HEPATITIS-C IN A FRENCH POPULATION-BASED SURVEY, 1994 - SEROPREVALENCE, FREQUENCY OF VIREMIA, GENOTYPE DISTRIBUTION, AND RISK-FACTORS

The aims of this study mere the following: 1) Co estimate the prevalen ce of hepatitis C virus (HCV) antibody (anti-HCV) in a population-base d survey of French residents not selected for risk factors; 2) to inve stigate the association between anti-HCV seropositivity, viremia, the infecting HCV genotype, and the alanine transaminase (ALT) level; and 3) to identify risk factors for HCV infection by a nested case control study within this survey sample. The anti-HCV seroprevalence survey w as per-formed in 6,283 volunteers (20- to 59-years-old) randomly selec ted from 45,377 consecutive individuals undergoing routine medical che ckup in social security medical centers covering 4 of the 22 ''regions '' of France, Seventy-two volunteers were anti-HCV positive, a elude p revalence of 1.15%. Fifty percent of these positive volunteers also ha d an abnormal ALT level and 81% were HCV-RNA positive by polymerase ch ain reaction (PCR), The prevalence weighted for age, sex, and place of residence was 1.05% (95% CI: 0.75-1.34). The weighted prevalence was lower among men > 40-years-old (0.5%; 95%, CI: 0.1-1.0) and was close to 1% in all other age and sex groups. Prevalence was inversely correl ated with socioprofessional status with the highest rate being found a mong those with no paid employment (2.2%; 95% CI: 1.3-3.0). The HCV pr evalence (1.7%; 95% CI: 1.0-2.3) was highest in southeastern Prance, S eventy-eight percent of positive intervenous (IV) drug abusers were in fected with HCV genotypes 1a or 3, whereas 80% of the transfusion-asso ciated cases were infected by HCV genotypes 1b or 2a. Only three varia bles were significantly associated with HCV seropositivity in multivar iate analysis: IV drug abuse (21 cases, 14 men all < 40-years-old), pr evious transfusion (22 cases, 18 women), and not having paid employmen t. Although routes of transmission other than IV drug abuse and transf usion may not be formally excluded they were not found to be statistic ally significant. Hepatitis C appears to be a major public health conc ern in France. A more active screening policy may be required because only 17 of 12 cases (24%) were aware of their HCV seropositivity befor e enrollment in the study.