The facts about...

Viral hepatitis

What is viral hepatitis?

Viral hepatitis is inflammation of the liver caused by a virus. It is common worldwide, and in England and Wales during 1991, over 9,000 cases were notified. Until recently only two major types were recognised; hepatitis A and hepatitis B. Other types were often called non-A non-B hepatitis. New viruses such as hepatitis C and E and the delta agent (hepatitis D) have now been discovered and as research continues more viruses which can cause this infection may be identified. Viruses such as Epstein-Barr virus, cytomegalovirus and yellow fever virus can also infect the liver and produce a hepatitis-like illness.

How do you catch viral hepatitis?

It can be caught in different ways depending on the type of virus causing the infection. Hepatitis A and E are spread by the consumption of food and drinking water contaminated with infected faeces; faecal-oral spread. Hepatitis B, C and D are spread by contact with blood or other body fluids from an infected person; blood-borne spread.

What are the symptoms of acute viral hepatitis?

These are very variable. Many patients have no symptoms at all, others just feel 'off colour' for a few days. The first symptoms noticed by most patients are often tiredness, weakness, muscle pains and headaches followed shortly by loss of appetite, nausea, vomiting and discomfort on the right side of the upper abdomen. These symptoms usually last for about three to ten days. They are followed by jaundice (a yellowing of the eyes and skin) and often dark urine with pale stools and a mild fever. The jaundice can last for up to six weeks during which the patient generally begins to feel better. Tiredness is usually the last symptom to disappear. Some patients also have painful joints and those with severe jaundice often complain of intense itching of the skin.

How is the diagnosis of viral hepatitis made?

The diagnosis is usually confirmed by laboratory tests on blood samples. The blood levels of liver enzymes are raised, particularly when the patient is jaundiced. These usually return to normal several weeks after the jaundice and other symptoms have subsided. Additional blood tests can be performed which will help to identify the virus causing the acute illness. This is important as hepatitis B and C can persist in the body to cause a chronic infection. Blood samples collected six months or more after the acute illness will show either raised serum liver enzymes or persistence of the virus if chronic hepatitis has occurred.

What is the treatment for viral hepatitis?

Most patients can be cared for at home. Ample bed-rest together with a light diet and non-alcoholic fluids during the early part of the illness are recommended. Occasionally admission to hospital is advised because of persistent vomiting or development of suspected liver failure. There is no specific anti-viral treatment for acute viral hepatitis. Depending on the cause, certain forms of chronic hepatitis may be treated with steroids, interferon or other anti-viral agents. A liver transplant may be considered in cases of fulminant acute hepatitis or if liver failure develops.

How do the types of viral hepatitis differ from one another?

Hepatitis A: This is a very common infection occurring worldwide especially in areas of poor hygiene and sanitation. Large outbreaks of infection can occur. In England and Wales during 1991, over 7,000 cases were confirmed by laboratory tests although many more cases go undetected. The hepatitis A virus is excreted in the faeces of cases for about one week before and one week after their jaundice appears. The virus is transmitted by faecal-oral spread. The incubation period of the illness is between two and six weeks and the severity of infection varies with age; children often have no symptoms. Hepatitis A virus only very rarely causes chronic hepatitis. To help prevent spread of the infection, everyone should wash their hands thoroughly before meals, before preparing food and after using the toilet or changing nappies. People who live in the same household as a case of hepatitis A should be offered an injection of human normal immunoglobulin. Travellers to parts of the world where hepatitis A is common, such as countries outside Northern and Western Europe, North America, Australia and New Zealand, should always peel raw fruit and vegetables before eating them, drink boiled or bottled water and not use ice cubes in their drinks. A vaccine is now available to prevent hepatitis A in people who are frequent travellers to these countries or who reside in such areas for more than three months. Human normal immunoglobulin may be given to cover shorter visits of one or two months.

