I was diagnosted for syphilis on Jan 06, with RPR titer 1:32 and HIV negative. Doctor ordered 4 courses of peniciline intramuscular. After the treatment i checked RPR titer was 1:8 Feb 11. Because of the results doctor ordered another four courses of peniciline intramuscular, one each week, after RPR titer was 1:2 Apr 11, now i check again and RPR titer is 1:4 May 03. What it means? Treatment failed? Should I go and test for HIV? Should i be worry about? In the meantime of the treatment and last test i have not any sexual risk (abstinence) Please help me. Thanks