Using risk-tracing snowball approach to increase HIV case detection among high-risk populations in Cambodia: an intervention study

Snowball Sampling Study Design for Serosurveys Early in Disease Outbreaks

Serological surveys can provide evidence of cases that were not previously detected, depict the spectrum of disease severity, and estimate the proportion of asymptomatic infections. To capture these parameters, survey sample sizes may need to be very large, especially when the overall infection rate is still low. Therefore, we propose the use of "snowball sampling" to enrich serological surveys by testing contacts of infected persons identified in the early stages of an outbreak. For future emerging pandemics, this observational study sampling design can answer many key questions, such as estimation of the asymptomatic proportion of all infected cases, the probability of a given clinical presentation for a seropositive individual, or the association between characteristics of either the host or the infection and seropositivity among contacts of index individuals. We provide examples, in the context of the coronavirus disease 2019 (COVID-19) pandemic, of studies and analysis methods that use a snowball sample and perform a simulation study that demonstrates scenarios where snowball sampling can answer these questions more efficiently than other sampling schemes. We hope such study designs can be applied to provide valuable information to slow the present pandemic as it enters its next stage and in early stages of future pandemics.

Increasing the HIV testing among MSM through HIV test result exchange mechanism: study protocol for a cluster randomized controlled trial

Background

HIV testing is an essential gateway to HIV prevention and treatment thus controlling the HIV epidemic. More innovative interventions are needed to increase HIV testing among men who have sex with men (MSM) since their testing rate is still low. We proposed an online HIV test results exchange mechanism whereby the one without a certified online HIV report will be asked to test HIV for exchanging HIV report with others. The exchange mechanism is developed as an extension to the existing online HIV testing service system. Through the extended system, MSM can obtain certified online HIV reports and exchange their reports with friends via WeChat. This study aims to assess effectiveness of the exchange mechanism to increase the HIV testing rate among MSM.

Methods

This study will use a cluster randomized controlled trial (RCT) design. Participants are recruited based on the unit of individual social network, the sender and the receivers of the HIV report. An individual social network is composed of one sender (ego) and one or more receivers (alters). In this study, MSM in an HIV testing clinic are recruited as potential egos and forwarded online reports to their WeChat friends voluntarily. Friends are invited to participate by report links and become alters. Ego and alters serve as a cluster and are randomized to the group using the certified online HIV report with exchange mechanism (intervention group) or without exchange mechanism (control group). Alters are the intervention targeting participants. The primary outcome is HIV testing rate. Other outcomes are sexual transmitted infections, sexual behaviors, HIV testing norms, stigma, risk perception and HIV report delivery. The outcomes will be assessed at baseline and follow-up questionnaires. Analysis will be according to intention to treat approach and using mixed-effect models with networks and individuals as random effects.

Discussion

This is the first study to evaluate the effectiveness of an HIV test result exchange mechanism to increase the HIV testing among MSM. This assessment of the intervention will also provide scientific evidence on other potential effects. Findings from this study will yield insights for sustainability driven by communities' intrinsic motivation.

Trail registration: ClinicalTrials.gov NCT03984136. Registered 12 June 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06484-y.

A scoping review of HIV epidemiologic, sociocultural and programmatic studies related to transgender women and men who have sex with men in Cambodia, 1999-2019

Background

Cambodia is widely credited for its successful HIV epidemic control. However, in recent years there have been signs of increasing HIV prevalence among men who have sex with men (MSM) and transgender women (TGW). This paper reviews HIV epidemiological, social science and HIV program implementation studies conducted over the past 20 years to explore possible reasons for the rising HIV prevalence among these groups and to formulate recommendations for improved policies, HIV programmatic interventions and further research.

Methods

For this scoping review, we searched the PubMed and Google Scholar databases for scientific publications related to HIV and MSM and TGW in Cambodia published since 1999. From each of the returned citations we subsequently studied reference lists to find additional data sources. We also searched websites for reports commissioned by national and international governmental and non-governmental organizations.

Results

Twenty-seven relevant studies and papers were found and reviewed; most were epidemiological in nature. Recent epidemiological studies and reports show an increase in HIV prevalence among Cambodian MSM and TGW. The epidemiology of HIV infection in these groups has been relatively well-described and analyzed. While initially MSM and TGW were grouped together, in more recent years they have been studied in their own right, recognizing their specific HIV and other prevention needs. Few studies were found investigating Cambodian same-sex cultures and social and cultural contexts in which HIV transmission among MSM and TGW occurs. A few evaluation studies were found, but it remains unknown how effective current HIV service implementation modalities are, or how successful strategies to increase access to essential HIV prevention, testing and treatment services have been employed for MSM and TGW in Cambodia.

Conclusions

Research about Cambodian MSM and TGW in the context of HIV primarily concerns bio-behavioral knowledge generation. Cambodia is unlikely to achieve control of the HIV epidemic among MSM and TGW without doing better in-depth social science research on its multiple sexual- and gender minority cultures, and without understanding what differentiated implementation modalities, strategies and approaches are most effective to address HIV among its increasingly diverse MSM and TGW populations.

Biometrics and public health surveillance in criminalised and key populations: policy, ethics, and human rights considerations

Widespread public health surveillance efforts focused on key populations (men who have sex with men, sex workers, people who inject drugs, and others) gather data on population sizes, HIV prevalence, and other information for planning and resource allocation. Biometric identification might improve this data gathering. However, in the context of extensive criminalisation of these populations, the use of biometrics such as fingerprints raises concerns that are insufficiently addressed in current policies. These concerns include infringing privacy, exposing participants to risks of legal action or violence, biasing surveillance results, and undermining trust in the health system. We set out key ethics and human rights considerations regarding the use of biometrics in HIV surveillance among these populations, and outline a typology of jurisdictions wherein such methods might be considered, based on data about legal, political, and social environments. In this Review, we suggest that the biometrics approach is not currently likely to be appropriate in many jurisdictions.