Hepatitis refers to an inflammatory condition of the liver. It’s commonly caused by a viral infection, but there are other possible causes of hepatitis. These include autoimmune hepatitis and hepatitis that occurs as a secondary result of medications, drugs, toxins, and alcohol.
Your liver is located in the right upper area of your abdomen. It performs many critical functions that affect metabolism throughout your body, including:
- bile production, which is essential to digestion.
- filtering of toxins from your body.
- excretion of bilirubin (a product of broken-down red bloodcells),cholesterol, hormones, and drugs.
- breakdown of carbohydrates fats, and proteins.
- activation of enzymes, which are specialized proteins essential to body functions.
- storage of glycogen (a form of sugar), minerals, and vitamins (A, D, E, and K).
- synthesis of blood proteins, such as albumin.
- synthesis of clotting factors.
The 5 types of viral hepatitis
Viral infections of the liver that are classified as hepatitis include hepatitis A, B, C, D, E and G.
A different virus is responsible for each type of virally transmitted hepatitis.
Hepatitis A is always an acute, short-term disease, while hepatitis B, C, and D are most likely to become ongoing and chronic. Hepatitis E is usually acute but can be particularly dangerous in pregnant women.
At one time, hepatitis A was referred to as “infectious hepatitis” because it could be spread easily from person to person like other viral infections. Infection with hepatitis A virus can be spread through the ingestion of food or water, especially where unsanitary conditions allow water or food to become contaminated by human waste containing hepatitis A (the fecal-oral mode of transmission). Hepatitis A typically is spread among household members and close contacts through the passage of oral secretions (intimate kissing) or stool (poor hand washing). It also is common to have infection spread to customers in restaurants and among children and workers in day care centers if hand washing and sanitary precautions are not observed.
HBV hepatitis was at one time referred to as “serum hepatitis,” because it was thought that the only way HBV could spread was through blood or serum (the liquid portion of blood) containing the virus. It is now known that HBV can spread by sexual contact, the transfer of blood or serum through shared needles in drug abusers, accidental needle sticks with needles contaminated with infected blood, blood transfusions, hemodialysis, and by infected mothers to their newborns. The infection also can be spread by tattooing, body piercing, and sharing razors and toothbrushes (if there is contamination with infected blood). About 5% to 10% of patients with HBV hepatitis develop chronic HBV infection (infection lasting at least six months and often years to decades) and can infect others as long as they remain infected. Patients with chronic HBV infection also are at risk of developing cirrhosis, liver failure, and liver cancer.
HCV hepatitis was previously referred to as “non-A, non-B hepatitis,” because the causative virus had not been identified, but it was known to be neither HAV nor HBV. HCV usually is spread by shared needles among drug abusers, blood transfusion, hemodialysis, and needle sticks. Approximately 75-90% of transfusion-associated hepatitis is caused by HCV. Transmission of the virus by sexual contact has been reported, but is considered rare. An estimated 75% to 85% of patients with acute HCV infection develop chronic infection. Patients with chronic HCV infection can continue to infect others. Patients with chronic HCV infection are at risk for developing cirrhosis, liver failure, and liver cancer.
Hepatitis D, E and G
There also are viral hepatitis types D, E, and G. The most important of these at present is the hepatitis D virus (HDV), also known as the delta virus or agent. It is a small virus that requires concomitant infection with HBV to survive. HDV cannot survive on its own because it requires a protein that the HBV makes (the envelope protein, also called surface antigen) to enable it to infect liver cells. The ways in which HDV is spread are by shared needles among drug abusers, contaminated blood, and by sexual contact; essentially the same ways as HBV
Individuals who already have chronic HBV infection can acquire HDV infection at the same time as they acquire the HBV infection, or at a later time. Those with chronic hepatitis due to HBV and HDV develop cirrhosis (severe liver scarring) rapidly. Moreover, the combination of HDV and HBV virus infection is very difficult to treat.
Hepatitis E virus (HEV) is similar to HAV in terms of disease, and mainly occurs in Asia where it is transmitted by contaminated water.
Hepatitis G virus (HGV, also termed GBV-C) was recently discovered and resembles HCV, but more closely, the flaviviruses. The virus and its effects are under investigation, and its role in causing disease in humans is unclear.
Who is at risk for viral hepatitis?
People who are most at risk for developing viral hepatitis are:
- Workers in the health care professions.
- Sewage and water treatment workers.
- People with multiple sexual partners.
- Intravenous drug users.
- People with hemophilia who receive blood clotting factors.
What are the symptoms and signs of viral hepatitis?
The period of time between exposure to hepatitis and the onset of the illness is called the incubation period. The incubation period varies depending on the specific hepatitis virus. Hepatitis A virus has an incubation period of about 15 to 45 days; Hepatitis B virus from 45 to 160 days, and Hepatitis C virus from about 2 weeks to 6 months.
Many patients infected with HAV, HBV, and HCV have few or no symptoms of illness. For those who do develop symptoms of viral hepatitis, the most common are flu- like symptoms including:
- Loss of appetite.
- Aching in the abdomen.
- Dark urine.
- Light-colored stools.
- Jaundice (A yellow appearance to the skin and white portion of the eyes.
Tips to prevent hepatitis
Practicing good hygiene is one key way to avoid contracting hepatitis. The use of vaccines is also an important key to preventing hepatitis. Vaccinations are available to prevent the development of hepatitis.