Drug-related infectious diseases: health and social responses

Overview

Key issues

The sharing of injecting equipment increases the risk of transmitting and acquiring blood-borne infections, such as HIV and hepatitis B and C viruses (HBV and HCV). Marginalised groups, including people with serious drug problems, whether or not they inject, may also be at increased risk of contracting other infectious diseases, such as tuberculosis.

Hepatitis C is the most prevalent blood-borne viral infection among people who inject drugs. The availability of highly effective treatments for hepatitis C has led to a shift in focus towards addressing the high rates of HCV infection found among people who inject drugs. Chronic HCV infection can result in death from severe liver disease, such as cirrhosis and liver cancer.

Historically, interventions targeting people who inject drugs – primarily opioid agonist treatment (¹), needle and syringe programmes and harm reduction measures to reduce risk behaviours – were mainly focused on reducing HIV transmission. The success of these measures can be seen in the low proportion of HIV transmission attributed to drug injecting (about 5 % of diagnoses for which the route of transmission is known), a rate which has been stable for the past decade. Nevertheless, the risk of HIV infection associated with injecting drug use remains high in some countries, and injecting-related HIV outbreaks still occur in Europe.

Evidence and responses

• Providing opioid agonist treatment and other effective drug dependence treatment to people who inject drugs.
• Needle and syringe programmes providing sterile injection equipment and education on safer use to people who inject drugs.
• Vaccinating against hepatitis A and B, tetanus, influenza and COVID-19, in addition to making the pneumococcal vaccine available to at-risk individuals.
• Routine testing for HIV, HCV (plus HBV for those who are unvaccinated), and other infections such as tuberculosis, integrated into drug treatment and harm reduction services.
• Referral and treatment provision for those found to be infected, including direct-acting antiviral treatments for HCV.
• Health promotion focused on safer injecting behaviour, sexual health (including condom use), and disease prevention, testing and treatment.
• Individual interventions using proactive, multi-component approaches that are adapted to user needs and local conditions.

European picture

• All but one country monitored by the EMCDDA provide clean injecting equipment free of charge via specialised outlets. However, throughout Europe there are considerable variations in coverage, indicating a need to increase service provision in some countries.
• Opioid agonist treatment is provided across Europe but coverage remains low in a number of countries, including some which report risk factors for HIV or HCV infection among people who inject drugs.
• A majority of EU countries have adopted strategies for dealing with hepatitis C and most have introduced direct-acting antiviral treatments for HCV, although coverage remains low.
• A number of EU-level initiatives have sought to share knowledge on good practice (e.g. HepCare, JA Integrate), while an EMCDDA initiative on HCV has developed tools to support stakeholders in drug service settings in reducing barriers to HCV testing and care for people who inject drugs.

Key issues related to drug use and infectious diseases

The objectives of ending the HIV/AIDS epidemic and combating viral hepatitis are part of the United Nation’s 2030 Agenda for Sustainable Development. These goals have been transformed into a set of ‘Commitments to End AIDS by 2030’ by UNAIDS and a global health strategy on viral hepatitis by the World Health Organization (WHO), accompanied by an action plan for an effective health sector response to viral hepatitis in the WHO European Region. The aim is to achieve a reduction in the incidence of chronic HBV and HCV infections of 90 %, and a reduction in mortality from chronic HBV and HCV infections of 65 %, by 2030.

Injecting drug use remains an important mode of HIV transmission in some EU countries, and local outbreaks, mostly linked to stimulant injecting, continue to occur. In addition, despite falling rates over recent years, more than 1 in 10 new AIDS cases in the European Union are still attributed to injecting drug use. This may signal late diagnosis or bad case management, both of which are avoidable causes of harm to patients.

HCV infection is highly prevalent among injecting drug users in Europe. Infection is often asymptomatic, and many of those who are infected are unaware of it. The virus is associated with both acute and chronic hepatitis infection, with an estimated 75–80 % of those infected going on to develop chronic disease. Chronic hepatitis C can lead to severe liver disease, such as cirrhosis and cancer, which may result in death. The prevalence of HCV antibodies (a marker of having been infected by the virus) among national samples of people who inject drugs is very variable, but is considerably higher than the levels found in the general population, with some countries reporting rates in excess of 50 %.

