Hepatitis C becomes chronic in 75-85% of cases. In chronic cases, 5-20% develop cirrhosis and 1-5% die from cirrhosis or liver cancer. Transmission is by injection drug use or needle sticks. Sexual transmission and mother-to-child transmission is uncommon except in cases with HIV coinfection.
CASES/YEAR
4,000,000 (US); 71,000,000 (Global)
OTHER NAMES
HCV infection; Parenterally transmitted non-A, non-B hepatitis;
INCUBATION
15-160 days (mean of 50 days); [PPID, p. 1552]
INITIAL SYMPTOMS
Usually asymptomatic or mild symptoms (nausea, anorexia, and abdominal discomfort); [CCDM]
PRECAUTIONS
Standard. "See specific recommendations for care of patients in hemodialysis centers." [CDC 2007 Guideline for Isolation Precautions] Communicability "may persist indefinitely among persons with chronic infection." [CCDM, p. 266]
COMMENTS
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 70-75% 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. 232]
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] 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]
PREVENTION AND TREATMENT:
The main routes of infection are intravenous drug use (industrialized countries) and contaminated medical or surgical instruments (developing countries). [Cecil, p. 962-3] 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-2020] 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. 1565]
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, p. 970]
SCOPE
Global; Increased risk if exposed to: transfusion not screened for HCV; medical or dental procedure with contaminated equipment; work in medicine/dentistry; or shared needles for acupuncture, tattooing, or injecting drugs. [CDC Travel, p. 232]
SIGNS & SYMPTOMS
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>arthralgia
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>fatigue, weakness
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>fever
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>myalgia
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G abdominal pain
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G blood in stool
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G hepatomegaly
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G jaundice
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G liver function test, abnormal
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G nausea, vomiting
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H splenomegaly
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N headache
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S petechiae and ecchymoses
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*bleeding tendency
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*cancer
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*cirrhosis
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*erythema nodosum
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*glomerulonephritis
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*hepatitis
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*myelitis
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*myocarditis
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*peripheral neuropathy
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*stupor, coma
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*weight loss
ENTRY
Needle (Includes Drug Abuse), Scalpel or Transfusion, Sexual Contact
RISK FACTORS
- Care for patients (bloodborne pathogen)
- Handle needles or surgical instruments
- Have a blood transfusion
- Injection drug users
- Travel to endemic area
- Work in a medical or research lab
TREATMENT
"Since 2014, several new all-oral direct-acting antiviral agents have been approved for use in the United States and other countries. These new treatment regimens are of short duration (typically 12 weeks) with few side effects and cure rates exceeding 90% for those who complete treatment . . . " [CDC Travel, p. 232]
REFERENCES FOR CASES/YEAR
1. (US) MMWR 2011: 1,229 cases; About 17,000 new cases/year; [Cecil, p. 962] 4 million have chronic HCV; [PPID, p. 1439] Use prevalence number for US cases per year;
2. (Global) 71 million chronically infected; [Cecil, p. 962] Use prevalence number for global cases per year;