Cathy Matheï

Seroprevalence of hepatitis C markers among intravenous drug users in western European countries: a systematic review.

Currently, the most important risk factor for hepatitis C virus (HCV) infection in Europe is intravenous drug use. To establish a better insight into the epidemiology of hepatitis C among intravenous drug users (IVDUs) in western European countries a systematic review on the prevalence of hepatitis C markers and their determinants was performed. Reports were identified by searches on Medline and on the internet and by screening reference lists of selected papers. The prevalence rates of anti‐HCV in western European IVDUs reported in the 66 studies selected for analysis, ranged between 37 and 98%. No relation was found between prevalence rates and mean age, mean duration of intravenous drug use, geographical area, setting of the study, method of recruitment or the year(s) of collection of samples. Eleven studies concerning the prevalence of HCV‐RNA in hepatitis C‐infected IVDUs were selected for analysis. Prevalence rates ranged from 26 to 86%. Based on five studies, a statistically significant positive linear relation was found between the mean age of study population and the prevalence of HCV‐RNA. Our analysis revealed considerable variation in prevalence rates of hepatitis C markers among IVDUs in western Europe. We found no conclusive explanation for this variability. Further research investigating the dynamics of the hepatitis C epidemic in IVDUs is necessary.

A comparison between the force of infection estimates for blood-borne viruses in injecting drug user populations across the European Union: a modelling study.

Summary.  A number of studies have been conducted in injecting drug user (IDU) populations in Europe, in which the prevalence of human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) was measured together with demographic and epidemiological information such as age and the age at first injection. A measure of the risk of becoming infected is the force of infection (FOI), defined as the per capita rate at which susceptible individuals acquire infection. The objective of this study was to estimate the FOI and its heterogeneity for HBV, HCV and HIV (where available) for IDU populations in a number of countries in Europe. Data were obtained from five countries: Belgium, the United Kingdom, Spain and Italy, and the Czech Republic, which provided two data sets. The model describes the prevalence of infection as a function of the FOI that may vary over time or duration of IDU. In addition to this, if two or more infections were being considered then a parameter describing the potential heterogeneity of the FOI within the IDU population was also estimated. The results here add to the growing evidence that new initiates to injecting are at an increased risk of blood‐borne viral infection compared with more experienced IDUs. In addition, there is evidence of individual heterogeneity of FOI estimates within the overall IDU populations. This suggests that different proportions of individuals in each population are at increased risk of infection compared with the rest of the population. Future interventions should identify and target these individuals. Moreover, changes over time in individual heterogeneity estimates of IDU populations may provide an indicator for measuring intervention impacts.

Molecular epidemiology of hepatitis C among drug users in Flanders, Belgium: association of genotype with clinical parameters and with sex- and drug-related risk behaviours

The aim of this study was to determine the genotypic variation of hepatitis C among drug users in Flanders and to relate the distribution of genotypes to the characteristics of the population. Hepatitis C virus RNA (HCV-RNA) quantification and genotyping was performed on stored samples from 161 anti-HCV-positive injecting and non-injecting drug users. Information on sociodemographic status, drug-related risk behaviour and sexual risk behaviour was available for each drug user. HCV-RNA was present in 152 of 161 samples (94.4%). Genotype 1 was predominant (48.7%), followed by genotype 3 (41.2%), genotype 4 (8.8%) and genotype 2 (1.4%). In the multivariate analysis, lack of a history of injecting drug use was confirmed as a statistically significant predictor for infection with genotype 1. Predictors for infection with genotype 3 were the presence of anti-HBc antibodies and a history of injecting drug use. Being tattooed emerged as a statistically significant predictor for infection with genotype 4. The 94.4% prevalence of HCV-RNA among anti-HCV-positive drug users was considerably higher than the 54–86% chronicity rate found globally among HCV-infected patients. The results of this study suggest the existence of separate transmission networks for injecting drug users and non-injecting drug users. Finally, the results suggest that tattooing practices play a role in the spread of HCV among drug users.

