Consent to participate was obtained from each participant before data collection. We did not collect any personally identifiable information. The study protocol and consent procedure were approved by the Medical Ethics Committee of the Hangzhou Center for Disease Control and Prevention (20190712).

We used an institution-based cross-sectional study design to collect data from colleges and gay organizations located in Zhejiang Province, China. We chose these 2 sites for 2 reasons. First, the number of new HIV infections among college students has increased significantly in recent years. Second, this significant increase of new HIV infections has occurred mainly in male students as HIV disproportionately impacts MSM [14]. Therefore, we conducted the survey in the context of colleges and gay organizations to efficiently reach sexually experienced male students.

All college students who were studying in the 44 colleges between September 2020 and November 2020 were invited to participate in the investigation. The inclusion criteria for participants were (1) students who were studying in the 44 colleges and (2) male students. The exclusion criteria were (1) people who were not students studying in the colleges, (2) people under 18 years, (3) female students, (4) foreign students, and (5) students who did not want to participate in the investigation. However, only male students who had a sexual experience in the previous year were incorporated into the analysis, and these sexually experienced male students had experiences of ejaculation before. The sample size was calculated based on a 7.6% and 19% HIV diagnosis risk for men who did not meet sexual partners on the internet and men who did respectively [8] (α=.05), which requires at least 290 participants.

Finally, 1045 sexually experienced male students completed the questionnaire and were incorporated into our analysis.

A paper-based questionnaire was used to collect related data among male college students; it was pretested and then revised based on the pretest. The following information was collected from the participants: sociodemographic characteristics (eg, age, education, residence, and years in school), sexual intercourse–related information (eg, sexual orientation, age at first sexual intercourse, and condom use), sexual intercourse–related behaviors in the past 6 months (eg, commercial, homosexual, and casual sexual intercourse and psychoactive drug use) and HIV and sexually transmitted disease (STD) knowledge. Years in school represents how many years it has been since a participant attended college. HIV and STD knowledge mainly represents college males’ understanding of the transmission routes and prevention methods for STDs such as HIV. HIV and STD knowledge was measured using the 18-item HIV Knowledge Questionnaire, which has been widely applied to HIV-related surveys in China and has been shown to have good validity [18], in addition to 4 questions measuring participants’ knowledge of other STDs, issued by the Hangzhou Center for Disease Control and Prevention. Responses were recorded as “true,” “false,” or “don’t know.” If the answer was correct, a score of 1 was assigned; a score of 0 was assigned if the answer was incorrect or a response of “don’t know” was provided. HIV and STD knowledge was measured by the total score, with a higher score indicating a higher level of HIV and STD knowledge.

Sociodemographic data from the male college students was analyzed using descriptive statistics with frequency and percentage. Risky sexual behavior was defined as having unprotected intercourse with 1 or more partners. Mann-Whitney U and Kruskal-Wallis tests were used to examine the differences regarding basic characteristics and risky sexual behaviors between men who meet sexual partners on the internet and those who do not. Moreover, sequential logistic regression models were employed to determine the independent influence of meeting sexual partners on the internet on unprotected intercourse with 1, 2, or more sexual partners (dependent variable) after controlling for other factors (eg, psychoactive drug use during intercourse, HIV knowledge, age, stage of study, years in school, field of study, residence, sexual orientation, and age at first intercourse). If the odds ratio (OR) is greater than 1, having the exposure increases the odds of engaging in the sexual risk behavior. The exposure decreases the odds of the sexual risk behavior if the OR is less than 1. All data analyses were completed using the statistical software SPSS (version 23.0; IBM Corp). Variables with P<.05 were considered statistically significant.

It is well known that the internet is a popular venue for MSM to seek sexual partners; for example, previous research has found that 40% of MSM used the internet to seek sexual partners [19-22]. However, besides this high-risk population, most college students also use the internet to find sexual partners [23], and this proportion was 51.9% (542/1045) among the sexually active male college students in our study. This is because nowadays, the universal use of smartphones and laptops allows young adults to spend more time in private to establish social relationships, including sexual relationships [24]. In addition, using the internet to find sexual partners is considered relatively anonymous and has a lower perceived risk of social rejection for sexually active people, especially those belonging to marginalized groups [25]. Indeed, in our study, we found that 79.2% (429/542) of students seeking a partner on the internet were homosexual or bisexual. Thus, it is not surprising that the free and generally nondiscriminatory space of the internet has become an appealing place for male college students to find sexual partners. In addition, compared to previous research which found that 33% of young people met sexual partners via the internet, our results showed a higher prevalence (542/1045, 51.9%) [26-29]. This may be because the participants in our study were sexually experienced male college students rather than the male students in general, which may lead to a higher proportion of participants using the internet to meet sexual partners. After analyzing web-based venues for meeting sexual partners using anonymous software, we found Momo, Tantan, Blued, and Aloha are the most commonly used (470/542, 86.7%) by male students with a high probability of risky sexual behaviors. This implies the importance of health promotion campaigns and interventions through these platforms, which are being used to find partners, especially for young students. Moreover, evidence has shown that integrating HIV prevention interventions into dating apps for MSM allows for the targeting of individuals who exhibit markers of risk in their profiles [30,31].

