Hepatitis is an inflammation of the liver usually caused by a virus or, less often, by certain medications or chemical agents, such as alcohol, carbon tetrachloride, and large amounts of panadol. The Hepatitis B and C viruses have infected 520 million people globally, many are infected with a hepatitis virus but have no symptoms.
The three most common types of hepatitis are labeled A, B, and C. Hepatitis A (HAV) is the most common form and is transmitted mainly by contaminated food or water. Most people recover completely from a hepatitis A infection although it can take up to six weeks for recovery.
Hepatitis B virus (HBV) is more serious than hepatitis A and can cause permanent liver damage. This infection is usually acquired through exposure to contaminated blood. Intravenous drug users who share contaminated needles are at highest risk, but persons who have multiple sexual partners, people who are healthcare workers, people who have repeated blood transfusions, and persons who need dialysis to maintain kidney function are also at risk. New blood donor screening tests have greatly reduced the dangers of blood transfusions, and a vaccine is available for people who are likely to come in contact with the virus.
Hepatitis C (HCV) is the form that causes the most serious lifelong problems. It is usually spread through exposure to contaminated blood or needles, often through body piercing or tattooing, or through sexual contact with someone who has the infection. Many people have the hepatitis C virus in their bodies, but most of them have no symptoms and are not aware of their risk for progressive liver disease. HCV can cause serious conditions and are the main reason people need liver transplants.
Some individuals who carry HBV and HCV can progress to further, serious liver conditions, including liver cirrhosis and liver cancer.
Hepatitis D (HDV), also called the delta agent, is a defective virus that requires the presence of hepatitis B for its expression and infection. It may be present when a person contracts HBV in a ‘co-infection’, or may be contracted later and cause a ‘superinfection’.
Hepatitis E is also called epidemic hepatitis. It shares many similarities with HAV and is responsible for waterborne hepatitis outbreaks in India, Burma, Afghanistan, Algeria, Mexico, and recently Sudan and Iraq.
In 1995, a new virus that causes hepatitis was discovered. It is known as the GB agent, so named after the initials of a surgeon who contracted this infection. Hepatitis G (HGV) is mild and does not commonly cause serious liver damage, yet it accounts for 9% of all hepatitis infections. HGV has been recently identified as a group of three virus sub-types of HCV.
Viral hepatitis occurs less commonly with other viral etiologies such as Epstein-Barr virus, cytomegalovirus, adenovirus, herpes simplex and the Coxsackie virus. Other types of hepatitis occur depending on the cause, but many of the manifestations are the same. Alcoholic hepatitis can follow a binge of ethanol consumption, or long term chronic alcohol abuse. Drug induced hepatitis can be caused by a number of pharmacological medications, such as methyldopa (for heart conditions), isoniazid (to treat TB) and panadol. Chronic autoimmune hepatitis is a chronic hepatitis of unknown origin that predominantly affects young and middle aged women.
Most people recover from hepatitis infections with no special treatment, although some become carriers of the infection. The term chronic hepatitis means active, ongoing inflammation of the liver persisting for more than six months that is detectable by biochemical and histologic means. It most commonly happens with HBV and HCV infections.
The symptoms of Hepatitis
It can be very difficult to tell the forms of hepatitis apart by their symptoms. Many people think they have the flu because of the fatigue, abdominal pain, loss of appetite, nausea, and vomiting that may occur at the initial stages of any hepatitis infection. The liver may be enlarged, causing abdominal tenderness with chronic diarrhea. Yellow skin (jaundice) and dark-colored urine can be important clues to a liver problem. For people that may have a chronic form of hepatitis, red palms and spider veins around the umbilicus may be present. Skin rashes and itching are also signs of a chronic condition. In males, a chronic condition can lead to gynoecomastia, which is when the male body starts to look more female, i.e. with breasts. Many people, especially those with HCV, will have no overt symptoms and the infection is found during a routine blood test.