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Hepatitis is an acute or chronic inflammation of the hepatocytes (liver cells which make up to about 70 - 80% of the total mass of the liver), resulting in damage to the liver. Most people associate hepatitis with viral hepatitis, but the term actually encompasses a much broader range of pathophysiological conditions leading to it. Among the non-infectious causes, it can be the result of chronic alcoholism, an autoimmune disorder or can be drug-induced. Some species of bacteria also cause hepatitis. However, viral hepatitis is undoubtedly more prevalent, and is more focused upon. Also, it has the potential of causing other deadly diseases such as liver cancer, which makes it all the more important to be aware of all aspects of this disease.

The causative agents of viral hepatitis are the hepatotropic viruses as well as some others like the Epstein-Barr virus (EBV) and the Cytomegalovirus (CMV). Among these, the incidence of hepatitis caused by the hepatotropic viruses is greater. The transmission of the viruses, their symptoms, progression of the disease, and treatment, all vary depending on which type a person gets infected with. The five types of hepatotropic viruses that cause hepatitis are hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis D virus and hepatitis E virus. There are two more types known as F and GB virus C (GBV-C), that are not known to cause the disease.

Hepatitis A

Hepatitis A has been known for a long time as "infectious hepatitis" and is caused by the hepatitis A virus (HAV). It causes acute infection but does not cause chronic hepatitis, and development of fulminant hepatitis, which is a severe form of viral hepatitis of a life-threatening nature, is rare. It also is not associated with the development of hepatocellular carcinoma or liver cancer, compared to the hepatitis B and C viruses that have a strong correlation with this type of cancer. It does not cause a carrier state. (A carrier state refers to the fact that the virus lies dormant in the body without causing symptoms, but can be transmitted to another person.)

Mode of Transmission
The virus is found in the feces of an infected person, 2-4 weeks before and about 5 to 6 days after the start of acute symptoms. The virus spreads through food and/or water, contaminated with the feces of persons infected with the virus. It also spreads by sexual practices (e.g., rimming) which entails anal-oral contact between an infected and uninfected person. The hepatitis virus A is, however, not spread by body fluids such as urine, saliva or semen. Another route through which the virus enters the body is through the consumption of seafood obtained from water contaminated with human sewage.

Symptoms
Hepatitis A may be asymptomatic; meaning that after contracting the virus, a person may have no symptoms at all and the only way he/she might come to know about it is through antibodies for anti-HAV, showing up in a blood test.

Those who suffer from an acute symptomatic infection usually have the following symptoms:
  • Malaise, which is a feeling of debility; the person feels drained of energy
  • Inability to eat proper meals due to loss of appetite
  • Bouts of nausea
  • Aches and pains (a person may have dull headaches and pain in joints and muscles)
  • Slight fever
  • Diarrhea
  • Appearance of dark-colored urine
  • Skin and eyes both look yellowish
  • The color of feces may become lighter
  • Enlarged liver
Diagnosis
  • Appearance of anti-HAV antibodies in the blood
  • Mild increase of the enzyme serum alkaline phosphatase
  • Prolongation of the prothrombin time
  • Elevated globulins in the blood
Treatment
There are no antiviral drugs for hepatitis A or any other kind of treatment aimed at eradicating the virus from the body. A person suffering from the acute infection needs to take rest to recuperate. Although there is no treatment, preventive measures in the form of hepatitis A vaccine can be taken, especially if a person is planning to undertake international travel. The Centers for Disease Control and Prevention (CDC) recommend all children between 12 to 23 months to be vaccinated. Vaccination is also recommended by them for the following high-risk groups: health care workers, homosexuals, street drugs users, those adopting a child, those working in a lab with HAV or who work with HAV-infected primates and those suffering from chronic liver disease.

Hepatitis B

It is widely known as "serum hepatitis" and is caused by the hepatitis B virus. It can cause acute as well as chronic hepatitis, fulminant hepatitis or a progressive chronic form of hepatitis leading ultimately to cirrhosis. It is associated with the development of hepatocellular carcinoma in those with the chronic infection. It can lead to a carrier state in a small percentage of blood donors and in newborn babies whose mothers have contracted the virus at some point in their life.

Mode of Transmission
Unlike the hepatitis A virus, the virus for hepatitis B does not spread by feces. It is present in blood at all stages of the infection, so it spreads easily through blood transfusion, intravenous drug use and accidental pricking with contaminated needles. It also appears in all body fluids like semen, saliva, breast milk and sweat. It spreads by sexual practices in both heterosexual and homosexual individuals. It can live outside the body for around a week, so it can enter the body via broken skin coming in contact with contaminated objects. The virus has an incubation period of 4-25 weeks.

Symptoms
Hepatitis B virus may cause an asymptomatic infection. The symptoms of acute infection are mostly the same as that for hepatitis A infection.

Symptoms of Acute Infection
  • A persistent feeling of tiredness
  • Nausea and vomiting
  • Loss of appetite
  • Pain in the abdomen and in the joints and muscles
  • Diarrhea
  • Jaundice
  • Some patients develop rash, fever and other severe symptoms
Symptoms of Chronic Infection
Individuals with chronic hepatitis B may exhibit no symptoms even as the virus silently wreaks havoc in their liver. They may often feel fatigued. There are no clear-cut symptoms indicative of chronic disease if it remains non-progressive.

Diagnosis
A number of serological tests diagnose the presence of hepatitis B virus. The presence of the HBsAg, anti-HBc and IgM anti-HBc is interpreted as a sign of acute infection, while in chronic infection, presence of HbsAg (for more than 6 months) and anti-HBc are taken to be positive. Also, presence of HBeAg and serum HBV DNA are also considered signs of chronic infection.

