Q: What is hepatitis?
A: Hepatitis is an inflammation of the liver. The condition can be self-limiting or can progress to fibrosis (scarring), cirrhosis or liver cancer. Hepatitis viruses are the most common cause of hepatitis in the world but other infections, toxic substances (e.g. alcohol, certain drugs), and autoimmune diseases can also cause hepatitis.
There are 5 main hepatitis viruses, referred to as types A, B, C, D and E. These 5 types are of greatest concern because of the burden of illness and death they cause and the potential for outbreaks and epidemic spread. In particular, types B and C lead to chronic disease in hundreds of millions of people and, together, are the most common cause of liver cirrhosis and cancer.
Hepatitis A and E are typically caused by ingestion of contaminated food or water. Hepatitis B, C and D usually occur as a result of parenteral contact with infected body fluids. Common modes of transmission for these viruses include receipt of contaminated blood or blood products, invasive medical procedures using contaminated equipment and for hepatitis B transmission from mother to baby at birth, from family member to child, and also by sexual contact.
Acute infection may occur with limited or no symptoms, or may include symptoms such as jaundice (yellowing of the skin and eyes), dark urine, extreme fatigue, nausea, vomiting and abdominal pain.
Q: What are the different hepatitis viruses?
A: Scientists have identified 5 unique hepatitis viruses, identified by the letters A, B, C, D, and E. While all cause liver disease, they vary in important ways.
Hepatitis A virus (HAV) is present in the faeces of infected persons and is most often transmitted through consumption of contaminated water or food. Certain sex practices can also spread HAV. Infections are in many cases mild, with most people making a full recovery and remaining immune from further HAV infections. However, HAV infections can also be severe and life threatening. Most people in areas of the world with poor sanitation have been infected with this virus. Safe and effective vaccines are available to prevent HAV.
Hepatitis B virus (HBV) is transmitted through exposure to infective blood, semen, and other body fluids. HBV can be transmitted from infected mothers to infants at the time of birth or from family member to infant in early childhood. Transmission may also occur through transfusions of HBV-contaminated blood and blood products, contaminated injections during medical procedures, and through injection drug use. HBV also poses a risk to healthcare workers who sustain accidental needle stick injuries while caring for infected-HBV patients. Safe and effective vaccines are available to prevent HBV.
Hepatitis C virus (HCV) is mostly transmitted through exposure to infective blood. This may happen through transfusions of HCV-contaminated blood and blood products, contaminated injections during medical procedures, and through injection drug use. Sexual transmission is also possible, but is much less common. There is no vaccine for HCV.
Hepatitis D virus (HDV) infections occur only in those who are infected with HBV. The dual infection of HDV and HBV can result in a more serious disease and worse outcome. Hepatitis B vaccines provide protection from HDV infection.
Hepatitis E virus (HEV) is mostly transmitted through consumption of contaminated water or food. HEV is a common cause of hepatitis outbreaks in developing parts of the world and is increasingly recognized as an important cause of disease in developed countries. Safe and effective vaccines to prevent HEV infection have been developed but are not widely available
What Is Hepatitis?
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. Autoimmune hepatitis is a disease that occurs when your body makes antibodies against your liver tissue.
The liver is located on the right upper quadrant of your abdomen. It performs many critical functions that affect metabolism throughout your body, including:
- bile production that’s essential to digestion
- filtering of toxins from the body
- excretion of bilirubin, cholesterol, hormones, and drugs
- metabolism of carbohydrates, fats, and proteins
- activation of enzymes, which are specialized proteins essential to metabolic functions
- storage of glycogen, minerals, and vitamins (A, D, E, and K)
- synthesis of plasma proteins, such as albumin
- synthesis of clotting factors
According to the Centers for Disease Control and Prevention (CDC), there are 4.4 million Americans currently living with chronic hepatitis. Many more people don’t even know that they have it.
