Hepatitis is an inflammation of the liver, most commonly caused by a viral infection. There are five main hepatitis viruses, referred to as types A, B, C, D and E. These five types are of greatest concern because of the burden of illness and death they cause and the potential for outbreaks and epidemic spread. In particular, types B and C lead to chronic disease in hundreds of millions of people and, together, are the most common cause of liver cirrhosis and cancer.
Hepatitis A and E are typically caused by ingestion of contaminated food or water. Hepatitis B, C and D usually occur as a result of parenteral contact with infected body fluids. Common modes of transmission for these viruses include receipt of contaminated blood or blood products, invasive medical procedures using contaminated equipment and for hepatitis B transmission from mother to baby at birth, from family member to child, and also by sexual contact.
Acute infection may occur with limited or no symptoms, or may include symptoms such as jaundice (yellowing of the skin and eyes), dark urine, extreme fatigue, nausea, vomiting and abdominal pain.
- Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic disease.
- The virus is transmitted through contact with the blood or other body fluids of an infected person - not through casual contact.
- About 2 billion people worldwide have been infected with the virus and about 350 million live with chronic infection. An estimated 600 000 persons die each year due to the acute or chronic consequences of hepatitis B.
- About 25% of adults who become chronically infected during childhood later die from liver cancer or cirrhosis (scarring of the liver) caused by the chronic infection.
- The hepatitis B virus is 50 to 100 times more infectious than HIV.
- Hepatitis B virus is an important occupational hazard for health workers.
- Hepatitis B is preventable with a safe and effective vaccine.
- Hepatitis A is a viral liver disease that can cause mild to severe illness.
- It is spread by faecal-oral (or stool to mouth) transmission when a person ingests food or drink contaminated by an infected person's stool.
- The disease is closely associated with poor sanitation and a lack of personal hygiene habits, such as hand-washing.
- An estimated 1.4 million cases of hepatitis A occur annually.
- Epidemics can be explosive in growth and cause significant economic losses: 300 000 were affected in one
- Improved sanitation and the Hepatitis A vaccine are the most effective ways to combat the disease.
- Hepatitis C is a liver disease caused by the hepatitis C virus (HCV).
- HCV infection sometimes results in an acute symtomatic illness. It can range in severity from a mild illness lasting a few weeks to a serious, lifelong chronic condition that can lead to cirrhosis of the liver and liver cancer.
- HCV is transmitted through contact with the blood of an infected person.
- About 130–170 million people are chronically infected with hepatitis C virus, and more than 350 000 people die from hepatitis C-related liver diseases each year.
- HCV infection is curable using increasingly effective antivirals.
- Despite ongoing research, there is currently no vaccine to prevent hepatitis C virus infection.
