HIV and STI testing coverage stays low in Hong Kong as age and sex shape preferences

Only 40 percent of sexually experienced adults in Hong Kong who reported higher-risk sexual behaviour had ever been tested for HIV or a sexually transmitted infection, according to a prospective population-based study conducted between 2021 and 2023. The finding comes from a two-wave survey of 1,112 heterosexual adults recruited by geographically clustered random sampling, with free self-sampled STI testing offered at baseline and at one-year follow-up. The study, published in Archives of Public Health, set out to profile testing patterns and preferences across the general population in order to inform the service strategies needed to pursue the World Health Organization’s 2030 targets for public health control of HIV and STIs.

The cohort included 680 female and 432 male participants, all of whom were sexually experienced. Around 73 percent of the female participants and 75 percent of the male participants reported being sexually active in the previous year. Higher-risk sexual behaviour was defined in the study as any concurrent sexual partnership, commercial sex, or more than four sex partners within the past year. By this definition, 28 percent of women aged 18 to 24 reported higher-risk behaviour, as did more than 30 percent of men in the 18 to 24, 40 to 49, and 60 to 69 age groups. Elevated risk was therefore not confined to the youngest participants but appeared in distinct bands across the male age range.

Testing history lagged well behind this risk profile. Among individuals with higher-risk sexual behaviour, only 40 percent had ever been tested for HIV or STI, and coverage was even lower among older adults within that group. Younger age and male sex were significantly associated with having undergone an HIV test, while older adults and women were less likely to have done so. For STI testing specifically, the study found no significant difference by age or sex. Roughly 10 percent of all participants reported a history of STI diagnoses, including genital warts, chlamydia and gonorrhoea, and 89 percent of those diagnoses had occurred more than two years before the survey.

Awareness of where testing could be obtained was another weak point. More than half of the participants were unaware of HIV and STI testing venues. When participants did weigh up testing, cost and privacy emerged as common factors affecting their decisions, and the weight of these considerations varied across age groups. Service preferences diverged along the same lines. Older adults preferred testing in physical venues with healthcare professionals, whereas younger adults preferred non-governmental organisations and online test kits. The authors conclude that testing intention and service preference varied by age, suggesting that different types of testing services are needed if coverage is to be scaled up.

The study also tested whether offering free self-sampled STI testing could convert stated risk into actual testing behaviour. Among participants who reported higher-risk sexual behaviour but had never been tested for STI, some 40 percent submitted their samples for STI testing at baseline and/or follow-up. The authors interpret this as evidence that self-sampled testing could capture additional higher-risk never testers, a group that conventional venue-based services had evidently failed to reach, given the low lifetime testing coverage documented in the same cohort.

Methodologically, the study followed a prospective design with a baseline online survey conducted in 2021 to 2022 and a one-year follow-up survey in 2022 to 2023, supplemented by the offer of free self-sampled STI testing. Factors associated with testing history were examined using multivariable logistic regression, which allowed the researchers to estimate the independent contributions of age, sex and risk behaviour while adjusting for other variables in the model. The sample was restricted to heterosexual, sexually experienced individuals in Hong Kong, so the findings describe that population and do not extend to men who have sex with men or to other settings. Because the sample was recruited through geographically clustered random sampling rather than from clinics, it offers a view of testing coverage in the community rather than among service users.

The results arrive against the backdrop of the World Health Organization’s 2030 targets for public health control of HIV and STIs, which the authors identify as requiring high testing coverage of the population at risk. The Hong Kong data suggest that this precondition is currently unmet among the very people whose behaviour places them at elevated risk. The combination of low lifetime testing, low awareness of testing venues, and age-graded preferences for how testing is delivered points, in the authors’ assessment, toward a diversified service model: physical clinical venues for older adults, and NGO-based and online self-sampling options for younger adults, with self-sampled testing serving as a route into testing for higher-risk individuals who have never been screened.

The study’s own framing is measured. It documents coverage, associations and preferences in one city over a defined two-year window, and it identifies self-sampled STI testing as a mechanism that reached a substantial minority of previously untested higher-risk participants within the study period. It does not claim that self-sampling alone would close the coverage gap, nor does it report long-term outcomes of the testing it facilitated. What it does establish is a quantified baseline: in this Hong Kong population sample, higher-risk behaviour was spread across age and sex groups in distinctive patterns, lifetime HIV and STI testing among those at higher risk stood at 40 percent, and the levers that might raise that figure, from venue awareness to privacy, cost and delivery mode, differed systematically by age.

Subject of Research: HIV and STI testing coverage and service preferences in the general adult population of Hong Kong

Article Title: Variability of HIV/STI testing coverage and preferences as differentiated by age, sex and risk behaviours – a prospective population-based study in Hong Kong, 2021–2023

Article References: Wong, N. S., Chung, S. L., Wong, E. L.-Y., Tam, Z. P.-Y., Cheung, A. W.-L., Wang, Z., Li, C., Chan, D. P.-C., & Lee, S. S. (2026). Variability of HIV/STI testing coverage and preferences as differentiated by age, sex and risk behaviours – a prospective population-based study in Hong Kong, 2021–2023. Archives of Public Health. https://doi.org/10.1186/s13690-026-02117-5

Image Credits: AI Generated

DOI: 10.1186/s13690-026-02117-5

Keywords: HIV testing, STI testing, Hong Kong, population-based study, self-sampled testing, sexual health, higher-risk behaviour, testing coverage, age differences, public health, WHO 2030 targets, Variability