An emerging public health threat

Nearly 4 million Americans are infected with hepatitis C. Most are unaware of their infection. The National Institutes of Health (NIH) estimates that an additional 30,000 people are newly infected each year. Called "an emerging public health threat," hepatitis C is a leading cause of cirrhosis and liver cancer. It is also now the leading reason for liver transplantation in the United States.



Hepatitis A, B, and C

Of six known hepatitis viruses—A, B, C, D, E, and G—the most common are hepatitis A, B, and C. Hepatitis A (HAV), the least serious form, does not progress to chronic disease. A small proportion of individuals with hepatitis B—5 to 10 percent—develops chronic disease.

Chronic hepatitis B (HBV) and C (HCV) are the most common causes of chronic viral hepatitis in the United States, posing serious risks for long-term medical complications, especially if left untreated. The American Liver Foundation estimates that HCV will cause approximately 10,000 deaths annually, and HBV will cause 5,000 deaths. And unlike other life-threatening illnesses, hepatitis usually claims individuals in their most productive years; almost 50 percent of deaths occur before the age of 60.

As many as 85 percent of individuals who contract acute hepatitis C progress to chronic disease. About 20 percent of those patients develop cirrhosis within 2 decades. Each year after cirrhosis develops, the risk of developing cancer is 1 to 4 percent.

Although hepatitis A, B, and C remain diseases that warrant better preventive measures, some progress has been made in the areas of better diagnostic techniques and more effective treatments.

About 40 percent of patients with hepatitis C have a history of IV drug use. Forty percent do not know the source of infection. The remaining 20 percent of hepatitis C infections may be attributed to household contact with a known case of hepatitis, sexual contact with multiple partners, transfusion-associated disease, or occupational exposure.



Hepatitis C

Hepatitis C, the most common form of chronic viral hepatitis infection, is a slow, progressive virus that can cause liver injury over years, even decades, often without specific symptoms. Symptoms may include loss of appetite, fatigue, decreased exercise tolerance, arthralgia, vomiting, stomach pain, depression and—in rare cases—jaundice. Chronic fatigue is the most salient symptom.

The average incubation period for hepatitis C is usually 6 to 7 weeks, with a range extending from 2 weeks to 26 weeks. Symptomatic illness develops in about 30 to 40 percent of individuals with acute infection; 20 to 30 percent will have jaundice.



Diagnosing chronic hepatitis C

Acute and chronic forms of hepatitis are diagnosed using a variety of tests and assays. Persistent elevation in blood levels of the liver enzyme, alanine aminotransferase (ALT), is the key biochemical market of the disease. Also, HCV RNA, or genetic material from the hepatitis virus, is detectable in the blood of most patients.

A systematic evaluation of a patient with abnormal ALT levels may proceed as shown:



Suggested Approach to the Patient
With Raised Serum Aminotransferase
(>Two Times the Upper Limit of Normal)
  • Take a detailed history with particular attention to potential hepatic insults
  • Review list of therapeutic drugs used
  • Do a careful physical exam (liver, spleen, etc.)
  • Obtain serologic tests for viral hepatitis (HbsAg, anti-HCV)
  • Recheck ALT and AST at 3 and 6 months
  • Review other conventional lab tests
    - Is serum albumin normal?
    - Are serum globulins increased > 3 to 5 gms?
    - Is serum cholesterol normal?
    - Is CBC normal (hct, hgb, WBC, platelets)?
  • Alcohol history
  • Recent weight gain


Routine blood and serum tests for hepatic disease include:



Routine Blood/Serum Tests for Hepatic Disease

Test

Normal Range

Diagnostic Value

Alanine aminotransferase (ALT)   5 IU/L to 35 IU/L   Hepatocellular disease
Aspartate aminotransferase (AST)   5 IU/L to 40 IU/L   Hepatocellular disease
Alkaline phosphatase   35 IU/L to 130 IU/L   Cholestasis, hepatic infiltration
Gamma glutamyl
transpeptidase (GGTP)		   10 IU/L to 48 IU/L   Alcohol abuse, biliary diseases,
cholestasis
Gamma-globulin   5 g/L to 15 g/L   Chronic hepatitis and cirrhosis
Total bilirubin   5 mmol to 17 mmol   Jaundice, hemolysis
Direct bilirubin   <5 mmol   Jaundice


Regarding testing and the interpretation of results, it is useful for healthcare providers to know the sequence of events following infection with HCV. Within 2 to 4 weeks following infection, HCV RNA can be found in the liver. This marker will precede the elevation of ALT, which is not usually measurable until approximately 8 weeks after infection. Second-generation and third-generation HCV antibody tests may be indicative after 8 weeks. Consequently, if a patient suspected of being at risk does not demonstrate markers for hepatitis, the tests should be repeated, since these patients may seroconvert within 4 months after infection.

Liver biopsy is essential in chronic hepatitis patients because progressive stages of chronic hepatitis are apparent in the erosive state of liver architecture. In mild disease, the biopsy may show inflammation of the portal zones. Moderate disease is shown by spotty areas of necrosis. In severe disease, necrosis of the limiting edge of the portal zone is evident.





Major risk factors for hepatitis B and C


HEPATITIS B
  • Hemodialysis
  • Patients of custodial institutions for developmentally disabled
  • Exposure to blood/blood clot products
  • Needle-stick injury
  • Sexual activity with multiple (heterosexual or homosexual) partners
  • IV drug use
  • Infants of HBV-positive mothers
  • Tattooing
  • Body piercing


HEPATITIS C
  • Hemophilia
  • Hemodialysis
  • Organ transplant
  • IV drug use
  • Blood transfusion prior to 1992
  • Needle-stick injury
  • Tattooing
  • Body piercing
  • Sexual activity with multiple partners


See "Available Treatment"