Prevalence of chronic HCV infection in EU/EEA countries in 2019 using multiparameter evidence synthesis.

Background: Epidemiological data are crucial to monitoring progress towards the 2030 Hepatitis C Virus (HCV) elimination targets. Our aim was to estimate the prevalence of chronic HCV infection (cHCV) in the European Union (EU)/European Economic Area (EEA) countries in 2019. Methods: Multi-parameter evidence synthesis (MPES) was used to produce national estimates of cHCV defined as: π = πrecρrec + πexρex + πnonρnon; πrec, πex, and πnon represent cHCV prevalence among recent people who inject drugs (PWID), ex-PWID, and non-PWID, respectively, while ρrec, ρex, and ρnon represent the proportions of these groups in the population. Information sources included the European Centre for Disease Prevention and Control (ECDC) national operational contact points (NCPs) and prevalence database, the European Monitoring Centre for Drugs and Drug Addiction databases, and the published literature. Findings: The cHCV prevalence in 29 of 30 EU/EEA countries in 2019 was 0.50% [95% Credible Interval (CrI): 0.46%, 0.55%]. The highest cHCV prevalence was observed in the eastern EU/EEA (0.88%; 95% CrI: 0.81%, 0.94%). At least 35.76% (95% CrI: 33.07%, 38.60%) of the overall cHCV prevalence in EU/EEA countries was associated with injecting drugs. Interpretation: Using MPES and collaborating with ECDC NCPs, we estimated the prevalence of cHCV in the EU/EEA to be low. Some areas experience higher cHCV prevalence while a third of prevalent cHCV infections was attributed to PWID. Further efforts are needed to scale up prevention measures and the diagnosis and treatment of infected individuals, especially in the east of the EU/EEA and among PWID. Funding: ECDC.

Self-reported HPV vaccination status and HPV vaccine hesitancy in a nationally representative sample of emerging adults in Croatia.

Introduction: The aim of this study was to determine self-reported human papillomavirus (HPV) vaccination status among emerging adults in Croatia, intention to get the HPV vaccine among unvaccinated individuals and correlates of HPV vaccine hesitancy. Methods: Data were collected via a cross-sectional survey based on a probabilistic national sample. The sample included 1,197 individuals aged 18-25 years (50.6% were women) who were recruited from November 2021 to February 2022 as part of the commercial online panel. Analyses included 981 participants who correctly answered two "attention trap" questions using descriptive statistics and multivariate analyses. The data were post-hoc weighted for gender and age and adjusted for clustering effect. To adjust standard errors for the sampling design, multivariate analyses were carried out using the complex samples module in the IBM SPSS 27 statistical software package. Results: Overall, 18.3% of participants (25.0% of women and 11.7% of men) reported that they were HPV vaccinated, while 21.9% did not know their HPV vaccination status. Of those vaccinated, 65.6% were women. The odds of being HPV-vaccinated were significantly higher among female participants. Among the unvaccinated, 35.4% expressed a willingness to get the vaccine. The odds of vaccination hesitancy were significantly lower among women, participants who reported a higher perceived risk of STIs, those who recognized that HPV could result in cervical cancer, and significantly higher among those who were more religious. Conclusion: Our findings suggest a need to increase HPV vaccination uptake in Croatia through raising awareness about HPV vaccine effectiveness and also through the implementation of strategies to make vaccination more available.

A pilot sentinel surveillance system to monitor treatment and treatment outcomes of chronic hepatitis B and C infections in clinical centres in three European countries, 2019.

BackgroundThe World Health Organization European Action Plan 2020 targets for the elimination of viral hepatitis are that > 75% of eligible individuals with chronic hepatitis B (HBV) or hepatitis C (HCV) are treated, of whom > 90% achieve viral suppression.AimTo report the results from a pilot sentinel surveillance to monitor chronic HBV and HCV treatment uptake and outcomes in 2019.MethodsWe undertook retrospective enhanced data collection on patients with a confirmed chronic HBV or HCV infection presenting at one of seven clinics in three countries (Croatia, Romania and Spain) for the first time between 1 January 2019 and 30 June 2019. Clinical records were reviewed from date of first attendance to 31 December 2019 and data on sociodemographics, clinical history, laboratory results, treatment and treatment outcomes were collected. Treatment eligibility, uptake and case outcome were assessed.ResultsOf 229 individuals with chronic HBV infection, treatment status was reported for 203 (89%). Of the 80 individuals reported as eligible for treatment, 51% (41/80) were treated of whom 89% (33/37) had achieved viral suppression. Of 240 individuals with chronic HCV infection, treatment status was reported for 231 (96%). Of 231 eligible individuals, 77% (179/231) were treated, the majority of whom had received direct acting antivirals (99%, 174/176) and had achieved sustained virological response (98%, 165/169).ConclusionTreatment targets for global elimination were missed for HBV but not for HCV. A wider European implementation of sentinel surveillance with a representative sample of sites could help monitor progress towards achieving hepatitis control targets.