HBV infection is less common as an effective vaccine is widely used in national immunisation programmes. However, people who use drugs may be missed by regular campaigns. Good data are lacking, but in Europe recent national estimates indicate that up to around 10 % of people who inject drugs may be infected with hepatitis B. HBV may be transmitted through sharing injection equipment, sexual contact, or from mother to child (in pregnancy, and during and after birth).

Drug injection also carries a risk for bacterial infections such as Staphyloccocus aureus, group A streptococcus (GAS) infections and wound botulism. Marginalised groups, including people with serious drug problems, whether or not they inject, may also be at increased risk of contracting infectious diseases such as tuberculosis and hepatitis A. Drug injecting may cause damage to veins and associated circulatory problems. For example, the grinding up and injecting of medications that come in tablet form, such as buprenorphine, may lead to a number of potentially serious health problems.

Although opioids are the predominant drugs injected in Europe, other substances, including amphetamines, cocaine and anabolic steroids, are injected by sizeable numbers of people. Stimulant injecting has been associated with more risky injection practices and HIV outbreaks, and there are some indications that the injection of stimulants may be increasing in Europe.

Regardless of which drugs are injected or inhaled, the major public health goals remain the same – reducing the transmission of infectious diseases acquired through sharing contaminated syringes, needles and other injecting and inhaling equipment, and improving the health of infected individuals.

Evidence and responses to drug-related infectious diseases

In recent years there has been a move towards addressing the prevention of infections in an integrated way, rather than focusing on individual diseases. Approaches intended to reduce infectious diseases among people who inject drugs include interventions geared towards preventing infection and reducing the risk of transmission, in addition to those that focus on treatment when infection does occur. Furthermore, broader public health approaches, such as the provision of outreach and low-threshold services and enabling environments, can lower the barriers to accessing treatment and thus reduce people’s vulnerability to infection. Empowering people who inject drugs to protect themselves may also provide an environment in which the transmission of infection is less likely to occur.

 

Reducing susceptibility to infection

Reducing overdose morbidity and mortality is a major public health challenge in Europe. A broader public health response in this area aims to reduce vulnerability among high-risk drug users, in particular by removing barriers to services and making them more accessible, as well as by empowering people to take fewer risks. This may include interventions such as the promotion of quality in care and treatment and the implementation of programmes supported by evidence; the provision of harm-reduction interventions; the development of national prevention policies, supported by a long-term commitment from policymakers and funding for treatment services; and the reinforcement of collaboration between different stakeholders in the provision of integrated healthcare services, including hepatitis C treatment for drug users.

Community-based, low-threshold drug services, offering voluntary testing for infectious diseases and counselling on risk behaviours as well as assistance in managing illnesses, may also increase the rates of vaccination against hepatitis A and B. The universal vaccination of children for hepatitis B and vaccination campaigns targeting high-risk groups mean that hepatitis B should become increasingly rare in the future. However, as vaccine coverage of populations of injecting drug users can be poor, they need to be viewed as a group for whom additional screening and vaccination using the WHO-recommended Accelerated Schedule would be appropriate. Vaccination should be offered to those who inject drugs at all service contact points, whether in low-threshold harm-reduction facilities, treatment services or prisons.

Preventing infection and reducing the risk of transmission

Integrated infectious disease services for people who inject drugs

It is important that services are provided within a coordinated multi-component programme in order to maximise their effectiveness. Such programmes also need to be tailored to the needs of different groups of people, who may have different patterns of injecting drug use. For instance, in some countries it may be important to translate materials into a specific set of languages and train staff and peer workers to work with migrant and ethnic minority populations.

Taking a systems approach that ensures that all of the available interventions are in place and working together to provide a ‘continuum of care’ has been recognised as essential. There is also a growing body of evidence on how drug treatment and harm-reduction service providers can support people who inject drugs to access testing and treatment, using innovative and creative methods and developing new models of care. These include, for example, nurse-led approaches, mobile services, pharmacy provision, shared-care models and the involvement of peer support workers.

In developing integrated testing and treatment models of care, giving consideration to transferability is essential as appropriate adaptation to the context and current service provision will be key to success. Increasingly important in recent years has been the success of antiviral treatments in reducing the burden of chronic diseases (HIV, HBV, HCV) among infected people who inject drugs. Providing antiviral treatment to this population reduces mortality and morbidity, as well as indirectly reducing onward transmission (this indirect effect has been labelled 'treatment as prevention').

