Prevalence of hepatitis C virus infection according to the year of birth: identification of risk groups.

Hepatitis C virus (HCV) screening according to the year of birth is recommended is some countries based on epidemiological data. The aim of this study was to analyze anti-HCV prevalence among people born between 1905 and 2015 in Argentina. Patients attending a tertiary care hospital in Buenos Aires, Argentina, from 2001 to 2015, who had a determination of anti-HCV, were included. Of 22,079 patients analyzed, 1,152 (5.2%; 95% confidence interval [CI]: 4.9%-5.5%) patients showed positive anti-HCV and 729 (3.3%; 95% CI: 3.1%-3.5%) patients showed detectable viremia. Three risk groups were identified (HCV prevalence): low-risk group-outpatient clinics/emergencies (2.8%); intermediate-risk group-in-patients (8%); and high-risk group-dialysis/transplants (27.2%). In the low-risk group, being born in 1973 or before was identified as a cut-off value for the risk of anti-HCV acquisition (area under the receiver-operator characteristic curve: 75.1 [95% asymptotic CI: 0.732-0.770; p < 0.001]). Ninety-one patients born after 1973 (0.8%) showed positive anti-HCV versus 457 individuals born in 1973 or before (5.8%), p < 0.001. In this group, positive anti-HCV was observed in 252 females (2.1%) and 296 males (4.1%), p < 0.001. In a multivariate analysis adjusted for gender, alanine-aminotransferase levels and HIV coinfection, being born in 1973 or before was independently identified as a risk for positive anti-HCV (adjusted odds ratio: 14.234 [95% CI: 9.993-20.277]; p < 0.001). People born in 1973 or before without other risk factors should be included in screening programs to link the highest possible number of HCV-infected patients to appropriate care and treatment.