Figure 1. Electron micrograph of purified hepatitis A virus. (Magnification ×165 000.)

Figure 2. Hepatitis A virus genome. The top line indicates the nucleotide (NT) number and the orientation of the positive-stranded RNA genome. The P1, P2 and P3 genome regions are indicated under this scale. The individual viral proteins are depicted within or above the rectangles, with common names for the capsid polypeptides shown below the respective locations. The covalently coupled VPg is shown by the circle at the extreme 5¢-end of the genome, while the polypyrimidine tract (pY1) and the location of the internal ribosomal entry site (IRES) structures are depicted by the hatched boxes. Viral protease cleavage sites are shown within the lower rectangle. The bold arrow indicates the primary cleavage site; solid line arrows indicate cleavage sites identified experimentally, while dotted line arrows indicate predicted cleavage sites. A, alanine; Q, glutamine; M, methionine; V, valine; T, threonine; S, serine; G, glycine; R, arginine; UTR, untranslated region.

Figure 3. Time course of a typical hepatitis A virus (HAV) infection. Ig, immunoglobulin.

Figure 4. Worldwide seroprevalence patterns of hepatitis A virus (HAV) infection endemicity. A country's endemicity of infection has been generalized from best available data and may vary within parts of the country. Green, very low endemicity; orange, low endemicity; yellow, intermediate endemicity; pink, high endemicity.