Epidemiology of HCV infection.

It is estimated that approximately 130-170 million people worldwide are infected with hepatitis C virus (HCV). According to data from WHO community and blood donor surveys, the African and Eastern Mediterranean countries report the highest prevalence rates (>10%). The rates of infection in the general population and the incidence of newly-acquired cases indicate an appreciable change in the epidemiology of the infection in recent years. Prior to the widespread screening of blood donations, infected blood and blood products represented a common source of infection. On the other hand, the high peak in HCV antibodies among the elderly in Italian epidemiological studies on the population at large reflects a cohort effect due to an epidemic of HCV infection occurring after the Second World War. According to data reported by the CDC Surveillance System, the incidence of acute hepatitis C has declined since the late 1980s. In 2005, as in previous years, the majority of such cases in North America and Northern Europe occurred among young adults and injected drug use was the most common risk factor. Other, less commonly reported modes of HCV acquisition are occupational exposure to blood, high-risk sexual activity, tattooing, body piercing and other forms of skin penetration. Finally, the overall rate of mother-to-child transmission from HCV-infected, HIV-negative mothers has been estimated at around 5% (coinfection with HIV raises this figure to 19.4%). HCV prevention relies on identifying and counseling uninfected persons at risk of contracting hepatitis C.