HIV incidence is below 0.1% per year among people who inject drugs in a large Vietnamese city, Professor Don Des Jarlais and colleagues report in the December issue of AIDS. They say the data clearly demonstrate that it is possible to achieve very low HIV incidence – ‘to end an HIV epidemic’ – among people who inject drugs in a middle-income country.
Background
While many high-income settings have shown that combination programmes for people who inject drugs (providing sterile syringes, opioid substitution treatment and HIV treatment) can reduce HIV incidence in this population, evidence was scarce that such programmes would have the same success in low- or middle-income settings such as Vietnam.
Vietnam experienced a heroin injecting epidemic in the 1970s, followed by an HIV epidemic among people who inject drugs in the early 2000s, with HIV prevalence as high as 60% in the city of Hai Phong in 2006.
In 2013, Vietnam’s policy towards drug users began to shift from a punitive system of compulsory drug detention centres to a programme of voluntary, community-based substance use treatment. Methadone maintenance treatment, access to sterile syringes and antiretroviral therapy (ART) for all people with HIV were scaled up by the authorities.
While funding from international donors has decreased in recent years, the national and provincial governments and increased their financial support. Hai Phong is the country’s fourth largest city and is one of the locations where interventions for drug users were implemented early and at scale.
Methadone maintenance treatment has been available since 2008, with approximately 4000 people receiving treatment at any one time in Hai Phong. To put this figure in context, there are estimated to be around 5000 current injecting drug users not receiving methadone.
Sterile syringes are readily available, primarily from local pharmacies. People who inject drugs are estimated to obtain an average of 450 syringes a year, which is 50% higher than the ‘high’ level recommended by UNAIDS.
Antiretroviral treatment for all people with HIV began to be implemented in 2016.
By 2018, the UNAIDS technical guidelines for combined prevention and care for people who inject drugs were fully implemented in Hai Phong.
The study
In order to assess how effective these measures were in terms of reducing HIV incidence among people currently injecting drugs in Hai Phong, investigators conducted four large community-based surveys, each year from 2016 to 2019. Eligible participants were adults with evidence of recent injection drug use, with recruitment via referral from peers. Participants were allowed to respond to several of the annual surveys, but only once in any year.
The surveys recruited 1383 participants in 2016, 1451 in 2017, 1444 in 2018 and 1268 in 2019.
Results
Around 95% of participants were male, a majority were married or living as married and their mean age was 40 years. All reported injecting heroin, which was verified by testing urine samples. Metamphetamine was also used by over 40% of participants, but primarily by ‘smoking’ (inhaling the drug after heating it). Less than 2% of metamphetamine users reported injecting it. Most participants reported obtaining an average of more than one syringe per day.
Over time, HIV prevalence declined modestly (30% to 26%) while hepatitis C prevalence remained stable (71% to 73%).
Comparing the surveys from 2016 to 2019, there were statistically significant changes in several indicators of engagement with health services and risk behaviour.
- Use of methadone (based on testing urine samples) increased from 42% to 61% (p<0.001).
- The percentage of HIV-positive participants receiving ART increased from 52% to 86% (p<0.05).
- The proportion reporting daily or more frequent heroin injection declined from 80% to 62% (p<0.05).
- The percentage reporting syringe sharing in the last six months was low and declined from 5% to 2% (p<0.05), although the researchers acknowledge that some respondents may have been reluctant to admit this behaviour to researchers.
- The proportion of people who inject drugs most likely to transmit HIV through syringe sharing – those who are HIV-positive, not on ART and sharing syringes – was very low, and declined over time (0.7% to 0.1%, p<0.05).
HIV incidence (new HIV infections) was measured in three ways. Rates were very similar and low by each method.
- Among survey participants taking their first HIV test, HIV recency testing was used to identify seroconversions in the previous six months. There were zero new infections, based on data for 2569 people and 1285 years at risk.
- Among people taking part in multiple surveys, there were zero new infections in 418 people during 696 years at risk.
- A cohort of survey participants was recruited to join a programme offering methadone maintenance treatment and other support. This cohort was tested for HIV every six months. There were three new infections in 807 people during 1483 years at risk.
The overall incidence rate, based on the three infections in 2569 individuals during a total of 3464 years at risk, was 0.085% (95% confidence interval 0.02 – 0.25).
“Methadone maintenance treatment, access to sterile syringes and antiretroviral therapy (ART) for all people with HIV were scaled up by the authorities.”
The investigators had further information on two of the three HIV seroconversions. One occurred when the participant engaged in a new drug use/sexual relationship with a partner who did not disclose their HIV status. The second occurred shortly after the participant was released from drug detention: a period that is well-known for being high risk for HIV infection and overdose.
The investigators acknowledge that they might have missed some HIV seroconversions among drug users who did not participate in the study. Reasons for non-participation included concerns over confidentiality or transport to the survey sites. However, they see no reason to believe that these individuals – who had access to the same treatment and prevention services in the community – would have substantially higher HIV incidence than study participants. They also point out that the study reached about two thirds of the estimated 5000 active injecting drug users in Hai Phong.
The study found an HIV incidence below 0.1% a year, which is well below the target of 0.5% a year which the researchers had defined as a component for ending the HIV epidemic among people who inject drugs in Hai Phong. Moreover, they say that “even if HIV incidence had been 13 times higher among people who inject drugs who did not participate in the study, we would still have matched our target rate for ending the epidemic”.