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.

Digital technology and HIV, HCV and STI voluntary counselling and testing: good practice example from Croatia.

The aim of this paper is to introduce the digitalization process and its effects on better reach of the target population. Progress in the digitalization and e-health tools worldwide enables new opportunities in prevention, diagnostics and treatment for people living with HIV (PLHIV) and people in the risk of HIV infection, hepatitis C (HCV) and other sexually transmitted infections (STIs), especially in the context of the COVID-19 pandemic. The system already used for voluntary counselling and testing (VCT) at the CheckPoint Centre Zagreb run by the non-governmental organization (NGO) Croatian Association for HIV and Viral Hepatitis (CAHIV) was upgraded and adapted (due to the COVID-19 prevention epidemiological measures) and developed for implementation of the pilot project of feasibility and acceptability of home HIV self-testing (HIVST) among men who have sex with men (MSM) in Zagreb. A special feature of the HIVST mobile application enables an innovative approach in collecting clients' test result feedback. This paper presents the method of use digitalization of the VCT and HIVST activities to support and increase availability of screening testing. Described procedures of new technologies application in VCT services and preliminary results of the HIVST pilot project indicate that technology-delivered interventions can contribute and improve access and utilisation of HIV/STI prevention and care services.

Privacy-Preserving Partner Notification Service to Control Sexually Transmitted Infections.

Partner Notification (PN) processes are typically part of wider combination prevention efforts and focus on the notification of sexual partners to prevent Sexually Transmitted Infections (STIs), including Human Immunodeficiency Viruses and viral hepatitis. We present a free, voluntary, anonymous and GDPR-compliant Partner Notification service that offers enhanced security and privacy through a web and mobile application via a unique random codes.

A GDPR-Compliant Partner Notification Service.

Partner Notification processes focus on the notification of sexual partners to prevent the transmission of Sexually Transmitted Infections (STIs). The INTEGRATE Joint Action provides an integrated platform called RiskRadar, for combination prevention activities targeting STIs, including an anonymous, free and voluntary Partner Notification service. The presented service information flow ensures privacy, security and GDPR compliance which were identified as vital with similar tools. The service is available via web and mobile interfaces using a unique random code provided from authorised healthcare professionals to support privacy.

RiskRadar: development and pilot results of a technical intervention targeting combination prevention regarding HIV, viral hepatitis, sexually transmitted infections and tuberculosis.

BACKGROUND: The HIV pandemic impacts the lives of millions and despite the global coordinated response, innovative actions are still needed to end it. A major challenge is the added burden of coinfections such as viral hepatitis, tuberculosis and various sexually transmitted infections in terms of prevention, treatment and increased morbidity in individuals with HIV infection. A need for combination prevention strategies, tailored to high-risk key populations arises and technology-based interventions can be a valuable asset. The COVID-19 pandemic challenged the delivery of existing services and added stress to existing public health and clinical structures but also highlighted the potential of exploiting technical solutions for interventions regarding infectious diseases. In this paper we report the design process, results and evaluation findings from the pilots of 'RiskRadar'-a web and mobile application aiming to support combination prevention, testing and linkage to care for HIV, viral hepatitis, various sexually transmitted infections and tuberculosis. METHODS: RiskRadar was developed for the INTEGRATE Joint Action's aim to improve, adapt and pilot innovative digital tools for combination prevention. RiskRadar was designed iteratively using informed end-user-oriented approaches. Emphasis was placed on the Risk Calculator that enables users to assess their risk of exposure to one or more of the four disease areas, make informed decisions to seek testing or care and adjust their behaviours ultimately aiming to harm/risk reduction. RiskRadar has been piloted in three countries, namely Croatia, Italy and Lithuania. RESULTS: RiskRadar has been used 1347 times across all platforms so far. More than 90% of users have found RiskRadar useful and would use it again, especially the Risk Calculator component. Almost 49.25% are men and 29.85% are in the age group of 25-34. The application has scored 5.2/7 in the User Experience Questionnaire, where it is mainly described as "supportive" and "easy-to-use". The qualitative evaluation of RiskRadar also yielded positive feedback. CONCLUSIONS: Pilot results demonstrate above average satisfaction with RiskRadar and high user-reported usability scores, supporting the idea that technical interventions could significantly support combination prevention actions on Sexually Transmitted Infections.

