0071643192.pdf

(Barré) #1
HEPATITISA

RNA picornavirus; endemic worldwide; in the United States, over one-third of
all urban-dwelling adults seropositive for the anti-HAV antibody; common in
children <15 years old; most common cause of conjugated hyperbilirubinemia
in children; rare in persons >40 years old; highest rates seen in American Indians
and Alaska natives

TRANSMISSION
Fecal-oral, contaminated food and water worldwide

SYMPTOMS
■ Presents with flulike illness, malaise, anorexia, weakness, fever, RUQ pain,
jaundice, and pruritus; children are typically asymptomatic
■ Atypical presentations include acute liver failure, cholestasis (prolonged,
deep jaundice), and relapsing disease (2–18 weeks after initial presentation).

DIAGNOSIS
■ History:Inquire about ill contacts, substandard water supply, travel, and
contaminated food (shellfish and green onions).
■ Labs:Anti-HAV IgM (acute infection); anti-HAV IgG (prior exposure, vac-
cination); anti-HAV total measures IgM and IgG (acute infection, prior
exposure, vaccination)

TREATMENT
■ Supportive, rarely progresses into fulminant infection
■ Avoid alcohol and acetaminophent (Tylenol) during acute infection.

HEPATITISB

Some 400 million people worldwide have chronic HBV, including >1 million
in the United States. Transmission can be perinatal (the most common cause
worldwide), sexual, or percutaneous. Age at infection is inversely related to
the risk of chronic infection. Of all patients with chronic HBV, 15–20%
develop cirrhosis and 10–15% develop hepatocellular carcinoma.

TRANSMISSION
Maternal→fetal, body fluids through sexual contact, IVDA.

SYMPTOMS
Similar to acute hepatitis A

DIAGNOSIS(SEETABLE11.12)
■ HBsAg:Surface antigen indicates activeinfection.
■ Anti-HBs:Antibody to HBsAg indicates past viral infection or immunization.
■ Anti-HBc:IgM is an early marker of infection; IgG is the best marker for
prior HBV exposure. IgM may also become detectable in reactivation of
HBV.
■ HBeAg: Proportional to the quantity of intact virus and, therefore,
infectivity; some HBV variants (called precore mutants) cannot make
HBeAg.

ABDOMINAL AND GASTROINTESTINAL


EMERGENCIES
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