HIV and hepatitis C prevalence, and related risk behaviours among people who inject drugs in three cities in Croatia: Findings from respondent-driven sampling surveys

Prevalence of HIV and Hepatitis C and access to opioid substitution treatment among people who inject drugs in three cities in Croatia: findings from the second wave of respondent-driven sampling surveys

BACKGROUND

The second wave of integrated bio-behavioural surveys was conducted among people who inject drugs (PWID) in the cities of Zagreb, Split, and Rijeka in Croatia to estimate the prevalence of HIV and hepatitis C virus (HCV) antibodies and sexual and injecting risk behaviours.

METHODS

Respondent-driven sampling (RDS) was used to recruit a total of 301 PWID in Split, 130 in Rijeka, and 86 in Zagreb from March to July 2022. Participants provided biological specimens for HIV and HCV testing and completed a behavioural questionnaire. RDS-Analyst software was used to calculate weighted population estimates with 95% confidence intervals (95% CI).

RESULTS

Approximately one in four PWID were women (range from 24.3% in Zagreb to 29.9% in Rijeka). Overall, HIV prevalence was low, with no cases identified in Zagreb, and 0.6% and 0.8% in Split and Rijeka, respectively. HCV antibody prevalence was 37.2% among PWID in Zagreb and Rijeka, and as high as 59.5% in Split. Testing for HIV and HCV in the 12 months before the survey was reported by 11.3-19.8% and 17.3-21.6% of PWID across the cities, respectively. Use of needles and syringes in the past 30 days that had already been used by someone else was reported by 8.9-26.5% across the cities. A large proportion of PWID-54.0% in Zagreb, 31.0% in Rijeka and 29.9% in Split-never used needle and syringe exchange programmes. Being in drug addiction treatment at the time of the survey was reported by 50.8% in Split, 57.3% in Rijeka and 73.3% in Zagreb. Injecting cocaine in 30 days before the survey was common, ranging from 12.7 to 32.1% across the cities.

CONCLUSION

HIV prevalence continues to be low among PWID in Croatia, whereas HCV prevalence is substantial. Due to low coverage of HIV and HCV testing and insufficient use of harm reduction services, there is a potential for further spread of drug-related infectious diseases in this population.

Characterising people who inject drugs, and association with HIV infection: A situation analysis in Kampala City, Uganda

Uganda implements interventions for injection drug use, but significant barriers hinder efforts to effectively reach and support persons who inject drugs (PWID). We describe characteristics of PWID, and associated risk behaviour, to inform the designing of programmes that are tailored to clients' needs and preferences. A cross-sectional survey (August 23rd to December 5th, 2023) in Kampala interviewed 354 PWID (≥18-years) at selected venues(bars,lodges, street corners and ghetto). Peer eductors and counsellors administered a structured questionnaire covering socio-demographics, drug use, sexual risk, and medical history. HIV serostatus was determined by self-report or testing for consenting participants without history of recent testing Binary logistic regression was used to establish the relationship between HIV infection and risky drug- and sexual behaviour of PWID. Participants were predominantly Ugandan (95.2%), male (73.2%), unmarried (55.9%), unemployed (81.8%), with higher levels of education and varying ages. Mental disorders were prevalent, with 48.7% reporting at least one underlying condition, including depression (30.8%) and anxiety (9.6%). Physical health issues included fever (32.9%), cough (32.5%), malaria (22%), and sexually transmitted infections (15%). Over 82.6% were introduced to drugs by close acquaintances. HIV prevalence among participants was 3.7%, higher in females (8.4%) and non-Ugandans (16.7%). Being female and experiencing difficulty accessing sterile injection materials were associated with HIV-positive status. Our study provides valuable insight into the socio-demographic, mental, physical health, and HIV risk behaviour of PWID in Kampala, Uganda. The findings indicate significant vulnerabilities to injecting drug use, mental disorders, and high-risk behaviors that predispose this population to HIV infection. Despite a low HIV prevalence in this population compared to previous estimates, the interplay between drug use, risky injecting practices, and sexual behaviour suggests an urgent need for targeted interventions to address these intertwined challenges.

