HCV and HIV infection among intravenous drug abusers in eastern Sicily

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 and risk factors for hepatitis C among injection drug users in Baltimore, Maryland

Between 1988 and 1996, the incidence of and risk factors for hepatitis C virus (HCV) infection were studied in a cohort of injection drug users in Baltimore, Maryland. By second-generation antibody testing of stored serum samples, 142 participants were found to be susceptible to HCV at the time they entered the study. After a median follow-up of 6.5 years, 43 participants (30.3%) developed antibodies to HCV (anti-HCV). The overall incidence was 6.4 cases per 100 person-years, but a substantial decline in the annual incidence rate was observed after the first 2 years (1988 to 1990, 13.4/100 person-years; 1991 to 1996, 2.3/100 person-years [P = 0.0001 for trend]). Participants who acknowledged active drug use, especially those who acknowledged frequent use and sharing of drug paraphernalia, were at increased risk of HCV infection. However, high-risk sexual practices were not associated with HCV seroconversion. Efforts to reduce HCV infection must be focused on curbing drug use and especially on the sharing of needles and drug paraphernalia.

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.

Hepatitis C virus infection in an HIV-positive population in Normandy: antibodies, HCV RNA and genotype prevalence

The prevalence and the characteristics of hepatitis C virus infection (HCV) in 161 HIV-positive patients were studied. HCV seroprevalence was determined by enzyme immunoassay and recombinant immunoblot assay (RIBA). Two different reverse transcriptase polymerase chain reaction (RT-PCR) methods were also used to test the HCV-seropositive samples and 50 EIA-negative sera used as controls. The RNA HCV-positive sera were genotyped by the LiPA procedure. Associations of HCV status with demographic characteristics and risk factors were assessed by chi 2 and Fisher's exact tests. The seroprevalence of HCV was 34.2% with a significant difference between blood and sexual exposure risk groups (60.6% vs. 13.6%, respectively; P < 0.0001). Thirty-six of the 55 anti-HCV-positive sera were also positive for HCV RNA, and PCR detected HCV RNA in 8 HCV-seronegative patients. Various RIBA profiles were found and all sera were positive for antibodies to the c33 protein. A proportion of sera had elevated levels of transaminase activity (37.2%), and abnormal liver function as associated with HCV infection. Forty-two samples were genotyped and five genotypes and subtypes of the HCV virus were detected. Genotype 1a was the most frequent in this cohort, although genotype 1b is generally more common in France. The majority (94.1%) of the patients with genotype 1a had a history of blood exposure, which may account for the difference.