Anti-hepatitis C antibody prevalence among intravenous drug addicts in the Catanzaro area

Hepatitis C virus: laboratory surveillance in England and Wales, 1992-2004

Between 1992 and 2004, a total of 49,819 confirmed hepatitis C infections have been reported to the Health Protection Agency (HPA) by laboratories in England and Wales; the annual number of reports increased from 241 in 1991 to 8149 in 2004. Most reports with a known risk factor were in injecting drug users (87%, 12,438/14,221), but 71% (35,598/49,819) of the total had no reported identified risk. The age-sex distribution of the latter cases was similar to that in injecting drug users. Using names to assign ethnicity, individuals with South Asian names had an older age distribution and a different risk factor profile from non-South Asians. Using published age-specific prevalence data from 1996, it was estimated that around 28,1764 cases of hepatitis C infection exist in England and Wales, and that only 17% of these cases have been reported to the HPA. Surveillance reports continue to provide important information regarding trends in hepatitis C infection in specific risk groups.

Hepatitis C virus infection and injection drug users: prevention, risk factors, and treatment

Injection drug users (IDUs) are the largest group of persons infected with hepatitis C virus (HCV), with a prevalence of 50%-90%. The transmission of HCV is not the effect of the drug injected but of sharing contaminated equipment. For the sake of prevention, we have to know which factors are more likely to lead to HCV seroconversion and which particular situations and environments are risk factors for equipment sharing. As far as therapy is concerned, some studies have shown that treatment for HCV infection in IDUs during substitution treatment for drug dependency is as successful as is treatment of patients who are not IDUs. Screening and early treatment of IDUs could play an important role in controlling HCV infection. The rate of reinfection may not as high as supposed. All studies dealing with treatment for HCV infection in IDUs have stressed the necessity of collaboration among hepatologists and specialists in addiction medicine, social workers, and psychotherapists.

The prevalence of hepatitis C in England and Wales

OBJECTIVES

To estimate the background population prevalence of hepatitis C in England and Wales, observe the prevalence over time and assess the extent of infection outside of known risk groups.

METHODS

Sera from residual specimens from adult patients submitted to laboratories in England and Wales were tested for anti-HCV. Testing was carried out using a cost-effective pooling strategy.

RESULTS

Although the prevalence of anti-HCV was highest in 1986 (1.07%), in the multivariable analysis, prevalence did not vary significantly between the 3 periods 1986, 1991 and 1996 (P=0.14). The prevalence of infection was higher in males than in females (P=0.0013). An age-period-cohort analysis revealed a cohort effect due to a lower HCV prevalence in the most recent birth cohorts, that is, those born between the calendar years 1971-1975 and 1976-1980.

CONCLUSIONS

The majority of HCV infections in England and Wales were probably acquired before 1986. Infections in younger males identified in 1996 may signify more recent acquisition by injecting drug use.

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.

Incidence rate and risk factors for HCV seroconversion among injecting drug users in an area with low HIV seroprevalence

We conducted a study on injecting drug users attending one of 3 drug treatment centres in Naples, to estimate HIV and hepatitis C virus (HCV) incidence rates and to identify risk factors for seroconversion. Incidence rates were estimated using as denominator the person-time of follow-up of participants who were negative for both HIV and HCV at enrollment and who were retested within 6-12 months. Information on risk factors was collected using a standardized questionnaire. A nested case-control analysis was performed comparing seroconverters with persistently HCV-negative individuals. None of the initially non-infected participants seroconverted for HIV, while the incidence rate for HCV infection was approximately 29 per 100 person-years. Analysis of risk factors showed that age > 28 years and injecting use of cocaine were associated with HCV seroconversion. The protective role of methadone treatment was also marginally significant. Our findings suggest that HCV infection may represent an important public health problem in areas with low HIV circulation. The identification of specific risk factors for HCV infection is needed to plan effective prevention strategies.