Characterising People who inject drugs, and association with HIV infection: A Situation Analysis in Kampala city, Uganda

Background

Uganda has implemented targeted interventions to address the rising burden of injection drug use, yet barriers persist in reaching persons who inject drugs (PWID). This study describes the characteristics of people who inject drugs, physical and mental health states, and associated risk behaviors, to inform the designing of programs that are tailored to client's needs and preferences.

Methods

A cross-sectional survey was conducted between August and December 2023 at selected hotspots in Kampala, interviewing 499 PWID aged ≥18 years. Data was collected using a semi-structured questionnaire administered by peer educators and Uganda Harm Reduction Network (UHRN) counselors. Measurements included socio-demographics, injecting drug use and sexual risk behaviors, and medical history. HIV serostatus was dtermined by self-report and testing for participants who had no recent history of testing and consented to be tested. Binary logistic regression was used to establish the relationship between HIV infection and risky drug- and sexual behaviors of PWID.

Results

Participants were predominantly Ugandan (95.2%), male (73.2%), unmarried (55.9%), unemployed (81.8%), with higher levels of education and varying ages. Mental disorders were prevalent, with 48.7% reporting at least one underlying condition, including depression (30.8%) and anxiety (9.6%). Physical health issues were also noted, with reported cases of fever (32.9%), cough (32.5%), malaria (22%) and sexually transmitted infections (STIs) (15%).Regarding drug use patterns, the majority (82.6%) were introduced to drugs by close acquaintances, with 70.9% categorized as people who inject drugs. HIV prevalence among injecting drug users was 3.7%, with higher rates among females (8.4%) and non-Ugandans (16.7%). Being female and experiencing difficulty accessing sterile injection materials were associated with HIV-positive status, highlighting the complex interplay between socio-demographic factors, risk behaviors, and HIV infection among individuals with injecting drug use Disorder in Uganda.

Conclusion

Our study provides a comprehensive insight into the socio-demographic, mental, physical health, and HIV risk behavoir of PWID in Kampala, Uganda. The findings indicate significant vulnerabilities to injecting drug use, mental disorders, and high-risk behaviors that predispose this population to HIV infection. Despite a low HIV prevalence compared to previous estimates, the interplay between drug use, risky injecting practices, and sexual behaviors suggests an urgent need for targeted interventions to address these intertwined challenges.

Seroprevalence Trends and Molecular Epidemiology of Viral Hepatitis in Croatia

Viral hepatitis is a significant cause of morbidity and mortality worldwide. In Croatia, hepatitis B virus (HBV) and hepatitis C virus (HCV) are widely distributed, especially in some high-risk groups such as people who inject drugs (PWID), prisoners, and highly promiscuous groups. The seroprevalence of HBV ranges from 7.0% in the general population to 38.8% in PWID, depending on the region. The seroprevalence of HCV is highest among PWID (29-75.5%) as compared to 0.9% in the general population. Analyzing the distribution of HCV genotypes, no substantial changes in the molecular epidemiology of the two most frequent HCV genotypes (1 and 3) in the past 20 years were observed. However, the predominance of subtype 1b compared to subtype 1a as detected in 1996-2005 was not confirmed in 2008-2015. Hepatitis A virus (HAV) incidence was high in the past with a decreasing trend since the 2000s, except for an outbreak in 2017-2018 as part of the large European outbreak, which was mainly among men who have sex with men. Hepatitis E virus (HEV) is an emerging virus detected for the first time in Croatia in 2012. The seroprevalence of HEV is high among hemodialysis patients (27.9%) and liver transplant recipients (19.3-24.4%). In addition, higher seroprevalence rates were observed in animal-related professions (e.g., veterinarians, 15.2%; hunters, 14.9%). All detected HEV strains belonged to genotype 3.

