Syphilis Positive

Question

Dr.

I am a gay man that tested positive for syphilis. During that same time I tested negative for HIV. I am allergic to penicillin so I had to take doxcycline (SP). Because we were uncertain of what stage of syphilis I had we went for a fairly large dose (about 28 days worth). After I finished my course of antibiotics I was tested for syphalis and HIV again. This time I had the same titer level (my doc says I should not worry about this because it is so soon after my course of antibiotics and that by the 3rd month that level should go down). What is really disturbing is that my HIV western Blot test has come back indeterminate. Can my syphalis cause this indeterminate status? Should I trust these results even thought i did not have an ELISA test first?

Answer

Hello,

If you did not have a repeatedly reactive (positive) ELISA test before running a Western Blot test, your Western Blot result is not reliable. There is a 2% rate of false-positives and a 4% to 20% rate of indeterminate results with Western Blot tests. I would suggest you disregard the isolated Western Blot result and begin your HIV screening properly with an ELISA (or EIA or rapid test). If negative, that's as far as you need to go with testing to confirm your HIV-negative status (assuming the FDA-approved antibody test is run three months or more from your last potential HIV exposure). If your ELISA is positive, you should then and only then follow up with a Western Blot test.

Good luck.

Dr. Bob