To our knowledge, we report here the first internet-based screening program for three prevalent STIs in men. A prior report demonstrated that internet-based screening was feasible in low-risk men (chlamydia prevalence 4%) 25
, but did not include gonorrhea or trichomonas, two highly prevalent STIs. As more individuals access the internet to obtain health information, conduct health transactions, and find sex partners, integrating testing of prevalent STIs into this medium may be increasingly important 26
Similar to internet-based screening in women, internet-based screening in men also reached very high-risk men with a high prevalence of STIs (21%). Prevalence of chlamydia (13%) was greater than in high-risk men across the United States, including incarcerated young men (6.8–7.9%) 22, 27
and male youth in inner-city schools (7.5–10.1%) 15, 28
. Men in certain urban areas in this study, including Baltimore and Denver, had chlamydia prevalence (18% and 17%, respectively) equal to or higher than high-risk men in STI clinics 29
Prevalence of trichomonas (10%) was only slightly higher in STI clinics (12–13%) 29, 30
. Although gonorrhea prevalence (0.8%) was much higher in STI clinics (12.8%) 30
, our prevalence was similar in community-dwelling men in the highest risk age-group nationwide (0.45%, ages 20–24). The lower prevalence of gonorrhea versus reported symptoms suggests we reached mostly high-risk, asymptomatic men, because in men gonorrhea is most often symptomatic, which leads them to be tested. Prevalence of co-infection with chlamydia was similar in female patients in emergency departments (8%) 31
In this study, men also had a high prevalence of prior STIs (34%). Although 29% of men reported having a partner who has had an STI, only 11% of those men reported always using a condom during sex, two synergistic high-risk behaviors. More than half of men reported a recent new partner and more than a third reported multiple partners in the past three months.
Certain demographic characteristics were associated with STI positivity. From STI surveillance data, males in their late teen-early 20s have the highest prevalence of chlamydia and gonorrhea 1
, which is consistent with our finding that age was independently associated with STI positivity. After controlling for income, location, and age, and examining factors such as perceptions of testing confidentiality and insurance status, which can affect healthcare access 32
, Black Race was associated with increased STI prevalence, which is consistent with prior studies 22, 27
. However, previously reported unmeasured factors, including perceptions of discrimination, lack of perception of risk, unavailability of services, and healthcare staff prejudices 32
, might help to partially explain this association.
Although few men reported race as “other”, those men had very high odds of STI positivity. The public health impact of this finding is unclear. Although smaller studies have not shown an association between poverty and STI prevalence 33
, results from larger nationwide studies 34
agree with our finding that income is independently associated with STI positivity. The observed dose-response relationship of increased STI prevalence with decreased income provides greater evidence for this association. Not surprisingly, STI prevalence varied by geographic location, which has been previously reported 1
Certain risk behaviors were also associated with STI positivity. As expected 35
, lack of consistent and correct condom use was associated with increased STI positivity in a dose-response relationship, and the magnitude of the association (odd ratio 4.96 for the “Never” use category) is convincing of the efficacy of condoms against STI transmission. However, several known behavioral risk factors were not associated with STI positivity in our study, including multiple or new sex partners 36
, male-to-male sex 1
, and prior STIs 10
. The lack of association between increased STI positivity and these risk factors might be largely explained by condom use. Men with multiple or new partners, and men who had sex with men, reported using condoms significantly more frequently than those who did not report these risk factors. No association between prior STIs and STI positivity was found in this study; the other study examining internet-based testing found a similar lack of association 25
Men who submitted a sample found internet-based screening acceptable. Penile swabs were perceived as safe, and the vast majority of men rated swabs as “Very easy” or “Easy” to self-collect. Seventy-seven percent of men preferred a self-administered STI specimen, suggesting that internet-based screening might capture a population that would otherwise not be tested. Importantly, the vast majority of men who submitted a sample would use internet-based screening again, suggesting its high overall acceptability. Although our study had a high return rate (31%) of samples for an internet-based service, the acceptability for men who did not submit a sample is unknown.
Internet-based screening, especially if provided free of charge, may overcome barriers to STI testing for multiple high-risk populations who might not otherwise be tested. Over 45% of the men accessing internet-based screening had no health insurance, a known barrier to STI testing 32
. Youth can lack money and fear breach of privacy. Youth comprised 11% of men who accessed internet-based screening and 70% of participants felt internet-based screening was private. Low-income Blacks, an underserved population for STI screening 32
, were reached in large proportions. Screening for STIs can be cost-effective in high-risk men 37
, and the prevalence of chlamydia in this study (13%) was even higher than in high-risk groups (2.3%–3.2%). Self-testing costs appear to be lower than clinic testing costs, even accounting for partial kit return rates. Using estimated indirect costs for clinic testing of chlamydia and gonorrhea ($62/visit 38
), provider costs ($25/visit), direct costs for testing in our laboratory ($30/test), direct costs of our mailed kits ($10/kit), and the 31% kit return rate, we estimated total costs for clinic testing to be $117/test, and for self-testing, $62/test. We estimated self-testing yielded a net savings of $55/test.
Several limitations to our findings exist. Because internet-based screening was voluntary and is inherently targeted to individuals who use the internet, self-selection might have biased the results. Men who use the internet to find sex partners 39
are at higher risk for having an STI, which might have led to false associations. However, this effect was likely minimal, because risk factors reported in this study are well-established. In fact, a newer report suggests no association between having sex partners found on the internet and STI prevalence 26
, perhaps because internet use for all types of activities, including finding sex partners, has become normalized across many populations. Because risk factors were self-reported, recall difficulties might have introduced reporting errors. While some data were missing, their effect was likely minimal because few (9%) individuals were excluded in the final multivariable model.
Lack of access to computers due to low income and low educational level could challenge the effectiveness of internet-based screening. However, recent evidence suggests most adults living in public housing have access to a computer, and disparities are narrowing 40
. Although internet-based screening for STIs such as syphilis and HIV cannot be easily be conducted, these STIs are far less prevalent nationwide than chlamydia, gonorrhea, and trichomonas.
AC2 TMA testing was recently reported to have less sensitivity for chlamydia and gonorrhea in self-collected glans specimens 41
. However, AC2 testing was more sensitive in male penile swabs in our study compared to first-catch urine. We do not have an explanation for these differences. Additional characterization of AC2 performance in male penile and glans swabs is needed.
Internet-based screening can reach a high-risk population for STI testing and treatment. Risk factors for STIs in this population reflect known STI risk factors. Because persons at greatest risk for STIs face barriers and have a high preference for self-testing, internet-based screening has the potential to reach populations which might not otherwise access STI testing. While internet-based screening is likely cost-saving, detailed, additional cost effectiveness studies will be needed and certain measures, such as implementation of secure web-based result notification, could increase efficiency. With additional data in this nascent area, more data might provide further clarification on the role of STI screening in men to inform future guidelines. In an era of healthcare reform and transition, internet-based services could provide additional options to provide low-cost, accessible healthcare.