Hepatitis
Your liver helps your body digest food, store energy and remove poisons. Hepatitis is a swelling of the liver that makes it stop working well. It can lead to scarring, called cirrhosis, or to cancer.
Viruses cause most cases of hepatitis. The type of hepatitis is named for the virus that causes it; for example, hepatitis A, hepatitis B or hepatitis C. Drug or alcohol use can also lead to hepatitis. In other cases, your body mistakenly attacks its own tissues. You can help prevent some viral forms by getting a vaccine. Sometimes hepatitis goes away by itself. If it does not, it can be treated with drugs. Sometimes hepatitis lasts a lifetime.
Some people who have hepatitis have no symptoms. Others may have
Viruses cause most cases of hepatitis. The type of hepatitis is named for the virus that causes it; for example, hepatitis A, hepatitis B or hepatitis C. Drug or alcohol use can also lead to hepatitis. In other cases, your body mistakenly attacks its own tissues. You can help prevent some viral forms by getting a vaccine. Sometimes hepatitis goes away by itself. If it does not, it can be treated with drugs. Sometimes hepatitis lasts a lifetime.
Some people who have hepatitis have no symptoms. Others may have
- Loss of appetite
- Nausea and vomiting
- Diarrhea
- Dark-colored urine and pale bowel movements
- Stomach pain
- Jaundice, yellowing of skin and eyes
Hepatitis A
Hepatitis A is one type of hepatitis - a liver disease - caused by the hepatitis A virus (HAV). The disease is spread primarily through food or water contaminated by stool from an infected person. You can get HAV from
The hepatitis A vaccine can prevent HAV. Healthy habits also make a difference. Wash your hands thoroughly before preparing food, after using the toilet or after changing a diaper. International travelers should be careful about drinking tap water.
- Eating food prepared by someone with HAV who did not wash their hands after using the bathroom
- Having anal/oral sex with someone with HAV
- Not washing your hands after changing a diaper
- Drinking contaminated water
The hepatitis A vaccine can prevent HAV. Healthy habits also make a difference. Wash your hands thoroughly before preparing food, after using the toilet or after changing a diaper. International travelers should be careful about drinking tap water.
Hepatitis B
Hepatitis B spreads by contact with an infected person's blood, semen or other body fluid. An infected woman can give hepatitis B to her baby at birth. If you get HBV, you may feel as if you have the flu, or you may have no symptoms at all. A blood test can tell if you have it. HBV usually gets better on its own after a few months. If it does not get better, it is called chronic HBV, which lasts a lifetime. Chronic HBV can lead to scarring of the liver, liver failure or liver cancer.
There is a vaccine for HBV. It requires three shots. All babies should get the vaccine, but older children and adults can get it too. If you travel to countries where Hepatitis B is common, you should get the vaccine.
There is a vaccine for HBV. It requires three shots. All babies should get the vaccine, but older children and adults can get it too. If you travel to countries where Hepatitis B is common, you should get the vaccine.
Hepatitis C
It usually spreads through contact with infected blood. It can also spread through sex with an infected person and from mother to baby during childbirth. Most people who are infected with hepatitis C don't have any symptoms for years. A blood test can tell if you have it. Usually, hepatitis C does not get better by itself. The infection can last a lifetime and may lead to scarring of the liver or liver cancer. Medicines sometimes help, but side effects can be a problem. Serious cases may need a liver transplant.
There is no vaccine for HCV.
Hepatitis D
Hepatitis D or delta hepatitis is caused by the hepatitis delta virus (HDV), a defective RNA virus. HDV requires the help of a hepadnavirus like hepatitis B virus (HBV) for its own replication. How is HDV spread?
HDV is transmitted percutaneously or sexually through contact with infected blood or blood products.
Blood is potentially infectious during all phases of active hepatitis D infection. Peak infectivity probably occurs just before the onset of acute disease.
Who is at risk for infection?
