The differential impacts of early detection and accelerated antiretroviral therapy on the epidemiologic trend of sexually acquired HIV infection in Hong Kong

Objectives

To assess impacts of early detection and prompt antiretroviral therapy (ART) on the latest epidemiologic situation to inform intervention strategy.

Methods

We analysed data from two clinical cohorts in Hong Kong where sexual transmission accounted for the majority of HIV infections. The two cohorts comprised patients newly diagnosed in 2007–2008 and 2016–2018 respectively. Secular trend and differences between men who have sex with men (MSM) and heterosexual patients were examined. Predictors of late presentation (defined as CD4 ≤350 or AIDS-defining illness within 3 months of diagnosis) and prolonged interval between diagnosis and ART initiation were assessed by multivariable regressions.

Results

There were 1,136 newly diagnosed HIV patients with 644 in the first and 492 in the second cohort, a majority (91.7%) presented with sexually acquired infection. There were less MSM in the first than the second cohort (50.3%% vs 87.8%, χ2 = 117.05, p<0.001). The mean (SD) number of days between diagnosis and ART initiation decreased from 514.3 (516.1) to 61.8 (94.2) days across the two cohorts. Younger age, non-Chinese, outpatient-based service and lower CD4 count were predictors of faster ART initiation in the first but not in the second cohort. Interval between diagnosis and ART initiation became highly uniform among groups in the second cohort. Nearly 60% were classified as late presenters in both cohorts. Heterosexuals (aOR 1.58, 95% CI 1.13–2.19) had a higher risk of late presentation.

Conclusions

There was remarkable improvement in acceleration of ART initiation. Clinical implementation of accelerated ART recommendations has been effective for both MSM and heterosexuals. Late presentation was more marked among heterosexuals and remained a problem. The continued phenomenon of late presentation could offset the epidemiologic gains from accelerated ART initiation.

Incorporation of Estimated Community Viral Load Before HIV Diagnosis for Enhancing Epidemiologic Investigations: A Comparison Between Men Who Have Sex With Men and Heterosexual Men in Hong Kong

Currently, no studies have specifically incorporated population-level viral load measures for analyzing temporal trends of HIV infection in the Asia Pacific. With the use of longitudinal data from 950 HIV-infected heterosexual male and 1331 men who have sex with men managed at a major HIV clinic in Hong Kong between 1985 and 2012, viral load changes at population levels were compared. We back-calculated seroconversion year of each diagnosed patient and estimated the population-level viral load under the framework recommended by the Centers for Disease Control and Prevention. Full community viral load, a newly designed measure incorporating diagnosed and undiagnosed HIV-infected patients, was 3 to 8 times higher than community viral load derived from diagnosed patients only. The growth curve of full community viral load was 5 years ahead of other viral load measures, the shape of which lent support to the phenomenon of local transmission of men who have sex with men but not among heterosexual male in the predominantly Chinese HIV community in Hong Kong.

Risk of HIV infection among men having sex with men in Kathmandu Valley, Nepal

Despite extensive distribution of free condoms and lubricants to prevent HIV transmission among men having sex with men (MSM) in Nepal, the prevalence of HIV and risky sexual behaviors remain high. The influence of individual-level, social-capital, and social-structural factors on HIV risk has been insufficiently explored in MSM. The authors assessed association of these factors with HIV risk among 150 MSM enrolled using snowball sampling in the Kathmandu Valley. HIV risk was calculated on the basis of number and type of sexual partners and condom use during anal sex. Multivariate analysis showed a high risk of HIV infection was significantly associated with being involved in sex work, having no knowledge of male sexually transmitted infection (STI) symptoms, and having a history of STI symptoms. HIV prevention could be made more effective by targeting MSM who are involved in sex work and by improving their knowledge of male STI symptoms and early diagnosis and treatment.