New drug users less likely to share needles, have HIV, in Russian study

A significant decline in risky injecting practices and a decline in HIV prevalence in new drug injectors was seen in a Russian city severely affected by HIV between 2001 and 2004, despite the lack of needle and syringe exchange, researchers from the London School of Hygiene report in the April 15^th edition of the Journal of Acquired Immune Deficiency Syndromes.

The researchers believe that word of mouth, and growing awareness of the rising number of HIV diagnoses, contributed to the shoft, but also note that changes in the drug market during the study period may have driven the change in injecting and equipment sharing practices.

Several major cities worldwide have witnessed explosive outbreaks of HIV due to injecting drug use. In these contexts, some research suggests that new injectors might adopt riskier behaviours, or alternately, within the context of an HIV outbreak, new injectors might adopt safer behaviours than longer term injectors. Thus, measuring behavioural change in targeted populations may help to monitor risks in a changing epidemic.

Therefore investigators from the London School of Hygiene and Tropical Medicine examined two anonymous, cross-sectional community-recruited surveys of injecting drug users in Toggliatti city, which is in the Samara region of Russia.

They also conducted a review of new HIV diagnoses in the region since 2000.

Participants in both surveys had used injection drugs in the previous four weeks and consented to HIV testing via oral fluid samples. The participants analysed were injecting drug users who had injected for three years or less (recent injectors): 138 people in 2001 and 96 in 2004.

Participants were identified by respondent-driven sampling, in which those initially recruited act as 'seeds' for an expanding chain of referrals. Mathematical modelling was then used to estimate population effects. Injection drug use was estimated to occur in 5.4% of the registered population of the city, but in 2.7% of the assumed genuine population, close to 1 million people.

In 2004, a lower proportion of injecting drug users reported injecting daily, using used needles, syringes or filters, or front-loading – when a solution of drug is passed from a donor syringe into another person by removing the needle. Although fewer injecting drug users in 2004 reported contact with drug treatment services, needle exchange or outreach workers, more had been tested for HIV.

Overall HIV prevalence was high among injecting drug users, but it declined between 2001 and 2004, from 56% to 38.5% A significantly lower prevalence of HIV was found among new injectors in 2004 (11.5%, 95% CI: 5.0 - 17.9) than in 2001 (55.2%, 95% CI: 46.7 - 63.8). A history of drug treatment was associated with a reduced likelihood of testing positive for HIV, while increased odds of HIV were associated with exchanging sex for drugs and sex work, duration of injection (odds ratio 1.4 per year), and front-loading. Most injecting equipment was obtained from pharmacies in both surveys.

Examination of surveillance data revealed that in 2000, 97% of new HIV cases were linked with IDU whereas that figure had fallen to 56.4% by 2004.

The reduction in HIV among new injectors in 2004 seems likely to be related to general risk awareness and changes in injection practice rather than interventions through services, such as needle exchanges. However, the authors suggest that “IDUs, and IDUs involved in sex work specifically, should be targets for sexual risk reduction interventions”.

Given the nature of IDU-related health services in this region, the authors write that “we emphasize the need for increasing access to voluntary and confidential HIV testing in combination with increasing the accessibility of sterile injecting equipment through pharmacies”.