Men who reported meeting sexual partners on the internet also reported a higher frequency of psychoactive drug use and unprotected sexual intercourse compared with men who did not meet their partners on the internet. This result was consistent with previous studies [32]. But the high proportion of MSM among the sexually experienced males in our study may also lead to a high observed proportion of those who use psychoactive drugs. Indeed, evidence has also shown that up to 70% of MSM used psychoactive drugs [32]. Moreover, in our study, the association between meeting sexual partners on the internet and risky sexual behaviors remained significant even after adjusting for sociodemographic covariates and other HIV-related factors. However, it is unclear whether using the internet to meet sexual partners is a risk factor in itself or whether high-risk young adults tend to exhibit their risky sexual behaviors by meeting partners anonymously on the internet. But the internet is certainly an important venue for seeking partners for young adults; thus, awareness campaigns are urgent to target young college students who have recently met a new sexual partner on the internet.

We also found that risky sexual behaviors are more strongly associated with the purpose of finding a partner on the internet. For example, the likelihood of risky sexual behaviors was almost 30%-50% higher for those who find partners for sexual intercourse rather than romantic reasons. A study in Norway also suggested that associations between high-risk sexual behavior and seeking partners on the internet are more likely to be due to the individual’s aim for seeking partners using social media rather than all the related high-risk behaviors [33]. To maintain and promote the health, including reproductive health, of young people, it is also important to target high-risk sexual behaviors among male college students, especially bisexual male students who may transmit STDs to both men and women [34,35]. Further, HIV and STD knowledge was found to be an effective measure against risky sexual behavior [36]. However, the probability of risky sexual behaviors actually increased with a higher level of HIV and STD knowledge among male students who meet partners on the internet. This may be because although most young men are mindful of the risks of sexual behaviors [37,38], they may not always be aware of the consequences of their own risk-taking. In addition, sensation-seeking and a lack of impulse control among these young adults may also increase their likelihood of engaging in risky sexual behaviors [39]. Moreover, young people tend to focus on the benefits rather than the risks associated with engaging in sexual behaviors with partners they meet on the internet [40]; this leads to them feeling less vulnerable to the negative consequences associated with these behaviors. This may remind us that focusing on traditional education through knowledge inculcation (eg, teaching students about HIV transmission routes or risk factors for STDs) among male college students is not effective enough to reduce the likelihood of risky sexual behaviors, especially for students meeting partners on the internet. Instead, enhancing their awareness of the negative consequences of risky sexual behaviors may be effective. For example, this approach may involve communicating the negative effects of risky sexual behaviors on life, study, work, and social communication by interviewing HIV-positive students in the form of a video to deter students from engaging in high-risk sexual behaviors to some extent. To avoid the transmission of STDs by individuals with latent infections who do not know their HIV status, it is vital to increase HIV testing among high-risk college students. Furthermore, considering the continued high prevalence of risky sexual behaviors among people diagnosed with HIV, especially in low- and middle-income countries [41], it is urgent to increase surveillance of positive cases to reduce HIV transmission among college students. Simultaneously, treatment as prevention has been shown to be an effective way to reduce HIV incidence; thus, improving pretest and posttest counselling to promote adherence to highly active antiretroviral therapy is also important for HIV prevention [42].

Our study suggests that most sexually experienced male college students engage in sexual behaviors with partners they meet on the internet. Those who met partners on the internet exhibited higher levels of risky sexual behaviors although they had sufficient HIV and STD knowledge, especially those who sought partners for intercourse. Therefore, it is urgent to offer support to help young male students better assess the risks of sexual behaviors on the internet, especially those who aim to find sexual partners. However, the traditional method of health education by spreading knowledge seems ineffective to reduce the likelihood of risky sexual behaviors, especially for students meeting partners on the internet. Instead, enhancing their awareness of the negative consequences (eg, conveying the negative effects on life) of risky sexual behaviors may be effective to deter these high-risk students to some extent. Moreover, it is vital to strengthen HIV testing among sexually experienced college students to avoid transmission by those with latent infections who do not know their HIV status.

Our study has some limitations. First, considering the cross-sectional study design, the data can only provide an indication of the association between sexual partner–seeking on the internet and high-risk sexual behaviors. The causal relationship between these behaviors cannot be decided; that is, it is unclear whether meeting sexual partners via the internet is a risk in itself or whether high-risk young adults tend to exhibit their risky sexual behaviors by meeting partners anonymously on the internet. Second, due to the social desirability bias, the participants may have underreported related risk behaviors. Third, considering the sample consisted of sexually experienced male students and the study was conducted in the settings of colleges and gay organizations, the results cannot be generalized to the overall population of college students. Moreover, given the significant variation in cultures, economies, and traditions across China, data from one province are unlikely to be nationally representative. Furthermore, future studies should pay more attention to the effects of possible endogenous variables influencing high-risk sexual behaviors.