Personality dysfunction in opiate addicts on opioid substitution treatment and the risk of HCV infection

Background

Impulsivity, affective instability, and neglect of oneself and other people's safety as symptoms of personality dysfunction are associated with risky behaviors regarding the transmission of infectious diseases either sexually or by intravenous drug abuse.

Objective

The aim of this study was to analyze the association between hepatitis C virus (HCV) infection and personality dysfunction in opiate addicts on opioid substitution treatment.

Methods

This was a cross-sectional, observational investigation of patients over 18 years of age who were actively participating in opioid substitution treatment at five centers in Bosnia and Herzegovina. The occurrence of HCV infection was the primary study outcome, and personality functioning, the main independent variable, was assessed using the Severity Indices of Personality Problems (SIPP-118) questionnaire. The association between scores of personality functioning domains items and HCV infection status was determined by binary logistic regression analysis.

Results

Patients on opioid substitution therapy with HCV infection more frequently had personality disorders (OR 2.168, 95% CI 1.161-4.05) and were treated longer than patients without HCV infection (OR 1.076, 95% CI 1.015-1.14). HCV infection was associated with lower self-respect (OR 0.946, 95% CI 0.906-0.988), decreased capacity to have enduring relationships with other people (OR 0.878, 95% CI 0.797-0.966), and lower capability to cooperate with others (OR 0.933, 95%CI 0.888-0.98). On the other hand, except for self-respect, other elements of the Identity Integration domain (enjoyment, purposefulness, stable self-image, and self-reflexive functioning), when more functional, increased the risk of HCV infection.

Conclusions

Our study demonstrates that opiate addicts on opioid substitution treatment have a higher risk of HCV infection if their personality is dysfunctional, especially in the aspects of self-respect, enduring relationships, and cooperativity. The risk is even higher in addicts who have an established diagnosis of any kind of personality disorder.

HIV seroprevalence in five key populations in Europe: a systematic literature review, 2009 to 2019

Background

In Europe, HIV disproportionately affects men who have sex with men (MSM), people who inject drugs (PWID), prisoners, sex workers, and transgender people. Epidemiological data are primarily available from national HIV case surveillance systems that rarely capture information on sex work, gender identity or imprisonment. Surveillance of HIV prevalence in key populations often occurs as independent studies with no established mechanism for collating such information at the European level.

Aim

We assessed HIV prevalence in MSM, PWID, prisoners, sex workers, and transgender people in the 30 European Union/European Economic Area countries and the United Kingdom.

Methods

We conducted a systematic literature review of peer-reviewed studies published during 2009–19, by searching PubMed, Embase and the Cochrane Library. Data are presented in forest plots by country, as simple prevalence or pooled across multiple studies.

Results

Eighty-seven country- and population-specific studies were identified from 23 countries. The highest number of studies, and the largest variation in HIV prevalence, were identified for MSM, ranging from 2.4–29.0% (19 countries) and PWID, from 0.0–59.5% (13 countries). Prevalence ranged from 0.0–15.6% in prisoners (nine countries), 1.1–8.5% in sex workers (five countries) and was 10.9% in transgender people (one country). Individuals belonging to several key population groups had higher prevalence.

Conclusion

This review demonstrates that HIV prevalence is highly diverse across population groups and countries. People belonging to multiple key population groups are particularly vulnerable; however, more studies are needed, particularly for sex workers, transgender people and people with multiple risks.

Association between opioid agonist therapy use and HIV testing uptake among people who have recently injected drugs: a systematic review and meta-analysis

BACKGROUND AND AIM

Globally, nearly one in five people who inject drugs (PWID) are living with HIV, and the rate of new HIV infections in PWID is increasing in some settings. Early diagnosis is crucial for effective HIV control. We reviewed the evidence on the association between opioid agonist therapy (OAT) and HIV testing uptake among PWID.

