Towards Targeted Interventions in Low- and Middle-Income Countries: Risk Profiles of People Who Inject Drugs in Haiphong (Vietnam).

People who inject drugs (PWID) are a dominant risk group afflicted by blood-borne viruses, mental health disorders, and social precariousness. Risk reduction interventions are administered to PWID regardless of their characteristics or specific risks. The objective of this cross-sectional analysis was to empirically identify profiles of PWID regarding their drug use, risk behaviors, and mental health in order to tailor adapted interventions taking into account limited access to comprehensive care in middle-income countries. PWID were recruited using respondent-driven sampling. PWID with urine testing positive for heroin or methamphetamine and manifesting recent skin injection marks were enrolled. Classification of participants was based on drug use, injection, risky sexual behavior, and mental health data. This was subjected to multiple correspondence analysis followed by hierarchical cluster analysis combined with K-means methodology. From October 2016 to January 2017, 1490 participants were recruited of which 1383 were eligible and enrolled. HCV prevalence was 70.5% and HIV prevalence 29.4%. The cluster analysis identified five distinct profiles: profile 1: recent injection practices and high alcohol consumption, profile 2: at-risk injection and sexual behaviors with precarious situations, profile 3: no sexual activity and older age, profile 4: frequent injections with high methamphetamine use, and profile 5: stable partnerships and less frequent injections. Our study has identified profiles of PWID at particularly high risks, and they should thus be targeted for interventions tailored to their specific risks.

Increased Methamphetamine Use among Persons Who Inject Drugs in Hai Phong, Vietnam, and the Association with Injection and Sexual Risk Behaviors.

Methamphetamine use has increased significantly in Southeast Asia in the last 5-10 years, but there is little research on risk behaviors associated with the increase in this region. We evaluate injection and sexual risk behaviors associated with current methamphetamine use among heterosexual persons who inject drugs (PWID) in Hai Phong, Vietnam. We recruited 1336 PWID and assessed associations between methamphetamine use, injection and sexual risk behaviors, stratified by HIV serostatus. There were several statistically significant associations between methamphetamine use and sexual risk behaviors among HIV-positive PWID, but we did not find any associations between methamphetamine use and injection risk behaviors. Methamphetamine may increase the likelihood of PWID transmitting HIV to non-injecting primary sexual partners, as it can reduce ART adherence and can lead to weakening of the immune system and increased HIV viral loads. All participants were injecting heroin, and methamphetamine use may interfere with opiate use treatment. Public health efforts should focus on the large increase in methamphetamine use and the associated sexual risk behaviors. Emphasis on sexual risk behavior, particularly among those who are HIV-positive, in conjunction with continued monitoring of ART adherence and HIV viral loads, is critical.

Using dual capture/recapture studies to estimate the population size of persons who inject drugs (PWID) in the city of Hai Phong, Vietnam.

BACKGROUND: Good estimates of key population sizes are critical for appropriating resources to prevent HIV infection. We conducted two capture/recapture studies to estimate the number of PWID currently in Hai Phong, Vietnam. METHODS: A 2014 respondent-driven sampling (RDS) survey served as one capture, and distribution of cigarette lighters at drug use "hotspots" in 2016 served as another "capture." A 2016 survey using RDS, conducted 1 week after lighter distribution, served as "recapture" for both captures. Recaptured participants in the two surveys were identified with a computerized fingerprint reader. Recaptured participants from the lighter distribution were asked to show their lighters. RESULTS: 1385 participants were included in the "recapture" survey. They were 94% male and had a median age of 39. All (100%) injected heroin, and HIV prevalence was 30%. 144 of the 603 participants in the 2014 survey and 152 of the 600 PWID who had received lighters were "recaptured" in the 2016 survey. After adjusting for police suppression of drug use hotspots and conducting sensitivity analyses, our best estimate of the population size from the lighter recapture was 4617 (95% CI: 4090-5143), and our best estimate from the 2014 survey recapture was 5220 (95% CI: 4568-5872). A combined best estimate of the PWID population in Hai Phong is 5000, range 4000-6000. CONCLUSIONS: The capture/recapture studies produced consistent estimates. Adding a lighter/token distribution to planned RDS surveys may provide an inexpensive method for estimating PWID population size. Analyses of the estimates should include contextual information about the local drug scene.