Prevalence of hepatitis C in drug users in Flanders: determinants and geographic differences

The prevalence of hepatitis C and related risk factors in drug users were compared in two geographic regions in Belgium, the city of Antwerp and the mixed urban-rural area of Limburg. All 310 participants were surveyed and screened for hepatitis B, hepatitis C and HIV. Prevalence rates of anti-HCV, anti-HBc and anti-HIV were 71, 62 and 4% in Antwerp and 46, 21 and 0% in Limburg respectively. Injecting drug use, duration of injecting drug use, work as a commercial sex-worker, originating from Turkey or Northern Africa, marginalization and anti-HBc positivity were identified as independent predictors for hepatitis C infection. In this study an important difference in HCV seroprevalence among drug users in a methadone maintenance programme across two geographic regions in Belgium was demonstrated. This was explained not only by variations in drug-related risk behaviour, but also by differences in sexual risk behaviour and socio-economic status.

The prevalence of cardiac dysfunction and the correlation with poor functioning among the very elderly

BACKGROUND Little is known about the relationship between cardiac dysfunction and poor functioning in the elderly. This study sought to describe the prevalence of cardiac dysfunction in the very elderly and to investigate the correlation between echocardiographic abnormalities and indicators of poor functioning. METHODS A cross-sectional analysis within the BELFRAIL (BF(C80+)) study of 567 subjects aged 80 years and older. The clinical research assistant performed an examination including performance testing, questionnaires and technical examinations. Echocardiography was performed at the subjects home by a cardiologist using a portable system. RESULTS The mean age of the participants was 84.7 years and 62.9% were women. Severe cardiac dysfunction was found in 19.3% and was defined as systolic dysfunction (5.8%), valvular heart disease (10.4%) or isolated severe diastolic dysfunction (3.1%). Severe cardiac dysfunction showed to be an independent identifier of poor performance (OR 1.8 (95% CI 1.1-3.2)), a low LAPAQ (LASA Physical Activity Questionnaire) score (OR 1.9 (95% CI 1.2-3.3)) and a high GDS-15 (Geriatric Depression Scale) score (OR 1.7 (95% CI 1.0-2.9)). This relationship was mainly explained by the independent correlation between aortic stenosis and poor functioning. Classic indicators of systolic and diastolic dysfunction were not able to identify participants with poor functioning. CONCLUSION This study shows the very elderly represent a heterogeneous group of subjects with a high prevalence of comorbidities, among whom poor functioning might be triggered by multiple causes. Severe cardiac dysfunction, and more specifically aortic stenosis, showed an independent relationship with poor functioning.

The epidemic history of hepatitis C among injecting drug users in Flanders, Belgium

Summary.  We employed recently developed statistical methods to explore the epidemic behaviour of hepatitis C subtype 1a and subtype 3a among injecting drug users (IDUs) in Flanders, Belgium, using new gene sequence data sampled among two geographically distinct populations of IDUs. First the extent of hepatitis C transmission across regions/countries was studied through calculation of association indices. It was shown that viral exchange had occurred between both populations in Flanders as well as across international borders. Furthermore, evidence was found suggestive of subtypes 1a and 3a predominantly circulating in subpopulations of Flemish IDUs, exhibiting different degrees of travelling/migration behaviour. Secondly, through coalescent‐based analysis the viral epidemic history of the hepatitis C subtype 1a and 3a epidemics was inferred. Evidence was found for different dynamic forces driving both epidemics. Moreover, results suggested that the hepatitis C subtype 3a epidemic has reached a steady state, while the hepatitis C 1a epidemic has not, which therefore might become the predominant subtype among IDUs.

A framework provided an outline toward the proper evaluation of potential screening strategies.

OBJECTIVES Screening tests are often introduced into clinical practice without proper evaluation, despite the increasing awareness that screening is a double-edged sword that can lead to either net benefits or harms. Our objective was to develop a comprehensive framework for the evaluation of new screening strategies. STUDY DESIGN AND SETTING Elaborating on the existing concepts proposed by experts, a stepwise framework is proposed to evaluate whether a potential screening test can be introduced as a screening strategy into clinical practice. The principle of screening strategy evaluation is illustrated for cervical cancer, which is a template for screening because of the existence of an easily detectable and treatable precursor lesion. RESULTS The evaluation procedure consists of six consecutive steps. In steps 1-4, the technical accuracy, place of the test in the screening pathway, diagnostic accuracy, and longitudinal sensitivity and specificity of the screening test are assessed. In steps 5 and 6, the impact of the screening strategy on the patient and population levels, respectively, is evaluated. The framework incorporates a harm and benefit trade-off and cost-effectiveness analysis. CONCLUSION Our framework provides an outline toward the proper evaluation of potential screening strategies before considering implementation.

