Hepatitis C virus infection in children

The prevalence of hepatitis C virus (HCV) infection is relatively low in ch ildhood, with anti-HCV prevalence rates of 0.1-0.4% in the Western world. T o date, blood transfusion has been the principal route of acquisition of HC V in children, but there is evidence that vertical transmission is overtaki ng it. The overall risk of vertical perinatal transmission of HCV is about 5%, although it increases with HIV co-infection and higher maternal viraemi a. The mode of delivery and breastfeeding do not seem to affect the vertica l transmission of HCV; Diagnosis of perinatal transmission relies on determ ination of ALT levels and the presence of HCV after the second month, while maternal anti-HCV antibodies mag persist until 18 months of life. After in fancy a variable percentage of perinatally infected children are anti-HCV n egative; thus, detection of HCV-RNA is necessary for accurate diagnosis. Th e natural history of HCV in childhood is not well understood and the outcom e depends on host and viral factors. The rate of progression to chronicity is about 60-80% in both post-transfusion and vertically acquired HCV infect ion. Compared with adult patients, chronic hepatitis C in children is chara cterized by both low ALT levels and low viral load, as well as by the milde st histological and immunohistochemical forms of chronic hepatitis. The pro gnosis is usually worse in multitransfused, thalassaemic children and those who have had cancer. Experience of treatment of chronic hepatitis C in chi ldren is limited, with about 40% having a sustained response to the interfe ron therapy. It is necessary to perform long-term follow-up and multicentre treatment st udies to improve knowledge of the natural history of HCV in children, as we ll as that of the efficacy of anti-viral therapy in childhood.