Comments
INITIAL SYMPTOMS:
Usually asymptomatic or mild symptoms (nausea, anorexia, and abdominal discomfort); [CCDM]
EPIDEMIOLOGY
20% to 30% of cases are asymptomatic. 75% to 85% of acute infections become chronic. In chronic cases, 5% to 20% develop cirrhosis and 1% to 5% will die from cirrhosis or liver cancer. Transmission is primarily parenteral, e.g. injection drug use or needle sticks. Sexual transmission and mother-to-child transmission is uncommon except in cases with HIV coinfection. [CCDM, p. 264-6] About 75-85% of people who seroconvert to anti-HCV develop persistently detectable viremia. After 20 years of chronic infection, about 10-20% develop hepatic cirrhosis. [CDC Travel, p. 196]
FINDINGS:
Other common symptoms are loss of appetite, dark urine, and light-colored stools. Rarely seen in the USA is fulminant hepatitis with bleeding diathesis (GI bleeding) and coma. [ID, p. 761, 770] Some patients have a serum-sickness like illness with urticaria and arthralgias that usually resolves with the onset of jaundice. Hypersplenism with thrombocytopenia and leukopenia can occur in chronic hepatitis C infections. [PPID 7th Ed., p. 1584, 1605-6] 1/3 to 1/2 of patients with chronic hepatitis C have cryoglobulinemia, symptomatic in only 1% of cases with purpura, vasculitis, neuropathy, or glomerulonephritis. [ID, p. 761, 770, 782] Cryoglobulinemia patients also have fatigue, arthralgias, and hives. [Cecil, p. 977]
PREVENTION AND TREATMENT:
The main routes of infection are intravenous drug use (industrialized countries) and contaminated medical or surgical instruments (developing countries). [Cecil, p. 970] Before routine screening of blood donors with anti-HCV beginning in 1992, hepatitis C caused most cases of post-transfusion hepatitis. About 2-3% of the world's population is infected with hepatitis C. The treatment of choice for chronic hepatitis (40-80 % response rate) is a combination of ribavirin and slow-release interferons. [CCDM, p. 293-5] About 15-25% of patients clear the infection without treatment. [5MCC-2015] Hepatitis C RNA can be detected as early as 10 days after exposure. Hepatitis C antibodies can be detected at a median of 50 to 70 days after exposure. After an accidental needlestick injury to a healthcare worker, hepatitis C can be excluded when six months have passed and the HCV antibodies are negative and the liver enzymes are not elevated. [JAMA 2002;287(18):2406-12] A single determination of negative liver enzymes does not exclude ongoing liver injury. [Guerrant, p. 430] The average risk for seroconversion after a needlestick or cut exposure to HCV-infected blood is approximately 1.8%. [www.nccc.ucsf.edu/hiv_clinical_resources/pep_guidelines] Condoms recommended for hepatitis C patients with multiple sexual partners or sexually transmitted diseases; Hepatitis C patients should not share razors, toothbrushes, and nail clippers. [PPID, p. 1445]
For updated text and symptoms of infectious diseases, see iddx.com.
Diagnostic
Screen with HCV antibody (>99% sensitivity); False negatives if <70 days since exposure, dialysis, or HIV positive; Confirm with HCV RNA. [ABX Guide] Persistence of HCV RNA >6 months = chronic infection; [Cecil]