Prognostic value of circulating cytokines on overall survival and disease-free survival in cancer patients

Through their tumor-promoting and/or tumor-suppressive properties, cytokines can influence progression of cancer. We systematically reviewed the current literature on the prognostic value of the circulating cytokines IL-1α/β, IL-6, IL-8, IL-10, IL-12, TNF-α, TGF-β and IFN-γ to predict overall and disease-free survival in any type of cancer patients. PubMed was systematically searched and based on eligibility assessment using our five criteria of the Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK) checklist, six unique studies were reviewed. Elevated IL-6 and IL-10 levels seem independently associated with worse prognosis in terms of overall and disease-free survival. The prognostic value of IL-1α/β, IL-8, IL-12, TNF-α, TGF-β and IFN-γ could not be demonstrated. The small number of selected studies underlines the need for large well-designed prospective studies, using the REMARK checklist as a guideline, to determine which cytokines have prognostic value on survival in cancer patients.

Prevalence and Prognostic Impact of Valve Area-Gradient Patterns in Patients ≥80 Years With Moderate-to-Severe Aortic Stenosis (from the Prospective BELFRAIL Study).

Although degenerative aortic valve stenosis (AS) is common with increasing age, limited data exist regarding the prevalence and prognostic impact of its various valve area-gradient patterns in patients ≥80 years. To test this, echocardiograms were obtained in 542 randomly selected subjects aged ≥80 years recruited in the Belgium Cohort Study of the Very Elderly study (BFC80+). Subjects were divided into 3 groups: no or mild AS, moderate AS, and severe AS. Patients with severe AS were further stratified into those with high mean gradients (HG-AS) and those with paradoxically low mean gradients (LG-AS). Prevalence of moderate-to-severe AS was 14.7% and that of severe AS was 5.9%. In patients with severe AS, most (72%) exhibited paradoxical LG-AS. All patients with severe HG-AS were asymptomatic at the time of inclusion, whereas 48% of those with severe paradoxical LG-AS had significant symptoms. During follow-up, there were 2 aortic valve replacements and 230 deaths, of which 100 (43%) were of cardiovascular origin. Five-year overall survival rate was significantly worse in severe HG-AS than in any of the other groups (22 ± 14% vs 62 ± 2% in no or mild AS, 48 ± 7% in moderate AS, and 43 ± 10% in severe paradoxical LG-AS, p <0.01). Survival rate was similar among severe paradoxical LG-AS with and without low flow. In conclusion, in this large population-based sample of subjects ≥80 years, the prevalence of severe AS was 5.9%. Most of these subjects presented with the severe paradoxical LG-AS and a third of them were symptomatic. In this elderly community, severe HG-AS is a major determinant of prognosis, even in the absence of symptoms, whereas severe paradoxical LG-AS seems to behave similarly to moderate AS.

Association between recent herpes zoster but not herpes simplex infection and subsequent risk of malignancy in women: a retrospective cohort study

The association between herpes zoster and subsequent cancer risk is still unclear. Consequently, doubts remain regarding the need for investigation of herpes patients for co-existing or subsequent malignancy. This is a retrospective cohort study comparing cancer risk in patients after herpes zoster and age-/sex-matched non-herpes zoster patients, in a primary care-based continuous morbidity database. We tested for interaction by gender, age, diabetes, HRT use or antiviral therapy. Analyses were repeated for patients with and without herpes simplex. The hazard ratio (HR) comparing cancer risk in herpes zoster vs. control patients was significant in all women, women aged > 65 years and subgroups of breast and colorectal cancer (HRs 1·60, 1·82, 2·14, 2·19, respectively). For men, a significant association was found for haematological cancers (HR 2·92). No associations were found with herpes simplex. No interaction was identified with antiviral therapy, diabetes or HRT treatment. We concluded that there was a moderate significant association between herpes zoster and subsequent cancer risk in women aged > 65 years, without any influence of antiviral therapy. No association was found with herpes simplex. There is insufficient reason for extensively testing older patients with herpes zoster or herpes simplex for the presence of occult cancer.