Infectious dose/dose response: The infectious dose is unknown (Bidawid et al. 2000) but is presumably similar to other RNA enteroviruses (10–100 particles; FDA 2003).
Levels in seafood: Several studies have demonstrated the presence of hepatitis A virus in bivalve molluscs grown in waters subject to human faecal pollution (Table 4.7). The prevalence of contamination is typically higher in shellfish taken from waters closed for harvest, but significant rates of contamination have been demonstrated in areas open for harvest.