Establishing links between drug and sexual health service providers may be particularly important for responding effectively to the spread of infections related to the injection of stimulants and other drugs by men who have sex with men. Prevention interventions for this group include testing and treatment for infections, health education and the distribution of prevention materials, including condoms, lubricants and sterile injecting equipment. To prevent sexually acquired HIV infection, pre-exposure prophylaxis is an additional option for populations at the highest risk.

Considering that prisons are high-risk environments for the transmission of blood-borne infections, a comprehensive approach to harm reduction in this setting is expected to play a significant role in the health of the prison population, as well as in the community in general. Yet, addressing infectious diseases in prisons may be particularly challenging because of the costs involved, the need for collaboration with infectious disease and drug dependence specialists, and other factors such as structural barriers in the prison system. Integrated services are thus an important component of interventions in this setting, particularly with regard to the need for collaboration and partnership between prison and community healthcare services to promote and facilitate uninterrupted care.

Provision of opioid agonist treatment

Opioid agonist treatment represents the main approach to the treatment of opioid dependence in Europe and is part of a wider range of treatment options available to heroin users. Opioid agonist medications, such as methadone and buprenorphine, are morphine-like substances that mimic the effects of the naturally occurring substances extracted from opium, such as pain relief and respiratory depression, stabilising brain functions and preventing craving and withdrawal. These medications are typically prescribed over prolonged periods (usually more than six months).

People in treatment inject less frequently and engage in less risky injecting behaviour. Opioid agonist treatment has been a key response in efforts to reduce the number of opioid-related deaths as well as contributing to lowering the levels of high-risk opioid use and the number of HIV infections among injecting drug users in Europe. It also plays an important role in preventing the spread of viral hepatitis. The achievement of these outcomes depends largely on the motivation and circumstances of each individual and the quality and effectiveness of the treatment delivered, as well as on the wider network of health and social services supporting the recovery of the client in opioid agonist treatment. The impact of opioid agonist treatment in preventing the spread of infectious diseases among people who inject drugs appears to be particularly effective when it is combined with needle syringe programmes.

Provision of needles and syringes, and other harm-reduction equipment

Among people who inject drugs, the sharing of needles and syringes is the key risk factor for acquiring blood-borne diseases. Needle and syringe programmes aim to provide sterile syringes and hypodermic needles, and other injecting equipment, as a measure to prevent the risk of infection. These programmes may be implemented within a package of harm-reduction measures, and often include a component of information and education. Needles and syringes can be obtained for free or in exchange for used ones. These programmes can be implemented in different settings, including low-threshold services, pharmacies and prisons. Methods of distribution will vary by country and setting.

There is moderate quality evidence that needle and syringe programmes are effective for the prevention of HCV, HIV and in reducing injecting risk behaviour among people who inject drugs. However, to have a significant impact on the rates of HIV and HCV transmission in this population, it is necessary for needle and syringe programmes to be provided at a sufficiently large scale and in combination with other responses, such as treatment (combined prevention).

In addition to needle and syringe programmes, the provision of other types of equipment, for example sterile cookers or filters, may reduce injecting risk behaviours. Providing filters may be particularly important in countries where people inject substances that come in the form of tablets, such as buprenorphine, which can result in a range of health complications that are difficult and expensive to treat.

Testing and treatment provision for HIV and viral hepatitis

In many countries, community-based, low-threshold drug services offer testing for infectious diseases, and there is increasing evidence to show that this is a cost-effective approach. EU minimum quality standards for drug treatment promote routine voluntary and confidential testing for blood-borne diseases through community agencies, counselling on risk behaviours and assistance in managing illnesses. These services may also increase rates of vaccination against hepatitis A and B.

The past decade has seen important biomedical advances that have made a significant contribution to the early diagnosis of HIV and viral hepatitis, while new medications have significantly enhanced the effectiveness of the treatment of chronic hepatitis. Nevertheless, testing rates remain low among people who inject drugs, and effective approaches to promote testing as the first element of a cascade of care are particularly needed. Early diagnosis of HIV, HCV or HBV is crucial as it is the first step in accessing treatment and subsequently preventing onward transmission (treatment as prevention). Among other factors, stigma and marginalisation remain important barriers to testing for blood-borne viral infection among people who inject drugs, which may thus delay diagnosis and treatment.

