Hepatitis C virus infection in cameroon: A cohort-effect

International audience; A hepatitis C virus (HCV) serological study conducted in 2003 on 1,434 individuals in Yaounde and other HCV seroepidemiological studies on 2,066 sera sampled between 1993 and 1997 in four geographically distinct rural areas (Ntem, Mekas, Yokadouma, and Nditam) in Cameroon, are described. Two patterns of HCV seroprevalence were observed. The first pattern, represented by Nditam and Yokadouma populations, showed low HCV seroprevalence rates (2.9% and 3.3%, respectively) increasing moderately with age (9.0% and 16.7% after age 50). The second pattern showed high seroprevalence rates (6.9% for Yaounde, 14.4% and 16.7% for Ntem and Mekas, respectively). These rates increased dramatically with age (32.8%-49.5% after age 50). The age-specific anti-HCV prevalence curve of the 1993 Mekas survey paralleled those of the 1997 Ntem and 2003 Yaounde surveys. Using the year of birth as the x-axis, the three curves closely matched each other. This clearly indicates a cohort effect for which the seroprevalence trends are clearly related with the year of birth, rather than the age. The highest prevalence was observed among people born around 1940.