VIRAL HEPATITIS

Acute viral hepatitis is a systemic infection predominantly affecting the liver. Clinically characterized by malaise, nausea, vomiting, diarrhea, and low-grade fever followed by dark urine, jaundice, and tender hepatomegaly; may be subclinical and detected on the basis of elevated aspartate and alanine aminotransferase (AST and ALT) levels. Hepatitis B may be associated with immune-complex phenomena, including arthritis, serum sickness-like illness, glomerulonephritis, and a polyarteritis nodosa–like vasculitis. Hepatitis-like illnesses may be caused not only by hepatotropic viruses (A, B, C, D, E) but also by other viruses (Epstein-Barr, CMV, coxsackievirus, etc.), alcohol, drugs, hypotension and ischemia, and biliary tract disease (Table 155-1).

TABLE 155-1: Clinical and Epidemiologic Features of Viral Hepatitis
FEATURE	HAV	HBV	HCV	HDV	HEV
Incubation (days)	15–45, mean 30	30–180, mean 60–90	15–160, mean 50	30–180, mean 60–90	14–60, mean 40
Onset	Acute	Insidious or acute	Insidious or acute	Insidious or acute	Acute
Age preference	Children, young adults	Young adults (sexual and percutaneous), babies, toddlers	Any age, but more common in adults	Any age (similar to HBV)	Epidemic cases: young adults (20–40 years); sporadic cases: older adults (>60)
Transmission Fecal-oral Percutaneous Perinatal Sexual	+++ Unusual − ±	− +++ +++ ++	− +++ ±^a ±^a	− +++ + ++	+++ − − −
Clinical Severity Fulminant Progression to chronicity Carrier Cancer Prognosis	Mild 0.1% None None None Excellent	Occasionally severe 0.1–1% Occasional (1–10%) (90% of neonates) 0.1–30%^c + (neonatal infection) Worse with age, debility	Moderate 0.1% Common (85%) 1.5–3.2% + Moderate	Occasionally severe 5–20%^b Common^d Variable^g ± Acute, good Chronic, poor	Mild 1–2%^e None^f None None Good
Prophylaxis	Ig, inactivated vaccine	HBIG, recombinant vaccine	None	HBV vaccine (none for HBV carriers)	Vaccine
Therapy	None	Interferon Lamivudine Adefovir Pegylated interferon^h Entecavir^h Telbivudine Tenofovir^h	Pegylated interferon ribavirin telaprevir,ⁱ boceprevir,ⁱ simeprevir, sofosbuvir, ledipasvir, paritaprevir/ritonavir ombitasvir, dasabuvir daclatasvir, velpatasvir, grazoprevir, elbasvir	Pegylated interferon ±	None^j

_aPrimarily with HIV co-infection and high-level viremia in index case; more likely in persons with multiple sex partners or sexually transmitted diseases; risk ∼5%.

_bUp to 5% in acute HBV/HDV co-infection; up to 20% in HDV superinfection of chronic HBV infection.

_cVaries considerably throughout the world and in subpopulations within countries; see text.

_dIn acute HBV/HDV co-infection, the frequency of chronicity is the same as that for HBV; in HDV superinfection, chronicity is invariable.

_e10–20% in pregnant women.

_fExcept as observed in immunosuppressed liver allograft recipients or other immunosuppressed hosts.

_gCommon in Mediterranean countries; rare in North America and western Europe.

_hFirst-line agents.

_iNo longer recommended.

_jAnecdotal reports and retrospective studies suggest that pegylated interferon and/or ribavirin are effective in treating chronic hepatitis E, observed in immunocompromised persons; ribavirin monotherapy has been used successfully in acute, severe hepatitis E.

Abbreviation: HBIG, hepatitis B immunoglobulin. See text for other abbreviations.

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