Hepatitis A, B, C, D, E
Hepatitis is an inflammation of the liver that is caused by a variety of infectious viruses and noninfectious agents leading to a range of health problems, some of which can be fatal. There are five main strains of the hepatitis virus, referred to as types A, B, C, D and E. While they all cause liver disease, they differ in important ways including modes of transmission, severity of the illness, geographical distribution and prevention methods. 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, liver cancer and viral hepatitis-related deaths. An estimated 354 million people worldwide live with hepatitis B or C, and for most, testing and treatment remain beyond reach.
Many people with hepatitis A, B, C, D or E exhibit only mild symptoms or no symptoms at all. Each form of the virus, however, can cause more severe symptoms. Symptoms of hepatitis A, B and C may include fever, malaise, loss of appetite, diarrhoea, nausea, abdominal discomfort, dark-coloured urine and jaundice (a yellowing of the skin and whites of the eyes). In some cases, the virus can also cause a chronic liver infection that can later develop into cirrhosis (a scarring of the liver) or liver cancer. These patients are at risk of death.
Hepatitis D (HDV) is only found in people already infected with hepatitis B (HBV); however, the dual infection of HBV and HDV can cause a more serious infection and poorer health outcomes, including accelerated progression to cirrhosis. Development of chronic hepatitis D is rare.
Hepatitis E (HEV) begins with mild fever, reduced appetite, nausea and vomiting lasting for a few days. Some persons may also have abdominal pain, itching (without skin lesions), skin rash or joint pain. They may also exhibit jaundice, with dark urine and pale stools, and a slightly enlarged, tender liver (hepatomegaly), or occasionally acute liver failure.