Expanded antiretroviral treatment, sexual networks, and condom use: Treatment as prevention unlikely to succeed without partner reduction among men who have sex with men in China

Assessing Direct and Spillover Effects of Intervention Packages in Network-randomized Studies

BACKGROUND

Intervention packages may result in a greater public health impact than single interventions. Understanding the separate impact of each component on the overall package effectiveness can improve intervention delivery.

METHODS

We adapted an approach to evaluate the effects of a time-varying intervention package in a network-randomized study. In some network-randomized studies, only a subset of participants in exposed networks receive the intervention themselves. The spillover effect contrasts average potential outcomes if a person was not exposed to themselves under intervention in the network versus no intervention in a control network. We estimated the effects of components of the intervention package in HIV Prevention Trials Network 037, a Phase III network-randomized HIV prevention trial among people who inject drugs and their risk networks using marginal structural models to adjust for time-varying confounding. The index participant in an intervention network received a peer education intervention initially at baseline, then boosters at 6 and 12 months. All participants were followed to ascertain HIV risk behaviors.

RESULTS

There were 560 participants with at least one follow-up visit, 48% of whom were randomized to the intervention, and 1,598 participant visits were observed. The spillover effect of the boosters in the presence of initial peer education training was a 39% rate reduction (rate ratio = 0.61; 95% confidence interval = 0.43, 0.87).

CONCLUSIONS

These methods will be useful for evaluating intervention packages in studies with network features.

Assessing Direct and Spillover Effects of Intervention Packages in Network-Randomized Studies

Intervention packages may result in a greater public health impact than single interventions. Understanding the separate impact of each component in the overall package effectiveness can improve intervention delivery. We adapted an approach to evaluate the effects of a time-varying intervention package in a network-randomized study. In some network-randomized studies, only a subset of participants in exposed networks receive the intervention themselves. The spillover effect contrasts average potential outcomes if a person was not exposed themselves under intervention in the network versus no intervention in a control network. We estimated effects of components of the intervention package in HIV Prevention Trials Network 037, a Phase III network-randomized HIV prevention trial among people who inject drugs and their risk networks using Marginal Structural Models to adjust for time-varying confounding. The index participant in an intervention network received a peer education intervention initially at baseline, then boosters at 6 and 12 months. All participants were followed to ascertain HIV risk behaviors. There were 560 participants with at least one follow-up visit, 48% of whom were randomized to the intervention, and 1,598 participant-visits were observed. The spillover effect of the boosters in the presence of initial peer education training was a 39% rate reduction (Rate Ratio = 0.61; 95% confidence interval= 0.43, 0.87). These methods will be useful to evaluate intervention packages in studies with network features.

Treatment as Prevention: Concepts and Challenges for Reducing HIV Incidence

Four of the largest HIV prevention trials have been conducted in sub-Saharan Africa, enrolling hundreds of thousands of participants in catchment areas of millions of people. The trials have focused on community-level interventions to increase diagnosis and initiation of antiretroviral therapy (ART) to improve health and reduce HIV transmission. Universal test-and-treat strategies are deployed to achieve viral suppression thereby reducing risk to uninfected persons, known as treatment as prevention (TasP).

Protecting Men Who Have Sex With Men From HIV Infection With an mHealth App for Partner Notification: Observational Study

Background

Traditional partner notification methods have been implemented for HIV-infected patients, as well as HIV treatment, in order to identify people at risk of HIV infection, especially men who have sex with men (MSM), since they are more likely to have casual sex partners. These traditional methods have some limitations.

Objective

Our study focused on developing an mHealth app to improve partner notification in practice for MSM; the study then focused on evaluating the effects of the app.

Methods

We developed an mHealth app with different modules using Java and HTML5 and tested it in an MSM community to prevent HIV transmission. The HIV incidence stratified by different follow-up periods were calculated. Poisson regression and social networks were used to estimate the risk ratios and to identify the connection among MSM, respectively.

Results

In addition to the partner notification module, which is the kernel of the app, we developed a test result self-query module to enable MSM to get their approved test results in a timely manner, a prompt and warning module to alert users to protect themselves from high-risk conditions, and a health education module to teach users more skills regarding HIV/AIDS prevention. Over a 1-year duration, a total of 3186 MSM used the app, of which 678 had at least two HIV test results since becoming app users; they were included in the final analysis. Among 678 users, a total of 6473 self-queries and 623 partner notifications were recorded, which identified 180 social networks of MSM app users. Those who used the partner notification function were more likely to have self-queries (P<.001). The 678 MSM app users covered 296.47 person-years and contributed to 20 HIV seroconversions; the cumulative HIV infection incidence was estimated as 6.75 per 100 person-years (95% CI 4.38-10.01). We found that the longer the app was used, the lower the HIV incidence (>5 months vs ≤5 months: 2.22 per 100 person-years vs 6.99 per 100 person-years; risk ratio 0.32, 95% CI 0.12- 0.87).

Conclusions

The app developed in this study is consistent with the World Health Organization’s sensitivity and confidentiality recommendations; it has the potential to reduce the risk of HIV infection among MSM.

Interventions to improve the HIV continuum of care in China

PURPOSE OF REVIEW

To describe HIV epidemic and interventions for improving HIV continuum of care in China.

RECENT FINDINGS

The reported HIV epidemic has been continuously increasing, partially due to the expansion of active HIV testing campaign. Public health intervention programs have been effective in containing HIV spread among former plasma donors and people who inject drugs (PWID), but more infections occur among heterosexual men and women and young men who have sex with men. Of 1.25 million Chinese people are living with HIV, one-third do not know their status. About two-thirds of diagnosed individuals have used antiretroviral therapy (ART) and two-thirds of those on ART have achieved viral suppression, but some risk groups such as PWID have lower rates. The national free ART program has reduced adult and pediatric mortality and reduced heterosexual transmission. China faces great challenges to reduce HIV sexual transmission, improve the HIV continuum of care, and close the gaps to the UNAIDS Three "90" Targets.