HIV: testing and treatment

HIV testing may take place in specialist healthcare settings, including dedicated STI (sexually transmitted infections) and sexual health clinics, antenatal services and infectious disease units. It may also take place in non-specialist locations, such as general practice, community settings and hospital outpatient departments.

Fourth-generation serological assays are the typical diagnostic test employed in most healthcare settings. As these assays can detect both HIV antigens and antibodies, they have the potential to diagnose acute infection before the antibody response becomes detectable. Rapid diagnostic tests are also available on the market but they do not provide a definitive diagnosis. Instead, they are included as part of a ‘test for triage’ approach, which requires a confirmatory test to be performed in the event of there being a reactive test result. A diagnosis can usually be established on the same day.

Despite current testing strategies, many people with HIV infection are still diagnosed at an advanced stage of disease. For people living with HIV, antiretroviral therapy results in viral suppression, decreased rates of co-morbidities and the prevention of future opportunistic infections. Early diagnosis and initiation of antiretroviral therapy reduces morbidity and mortality, offering infected people a greater chance of a normal life expectancy and potentially reducing HIV transmission to others. The policy of ‘test-and-treat’ for HIV, in which antiretroviral therapy is started directly after an HIV diagnosis, is therefore important for addressing HIV infection among people who inject drugs.

HCV: testing and treatment

Testing is the gateway to accessing treatment, and in order to achieve the elimination of HCV, particular efforts are needed to reach the undiagnosed and those at risk of infection. Because infection is often asymptomatic, HCV-infected people who inject drugs may be unaware of their infection.

Early detection of HCV infection and treatment with highly effective direct-acting antiviral drugs has considerable potential to prevent liver disease and deaths. New direct-acting antiviral treatments for hepatitis C are available that cure the disease within a shorter time and with fewer side effects than previous treatment options. These all-oral combinations of direct-acting antiviral drugs can eliminate HCV infection in more than 90 % of cases in 8–12 weeks, and because of their safety and efficacy, they constitute the first-line treatment for HCV infection.

To successfully treat hepatitis C infection in people who inject drugs, access and referral pathways need to be extended, including by offering treatment in specialised drug services in community settings to increase uptake and availability. The co-location of hepatitis C treatment and opioid agonist treatment is likely to facilitate user access. Improving treatment adherence among people who inject drugs is a further important target. Case management, support services and the provision of education and training to improve health- and HCV-literacy among both people who inject drugs and service providers, as well as peer-driven interventions, are likely to be of benefit here.

Scaling up hepatitis C treatment is essential not only for reducing or preventing disease-related morbidity and mortality, but also for lowering the onward transmission of HCV infection among people who inject drugs. European clinical guidelines recommend that all patients with recently acquired or chronic HCV infection should be offered treatment without delay, and that urgent treatment should be considered for individuals at risk of transmitting the virus, such as people who inject drugs. Ideally, treatment should be tailored to individual needs and provided in a multidisciplinary setting.

HBV: testing and treatment

HBV testing allows the detection of the hepatitis B surface antigen (HBsAg). It is typically carried out either using a laboratory-based immunoassay or a rapid diagnostic test. Most rapid diagnostic tests can be performed with blood collected by finger stick sampling, and are quick and easy to perform.

Treatment for HBV infection, unlike hepatitis C treatment, is long-term and does not eliminate the virus, but suppresses HBV replication in 70 % to 80 % of recipients, as well as slowing down the progression to cirrhosis and development of hepatocellular carcinoma. In addition, the universal vaccination of children for hepatitis B and vaccination campaigns targeting high-risk groups mean that hepatitis B should become increasingly rare in the future.

Other prevention interventions

There is evidence that psychosocial interventions involving information, education, counselling or skills training, which are often implemented are effective in reducing injecting risk behaviours. Drug consumption rooms too may play a role in reducing injecting risk behaviours. 

