|Hepatitis B Version 4.1|
| The following documents related to hepatitis B have been
elaborated for informative purpose only. They have been written by
Stuart Millinship. This report has not been
written by the Health On the Net Foundation's team and the Foundation is
not responsible for the content of the Hepatitis B report.
What is Hepatitis
Hepatitis is an inflammation of the liver. It is usually caused by viral infections, toxic agents or drugs but may be an autoimmune response. It is characterised by jaundice, abdominal pain, liver enlargement and sometimes fever. It may be mild, or can be acute leading to fulminant hepatitis. Others form usually viral or alcoholic are chronic and can lead to cirrhosis and liver cancer.
There are many forms of viral hepatitis although they can have similar symptoms. The only way to discover if you have viral hepatitis and which variety you have is through blood tests. Liver function tests can give an indication of how much inflammation there is and other tests can determine which virus is responsible.
Hepatitis A (HAV) is caused by the hepatitis A virus.
The virus is excreted in the faeces of infected people and can be passed on when contaminated food or water is consumed by susceptible individuals. Hepatitis A is most commonly transmitted by person to person contact via faecal contamination but epidemics can occur from sources of contaminated food, water or ice cubes. Poor sanitation and overcrowding facilitate transmission and outbreaks are common in institutions, prisons and the military.
Many infections with hepatitis A do not produce any symptoms especially in children. When symptoms occur around 30 days after infection they are usually mild and last for around 1-2 weeks. The symptoms are characterised by sudden onset of fever, malaise, nausea, anorexia, and abdominal discomfort, followed in several days by jaundice. Occasionally, the symptoms are severe and convalescence can take several months due to being chronically tired. Occasionally hepatitis A can be fatal. These rare deaths usually occur in the elderly.
Once recovery from hepatitis A is complete you have life long immunity and cannot contract the virus again. Milk Thistle has been reported to reduce the recovery time following Hepatitis A infection.
A vaccination made from inactivated hepatitis A virus is now available and consists of an initial vaccination followed by a booster that is effective 94-100% of the time.
Hepatitis B is caused by the hepatitis B virus. The virus is very common in Asia, China, Philippines, China, Africa and the Middle east. In Europe and North America the incidence of known carriers is about 1 in a 1000 people. World wide, it is estimated that there are over 350 million hepatitis B carriers which represents 5% of the worlds population and it is estimated that 10 to 30 million people become infected with the virus each year.
Hepatitis B (HBV) is transmitted by the exchange of body fluids e.g. Blood, Semen, Breast Milk and in some circumstances saliva. People most at risk include:
Many cases of acute hepatitis B occur sporadically with no known source and studies have shown that prior unrecognised infection is common.
It is possible to be infected with the hepatitis B virus (HBV) and experience no illness or symptoms whatsoever. Commonest is an acute attack of hepatitis during which you may feel unwell, tired and lose your appetite. Sometimes there is the characteristic yellowish colour of jaundice best seen in the whites of the eyes. This can last from a few days to a few months. Itching skin and pale stools may also occur. In some cases hepatitis B can be fatal, especially in the elderly where mortality rates may be as high as 10 - 15%.
Around 90% of people infected with hepatitis B recover completely and become immune to the virus. Blood tests will show antibodies to hepatitis B indicating you have had hepatitis B but are now immune and cannot get hepatitis B again. However 10% of people infected with hepatitis B develop chronic infection, may have ongoing symptoms and they continue to be infectious for a variable length of time. Chronic infection is defined as having hepatitis B present for 6 months or more.
People with a chronic hepatitis infection are at risk of liver damage and around 20-30% of these progress to cirrhosis.
A safe and effective genetically engineered vaccine for hepatitis B is available. It is given in 3 intramuscular subcutaneous injections (just under the skin) generally over a period of 6 months and conveys immunity in 90 to 95% of people treated. At the end of the course of injections a blood test is taken to see if you have developed the required antibodies. For the 5 - 10% of people who do not respond some new research has shown that a repeat course of injections given intramuscularly can create an immune response in between 62-98% (depending on several factors) of those who did not respond or whose response did not last when given subcutaneously.
In the UK it is now recommended that the 3 injections are now given into the deltoid muscle to improve the likelihood of a response to the vaccine.
Once vaccinated it is important to be periodically tested to ensure that the body has sufficient levels of antibodies to prevent infection and a single booster dose may be required every 5 to 10 years to ensure immunity from infection.
If an unvaccinated individual is exposed to the virus accidentally, hepatitis B Immune globulin can be given. Ideally within 24 hours of exposure and no later than 7 days after exposure, a repeat dose is necessary 28 - 30 days later. Hepatitis B Immune globulin is generally given where there is a known risk of infection, e.g. via needle stick injury or to new-born infants born to Hepatitis B surface antigen positive mothers. In many cases hepatitis B immune globulin can prevent initial infection with hepatitis B but there are also a significant number of cases where it has not prevented infection after exposure.