METHODS

We conducted a systematic review searching MEDLINE, Scopus, Web of Science, Cochrane Central Register of Controlled Trials and PsycINFO for studies published from January 2000 to March 2019. Reference lists and conference proceedings were hand-searched. Observational and intervention studies were eligible for inclusion. Risk of bias was assessed using the Risk of Bias in Non-Randomised Studies of Interventions (ROBINS-I) tool. Meta-analyses were conducted using random-effects models.

RESULTS

Of 13 373 records identified, 11 studies from Australia, Europe, Malaysia and the United States were included. All studies had at least a serious risk of bias, largely due to confounding and selection bias, making it difficult to draw causal conclusions from the evidence. Ten studies provided data on the association between current OAT use and recent HIV testing. Six showed a positive association, while four provided little evidence of an association: pooled odds ratio (OR) = 1.71, 95% confidence interval (CI) = 1.28-2.27. Looking at having ever been on OAT and having ever been HIV tested, seven studies showed a positive association and three showed either weak or no evidence of an association: pooled OR = 3.82, 95% CI = 2.96-4.95.

CONCLUSIONS

Opioid agonist therapy may increase uptake of HIV testing among people who inject drugs, providing further evidence that opioid agonist therapy improves the HIV treatment care cascade.

Prevalence of latent tuberculosis infection and HIV among people who inject drugs in Iran

INTRODUCTION

Iran has an human immunodeficiency viruses (HIV) epidemic that is concentrated among people who inject drugs (PWID), who have higher risks of progression from latent tuberculosis infection (LTBI) to active disease. The aim of this study is to measure prevalence of LTBI, HIV infection and any risk behaviors among PWID in Iran.

METHODS

The cross-sectional study was conducted from August to December 2013 in six cities across Iran. A total of 420 PWID were recruited from drop-in centres using convenience sampling. Trained interviewers collected data on socio-demographic characteristics, drug use history and drug-related risk behaviors across the study sites. A tuberculin skin test (TST) was performed, and HIV infection was assessed by a rapid test. Multivariable modified Poisson regression and logistic regression were used for data analysis.

RESULTS

Prevalence of positive TST and HIV positivity was 35.7% and 8.6%, respectively. The prevalence of LTBI and HIV was significantly different across the cities of this study. Positive TST was independently associated with older age (APR 1.03, 95% CI 1.01, 1.05) and being HIV positive (APR 1.89, 95% CI 1.45, 2.47). HIV infection was associated with lifetime history of sharing syringes (AOR 3.28, 95% CI 1.44, 10.71) and lifetime number of imprisonment (AOR 1.09, 95% CI 1.03-1.14).

DISCUSSION AND CONCLUSIONS

Prevalence of LTBI infections among PWID is high and independently associated with HIV infection. Given that there are currently no TB services available within drop-in centres, programs which integrate TB case finding, TB preventive therapy, referral and care services for PWID are urgently needed.

Trends of Late Presentation to Care in Patients with Chronic Hepatitis C during a 10-Year Period in Croatia

Late presentation to care is the major obstacle to receiving treatment for chronic hepatitis C (CHC). Our aim was to analyze the prevalence and trends of late presenters (LP) at first consultations in Croatia during a 10-year period. This retrospective cross-sectional study included all adult CHC patients (n = 854) entering specialist medical care at the University Hospital for Infectious Diseases Zagreb between 2009 and 2018. LP was defined as liver stiffness measurement ≥ 9.5 kPa or biopsy METAVIR F ≥ 3. During the study period, mean patients' age increased from 37 to 52 years while HCV genotype distribution changed leading to the replacement of genotype 1b with 1a (g1b 32% to 21%; g1a 19% to 38%). A total of 320 (37.4%) were LP; they were older (47.5, IQR 40.5-57.6), and more commonly infected with g1b (34.1%) and g3 (42.5%). The prevalence of LP significantly increased from 31.9% in 2009 to 46.5% in 2018. Late presentation for care of CHC is increasing in Croatia suggesting a gap of diagnosing strategies in patients over 50 years.

