Aa
RPR Testing
Drs,
I am a heterosexual male, 38 years old, and had a one time brief unprotected (vaginal) sexual encounter with a female I met at a business conference late last year. I decided to get checked 14 weeks after the incident, too embarassed to see my family doctor, I used an online site and went to LabCorp (I know, I know). Everything checked out negative except I tested 1:1 for Syphilis using RPR. I tripped out, told my wife and went to my family doctor who re--tested me and was negative. My question, what would trigger an abnorma test. I have slight OCD and anxiety over this and am looking for an explanation that my doctor cannot give (other than the test is like a net looking for all kinds of fish, not just Syphilis). If I don't have syphilis, what could it be that tripped it? Lyme disease, HIV? What? Thanks!
I am a heterosexual male, 38 years old, and had a one time brief unprotected (vaginal) sexual encounter with a female I met at a business conference late last year. I decided to get checked 14 weeks after the incident, too embarassed to see my family doctor, I used an online site and went to LabCorp (I know, I know). Everything checked out negative except I tested 1:1 for Syphilis using RPR. I tripped out, told my wife and went to my family doctor who re--tested me and was negative. My question, what would trigger an abnorma test. I have slight OCD and anxiety over this and am looking for an explanation that my doctor cannot give (other than the test is like a net looking for all kinds of fish, not just Syphilis). If I don't have syphilis, what could it be that tripped it? Lyme disease, HIV? What? Thanks!
MEDICAL PROFESSIONAL
You don't say where you are, but most questions come from the United States, where syphilis is a rare disease. There are only about 20,000 new syphillis cases per year; it is one of the least common STDs in the US, less than half the frequency of new HIV infections. And most of the new syphilis cases, like HIV, occur in gay/bi men, and the heterosexually acquired cases are pretty much limited to just a few geographic areas. Following that theme, the chance that syphilis is present in a woman who is not a commercial sex worker, and especially a colleague at a business conference, is almost zero. Thus, it is almost impossible you caught syphilis during that encounter.
I am not entirely sure how to interpret your weakly positive RPR test. Presumably the repeat test by your doctor was not only a repeat RPR, but included a confirmatory test that was negative. If so, for sure you don't have syphilis. However, if there was only a repeat RPR and not yet a confirmatory test, you need to make sure that gets done.
In the chance the RPR result turns out to be a true positive, i.e. you have syphilis, probably it wasn't from the sexual encounter described above. A new case of syphilis acquried 14 weeks earlier generally would have a higher titer, at least 1:4 and usually 1:8 or higher.
So the bottom line is that it is most likely that your RPR result was a false positive. The standard terminology used by STD specialist is "biological false positive", or BFP. ("Biologic" is redundant, but it has been used by habit for over a century.) What causes BFP syphilis tests? Mostly no cause is found, and usually it has no health implications at any time. Certain immunologic diseases can cause it, as can allergic reactions to some drugs. BFP's are quite common in pregnant women, obviously not an issue here. HIV is not a cause; to my knowledge, Lyme disease doesn't do so either, but I'm less certain on that one.
Bottom line: Double check with your doctor that a syphilis confirmatory test was done and negative. If not, have that test. If it was done, follow your doctor's advice about whether or not further evaluation is needed. But mostly not. For my own patients with BFP, if the patient feels well and the physical examination is normal, I do not recommend any further testing of any kind.
I hope this helps. Best wishes-- HHH, MD
I am not entirely sure how to interpret your weakly positive RPR test. Presumably the repeat test by your doctor was not only a repeat RPR, but included a confirmatory test that was negative. If so, for sure you don't have syphilis. However, if there was only a repeat RPR and not yet a confirmatory test, you need to make sure that gets done.
In the chance the RPR result turns out to be a true positive, i.e. you have syphilis, probably it wasn't from the sexual encounter described above. A new case of syphilis acquried 14 weeks earlier generally would have a higher titer, at least 1:4 and usually 1:8 or higher.
So the bottom line is that it is most likely that your RPR result was a false positive. The standard terminology used by STD specialist is "biological false positive", or BFP. ("Biologic" is redundant, but it has been used by habit for over a century.) What causes BFP syphilis tests? Mostly no cause is found, and usually it has no health implications at any time. Certain immunologic diseases can cause it, as can allergic reactions to some drugs. BFP's are quite common in pregnant women, obviously not an issue here. HIV is not a cause; to my knowledge, Lyme disease doesn't do so either, but I'm less certain on that one.
Bottom line: Double check with your doctor that a syphilis confirmatory test was done and negative. If not, have that test. If it was done, follow your doctor's advice about whether or not further evaluation is needed. But mostly not. For my own patients with BFP, if the patient feels well and the physical examination is normal, I do not recommend any further testing of any kind.
I hope this helps. Best wishes-- HHH, MD
MEDICAL PROFESSIONAL
I am glad to be of help and happy it worked out that way. Take care.
Thank you for your time and dedication to this site, your answers are well explained and go a long away for those who are driven by anxiety! I just wanted to give my 2 cents and tell you how much your reply meant to me and my mental recovery!
Yes, in the situation above, a confirmatory test was given right away (without another RPR) and was negative. I just have to live with your (and my doctor's) answer that it was a fluke or as you put it BFP.
Thanks again, have a great week!
Yes, in the situation above, a confirmatory test was given right away (without another RPR) and was negative. I just have to live with your (and my doctor's) answer that it was a fluke or as you put it BFP.
Thanks again, have a great week!
You are reading content posted in the STDs Forum
Herpes spreads by oral, vaginal and anal sex.
Herpes sores blister, then burst, scab and heal.
STIs are the most common cause of genital sores.
Millions of people are diagnosed with STDs in the U.S. each year.
STDs can't be transmitted by casual contact, like hugging or touching.
Syphilis is an STD that is transmitted by oral, genital and anal sex.
