Today, I would like to present a case that we see all to often. A patient comes into our office, states that his girlfriend has chlamydia, and that he would like to be tested only for chlamydia. His understanding is that, if his girlfriend has chlamydia, then this is the only possible STD that he could have been exposed to. He admits to having multiple sex partners, but believes his girlfriend to be faithful, and thinks that if his girlfriend tested negative for Gonorrhea, then he must not have Gonorrhea, or he would have given it to her when he (presumably) gave her Chlamydia.
There are a few misconceptin that such a patient demonstrates.
First, while it is possible that he gave his girlfriend Chlamydia, it is just as possible that she gave him Chlamydia. While he admits to having been unfaithful, the fact of the matter is that more and more studies suggest that people who are unfaithful will tend to be untruthful when asked by their partners about this. This is the reasoning behind the CDC's recommendation that all Americans get tested for HIV, even long time married couples. Furthermore, she may have had Chlamydia for some time; there are studies that suggest as many as 70% of women with Chlamydia have no symptoms. It may be in fact true that she has been faithful, but the source is not as immediately apparent as our patient believes. Her exacerbation of symptoms that lead to the testing in the first place may be a result of something unrelated. It is also possible that the Chlamydia was discovered incidentally during a routine pap smear. This leads to a common second misconception that many patients have...
Many patients walk into our office after their partner has been tested and discovered to have something, with the belief that the partner was "tested for everything." The vast majority of patients who walk into our office believing that they or their partner have been tested for everything are mistaken. Women are now routinely screened for chlamydia during their pap smear if they have had multiple sex partners since their last pap, or are under the age of 26. Often, such screening reveals Chlamydia, HPV, Trichamonas or Gardnerella, but these are the only STD's that are commonly found incidentally during a routing GYN exam. Formal STD testing for Gonorrhea, HIV, syphilis, hepatitis B, hepatitis C and herpes must be specifically asked for, and even getting these tests does not encompass all of the possible STD's! There studies that show colonization rates of more than 50% by ureaplasma in sexually active adults! (Note: the wide variation in prevalence rates of ureaplasma reported by various studies suggest that we really have no idea how common it is).
A third misconception that this patient demonstrates is the belief that simply because his girlfriend has (suppossedly) only one STD, then he must have only one STD. The fact of the matter is that each time you have sex with another person, you have a chance of passing along any STD that you are currently infected with, and also have a chance of catching any STD that you are exposed to, and these risks are seperate risks for each and every STD that is "in the mix." So, imagine two people having sex for the first time: one of them has Chlamydia, syphilis, and HIV. The other has no infection. If after their first encounter, person #2 has urinary burning, discovers that she has Chlamydia (and only Chlamydia), and informs the other person of her test results. The other person may mistakenly believe that he has Chlamydia, and only Chlamydia. Testing person #1 for chlamydia, and only chlamydia, would be a disservice to this person AND to anyone else with whom he might have sex with in the future, as he would be unknowingly exposing his future partners to both Syphilis and HIV!
Let's look at two similiar hypothetical people in another way. Person #1 (female prostitute) has Gonorrhea, syphilis and HIV. Person #2 (male) has no STD at all during their first encounter. Person #2's risk of getting HIV during their first unprotected encounter is (we think) about a 1 in 1000 chance, while his risk of getting gonorrhea is greater than 50/50. Now imagine that these two people have sex 2 times. During the first encounter, because person #2 has no underlying inflammation along his urethra, he only gets gonorrhea. However, his risk of getting HIV from person #1 during their second encounter jumps from 1 in 1000 to 1 in 2 (again, the data from different sources show wide variability, and so I am not confident that we really know the actual risk, but this seems to be the concensus); a 50% chance of getting HIV. We think this has to do with his underlying state. The gonorrhea produces inflammation along the urethra, which increases the HIV virus's ability to penetrate his defences, and cause infection. So, even though the first person had 3 STD's, she only transmitted one of them during the first encounter, and this resulting underlying infection dramatically increased the probability of transmitting HIV during their second encounter.
In summary, keep these points in mind. 1) Having a partner with a documented STD does not guarantee that this is the only STD that you might have, nor is it certain that you have yet contracted said condition. 2) The obvious source of an STD may not be the actual source, as some STD's can be asymptomatic for quite some time. 3) If a partner states that they have been "tested for everything," try and get a copy of the test results and present them to your physician for review (with your partners permission...never provide another person's test results to anyone without that persons full knowledge and consent); make certain they they have in fact been "tested for everything." Communication is very important here. Even when I am talking to a patient, I sometimes discover that my understanding of what the patient is saying is not his or her understanding of what is being said (and vis versa). 4) Your underlying health influences your risk of contracting an infection with each exposure; this is particularly true of patients with underlying chronic illnesses, such as diabetes.
One final thought: numbers and percentages really are just guidelines. Infections can and do occur after a single unprotected sexual encounter. The only way to know if you've been infected is to get tested. Percentages and numbers should never be used as a substitute for testing and safe sex.
Well, I hope that this presentation was informative. Please feel free to leave comments or questions.
Warren Henslee, MD