Viral hepatitis: A brief introduction, review of management, advances and challenges

Table 1 Comparison of hepatotropic viruses hepatitis A-E

Hepatitis	A	B	C	D	E
Viral structure	Naked, ssRNA (Picornavirus)	Envelope, dsDNA (Hepadnavirus)	Envelope, ssRNA (Flavivirus)	Envelope, ssRNA (-ve) (Deltavirus)	Naked, ssRNA (Hepevirus)
Transmission	Faecal-oral	Parenteral, sexual	Parenteral, sexual	Parenteral, sexual	Faecal-oral
Incidence	1.4 million	> 250 million[88]	> 80 million	About 12 million (prevalence)[89]	20 million
Chronic infection	No	About 90% of infants infected; about 2%-6% adult infected	70% (55%-85%)	< 5% of those infected with HBV, > 80% of superinfection)[90]	No (very rarely in immunosuppressed adults)[91]
Other disease associations	None	HCC, cirrhosis	HCC, cirrhosis	Cirrhosis, fulminant hepatitis	None (cirrhosis in chronic HEV infection)
Treatment	Supportive	Viral suppressive therapy (see criteria for commencement of treatment below)	Eradication therapy DAA (gold standard)	PEG-IFN (sparse data)	Supportive

HBV: Hepatitis B virus; HEV: Hepatitis E virus; HCC: Hepatocellular carcinoma; DDA: Direct-acting antiviral.