Chronic HBV carriers are at risk for infection with HDV.
Individuals who are not infected with HBV, and have not been immunized against HBV, are at risk of infection with HBV with simultaneous or subsequent infection with HDV.
Since HDV absolutely requires the support of a hepadnavirus for its own replication, inoculation with HDV in the absence of HBV will not cause hepatitis D. Alone, the viral genome indeed replicates in a helper-independent manner, but virus particles are not released.
Where is HDV a problem globally?
The hepatitis delta virus is present worldwide and in all age groups.14, 21
Its distribution parallels that of HBV infection, although with different prevalence rates (highest in parts of Russia, Romania, Southern Italy and the Mediterranean countries, Africa and South America). In some HBV-prevalent countries such as China, HDV infection is disproportionately low.14
The natural reservoir is man, but HDV can be experimentally transmitted to chimpanzees and woodchucks that are infected with HBV and woodchuck hepatitis virus, respectively.19, 21, 24
When is a HDV infection life-threatening?
HDV infection of chronically infected HBV-carriers may lead to fulminant acute hepatitis or severe chronic active hepatitis, often progressing to cirrhosis.
Chronic hepatitis D may also lead to the development of hepatocellular carcinoma.11
Why is there no treatment for the disease?
Hepatitis D is a viral disease, and as such, antibiotics are of no value in the treatment of the infection.
There is no hyperimmune D globulin available for pre- or postexposure prophylaxis.
Disease conditions may occasionally improve with administration of a-interferon.15, 21, 25
Since no effective antiviral therapy is currently available for treatment of type D hepatitis, liver transplantation may be considered for cases of fulminant acute and end-stage chronic hepatitis D.
HDV is transmitted percutaneously or sexually through contact with infected blood or blood products.
Blood is potentially infectious during all phases of active hepatitis D infection. Peak infectivity probably occurs just before the onset of acute disease.
Who is at risk for infection?
Chronic HBV carriers are at risk for infection with HDV.
Individuals who are not infected with HBV, and have not been immunized against HBV, are at risk of infection with HBV with simultaneous or subsequent infection with HDV.
Since HDV absolutely requires the support of a hepadnavirus for its own replication, inoculation with HDV in the absence of HBV will not cause hepatitis D. Alone, the viral genome indeed replicates in a helper-independent manner, but virus particles are not released.
Where is HDV a problem globally?
The hepatitis delta virus is present worldwide and in all age groups.14, 21
Its distribution parallels that of HBV infection, although with different prevalence rates (highest in parts of Russia, Romania, Southern Italy and the Mediterranean countries, Africa and South America). In some HBV-prevalent countries such as China, HDV infection is disproportionately low.14
The natural reservoir is man, but HDV can be experimentally transmitted to chimpanzees and woodchucks that are infected with HBV and woodchuck hepatitis virus, respectively.19, 21, 24
When is a HDV infection life-threatening?
HDV infection of chronically infected HBV-carriers may lead to fulminant acute hepatitis or severe chronic active hepatitis, often progressing to cirrhosis.
Chronic hepatitis D may also lead to the development of hepatocellular carcinoma.11
Why is there no treatment for the disease?
Hepatitis D is a viral disease, and as such, antibiotics are of no value in the treatment of the infection.
There is no hyperimmune D globulin available for pre- or postexposure prophylaxis.
Disease conditions may occasionally improve with administration of a-interferon.15, 21, 25
Since no effective antiviral therapy is currently available for treatment of type D hepatitis, liver transplantation may be considered for cases of fulminant acute and end-stage chronic hepatitis D.
Hepatitis E
The hepatitis E virus is transmitted mainly through contaminated drinking water. It is usually a self-limiting infection and resolves within 4–6 weeks. Occasionally, a fulminant form of hepatitis develops (acute liver failure), which can lead to death.
Globally, there are approximately 20 million incident hepatitis E infections every year.