Viral infections of the liver that are classified as hepatitis include hepatitis A, B, C, D, and E. Hepatitis A is a milder version of the disease, and hepatitis C and D are more severe. Treatment options vary depending on what form of hepatitis you have and what caused the infection. You can prevent some forms of hepatitis through immunizations or lifestyle precautions
Types of Viral Hepatitis
Hepatitis A
This type derives from an infection with the hepatitis A virus (HAV). This type of hepatitis is most commonly transmitted by consuming food or water contaminated by feces from a person infected with hepatitis A.
Hepatitis B
This type derives from an infection with the hepatitis B virus (HBV). This type is transmitted through puncture wounds or contact with infectious body fluids, such as blood, saliva, or semen. Injection drug use, having sex with an infected partner, or sharing razors with an infected person increase your risk of getting hepatitis B. It’s estimated by the CDC that 1.25 million people in the United States have chronic hepatitis B and 350 million people worldwide live with this chronic disease.
Hepatitis C
This type comes from the hepatitis C virus (HCV). Hepatitis C is transmitted through direct contact with infected body fluids, typically through injection drug use and sexual contact. HCV is among the most common blood-borne viral infections in the United States. Approximately 2.7 million Americans are currently living with a chronic form of this infection.
Hepatitis D
This is also called delta hepatitis. Hepatitis D is a serious liver disease caused by the hepatitis D virus (HDV). HDV is contracted through puncture wounds or contact with infected blood. Hepatitis D is a rare form of hepatitis that occurs in conjunction with hepatitis B infection. It’s very uncommon in the United States.
Hepatitis E
Hepatitis E is a waterborne disease caused by the hepatitis E virus (HEV). Hepatitis E is mainly found in areas with poor sanitation and is typically caused by ingesting fecal matter. This disease is uncommon in the United States. However, cases of hepatitis E have been reported in the Middle East, Asia, Central America, and Africa, reports the CDC.
Hepatitis A and E are normally contracted from eating contaminated food or drinking contaminated water. Hepatitis B, C, and D are contracted through contaminated blood. These forms of hepatitis can be either acute or chronic. Types B and C usually become chronic.
Causes of Nonviral HepatitisAlcohol
Hepatitis can be caused by liver damage from excessive alcohol consumption. This is sometimes referred to as alcoholic hepatitis. The alcohol causes the liver to swell and become inflamed. Other toxic causes include overuse of medication or exposure to poisons.
Autoimmune Disease
The immune system may mistake the liver as a harmful object and begin to attack it, hindering liver function
Common Symptoms of HepatitisIf you have forms of hepatitis that are usually chronic (hepatitis B and C), you may not have symptoms in the beginning. Symptoms may not occur until liver damage occurs.
Signs and symptoms of acute hepatitis appear quickly. They include:
- fatigue
- dark urine
- pale stool
- abdominal pain
- loss of appetite
- unexplained weight loss
- yellow skin and eyes, which may be signs of jaundice
Since chronic hepatitis develops slowly, these signs and symptoms may be too subtle to notice.
How Is Hepatitis Diagnosed?
Physical Exam
During a physical examination, your doctor may press down gently on your abdomen to see if there’s pain or tenderness. Your doctor may also feel to see if your liver is enlarged. If your skin or eyes are yellow, your doctor will note this during the exam.
Liver Biopsy
A liver biopsy is an invasive procedure that involves the doctor taking a sample of tissue from your liver. This is a closed procedure. In other words, it can be done through the skin with a needle and doesn’t require surgery. This test allows your doctor to determine if an infection or inflammation is present or if liver damage has occurred.
Liver Function Tests
Liver function tests use blood samples to determine how efficiently the liver works. These tests check how the liver clears blood waste, protein, and enzymes. High liver enzyme levels may indicate that the liver is stressed or damaged.
Ultrasound
An abdominal ultrasound uses ultrasound waves to create an image of the organs within the abdomen. This test will reveal fluid in the abdomen, an enlarged liver, or liver damage.
Blood Tests
Blood tests used to detect the presence of hepatitis virus antibodies and antigen in the blood will indicate or confirm which virus is the cause of the hepatitis.
Viral Antibody Testing
Further viral antibody testing may be needed to determine if a specific type of the hepatitis virus is present.
