Objective To investigate the epidemiological characteristics of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) transmitted through sexual contact in men aged 50 and above in Shandong province and provide evidence for the development of targeted intervention measures for middle-aged and elderly men.

Methods Face-to-face questionnaire survey was conducted in randomly selected HIV-infected men aged 50 and above reported in Shandong province from 2013 to 2023. Information about their sociodemographic characteristics, sexual behaviours, and HIV testing results was collected. The cases were divided into two groups based on homosexual and heterosexual transmission patterns and the associated characteristics were analyzed.

Results  In 313 HIV-infected men aged 50 and above who completed this investigation, and 73.16% were transmitted through homosexual contact. Multivariate logistic regression analysis showed that the cases with stable job had higher proportion of homosexual transmission than those who were farmers and others(OR=7.93, 95%CI:2.25−27.95). The cases who were divorced or widowhood had higher proportion of homosexual transmission than those who were married (OR=2.65, 95%CI:1.30−5.40) . The cases with education level of junior high school had higher proportion of homosexual transmission than those with education level of primary school or below(OR=2.17,95%CI:1.04−4.53). Compared with the cases with local residency, those with residensy in other areas in Shandong province (OR=10.49, 95%CI:1.25−88.27) and in other provinces (OR=4.56, 95%CI:1.07−19.48) had higher proportions of homosexual transmission. The cases who had history of group living (OR=3.03, 95%CI:1.44−6.39) and history of sexually transmitted disease(STD) (OR=3.54,95%CI:1.32−9.54) had higher proportions of homosexual transmission.

Conclusion There were difference in characteristics of HIV/AIDS cases aged 50 and above and transmitted through homosexual and heterosexual contacts. Higher educational level, history of living with more than one man, history of STD and living in other areas were associated with higher proportion of homosexual transmission. Targeted educational and intervention measures should be taken for the high-risk groups with different characteristics.