Objective  To understand sex ratio of newly reported people living with HIV/AIDS (PLWHA) aged ≥50 years and infected through heterosexual contact in China during 2015 and 2019.

  Methods  The data of newly reported PLWHA aged ≥50 years and infected through heterosexual contact in China from 2015 to 2019 were collected from the China Information System for Disease Control and Prevention. Sex ratios of the PLWHA were analyzed in terms of diagnosis age and infection mode.

  Results  From 2015 to 2019, the number of newly reported PLWHA aged ≥50 years and infected through heterosexual contact increased from 29 765 to 60 591. Among them, the proportion of those infected through sex with spouse/regular partners decreased from 12.7% to 10.6%, while the proportions of those infected through commercial and non-commercial casual sex remained at high levels (46.0% and 39.5% averagely). Τhe sex ratios of the PLWHA increased from 1.8 in 50−59 year age group to 2.5 in 60−69 year age group and 6.8 in ≥70 year age group. With the increase of diagnosis age, sex ratios of the PLWHA infected through commercial and non-commercial casual sex increased from 10.4 and 1.1 in 50−59 year age group to 58.7 (Z=38.31, P<0.001) and 3.4 (Z=51.49, P<0.001) in ≥70 year age group respectively, but the sex ratio of those infected through sex with spouse/regular sexual contact remained at 0.2−0.4.

  Conclusion  In China, the differences in sex ratio existed in the reported PLWHA aged ≥50 years and infected through heterosexual contact in different age groups and infection mode groups. It is suggested to expand HIV testing, treatment and integrated behavioral intervention for high-risk populations, and utilize molecular epidemiology to explore HIV transmission chain in people aged ≥50 years to improve the efficiency of case detection.