The Internet provides new opportunities for sexual minorities to communicate and interact. Access to internet may facilitate coming-out for young MSM, sexual identity formation, and community building. On the other side the internet partly substitutes social and sexual venues where MSM congregate. Population and individual level aspects of internet communication among MSM were analysed based on data collected in the European MSM Internet Survey (EMIS).

EMIS was a large collaborative project of public health, academia and community based organisations from 35 European countries. The survey was online from June through August 2010, advertised on a large range of MSM websites. The questionnaire anonymously collected data from MSM across Europe. Among others, detailed information on the last sexual intercourse with a non-steady partner was collected.

The analysis is based on 174,209 eligible respondents. Participation rates in 38 countries with more than 100 respondents varied considerably (0.3 – 6.8/10,000 inhabitants) and correlated with internet access. A comparison of self-reported new diagnoses of HIV and national surveillance data suggests different relative sizes of MSM populations in different countries. Among men reporting a non-steady sex partner in the last 12 months, 58% had met this partner on the internet. Compared with partners met in venues, serostatus communication with internet partners was more frequent, respondents more often already had sex with their internet partners before, and partners were more often presumed HIV seroconcordant. Contrastingly, refraining from anal sex was less often an option for partners met on the internet.

Improved access to internet may increase the relative size of MSM populations by involving a larger number of individuals into sexual networks. With broadening access to internet risk reducing aspects like increased communication before sexual encounters become more pronounced. Promoting protective and preventive behaviours can counter adverse effects of the internet on the HIV epidemic.