Prevalence and correlates of infection with human immunodeficiency virus, hepatitis B virus, and hepatitis C virus among drug users in Italy: A cross-sectional study

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.

Incidence and Risk Factors for Hepatitis C Virus Infection among Illicit Drug Users in Italy

So far, only three small outdated studies have investigated hepatitis C virus (HCV) incidence and risk factors among illicit drug users (DUs) in Italy. Thus, during 2007-2010, we conducted a prospective cohort study among DUs attending 17 Italian rehabilitation centers serving urban areas. Two hundred eighty-four HCV-uninfected DUs were prospectively followed by interview and anti-HCV antibody and RNA testing every 6 months. Incidence was calculated using the person-years method. Infection predictors were assessed by time-dependent Cox analysis. Participants were mostly male (83.4%), under opioid substitution therapy (OST) (78.9%), non-injecting DUs (67.9%), and with a mean age of 30.8. Ninety-one of 224 DUs initially under OST interrupted treatment during the follow-up. Overall HCV incidence was 5.83/100 person-years at risk (PYAR) [95% confidence intervals (CI), 3.63-9.38]. The incidence did not significantly differ according the participants' sociodemographic characteristics or the degree of urbanization of the towns involved in the study. The incidence was higher for DUs under than for those not under OST (6.23 vs 4.50/100 PYAR; p = 0.681). Incidence was also higher for those with than for those without OST interruption (7.17 vs 5.04/100 PYAR; p = 0.55). However, all these differences were non-significant. At last follow-up visit, a significant decrease in frequency of sharing equipment for preparation/using drugs (by injection or not) was observed by analyzing either the whole cohort or DUs under OST only. Anti-HCV seroconversion resulted independently associated with sharing drug preparation/use equipment, backloading, having a HCV-positive sexual partner, or household and (marginally) intravenous injection. In this study, HCV incidence was non-negligible and OST seemed to lack effectiveness in reducing it. In Italy, implementation of combined harm reduction interventions and antiviral treatment of chronically infected DUs would be needed.

Risk factors for and incidence of acute hepatitis C after the achievement of blood supply safety in Italy: results from the national surveillance system

Surveillance systems for acute hepatitis C allow monitoring of disease incidence trends and transmission patterns. This study aimed to describe the epidemiological profile of reported cases of symptomatic acute hepatitis C in Italy after the achievement of blood supply safety. The incidence of symptomatic acute hepatitis C since 1991 was estimated. Risk factors for acute hepatitis C were analyzed for the period 2003-2010 through a case-control study within a population-based surveillance for acute viral hepatitis. From 1991 to 2010, the incidence decreased from 2 to 0.2 per 100,000, with a more evident decrease among persons aged 15-24 years. During 2003-2010, 1,053 cases were reported. Intravenous drug use (adjusted odds ratio [(adj) OR], 30.5; 95% confidence interval [CI], 18.9-49.1), cohabitation or sexual partnership with an hepatitis C virus (HCV) carrier ((adj) OR, 11.2; 95% CI, 6.6-19.2), nosocomial exposure ((adj) OR, 6.6; 95% CI, 4.6-9.4); unsafe sexual practices ((adj) OR, 3.1; 95% CI, 1.9-5.2), and cosmetic treatments with percutaneous exposure ((adj) OR, 1.7; 95% CI, 1.2-2.4) were independently associated with acute hepatitis C. Population attributable risk estimates indicated nosocomial exposure (39.6%) and intravenous drug use (30.5%) as responsible for most cases. In conclusion, the incidence of symptomatic acute hepatitis C is declining in Italy. Currently, the most important risk factors are: having an HCV-positive household or sexual partner, unsafe sexual practices, cosmetic percutaneous treatments, intravenous drug use, and nosocomial exposure; the latter two factors are responsible for most cases. Effective prevention programs for intravenous drug users and strict adherence to universal precautions in healthcare settings are needed.

Non-injection drug use and hepatitis C among drug treatment clients in west central Mexico

BACKGROUND

Research on hepatitis C virus (HCV) prevalence among non-injecting drug treatment clients in the United States, Europe and Asia indicate substantial differences by place. To date, little or no research on HCV and non-injection drug use (NIDU) has been conducted in Mexico.

METHODS

We examined the prevalence of HCV, hepatitis B virus (HBV), and HIV among non-injecting drug users (NIDUs) in community-based drug treatment (N=122) and NIDUs in a prison-based drug treatment program (N=30), both located in west central Mexico.

RESULTS

Among the community clients, prevalence was 4.1% (95% confidence interval [CI]: 1.8-9.2) for HCV, 5.7% for HBV (95% CI: 2.8-11.4), and 1.6% for HIV (95% CI: 0.4-5.8). Among the in-prison clients, prevalence was 40.0% (95% CI: 24.6-57.7) for HCV, 20.0% for HBV (95% CI: 9.5-37.3), and 6.7% for HIV (95% CI: 1.9-21.3). None of the clients were aware of being infected.

CONCLUSION

The HCV prevalence found for the NIDU community treatment clients ranks among the lower HCV estimates published for NIDUs in treatment to date. The prevalence found for the in-prison clients ranks among the higher, raising a concern of possible elevated HCV infection among NIDUs in the west central Mexico prison--one compounded by the finding that none of this study's clients knew they were HCV positive.

Hepatitis C prevalence in injecting drug users in Europe, 1990-2007: impact of study recruitment setting

Monitoring injecting drug users' (IDUs) health is challenging because IDUs form a difficult to reach population. We examined the impact of recruitment setting on hepatitis C prevalence. Individual datasets from 12 studies were merged. Predictors of HCV positivity were sought through a multilevel analysis using a mixed-effects logistic model, with study identifier as random intercept. HCV prevalence ranged from 21% to 86% across the studies. Overall, HCV prevalence was higher in IDUs recruited in drug treatment centres compared to those recruited in low-threshold settings (74% and 42%, respectively, P < 0·001). Recruitment setting remained significantly associated with HCV prevalence after adjustment for duration of injecting and recent injection (adjusted odds ratio 0·7, 95% confidence interval 0·6-0·8, P = 0·05). Recruitment setting may have an impact on HCV prevalence estimates of IDUs in Europe. Assessing the impact of mixed recruitment strategies, including respondent-driven sampling, on HCV prevalence estimates, would be valuable.