Treatment
There are many treatment options available for treating hepatitis B infection. Some of them are:

Interferon-alfa (Multiferon): It is an approved treatment for chronic infection with HBV. It is administered by subcutaneous or intramuscular injection three times a week for about 16 weeks. Adverse effects associated with interferon-alfa are fever, malaise, chills, muscle pain and many other flu-like symptoms.

Lamivudine: It is an orally administered drug with a dose of 100-300 mg, to be taken daily for more than a year. A combination treatment with interferon-alfa also gives good results in many patients. Resistance to lamivudine may develop in some persons after stopping the therapy.

Adefovir: It is administered orally at a dose of 100 mg daily for about a month. It is active against strains of hepatitis B that have become resistant to lamivudine. Other anti-viral drugs for hepatitis B are Famciclovir, Entecavir and Fialuridine.

The best course of action is to get vaccinated so that even if you do contract the infection, your immune system is ready for the virus. According to CDC, the vaccine can be administered as a shot by itself or in the same shot with other vaccines. High-risk groups who need to get vaccinated includes those at risk for hepatitis A. It also includes those who are on kidney dialysis and those who suffer from diabetes under 60 years of age.

Hepatitis C

Caused by the hepatitis C virus (HCV), hepatitis C has a high incidence of progressing to the chronic form of the disease. It can also lead to the development of hepatocellular carcinoma. Development of fulminant hepatitis with HCV is extremely rare. The infection can lead to an asymptomatic chronic carrier state in most people who become infected which in turn can lead to cirrhosis of the liver.

Mode of Transmission
The hepatitis C virus does not appear to spread by sharing food or drink of an infected person. It also does not appear in breast milk. The greatest spread of HCV is through contact with the blood of an infected individual. Any activity that involves using sharp objects with the blood of a person having the HCV is highly likely to spread the infection. High-risk sexual activity (involving cuts, bruises) can lead to HCV transmission.

Symptoms
The infection with HCV can be acute or chronic. Mostly, people remain asymptomatic after contracting the infection. The symptoms that do appear are similar to those of other hepatitis virus types like general malaise, nausea, vomiting, low-grade fever, fatigue, pain in muscles, dark urine and jaundice (yellowing of eyes and skin). The chronic state is also frequently asymptomatic, and the symptoms that do appear, do so only after the beginning of cirrhosis. The one feature that distinguishes HCV infection from others, is that there is a cycle of periods of dormancy followed by liver damage due to re-activation of the virus.

Diagnosis
The diagnosis is done by serological tests that test for anti-HCV antibodies. This test is called the second generation enzyme immunoassay (EIA-2). A PCR test for HCV RNA also is used to confirm the diagnosis.

Treatment
Treatment options are chosen by a doctor based on the risk posed by liver damage to the patient. Peginterferon-alfa-2a (Pegasys), peginterferon-alfa-2b (Peginterferon) or Ribavirin are used. According to CDC, a vaccine for hepatitis is not available, but efforts are underway to develop it.

Hepatitis D

It is known as Delta agent or hepatitis delta virus (HDV). It can cause infection only in the presence of HBV. If a person who is a chronic carrier of HBV contracts HDV, severe hepatitis may result. Also, mild hepatitis due to HBV may become fulminant in the presence of HDV.

Mode of Transmission
HDV is transmitted by blood of infected individuals and also by sexual contact. Many people become co-infected, that is, they get infected with both HBV and HDV by the same route. Drug users and those receiving contaminated injectables are at risk for infection. Hemophiliacs appear to be at a higher risk of acquiring both viruses.

Symptoms
After an incubation period of about 1-2 months, the symptoms of the acute infection start appearing which are similar to acute hepatitis by other hepatotropic viruses. General fatigue, loss of appetite and nausea are the symptoms in the beginning. Later, jaundice sets in, the symptoms of which are dark-colored urine, light clay colored feces, yellowish eyes and pale skin. Development of chronic infection occurs if there is superinfection, otherwise the risk is small.

Diagnosis
Serological tests that test for anti-HDV antibodies, like radioimmunoassay (RIA) or enzyme immunoassay (EIA) are done for diagnosing HDV.

Treatment
The only treatment for chronic hepatitis D is interferon-alfa, but response to it varies among different persons.

Although a vaccine for HDV is not available, HBV vaccine is useful to prevent infection by HDV because it can live only in the presence of HBsAg, which is made by HBV.

Hepatitis E

It is caused by the hepatitis E virus (HEV). Pregnant women are at a much higher risk of developing complications and even death due to HEV. Chronic infection is not caused by this virus and a carrier state too, is not known to develop. The risk for hepatocellular carcinoma is also not known to exist.

Mode of Transmission
It is transmitted by drinking water contaminated with HEV. It has an incubation period of 2-8 weeks.

Symptoms
Symptoms of acute infection with HEV are similar to the symptoms caused by other hepatotropic viruses.

Diagnosis
No approved diagnostic test is available in the U.S. for testing the presence of HEV.

Treatment
No drugs against HEV are available. Vaccine too, is not available in the U.S., although a vaccine has been approved for use in China.

Other viruses like the GB virus C have not been proved to cause hepatitis.

Thus, it is important to remember that vaccination, hygiene, staying away from high-risk sexual activities and avoiding drug abuse are the only sure ways to avoid contracting hepatitis viruses. As the old adage goes, prevention is better than cure.

Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice.