis 2010; 51:448–55. [DOI] [PMC free article] [PubMed] [Google Scholar]
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