“…Therefore, the detection of HAV-RNA in sera is practical and useful to study the molecular epidemiology of HAV infection. Nonetheless, HAV concentration in feces is usually higher than in sera and fecal shedding can persist for months after resolution of hepatitis (Yotsuyanagi et al, 1996). In fact, delayed fecal excretion of HAV is predominantly observed in neonates or young children, reflecting the importance of cell-mediated immunity in resolving the infection (Rosenblum et al, 1991).…”