Impact of schistosomiasis on increase incidence of occult hepatitis B in chronic hepatitis C patients in Egypt.

Co-infection of schistosomiasis, HBV and HCV is common in countries where schistosomiasis is endemic. Occult hepatitis B occurs in patients at high risk for HBV infection (e.g., patients on hemodialysis, patients receiving blood transfusions). Schistosomal infection is a risk factor of HBV infection that can increase the incidence of occult hepatitis B. We aimed to determine the prevalence of occult hepatitis B in chronic hepatitis C patients with and without schistosomiasis and to assess the effect of schistosomal infection on the increased risk of exposure to HBV infection and to occult hepatitis B. Two hundred chronic hepatitis C patients who were negative for HBsAg participated. All patients were tested for the following: Anti-schistosome antibodies, Anti-HBc, serum HBV DNA, CBC and liver function. The prevalence of occult hepatitis B in CHC patients with/without schistosomiasis were 12.8% and 8.5% (P=0.042), respectively. Next, 63.8% of CHC patients with schistosomiasis were exposed to HBV infection (Anti-HBc +ve) during their lifetime. In conclusion, the prevalence of occult hepatitis B is higher in CHC patients with schistosomiasis compared to those without schistosomiasis. Periodic laboratory investigations of Schistosoma mansoni, HBV and HCV are recommended for the early detection of the infection and, especially in endemic areas, to avoid infection complications.