A number of additional interventions have been explored with regard to their effectiveness in the prevention of infectious diseases in people who inject drugs, but the evidence here is less clear. Naltrexone, for instance, and particularly in the form of long-lasting implants, may have a positive effect in improving retention in treatment and reducing opioid use, but it remains unknown whether its use is effective in preventing HCV, HIV and injecting risk behaviours. It is not however, widely used in Europe.

Overview of evidence on… responses to drug-related infectious diseases

Statement	Evidence
	Effect	Quality
Opioid agonist treatment prevents HCV (primary infection and reinfection), HIV and injecting risk behaviour among people who inject drugs.	Beneficial	High
Sterile needle and syringe provision is effective for the prevention of HCV, HIV and injecting risk behaviour among people who inject drugs.	Beneficial	Moderate
The combination of opioid agonist treatment and needle and syringe provision prevents HCV infections and injecting risk behaviour among people who inject drugs.  While there are still not enough studies to assess the effect on HIV, considering the positive effect on HCV, experts assume the same positive effect on HIV infections.	Beneficial	Moderate
Psychosocial interventions involving information, education, counselling and/or skills training (IECS) to reduce injecting risk behaviours.	Beneficial	Moderate
Antiviral treatment against HIV, HBV and HCV among people using drugs is effective. Opioid agonist treatment improves adherence to the treatment regimen, therefore it should not be considered as a barrier to antiviral treatment access.	Beneficial	Moderate
Drug consumption rooms may play a role in reducing injecting risk behaviours.	Beneficial	Low
There is insufficient evidence to assess the impact of infectious diseases testing on HCV and HIV infections.	Unclear	Very low

Evidence effect key:
Beneficial: Evidence of benefit in the intended direction. Unclear: It is not clear whether the intervention produces the intended benefit. Potential harm: Evidence of potential harm, or evidence that the intervention has the opposite effect to that intended (e.g. increasing rather than decreasing drug use).

Evidence quality key:
High: We can have a high level of confidence in the evidence available. Moderate: We have reasonable confidence in the evidence available. Low: We have limited confidence in the evidence available. Very low: The evidence available is currently insufficient and therefore considerable uncertainty exists as to whether the intervention will produce the intended outcome.

European picture: availability of interventions responding to drug-related infectious diseases

The great majority of countries monitored by the EMCDDA provide clean injecting equipment free of charge via specialised outlets. There are, however, considerable differences between countries in the geographical distribution of such outlets and the proportion of injectors covered by needle and syringe programmes, with only a few reporting a level of coverage, through specialised and publicly funded drug programmes, above the 2020 target of 200 syringes per injecting drug user.

It is estimated that around 50 % of opioid-dependent persons in Europe receive some form of agonist treatment. National estimates, where available, vary widely, from about 10 % to around 80 %, highlighting both the heterogeneous situation found across Europe with respect to treatment coverage and the fact that treatment provision remains insufficient in many places, despite improvements in a number of countries (see Opioids: health and social responses). 

Although coverage has expanded to some extent in recent years, most EU countries do not meet the combined targets of opioid agonist treatment and needle and syringe provision, even in settings where other risk factors for HIV or HCV infection among people who inject drugs may be present, such as incarceration in prisons and other custodial facilities.

The European Centre for Disease Prevention and Control (ECDC) provides evidence-based guidance on the integrated testing of HBV, HCV and HIV. In 2021 the EMCDDA launched an online toolkit to support increased access to HCV testing and care in drug services. At the national level, most EU countries have adopted, or are preparing, specific hepatitis C strategies. Initiatives to tackle hepatitis C, directed at testing, counselling and treating people who inject drugs, have increased but still appear to be insufficient as HCV prevalence among this group is reported to be at medium or high levels, or indeed increasing, in most European countries. This is despite the evidence of the effectiveness of hepatitis C antiviral treatments for people who inject drugs. In part this may be explained by the high costs of the new medications, although barriers to detection and treatment for hepatitis C are also likely to play a role. Some of these obstacles are being addressed. The Fibroscan, a diagnostic tool that facilitates the detection of liver disease is now available, and new medications have reduced both treatment duration and negative side-effects, and therefore should facilitate compliance.

Testing and treatment of infectious diseases among people in prison has an important impact on public health. Although testing and treatment for HIV, HCV and HBV are available in many prisons across Europe, little is known about the levels of coverage and the numbers of people in treatment. Needle and syringe programmes, while widely implemented in the community, are available in prison in only three EU Member States. The ECDC and the EMCDDA provide guidance for preventing the spread of blood-borne viruses in prison settings.

