Monitoring drug-related infectious diseases in Europe

Background

Injecting drugs is a major risk factor for contracting infectious disease, in particular blood-borne viruses. The objectives of the drug-related infectious diseases (DRID) indicator are 1. to obtain reliable and comparable measures of incidence and prevalence of infectious diseases - primarily HIV, hepatitis C virus (HCV) and hepatitis B virus (HBV) infections - among people who inject drugs (PWID); 2. to collect information on risk factors, in order to inform policy makers. This poster is part of a set of five posters on the five EMCDDA key epidemiological indicators.

Methods

For prevalence estimates and risk factors, EMCDDA collects data from 28 European Member States, Norway and Turkey, where national experts use two main study designs: seroprevalence studies among PWID and monitoring of routine diagnostic testing for HIV, HCV and HBV offered in drug services, following EMCDDA current toolkit for data collection on infectious diseases epidemiology and behavioural indicators. The monitoring of HIV, HCV and HBV notifications among PWID is conducted by ECDC. A system to assess the data quality of the indicators is established in agreement with the national experts and the national focal points.

Results

In sero-prevalence studies from Poland, Latvia and Estonia conducted among PWID in 2016-17, more than 10% of users were HIV positive. In 2017, among all new diagnoses of HIV notified in Europe with known route of transmission, the percentage attributable to injecting drug use was 5% and has remained low and stable in the last decade. Between 2008 and 2017, the total number of new HIV diagnoses among PWID has declined (-42%), but some countries have documented outbreaks and Lithuania reported its highest number of new cases (136) in the last decade. HCV antibody prevalence among national samples of PWID in 2016–17 varied from 15 % to 82 %. Through 2011–17, declining HCV prevalence was reported in 6 countries, while 2 observed an increase. Despite universal HBV immunisation in several countries and targeted immunisation in others, in 6 countries with national data, between 1.4% and 9.4 % of drug injectors were estimated to be currently infected with HBV.

Conclusions and recommendations

Limitations of the indicator include comparability (study design and coverage vary across countries) and representativeness. Despite the downward trend in HIV cases linked to injecting drug use, recent clusters of HIV cases among injectors suggest that the control of HIV remains a challenge and requires continuous vigilance and high coverage of harm reduction services as patterns of drug use are evolving. While the prevalence of HCV remains very high among PWID, the elimination strategy and an effective treatment provide an opportunity to reduce the burden of viral hepatitis among PWID.