Internal Medicine

0521779407-09 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:12

Hepatitis C 689

■risk from blood transfusion <<0.01% per transfusion (>5% from

transfusions before 1990)

■risk to unborn child of infected mother∼5%, may be higher if mother

HIV-co-infected < 5% of sexual partners of affected patients get HCV

■10–40% of cases without obvious exposure history

Signs & Symptoms

■acute infection usually asymptomatic

■chronic infection:∼70% of patients develop chronic disease

■often detected when patient is asymptomatic

■early symptoms mild and nonspecific: malaise, fatigue, muscu-

loskeletal

■advanced disease: liver failure (jaundice, ascites, edema, ence-

phalopathy, GI bleeding); 2–4% annual risk of hepatocellular car-

cinoma if cirrhosis present

■less common manifestations: renal disease, essential mixed cryo-

globulinemia

tests

Laboratory

■basic studies: blood

➣early disease: elevated AST/ALT

➣advanced disease: elevated bilirubin and prothrombin time,

➣decreased albumin

■basic studies: urine

➣early disease: normal

➣advanced disease: bilirubinuria

Screening

■anti-HCV antibody: positive 2–3 months after infection

Confirmatory Tests

■recombinant immunoblot assay: largely replaced by next test

■qualitative HCV RNA test: positive within days of infection

Other Tests

■HCV genotype: used to assess duration of therapy

■quantitative HCV RNA test: measures viral load; used to assess

response to therapy

Imaging

■abdominal ultrasound or CT scan: not diagnostic

■early disease: usually normal