Seroprevalence and Risk Factors for HIV, Hepatitis B, and Syphilis in Populations with High-risk Behaviors in Croatia.

HIV and sexually-transmitted diseases (STDs) represent a significant public health problem worldwide. We analyzed the seroprevalence and risk factors for HIV, hepatitis B and syphilis in populations with high-risk behaviors in Croatia. During a three-year period, a total of 443 men who have sex with men (MSM) / bisexual persons, sex workers (SW) / clients of SW, persons with multiple sexual partners, and persons with a history of STD were tested for the presence of HIV, hepatitis B virus (HBV), and Treponema pallidum (syphilis) antibodies within the framework of second generation HIV surveillance. Participants were recruited from 11 Croatian counties, the vast majority among clients of voluntary counselling and testing centers. The overall prevalence of HIV, HBsAg, anti-HBc, and syphilis was 1.4%, 2.6%, 12.1%, and 3.4%, respectively. HBV and syphilis seroprevalence differed significantly between, genders with higher prevalence among men (anti-HBc 13.8% vs. 5.7%, P=0.043; syphilis 4.4% vs. 0%; P=0.049), as well as between age groups, with a steady increase according to age. Participants with a history of STD were more often seropositive than participants who did not report STD (HBsAg 8.2% vs. 1.0%, P=0.002; anti-HBc 32.4% vs. 6.4%, P<0.001; syphilis 12.0% vs. 1.7%, P<0.001). Syphilis seroprevalence was higher in homo / bisexual persons (12.2%) compared with heterosexual persons (1.2%, P<0.001). Logistic regression showed that history of STD was a significant risk factor for hepatitis B (HBsAg AOR=6.229, 95% CI=1.491-26.022; anti-HBc AOR=5.872, 95% CI=2.899-11.896) and syphilis seropositivity (AOR=5.572, 95% CI=1.751-17.726), while homo / bisexual behavior was associated with syphilis seropositivity (AOR=12.820, 95% CI=3.688-44.557). Our results highlight the importance of continuing STDs screening and prevention in at-risk populations.

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.

BACKGROUND: There are limited data on HIV and hepatitis C virus (HCV) epidemiology among people who inject drugs (PWID) in Croatia. This study aims to provide data on HIV and HCV prevalence and sexual and injecting risk behaviours among PWID in Zagreb, Split, and Rijeka. METHODS: Using respondent-driven sampling (RDS) we recruited from November 2014 to February 2015 a total of 176 PWID in Zagreb, 255 in Rijeka and 399 in Split. Participants provided biological specimens for HIV and HCV testing and completed a behavioural questionnaire. RESULTS: The proportion of female PWID ranged from 19.5% in Zagreb to 26.0% in Split. In the month before the survey, 2.5% of PWID in Split, 5.6% in Rijeka and 8.0% in Zagreb reported sharing non-sterile needles and syringes. Many PWID injected opioid substitution therapy (OST) in the month before the survey (57.0% in Zagreb and 57.5% in Split and Rijeka, respectively). Among PWID who had a casual sexual partner in the past 12 months (ranging from 39.2% in Split to 44.4% in Rijeka) condom use was low. Although HIV prevalence was low (0.2% in Rijeka and Zagreb, 0.3% in Split), HCV antibody prevalence was considerable (29.1% in Zagreb, 31.5% in Rijeka, 38.3% in Split). HIV and HCV testing coverage in the past 12 months was insufficient (6.8% and 7.0% in Split; 13.2% and 13.5% in Zagreb; 20.2% and 21.5% in Rijeka, respectively). CONCLUSION: We found a low-level HIV epidemic and a sizable HCV epidemic among PWID in Zagreb, Split and Rijeka. Presence of high-risk injecting and sexual behaviours together with inadequate HIV and HCV testing coverage call for development of a comprehensive approach to harm reduction and introduction of needle and syringe exchange programmes in prisons, as well as strengthening sexual health interventions.

