Factors associated with HIV and hepatitis C in the context of routes of drug administration among problem drug users in Latvia, 2018

Objectives: Injection drug use is associated with spread of infectious diseases, overdoses and other public health harms. Latest estimates on the numbers of people who inject drugs (PWID) revealed, that there were 7 715 PWID in 2016 in Latvia. In 2017 Latvia had the highest HIV incidence rate in EU, and injecting drug use was the second main mode of HIV transmission. We compared HIV, hepatitis C, and injecting risk among exclusive injectors and injectors who also reported other modes of drug administration among problem drug users in Latvia in 2018.

Materials and Methods: Data from 11th phase of Drug User’s Cohort Study (carried out in 2018 in 5 cities in Latvia) was used. Research was held by the Centre for Disease Prevention and Control of Latvia and NGO “DIA+LOGS”. Of the 478 recruitees, cross-sectional data on 320 PWID with the rapid test results on HIV and HCV were retained for the analysis. Multiple logistic regression using IBM SPSS 24.0 software was conducted.

Results: There were 28.7% (n = 134/467) exclusive and 71.3% (n = 333/467) non-exclusive drug injectors (IDUs) in the study sample. Amphetamine was the main drug injected and benzodiazepines and marijuana - main drugs used illicitly orally and by smoking. Exclusive IDUs have higher odds of injecting only one time per day than non-exclusive IDUs (OR 1.7; 95% CI 1.1 – 2.5). Non-exclusive IDUs have higher odds of sharing syringes (aOR 4.8; 95% 2.0–11.9) and paraphernalia (aOR 13.0; 95% CI 5.1–33.1), and also higher odds of having experienced an overdose (aOR 2.1; 95% CI 1.1–4.0) than exclusive IDUs. Nonexclusive IDUs have higher odds of being hepatitis C positive (90.2% vs 76.6%; aOR 4.0; 95% CI 0.7–21.5). 26.1% of non-exclusive and 21.8% of exclusive IDUs are HIV infected (aOR 0.9; 95% CI 0.4 – 1.9).

Conclusions: Nonexclusive IDU is associated with more risky injecting behaviour and with a tendency to have higher hepatitis C and HIV infection rates. It can be speculated that nonexclusive injectors are using harm reduction services less frequently and are polydrug users much more often than exclusive IDUs. Harm reduction and treatment services should pay more attention to nonexclusive drug users, by providing them relevant services specifically for their needs.