Systematic Review and Meta-Analysis of Global Prevalence of HBsAg and HIV and HCV Antibodies among People Who Inject Drugs and Female Sex Workers

The main objective of this study was to evaluate the prevalence of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), hepatitis C virus (HCV) and hepatitis B virus (HBV) and their co-infections among people who inject drugs (PWID) and female sex workers (FSWs). Data sources were searched from January 2008 to October 2018 in different databases. Data were analyzed in Stata 16 software using the Metaprop command. The results showed that the prevalence of HIV, HCV and HBV among PWID was 15%, 60% and 6%, respectively. The prevalence of HIV, HCV and HBV among FSWs was 5%, 1% and 3%, respectively. The prevalence of HIV/HCV, HIV/HBV, HCV/HBV and HIV/HCV/HBV co-infections among PWID was 13%, 2%, 3% and 2%, respectively. The prevalence of HIV/HCV and HIV/HBV co-infections among FSWs was 3% and 1%, respectively. The results show that the prevalence of HCV and HIV infections in PWID and the prevalence of HIV in FSWs is higher than their prevalence in the general population. Interventions for the prevention of HIV and HCV in PWID appear to be poor, and may not be sufficient to effectively prevent HIV and HCV transmission.

Prevalence of hepatitis C infection among the general population and high-risk groups in the EU/EEA: a systematic review update

Background

Although significant improvement in efficacy measured by a sustained virological response, the high acquisition costs of direct-acting antivirals limit the access for patients and influence the costs of healthcare resource utilisation in hepatitis C. It is important to have the latest estimates of prevalence, especially in high-risk groups, for cost of illness, cost-effectiveness and budget impact studies.

Methods

Original studies on the estimates of the prevalence among general and high-risk groups in the European Union/European Economic Area (EU/EEA) were retrieved from Medline and Embase for the period from 2015 to 2018. All included studies were evaluated for risk of selection bias and summarised together in a narrative form. Results from previous reviews and updated searches were compared per country among different populations, respectively.

Results

Among the 3871 studies identified, 46 studies were included: 20 studies were used for the estimate of the general population; 3 for men who have sex with men (MSM); 6 for prisoners; and 17 for people who inject drugs (PWID). Compared with the results reported in previous systematic reviews, the updated estimates were lower than previously in most available countries. Anti-HCV general population prevalence estimates ranged from 0.54 to 1.50% by country. The highest prevalence of anti-HCV was found among PWID (range of 7.90–82.00%), followed by prisoners (7.00–41.00%), HIV-positive MSM (1.80–7.10%), HIV-negative MSM (0.20–1.80%), pregnant women (0.10–1.32%) and first-time blood donors (0.03–0.09%).

Conclusions

Our study highlights the heterogeneity in anti-HCV prevalence across different population groups in EU/EEA. The prevalence also varies widely between European countries. There are many countries that are not represented in our results, highlighting the need for the development of robust epidemiological studies.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4284-9) contains supplementary material, which is available to authorized users.

Overdose mortality rates in Croatia and factors associated with self-reported drug overdose among persons who inject drugs in three Croatian cities

BACKGROUND

Drug overdose is the major cause of morbidity and mortality among persons who inject drugs (PWID). We assessed factors associated with the non-fatal drug overdose among PWID in three Croatian cities and national trends of overdose-related mortality (OM), and rates of uptake of opioid agonist drug treatment (OAT).

METHODS

We used a respondent-driven sampling method to recruit 830 PWID in Zagreb, Split and Rijeka in 2014/2015. Participants completed behavioural questionnaires that included questions about overdose history, and we used Poisson regression to assess factors associated with self-reported overdose. We used joinpoint regression to calculate national trends of OM from 2001 to 2015 and rates of uptake of drug treatment from 2005 to 2015.

