Hepatitis is the inflammation of the liver. Although hepatitis can be the symptom of many illnesses, including autoimmune diseases, it is most often caused by a viral infection.
There are five main types of viral hepatitis — A, B, C, D and E. Of those, Hepatitis A, B and C are the most common types in the United States, according to the Centers for Disease Control and Prevention.
Hepatitis, as it name implies, often has symptoms that affect liver functions. Those who are infected can experience mild illness like nausea and appetite loss, or more serious problems likejaundice and liver damage.
Hepatitis A and E are acute infections typically transmitted through food or water contaminated by fecal matter, according to the World Health Organization. The primary sources of the hepatitis A and E viruses are raw or undercooked food, food handled by people who have not properly washed their hands and water contaminated by animal or human waste.
Hepatitis B, C and D are usually contracted through infected body fluids, such as through sharing contaminated needles, blood transfusions or invasive medical procedures using contaminated equipment. Hepatitis B can also be contracted through sexual contact or from an infected mother to her newborn during delivery, according to the CDC.
Diagnosis & Tests
Acute liver infection is usually suspected when patients have symptoms such as jaundice and fatigue. Blood tests can then be used to determine the presence and quantity of hepatitis virus and antibodies in the body. The doctor may suggest getting a liver biopsy if chronic hepatitis B and C is suspected and there's a chance of liver damage.
Since liver damage can occur before there are any overt signs and symptoms, routine screenings for hepatitis B and C are recommended for people who have a high risk of coming in contact with the viruses. Regular testing is recommended for injection-drug users, men who have sex with other men, people taking immunosuppressive drugs, HIV-positive patients and their household and pregnant women, according to hepatitis B guidelines from the CDC.
Chronic infection and inflammation can lead to extensive scarring of the liver (cirrhosis) and impaired liver functions. While the estimated number of new infections in the United States has been declining, hepatitis B and C viruses can persist as chronic infections, according to statistics reported to the National Notifiable Disease Surveillance System. Both are leading causes of chronic liver disease and liver cancer in the United States.
Hepatitis B infections can also increase the risk of contracting hepatitis D, which cannot be contracted unless there's already a pre-existing hepatitis B infection, according to the Mayo Clinic. Hepatitis B can also cause kidney problems, and infected adults are more likely than children to experience kidney failure.
Both hepatitis A and E do not lead to chronic infections, according to the CDC. However, in rare cases, acute liver failure could occur in older adults and those who already have other chronic liver diseases.
Treatments & Medications
Most acute hepatitis brought on by the hepatitis A, B, C and E virus will resolve on its own over several weeks or months, according to the NIH. However, severe cases of acute hepatitis B can be treated with antiviral drugs such as lamivudine (trade name Epivir).
Chronic hepatitis B and C may be treated with antiviral medications such as pegylated interferon (peginterferon) injections or oral antivirals such as lamivudine for hepatitis B or ribavirin (trade name Copegus, Rebetol, Ribasphere) for hepatitis C. However, ribavairin must be taken with peginterferon in order for it to be an effective treatment against hepatitis C, according to the NIH. Liver transplants may be necessary if the liver is severely damaged.
Routine childhood hepatitis A vaccination, which was implemented in many parts of the United States base on 1999 recommendations, has significantly reduced new cases of Hepatitis A by 92 percent between 1995 (12 cases per 100,000 people ) to 2007 (one case per 100,000 people). Hepatitis B vaccination is also available and it is 95 percent effective in preventing viral infections and its chronic consequences, according to the WHO. Although there is no vaccine for hepatitis D, the disease can still be prevented by vaccinating against hepatitis B.