Table 35-1 Characteristics of Hepatitis Viruses. Hepatitis A Hepatitis B Hepatitis c Hepatitis D Hepatitis E Picornaviridae Hepadnaviridae Flaviviridae Unclassified H d Genus Hepatovirus Orthohepadnavirus Hepacivirus Metavirus Hepevirus Virion 27 nm, icosahedral42 nm, spherical 60 nm, spherical 35 nm, spherical 30-32 nm, icosahedral Envelope Yes(HBsAg) Yes Yes(HBsAg) Genome SSRNA dsDNA SSRNA sNA负链环状」sNA Genome size 7.5 kb 3.2kb 9,4kb 1.7kb 76b Stability Heat- and acid-stable Acid-sensitive Ether-sensitive, acid-sensitive Acid-sensitive Heat-stable Transmission Fecal-oral Parenteral Parenteral Parenteral Fecal-oral Prevalence Moderate Low, regional Regional Fulminant disease Rare Rare Rare Frequent In pregnancy Chronic disease Never Often Often Often Never OncogenIc No Yes Yes ? NoHepeviridae 负链环状