RESULTS

Lifetime prevalence of self-reported drug overdose in our RDS sample was 45.2%, while 4.1% of PWID reported overdose in the past 12 months; PWID who injected more than one type of drug in the past 12 months (adjusted prevalence ratio [aPR] = 4.56, 95% confidence intervals [CI] = 1.35-15.38) compared to injecting only heroin, and those enrolled in OAT (aPR = 1.94, 95% CI = 1.01-3.74) were more likely to report overdose in the past 12 months. We observed an increase in annual percent change (APC) of the national OM rates from 2001 to 2007 (APC = 22.5%, 95% CI = 16.3-29.0) and a decline from 2007 to 2015 (APC = -8.0%, 95% CI = -5.3- -10.5). The national rates of drug treatment enrollment increased from 2005 to 2010 (APC = 12.0%, 95% CI = 10.3-13.8), mostly due to increase in provision of buprenorphine from 2005 to 2008 (APC = 130.4%, 95% CI = 102.1-162.7).

CONCLUSION

Injecting more than one type of drugs and enrollment in OAT while still injecting drugs was positively associated with non-fatal overdose in our sample. To further reduce OM in Croatia we suggest improvements in coverage and delivery of OAT and establishment of provision of naloxone for PWID.

Risk behaviours and viral infections among drug injecting migrants from the former Soviet Union in Germany: Results from the DRUCK-study

BACKGROUND

High prevalence of drug use and injection-related risk behaviours have been reported among former Soviet Union (FSU)-migrants. To investigate hepatitis C (HCV) and HIV seroprevalence and related risk behaviours in this subgroup in Germany, we compared first generation FSU-migrants and native Germans using data from a sero-behavioural survey of people who inject drugs (PWID).

METHODS

Current injectors were recruited using respondent-driven sampling in eight German cities in 2011-2014. Questionnaire-based interviews were conducted and dried blood spots collected and tested for anti-HCV, HCV-RNA, and anti-HIV1/2. Descriptive and multivariable analyses (MVA) were performed.

RESULTS

A total of 208 FSU-born and 1318 native German PWID were included in the analysis. FSU-migrants were younger than Germans (median age: 33 vs. 39 years), and more often male (83.1% vs. 75.9%, p = 0.022). HCV seroprevalence was 74.5% in FSU-migrants vs. 64.6% in Germans (p = 0.006), HIV seroprevalence was 5.8% and 4.6%, respectively (p = 0.443). The proportion of FSU-migrants reporting injecting-related risk behaviours was higher than among Germans: injecting daily (39.4% vs. 30.2%, p = 0.015), with friends (39.2% vs. 31.2%, p = 0.038), cocaine (32.7% vs. 23.8%, p = 0.044), more than one drug (18.2% vs. 9.6%, p = 0.006), and sharing filters/cookers (35.5% vs. 28.0%, p = 0.045). No statistically significant differences were observed in HIV/HCV testing rates (range: 50.7%-65.6%), opioid substitution treatment (43.9% vs. 50.5%), and access to clean needles/syringes (89.8% vs. 90.3%). In MVA, risk for HCV-infection was increased in male FSU-migrants compared to German males (OR 3.32, p = 0.006), no difference was identified between female FSU-migrants and German females (OR: 0.83, p = 0.633).

CONCLUSION

Male FSU-migrants were at highest risk of being HCV infected. Therefore, targeted actions are needed to ensure access and acceptance of harm reduction measures, including HCV-testing and -treatment for this subpopulation of PWID.

Are we ready to treat hepatitis C virus in individuals with opioid use disorder: assessment of readiness in European countries on the basis of an expert-generated model

Individuals with a history of injecting drugs have a high prevalence of chronic hepatitis C (HCV) infection. Many have a history of opioid use disorder (OUD). Despite novel treatments with improved efficacy and tolerability, treatment is limited in the group. A faculty of experts shared insights from clinical practice to develop an HCV care-readiness model. Evidence and expert knowledge was collected. Ten experts developed a model of three factors (with measures): 'healthcare engagement', 'guidance' and 'place'. Overall, 40-90% of individuals with OUD engage with drug treatment services. Ten of 12 HCV guidelines provided specific advice for the OUD population. Ten of 12 OUD care guidelines provided useful HCV care advice. In 11 of 12 cases, location of HCV/drug treatment care was in different places. This readiness assessment shows that there are important limitations to successful HCV care in OUD. Specific actions should be taken: maintain/increase access to OUD treatment services/opioid agonist therapy, updating HCV guidance, locate care in the same place and allow wider prescribing of anti HCV medicines.