Implications for policy and practice

Basics

• Core interventions in this area include needle and syringe programmes, opioid agonist treatment, testing and treatment for infectious diseases, and health promotion activities.
• Many people who use drugs are unaware of their HIV, HCV or HBV infection status. Testing should be offered as part of the baseline package whenever there is any contact with drug services.
• HCV treatment is increasingly available but infection prevalence among people who inject drugs remains at medium or high levels across Europe.
• Vaccinating people who inject drugs against hepatitis A and B can substantially reduce the incidence of these infections and their serious health effects.

Opportunities

• The implementation of an integrated strategy to provide prevention, outreach, screening and hepatitis C treatments in coordination with harm reduction (including needle and syringe programmes) and drug treatment programmes (including opioid agonist treatment), both in the community and in prisons, could reduce liver disease and cancers and potentially eliminate hepatitis C as a public health threat among people who inject drugs.
• Access to and uptake of testing and treatment for infectious and sexually transmitted diseases can be increased by developing on-site screening at services for drug users such as drug treatment centres, drug consumption rooms or needle and syringe programmes.

Gaps

• Outbreaks linked to stimulant use continue to be documented and represent a serious threat to public health. Enhanced early detection, real-time surveillance and greater collaboration between national and regional agencies are important goals in this area.
• Currently, access to needle and syringe programmes and opioid agonist treatment is below recommended levels in many EU countries and needs to be improved. Collecting more data to improve estimates concerning the size and characteristics of the population of people who inject drugs, as well as the coverage of existing needle and syringe programmes, is important to allow more effective monitoring of key services. Additionally, better data on HCV treatment uptake are also needed to enable an accurate assessment of the adequacy of service provision.
• HIV infection in people who inject drugs is often diagnosed late and AIDS cases continue to be reported among this group. Enhanced HIV testing, immediate initiation of HIV treatment after diagnosis and higher retention levels in care are essential requirements to improve this situation.
• The provision of responses to prevent and treat drug-related diseases remains low in some high-risk settings such as prisons and other custodial facilities.

Data and graphics

The graphic below is taken from the Elimination barometer on viral hepatitis among people who inject drugs in Europe (prevention component). To view an interactive versions of the infographic below, as well as to access its source data, click on an the infographic.

 

Further resources

EMCDDA

• Best practice portal.
• EMCDDA guide to holding a stakeholder round-table on supporting hepatitis C testing and care in drug services, 2021.
• Manual: increasing access to hepatitis C testing and care for people who inject drugs, 2021.
• Increase access to hepatitis C (HCV) testing and care in drug services: a toolkit, 2021.
• Elimination barometer on viral hepatitis among people who inject drugs in Europe, 2021.
• Expert meeting on drug-related infectious diseases (DRID) 2020.
• Hepatitis C treatment for injecting drug users, Perspectives on drugs, 2015.
• Hepatitis C among drug users in Europe: epidemiology, treatment and prevention, Insights, 2016.
• Drug-related infectious diseases in Europe: update from the EMCDDA expert network, Rapid communication, 2017.
• Estimating trends in injecting drug use in Europe using national data on drug treatment admissions, Technical paper, 2015.
• Guidelines for testing HIV, viral hepatitis and other infections in injecting drug users, Manual, 2010.
• Prevention and control of infectious diseases among people who inject drugs, Joint publication, 2011.

Other sources

• UNODC, Publications: drug use and HIV (webpage).

About this miniguide

This miniguide provides an overview of the most important aspects to consider when planning or delivering health and social responses to drug-related infectious diseases, and reviews the availability and effectiveness of the responses. It also considers implications for policy and practice. This miniguide is one of a larger set, which together comprise Health and social responses to drug problems: a European guide.

Recommended citation: European Monitoring Centre for Drugs and Drug Addiction (2021), Drug-related infectious diseases: health and social responses, https://www.emcdda.europa.eu/publications/mini-guides/drug-related-infe….

Identifiers

HTML: TD-09-21-504-EN-Q
ISBN: 978-92-9497-675-8
DOI: 10.2810/775453