Virgins with Chlamydia
A lot of the studies I write about here rely on self-reportage. They have to, since there isn't really any other way of finding out about other people's sex lives than to ask them. Unfortunately, when people are asked personal questions in the context of a study on behavior, there's always the chance that they'll lie. This is especially likely when you're talking about something as potentially embarrassing as sex. An article in the most recent issue of Pediatrics highlights this fact. Researchers combined STI tests with surveys of sexual behavior in young adults and found that the results didn't quite match up.
The study compared tests for sexually transmitted infections and survey responses for 14012 (6636 male, 7376 female) participants of the National Longitudinal Study of Adolescent Health. The participants had been recruited from grades 7-12 in 1994 and were subjected to a follow-up survey this past year. The mean age of the participants at the time of the follow-up survey was 21.9. The subjects were interviewed in their homes with the aid of a computer survey. They were also asked to give urine samples to be tested for bacterial STIs, specifically Chlamydia, gonorrhea, and trichomoniasis. A total of 6% of the subjects tested positive for STIs. Of those who tested positive, 89.5% reported having had sex (specifically penile-vaginal sex) at least once in the past year, but a full 10.5% reported no piv sex in the past year and 6% reported never having had piv sex. Something fishy is clearly going on there.
There are several possible explanations for why so many of the study participants denied having sex in the past year (or ever) and yet tested positive for sexually transmitted infections. It's possible that they may have picked up the infection more than a year before. However the STIs in question are all bacterial infections and previous studies indicate that (at least in women) these infections clear up on their own with a year or two if there's no repeated sexual activity with an infected partner, so such a large percentage testing positive after a year of abstinence is unlikely. It's also possible that they could have picked up the infection from other types of sex, though again the large numbers belie this. It's rare to pass any of the three STIs tested for from oral/genital contact, and when they are contracted this way the path is usually from the genitals to the throat, not the other way around, and a urine test would not detect a throat infection. Transmission from anal sex is more likely, and since the researchers did not ask the subjects about any sexual activity other than piv it's a definite possibility for some of the subjects who tested positive- specifically for men who've penetrated an infected partner anally, again a urine test wouldn't show an anal infection. However, there were no differences seen between men and women in the rates of STI versus reported sexual contact, so again this seems unlikely. Some false positives are likely and it's possible than some respondents mis-rembered their sexual past rather than deliberately lied about it, but these don't seem like they would explain such high numbers either. The most likely explanation, frankly, is that some of those who tested positive for STIs lied about being abstinent.
That some young adults might lie about their sexual history to researchers is hardly surprisingly. Our culture is one that still puts a lot of pressure on young people to abstain from pre-marital sex (even as the entertainment industry makes it seem really fun and cool). The participants of this study in particular came of age during a period when abstinence only education was favored in many parts of the US. Many young people in the US are told by their parents, teachers, and religious leaders that having sex is wrong wrong wrong under any circumstances but marriage, and potentially shamed for engaging in it. Many of these youth would understandably rather lie to make themselves seem more sexually pure than they actually are than admit to having fallen. The fact that subjects were interviewed in person in their homes rather than anonymously makes it more likely that they would do so. This is one of the reasons that most surveys of sexual behavior take pains to make responses anonymous and to create the sense in participants that no one is judging them. Still, even in the most anonymous of surveys, people will tend to answer in ways that they believe make them look good and since being sexually active still carries a stigma among young people in this country, they'll inevitable tend to gloss over their sexual history. Basically, it's best to assume that numbers for any activity that can potentially be seen as shameful are underreported. The results of this study are not surprising, but it is a little disheartening to see that pushing abstinence is more likely to cause young people to lie about their behavior than to induce them to protect their health sexually. Sexually inactive people don't get Chlamydia*, but people who aren't fully informed about the risks and don't use proper protection do.
*unless they're babies who contracted it from their mothers, but I doubt that was the case here.
Dr. Pisaster has a doctorate in biophysics, not actually anything sexy. She does however enjoy having sex, reading about sex, and talking about sex. Especially when she's had a little whiskey.