Global, regional, and national burdens of HIV and other sexually transmitted infections in adolescents and young adults aged 10–24 years from 1990 to 2019: a trend analysis based on the Global Burden of Disease Study 2019

Sexually transmitted infections (STIs), including HIV, are major sexual health issues among adolescents and young adults globally, but data on the burden and trends of these diseases are sparse. We aimed to assess the trends in the burden of HIV and other STIs among adolescents and young adults aged 10-24 years from 1990 to 2019 on the global, regional, and national level.In this trend analysis based on the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we reported on the number, rates per 100 000 population, and average annual percentage changes (AAPCs) of incidence and disability-adjusted life-years (DALYs) of HIV and other STIs (syphilis, chlamydia, gonorrhoea, trichomonas, and genital herpes) at the global, regional, and national level among individuals aged 10-24 years. We further analysed these global trends by age, sex, and social development index (SDI). We also used joinpoint regression analysis to identify the year with the most substantial changes in global trends.Globally, the incidence of HIV among adolescents and young adults decreased from 34·5 per 100 000 population (95% uncertainty interval [UI] 29·3 to 39·7) in 1990 to 22·7 per 100 000 population (20·3 to 25·8) in 2019, AAPC -2·6 [95% CI -3·1 to -2·0]); specific years in which HIV incidence decreased significantly were 1998, 2005, and 2014. Incidence of other STIs increased from 6986·3 per 100 000 population (95% UI 5504·8-8645·0) in 1990 to 7088·7 100 000 population (5620·1-8697) in 2019 (AAPC 0·2 [95% CI 0·1-0·3]); we found a substantial decrease in the incidence of other STIs in 2011 only. The rate of decrease in the incidence of other global STIs between 2009 and 2019 was approximately one-fifth the rate of the decrease in the global incidence of HIV for the same time period (AAPC -0·7 [95% CI -0·8 to -0·7] vs AAPC -3·4 [-3·8 to -3·1]). Regionally, sub-Saharan Africa had the highest incidence and highest DALYs from HIV and other STIs, and Oceania and Eastern Europe had the largest increase in the incidence and DALYs from HIV and other STIs between 1990 and 2019. By SDI quintile, the middle-SDI countries had the largest increase in HIV incidence between 1990 and 2019 and the DALYs from other STIs in the same period decreased in all SDI quintiles. Globally, females accounted for 278 076 (65·8%) of the 0·42 million incident HIV cases in 2019 and 68 115 077 (51·6%) of the 132·0 million incident cases of other STIs. Of all age groups, adolescents aged 10-14 years had the largest increase in the incidence of other STIs between 1990 and 2019 (from 1158·9 per 100 000 population [95% UI 857·8-1556·5] in 1990 to 1215·4 per 100 000 population [893·5-1616·1] in 2019; AAPC 0·1 [95% CI 0·1-0·2]). The individual STIs with the highest incident rates varied between age groups and sex.Global HIV incidence among adolescents and young adults decreased between 1990 and 2019, with significant decreases coinciding with the implementation of antiretroviral therapy and pre-exposure prophylaxis. The incidence of other STIs in this population increased over the same period and only started decreasing in 2011, at a rate of only one-fifth of the rate of decrease of HIV. Earlier sexual health education and targeted STI screening are urgently required for adolescents and young adults.National Natural Science Foundation of China and the China Postdoctoral Science Foundation.