Last week, I went to get a battery of STD tests. Everything came back negative, except for the RPR, which reported a value of 1:2 reactive. The following line item shows treponema pallidum antibodies: negative.
I'm wondering if this means that the RPR is a false positive. In terms of recent medical history, I had cold symptoms (sinus congestion) about four weeks ago, and a persistent cough which lasted about 3 weeks. I had a flu shot a week before getting tested (so it overlapped somewhat with the cough).
In terms of sexual history, I'm a straight man, 30 years old. In the past year, I've had protected intercourse with two women (most recently five weeks ago), unprotected oral with the same two women, and have kissed several others. I never noticed any symptoms resembling a chancre.
Past medical history: nothing remarkable, except that I was a sickly child. Pneumonia three times, whooping cough twice, bronchitis multiple times.
1. What is the probability of an RPR false positive here? If the treponema pallidum antibodies show negative, is that a definitive verdict of "no syphilis"?
2. How long after initial exposure does it take to develop TP antibodies?
3. I'd like to get re-tested. How long does it make sense to wait before doing so?