Prevalence, risk factors, and genotype distribution of hepatitis C virus infection in the general population: A community-based survey in southern Italy (original) (raw)

In 1996 the prevalence, risk factors, and genotype distribu-subject (0.7%), type 2c in 66 subjects (44.6%), type 3a in 4 subjects (2.7%), and type 4 in two subjects (1.3%). These tion of hepatitis C virus (HCV) infection were assessed in the general population of a town in southern Italy. The sample figures differ from those of Italian patients with chronic liver disease in whom genotype 2 is more rare. None of the individ-was selected from the census by a systematic 1:4 sampling procedure. The participation rate was 96.6%. Among the uals was infected with more than one genotype. The distribution of the two most common HCV viral types (1b and 2c) 1,352 subjects enrolled, 195 (14.4%) tested reactive to antibody to HCV (anti-HCV) with enzyme immunoassay (EIA was not statistically different in terms of mean age, sex, or risk factors and suggests that they may have had a parallel 3). When further tested with recombinant immunoblot assay (RIBA 3), 170 subjects (87.2%) tested positive, 23 subjects spread in this community. These findings provide one of the highest overall anti-HCV prevalence rates in a general popula-(11.8%) had indeterminate results, and 2 subjects (1%) tested negative. Thus, the overall anti-HCV EIA-positive RIBA-con-tion with a likely cohort effect, i.e., decreased risk of infection along generations. These observations may indicate an epi-firmed prevalence was 12.6% (170 of 1,352 subjects) and increased from 1.3% in subjects younger than 30 years to demic or focus of hepatitis C that occurred several years earlier. The majority of anti-HCV-positive subjects in the 33.1% in those ¢60 years of age. This latter age group accounted for 72.3% of all anti-HCV-positive subjects. Females oldest age group and with no clinical evidence suggests that HCV infection is a very prolonged and indolent disease. tested positive more frequently than males (14.1% vs. 10.5%; P õ .05). Alanine transaminase (ALT) concentrations were (HEPATOLOGY 1997;26:1006-1011.) abnormal in only 4.1% (7/170) of anti-HCV EIA-positive RIBA-confirmed subjects. This suggests that ALT screening Hepatitis C virus (HCV) infection represents a major is not useful in the detection of anti-HCV-positive subjects health problem in Italy. It has been found to be highly prevain a general population. The results of multiple logistic regreslent in subjects with chronic liver disease 1-2 and strongly sion analysis showed that an age of less than 45 years, the associated with hepatocellular carcinoma. 3-4 use of glass syringes, and dental therapy were all independent General population surveys in different countries that depredictors of anti-HCV positivity. HCV RNA was detected by termined the prevalence of hepatitis C virus antibodies (antipolymerase chain reaction in 75.9% of the 195 anti-HCV EIA-HCV) have mainly consisted of voluntary or paid blood positive subjects: in 84.7% (144/170) of the RIBA-confirmed donors. Because these populations usually have special charsubjects; in 17.4% (4/23) tested as RIBA indeterminate; and acteristics regarding age, sex, socioeconomic level and selecin neither of the two subjects who tested RIBA negative. HCV tive procedures, they are not representative of the general type 1b was detected in 75 subjects (50.7%), type 2b in 1 population. Few studies using valid sampling procedures have provided reliable figures for anti-HCV prevalence in given areas. 5-12 Abbreviations: HCV, hepatitis C virus; anti-HCV, hepatitis C virus antibodies; HBV, On the basis of the phylogenetic analysis of the viral gehepatitis B virus; ALT, alanine transaminase; RIBA, immunoblot assay; anti-HBc, hepatinome, Okamoto et al. 13 classified HCV into four genotypes. tis B core antigen antibodies; RT-PCR, reverse-transcription polymerase chain reaction; Similarly, Simmonds et al. 14 classified the virus into six major OR, odds ratio; CI, confidence interval. types and a series of subtypes. The characteristics of HCV