Hepatitis B: About 500 laboratory confirmed new cases of acute hepatitis B occur each year in England and Wales. Between 5 and 10% of adults with acute hepatitis B become chronic carriers of the virus and may develop serious liver disease, such as chronic active hepatitis, cirrhosis or liver cancer later in their lives. Over 300 million people worldwide are chronic carriers of the hepatitis B virus. These are people whose blood remains infected with the virus for more than 6 months. In the United Kingdom, Northern Europe, North America and Australia, the incidence of chronic carriers in the population is low at between 0.1% to 1% , whereas in South East Asia, China and tropical Africa, up to 15% of the population are persistently infected. The hepatitis B virus is present in various body fluids including blood, semen and vaginal fluids. Infection may be spread by sexual exposure; exposure to blood-contaminated needles and syringes or other sharp objects; by contamination of broken skin, the eyes or mouth with infected blood; by transfusion of blood or other blood products; by bites from an infected person. For many years in the United Kingdom all blood donations have been tested for hepatitis B virus and transfusion associated hepatitis B is now very uncommon. The incubation period of hepatitis B is about 3 months. Very close (eg sexual) contacts of acute hepatitis B may be offered an injection of hepatitis B immunoglobulin as well as hepatitis B vaccine to try and prevent infection. Hepatitis B vaccine is also available to protect people at risk of infection as a consequence of their occupation or lifestyle.

Hepatitis C: At present the number of cases of hepatitis C infection throughout the world is uncertain. In the United Kingdom, between 1 in 250 and 1 in 1000 of the population show evidence of past infection with the virus. It is known to be spread by the blood-borne route, like hepatitis B, especially between intravenous drug abusers and following infected blood transfusions. Spread by sexual intercourse seems to be unusual but in many cases the route of infection is uncertain. The incubation period varies from two weeks to six months. The acute symptoms of hepatitis C are usually mild; about three-quarters of patients have no symptoms at all. However as many as half of those infected may develop a chronic infection which may lead to liver diseases later on. At present no vaccine is available to help stop the spread of this infection. Blood tests to detect antibody to hepatitis C virus have recently become available in this country and all blood donations are now tested for this virus.

Hepatitis D: The hepatitis D virus is also known as the delta agent, It is found worldwide especially in populations within the Amazon basin, Equatorial Africa, Middle East and Mediterranean basin. It is uncommon in the United Kingdom where the infection is found mostly in injecting drug users. Infection with hepatitis D can only coexist with hepatitis B, it cannot infect on its own. Hepatitis D is spread in the same way as the hepatitis B virus and can infect a patient simultaneously with hepatitis B virus or may infect a patient who is already infected with the hepatitis B virus. If the patient is infected with both hepatitis B and D viruses at the same time (co-infection) then acute hepatitis will develop after an incubation period of about three months. Chronic hepatitis rarely occurs in these circumstances. However, if a chronic hepatitis B carrier becomes infected with the hepatitis D virus (superinfection) then acute hepatitis may develop, after an incubation period of about 35 days. Chronic liver disease is common after a superinfection. Immunisation with hepatitis B vaccine will protect against the hepatitis D virus and this virus is excluded from blood donations by hepatitis B testing.

Hepatitis E: This is an important cause of large epidemics of acute viral hepatitis in India, Central and South East Asia, the Middle East, Northern, Eastern and Western Africa as well as Mexico. Contaminated water is the usual source of infection. Hepatitis E is uncommon in the United Kingdom and usually occurs in travellers returning from abroad. Hepatitis E is spread by the faecal-oral route like hepatitis A. However direct person to person spread of hepatitis E virus is much less common than with hepatitis A virus. The incubation period is between one and two months. The acute infection is usually mild and brief and does not progress to chronic hepatitis. Acute hepatitis E during pregnancy can cause serious complications and between 17 to 30% of infected pregnant women may die. Blood tests for this virus are not yet widely available and so the diagnosis is currently made by excluding other causes of viral hepatitis for which blood tests do exist. There is no vaccine at present.