Geographical distribution Hepatitis E is found worldwide and different genotypes of the hepatitis E virus determine differences in epidemiology. For example, genotype 1 is usually seen in developing countries and causes community level outbreaks while genotype 3 is usually seen in the developed countries and does not cause outbreaks. Globally, 70 000 deaths and 3.4 million cases of acute hepatitis E are attributable to infection with hepatitis E virus genotypes 1 and 2.
The highest seroprevalence rates (number of persons in a population who test positive for the disease) are observed in regions where low standards of sanitation increase the risk for transmission of the virus. Over 60% of all hepatitis E infections and 65% of all hepatitis E deaths occur in East and South Asia, where seroprevalence rates of 25% are common in some age groups. In Egypt, half the population aged above five years is serologically positive for the hepatitis E virus.
Transmission The hepatitis E virus is transmitted mainly through the faecal-oral route due to faecal contamination of drinking water. Other transmission routes have been identified, which include:
- foodborne transmission from ingestion of products derived from infected animals;
- zoonotic transmission from animals to humans;
- transfusion of infected blood products;
- vertical transmission from a pregnant woman to her fetus.
Hepatitis E is a waterborne disease, and contaminated water or food supplies have been implicated in major outbreaks. The ingestion of raw or uncooked shellfish has also been identified as the source of sporadic cases in endemic areas.
The risk factors for hepatitis E are related to poor sanitation in large areas of the world and shedding of the hepatitis E virus in faeces.
Symptoms The incubation period following exposure to the hepatitis E virus ranges from three to eight weeks, with a mean of 40 days. The period of communicability is unknown.
The hepatitis E virus causes acute sporadic and epidemic viral hepatitis. Symptomatic infection is most common in young adults aged 15–40 years. Although infection is frequent in children, the disease is mostly asymptomatic or causes a very mild illness without jaundice (anicteric) that goes undiagnosed.
Typical signs and symptoms of hepatitis include:
- jaundice (yellow discoloration of the skin and sclera of the eyes, dark urine and pale stools);
- anorexia (loss of appetite);
- an enlarged, tender liver (hepatomegaly);
- abdominal pain and tenderness;
- nausea and vomiting;
- fever.
In rare cases, acute hepatitis E can result in fulminant hepatitis (acute liver failure) and death. Overall population mortality rates from hepatitis E range from 0.5% to 4.0%. Fulminant hepatitis occurs more frequently during pregnancy. Pregnant women are at greater risk of obstetrical complications and mortality from hepatitis E, which can induce a mortality rate of 20% among pregnant women in their third trimester.
Cases of chronic hepatitis E infection have been reported in immunosuppressed people. Reactivation of hepatitis E infection has also been reported in immunocompromised people.
Diagnosis Cases of hepatitis E are not clinically distinguishable from other types of acute viral hepatitis. Diagnosis of hepatitis E infection is therefore usually based on the detection of specific antibodies to the virus in the blood.
Two additional diagnostic tests require specialized laboratory facilities and are used only in research studies. These are:
- reverse transcriptase polymerase chain reaction (RT-PCR) to detect the hepatitis E virus RNA;
- immune electron microscopy to detect the hepatitis E virus.
Treatment There is no available treatment capable of altering the course of acute hepatitis. Prevention is the most effective approach against the disease.
As hepatitis E is usually self-limiting, hospitalization is generally not required. However, hospitalization is required for people with fulminant hepatitis and should also be considered for infected pregnant women.
Prevention The risk of infection and transmission can be reduced by:
- maintaining quality standards for public water supplies ;
- establishing proper disposal systems to eliminate sanitary waste.
- maintaining hygienic practices such as hand washing with safe water, particularly before handling food;
- avoiding drinking water and/or ice of unknown purity;
- avoiding eating uncooked shellfish, and uncooked fruits or vegetables that are not peeled or that are prepared by people living in or travelling in highly endemic countries.