Hepatitis C bio-behavioural surveys in people who inject drugs-a systematic review of sensitivity to the theoretical assumptions of respondent driven sampling

BACKGROUND

New, more effective and better-tolerated therapies for hepatitis C (HCV) have made the elimination of HCV a feasible objective. However, for this to be achieved, it is necessary to have a detailed understanding of HCV epidemiology in people who inject drugs (PWID). Respondent-driven sampling (RDS) can provide prevalence estimates in hidden populations such as PWID. The aims of this systematic review are to identify published studies that use RDS in PWID to measure the prevalence of HCV, and compare each study against the STROBE-RDS checklist to assess their sensitivity to the theoretical assumptions underlying RDS.

METHOD

Searches were undertaken in accordance with PRISMA systematic review guidelines. Included studies were English language publications in peer-reviewed journals, which reported the use of RDS to recruit PWID to an HCV bio-behavioural survey. Data was extracted under three headings: (1) survey overview, (2) survey outcomes, and (3) reporting against selected STROBE-RDS criteria.

RESULTS

Thirty-one studies met the inclusion criteria. They varied in scale (range 1-15 survey sites) and the sample sizes achieved (range 81-1000 per survey site) but were consistent in describing the use of standard RDS methods including: seeds, coupons and recruitment incentives. Twenty-seven studies (87%) either calculated or reported the intention to calculate population prevalence estimates for HCV and two used RDS data to calculate the total population size of PWID. Detailed operational and analytical procedures and reporting against selected criteria from the STROBE-RDS checklist varied between studies. There were widespread indications that sampling did not meet the assumptions underlying RDS, which led to two studies being unable to report an estimated HCV population prevalence in at least one survey location.

CONCLUSION

RDS can be used to estimate a population prevalence of HCV in PWID and estimate the PWID population size. Accordingly, as a single instrument, it is a useful tool for guiding HCV elimination. However, future studies should report the operational conduct of each survey in accordance with the STROBE-RDS checklist to indicate sensitivity to the theoretical assumptions underlying the method.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015019245.

Correlates of anti-hepatitis C positivity and use of harm reduction services among people who inject drugs in two cities in Croatia

BACKGROUND

We assessed correlates of anti-hepatitis C (anti-HCV) positivity and utilization of needle and syringe exchange programs (NSEP) and opioid agonist treatment (OAT) among people who inject drugs (PWID) in two Croatian cities.

METHODS

We conducted a cross-sectional study using respondent-driven (RDS) sampling among PWID in Rijeka (N=255) and Split (N=399). We used RDS-weighted population estimates and multivariable logistic regression to explore correlates of anti-HCV positivity and NSEP and OAT utilization.

RESULTS

Seventy-eight percent (78.0%) of PWID in Rijeka and 61.5% in Split had been tested previously for HCV, while 21.5% and 7.0%, respectively, were tested for HCV in the past 12 months. Among PWID who report being infected with HCV, 24.9% in Rijeka and 11.3% in Split received anti-HCV treatment. In Rijeka, PWID who utilized NSEP and, in Split, those who were ever imprisoned, had higher odds of anti-HCV positivity. In Rijeka, PWID on OAT were more likely to use non-sterile injecting equipment and to inject for longer than 10 years. PWID enrolled in NSEP were more likely to inject opioid agonist medication (OAM) and less likely to use non-sterile injecting equipment. More than half of PWID reported misuse of OAM in the past month, while out of PWID enrolled in OAT, 65.4% in Rijeka and 88.7% in Split injected OAM in the month prior to the survey.

CONCLUSIONS

Key findings of the paper point to the need to scale up HCV testing and treatment, improve access to NSEP and the quality of OAT provisions in order to prevent its misuse among PWID.