[Prevalence of hepatitis C virus in urban and rural populations of northeast Brazil-pilot study]

Abstract

Hepatitis C virus can be found in all continents. However, differences exist with respect to its prevalence. In Brazil, epidemiological data are scarce, and are based, in their majority, on information obtained from blood donors and not from the general population. Our objective is to show the prevalence of anti-HCV in two distinct populations: one rural and one urban: Salvador, a metropolis, and Castro Alves, a rural village with very little contact with other populations. Eight hundred individuals from Salvador and 800 from Castro Alves were randomly visited. After obtaining consent, we collected blood samples for serology tests and determination of ALT levels. The anti-HCV antibody was tested using ELISA II (ABBOTT Labs), and confirmed by RIBA III (Chiron). We studied the prevalence of anti-HCV in two populations and its distribution with respect to age group and sex and ALT level. chi 2 and Fisher exact were used for the statistical analysis. Of the 800 individuals from Salvador, 44% were women and 56% were men. The age group varied from 10 to 70 years, with an average age of 42. Ten (1.25%) individuals were anti-HCV positive in the urban population and none in the rural population (P < 0.001). No evident correlation was found regarding sex and ALT level, between anti-HCV positive and anti-HCV negative individuals in the urban population. In conclusion, our results suggest a higher prevalence of HCV infection in the urban population probably due to a high level of exposure. The sero-epidemiological studies using blood donors do not reflect the epidemiological reality of HCV in Brazil due to selection bias which could overestimate its seroprevelence.