Repeat HIV testing at voluntary testing and counseling centers in Croatia: successful HIV prevention or failure to modify risk behaviors?

HIV testing plays a critical role in preventing the spread of the virus and identifying infected individuals in need of care. Voluntary counseling and testing centers (VCTs) not only conduct testing but they also provide counseling. Since a proportion of people who test negative for HIV on their previous visit will return for retesting, the frequency of retesting and the characteristics of those who retest may provide insights into the efficacy of testing and counseling strategies. In this cross-sectional, retrospective study of 1,482 VCT clients in Croatia in 2010, 44.3% had been tested for HIV before. The rate of repeat HIV testing is lower in Croatia than in other countries. Men who have sex with men (MSM) clients, those with three or more sexual partners in the last 12 months, consistent condom users with steady partners, and intravenous drug users were more likely to be repeat testers. This finding suggests that clients presenting for repeat HIV testing are those who self-identify as being at a higher risk of infection. Our data showed that testing positive for HIV was not associated with repeat testing. However, the effects of repeat testing on HIV epidemiology needs to be explored.

[Epidemiology of viral hepatitis]. / Epidemiologija virusnih hepatitisa.

Understanding the country-specific epidemiology of disease, which may vary greatly among countries, is crucial for identifying the most appropriate preventive and control measures. An overview of the local epidemiology of viral hepatitis in Croatia is given in this paper. The overall prevalence of hepatitis B in Croatia is low (less than 2% HBsAg carriers in the general population). Hepatitis B incidence and prevalence began to decline significantly following the introduction of universal hepatitis B vaccination in 1999. Information on HBsAg seroprevalence is derived from routine testing of certain subpopulations (pregnant women, blood donors) and seroprevalence studies mostly targeted at high-risk populations. Universal childhood vaccination against hepatitis B remains the main preventive measure. We recommend testing for immunity one to two months after the third dose of hepatitis B vaccine for health-care workers. The incidence and prevalence of hepatitis C have also been declining in the general population. The main preventive measures are ensuring safety of blood products, prevention of drug abuse, and harm reduction programs for intravenous drug users. Hepatitis A incidence has declined dramatically since fifty years ago, when thousands of cases were reported annually. In the last five years, an average of twenty cases have been reported per year. The reduction of hepatitis A is a consequence of improved personal and community hygiene and sanitation. Hepatitis D has not been reported in Croatia. The risk of hepatitis D will get to be even smaller as the proportion of population vaccinated against hepatitis B builds up. Hepatitis E is reported only sporadically in Croatia, mostly in persons occupationally in contact with pigs and in travelers to endemic countries. In conclusion, Croatia is a low prevalence country for hepatitides A, B and C. Hepatitis D has not been reported to occur in Croatia and there are only sporadic cases of hepatitis E. Since hepatitis A is a rare disease occurring sporadically, which is a consequence of improved sanitation and hygiene, hepatitides B and C are the main causes of viral hepatitis in Croatia. The introduction of universal mandatory hepatitis B vaccination of schoolchildren in 1999 resulted in a decrease in the incidence of hepatitis B, which is most pronounced in adolescents and young adults, and further decrease in the incidence and prevalence is expected as the pool of susceptible individuals decreases through vaccination. The incidence of hepatitis C is decreasing as well. In spite of a relatively favorable epidemiological situation, hepatitis B and C are still a significant public health burden with an estimated 25,000 persons chronically infected with HBV and about 40,000 persons chronically infected with HCV in Croatia.

Vaccine regulations in Croatia.

In this paper legal prerequisites for vaccine licensure in Croatia are discussed. The Croatian legislation concerning vaccine licensing, marketing authorisation and utilization is reviewed. The procedures for including a vaccine into the Mandatory Childhood Vaccination Programme are also discussed with focus on Human papillomavirus (HPV) vaccines. Non-obligatory vaccination recommendations are given when according to professional opinion; vaccination is beneficial for the vaccinee. There is little doubt that HPV vaccines should be recommended for preadolescent girls in Croatia. However, reaching a decision on its possible introduction into the Childhood Vaccination Programme will require careful consideration of the larger picture and a comparison of the cost-effectiveness of a mandatory vaccination against other competing public health priorities.