First of all, this is not a randomized clinical trial and the decision to give 1 dose or 3 doses of BPG depended on the assessment of physicians who might prefer to give the more enhanced, 3 doses of BPG to patients who were considered at a higher risk for recurrent syphilis or treatment failure such as a previous history of syphilis, higher RPR titers, early latent syphilis, or lower CD4 counts, higher plasma HIV RNA loads, a history of prior opportunistic infections and more advanced HIV disease. This evidence concerns the gene CD4 and latent syphilis.