Taken from the HEPV-L Hep C FAQ
Hepatitis C, formerly Non A - Non B hepatitis is caused by the hepatitis C virus. Hepatitis C is believed to cause between 150,000 and 250,000 new cases in the United States each year. Haemophiliacs and drug abusers are at the greatest risk, but anyone, of any status or age and in any walk of life, is at risk for acquiring the hepatitis C virus. Researchers have found that many people infected with hepatitis C don't even know it. From 20 to 40 percent of patients in inner-city hospitals are infected, as are 80 percent of drug users.
Taken from the HEPV-L Hep C FAQ:-
Most people with hepatitis C contracted it either through a blood transfusion or receiving blood products (plasma, etc.) that was contaminated with hepatitis C, or by sharing needles with intravenous drug users that were infected with hepatitis C. Prior to 1990 blood could not be screened for HCV. Thanks to HCV testing with modern sensitive methods, the risk of acquiring hepatitis C from blood transfusion is now less than 1%. The other means of acquiring hepatitis C include health care and laboratory workers that may get stuck with an infected needle or instrument, people receiving medical/dental procedures or people that had tattoos that were performed with poorly sterilised equipment. Infected mothers can pass the virus to the foetus in utero but this occurs less than 1% of the time. It may occur more readily if the mother is also infected with the human immuodeficiency virus (HIV) that causes AIDS
Cases of hepatitis C with no evidence of exposure through blood transfusions, needle stick or needle sharing are called "sporadic". How these individuals became infected is unknown.
The risk of sexual transmission of hepatitis C virus has not been thoroughly investigated but appears to be minimal.
Some people experience no symptoms after initial infection with the hepatitis C virus, however many people have a flu-like illness with fatigue, fever, muscular aches and pain, nausea and vomiting. Around 10% of patients become jaundiced but in the majority of cases these symptoms resolve. The acute phase of hepatitis C if rarely fatal.
Although symptoms resolve, around 80% of people infected with hepatitis C become chronically infected. Although frequently showing no symptoms the hepatitis C virus continues to reproduce and damage liver cells and after may years this may lead to liver disease including cirrhosis.
The is currently no vaccination available against hepatitis C.
As Hepatitis C and other diseases can be spread by using something with infected blood on it (even though it may not be visible) you can reduce the risk of infection by not sharing items of personal hygiene that may be contaminated such as razors, nail clippers, scissors, tooth brushes etc.
Hepatitis C is a large and complicated subject The majority of information contained within this document on hepatitis C and some general hepatitis information is taken from the HEPL-V Hepatitis C FAQ. This can be obtained by sending the command GET HEPV-L FAQ as a message to email@example.com or by sending a request to the author Patricia Johnson at firstname.lastname@example.org
The Hepatitis D Virus (HDV) is a unique, defective RNA virus that can only infect an individual in the presence of hepatitis B. It occurs either as a co-infection with acute hepatitis B or as a superinfection in people with chronic hepatitis B. Hepatitis D is mostly found among IV drug users, but transmission by other routes is possible.
Infection with hepatitis D can make the acute phase of hepatitis B unusually severe. It can cause an acute "exacerbation" in chronic hepatitis B carriers (superinfection), or cause a relatively aggressive course of chronic hepatitis B.
Some recent research as shown that hepatitis D can exist without Hepatitis B being present. But the presence of hepatitis B is required for the initial infection to take place.(?)
The hepatitis E virus is transmitted in the same manner as hepatitis A and produces similar symptoms. Hepatitis E does not cause chronic infection and has a similar prognosis to hepatitis A infection.
There is currently no vaccine available against hepatitis E.
Hepatitis F appears to be transmitted by the oral fecal route in a similar manner to hepatitis A and E although the epidemilogy of the virus has not yet been fully established.
In several cases of non-A-E hepatitis reported in western Europe, the United States and India, virus-like particles were observed in stool samples using an electron microscope. The virus called HAF consists of double-stranded DNA and is substantially different from HAV and HEV, both of which are RNA based.
Currently there is no serological test for diagnosing hepatitis F in cases of acute hepatits but electron microscopy of stool samples may be of assistance after tests for other viruses have failed.
Available studies demonstrate that HGV-infection is a blood transfusion and parenterally transmitted disease; HGV-infection is relatively mild in most cases; among transfusion recipients, HGV-infection is about as frequent in those formally diagnosed with hepatitis as in those with only mild ALT elevations; HGV and hepatitis C virus can be transmitted simultaneously and result in persistent co-infection; HGV-infection can be persistent and cause chronic hepatitis. ; the prevalence of HGV is higher than that of hepatitis C virus and unrelated to the ALT status of the blood donor; and the role of HGV in fulminant hepatitis and hepatocellular carcinoma has not been delineated.
The viruses that cause hepatitis G (GBV-A, GBV-C and GBV-C) are RNA based and in the same family as hepatitis C.
As a relatively 'new' disease there is still much research to be performed and information is relatively scarce. At the time this document was written it appears that HGV has uncertain pathogenic potential.
|http://www.hon.ch/Library/Theme/HepB/intro.html||Last modified: Fri Nov 1 2002|