There are over 100 different forms of liver diseases. We will talk here about the most common types: Hepatitis A, Hepatitis B, Hepatitis C, Fatty Liver and Cirrhosis.
Each of us are exposed to harmless viruses like the common cold (i.e. rhinovirus) and the body`s immune system will wipe out the virus. However, not all acute infections are so harmless. Viral infection such as influenza (including avian flu and influenza A) can be fatal although the majority of people will recover over a short period of time. Viral infection also attack specific organs in the body. Hepatitis A, B and C are all viruses that attack the Liver.
Hepatitis A is:
- The most commonly seen hepatitis virus
- A type of acute viral infectious disease
- A highly contagious liver disease that has the potential of making the patient critically ill
- Commonly perceived as being contracted during travel but many cases of hepatitis A infection are non-travel related
- Preventable by appropriate vaccination
Globally hepatitis A affects 1.5 million people on a yearly basis. Some reports indicate that the actual number of infections may be up to 10 times higher since the disease is often asymptomatic (does not have noticeable symptoms) and so goes undiagnosed. In Canada, there were 3500 cases diagnosed in 1991 but less than 400 cases in 2003. In adults, 25% of the cases required hospitalization.
Transmission & Risk Factors
This particular virus is transmitted primarily by the fecal-oral route when a person ingestes food or drinking water that has been contaminated by the feces of an infected person. Transmission usually occurs in places where people are in close proximity, co-habiting, or ingesting contaminated food or water. The virus can survive in water for up to 10 months.
Other risk factors or routes of hepatitis A infection include:
- Food and drinks prepared by infected personnel who do not follow all safety protocols
- Through consuming contaminated imported food
- Having close contact with an infected person
- Travel in areas were the disease is common – whether living abroad, visiting for pleasure, or visiting for work (Africa, Asia, Latin America, Eastern Europe, Mexico and the Caribbean)
- Children – as it is usually asymptomatic for children, they could unknowingly spread the virus to other children or adults
- Poor sanitation standards
- Eating raw/uncooked seafood and shellfish products
Once infected with hepatitis A the majority of the population will have lifetime immunity against the virus after they recover. However, approximately 15% of the patients do not recover completely and will relapse in a year’s time.
Hepatitis B is:
- A common virus
- Approximately 400 million people carry this virus worldwide
- Approximately 75% of Hep B carriers live in Asia
- Amongst the carriers, approximately 20-25% will die of liver cancer or cirrhosis
- In the majority of Asian countries approximately 10% of the population are carriers. Although it is a serious problem imposed on the public health system public awareness of this disease is relatively low. One of the reasons is due to the nature of this disease as a chronic asymptomatic disease (has no noticable symptoms).
Transmission & Risk Factors
The Hep B virus is spread through blood and other bodily fluids, not food. A common misconception is that if I am careful with what I eat, I will not contract the hep B virus. As mentioned earlier, the majority of the carriers are infected with this virus at birth – vertical transmission (from mother to baby during pregnancy or childbirth).
Other routes of transmission include:
- Coming in contact with contaminated instrument during dental appointments
- Sharing syringes
- Receiving repeatedly used needles that are not cleaned properly during acupuncture
- Body tattoo or piercing with contaminated instuments
- Sexually transmitted
- Receiving contaminated blood products during blood transfusion (rarely happens nowadays)
As with any other illness, the sooner you get treatment for hep B the better the result. The effect and results will certainly be better if the treatment is started at a younger age because much damage may have already occurred to the liver at an older age. There is no current treatment to completely eliminate or cure this virus. However, in the past 10 year it has been proven that drugs can effectively supress and control the virus to minimize the damage to the liver.
Hepatitis C is a virus similar to Hep A and Hep B in that it also attacks the liver. Acute Hep C usually has no warning symptoms so many people are unaware when they are infected. Hep C will stay in the liver long-term. If the virus is not successfully treated the patient will have it for the rest of their life. Such prolonged viral infection is called “chronic” infection.
Chronic Hep C affects approximately 1-2% of the North American population. British Columbia has one of the highest infection rates in Canada. It is estimated that in B.C. 45 to 60 thousand people have chronic hepatitis C and that many people have yet to be diagnosed. The natural progression of a hepatitis C infection can last for decades. For most of that time Hep C remains silent (no symptoms are noticeable). It is usually not until later stages that it becomes diagnosed during a blood test. Over time, inflammation and scarring of the liver will gradually and slowly develop in hepatitis C patients with about 10-20% of patients developing severe scarring and cirrhosis. After 20-30 years of infection patients are at high risk of being at the last stage of liver failure.
Hepatitis C is transmitted through coming in contact with contaminated bodily fluids. There was a period of time where testing for Hep C prior to blood transfusion was not a common practice and prior to 1991 there was no such a thing as a blood test. These days blood is tested for Hep C before any transfusions.
Common routes of infection are due to:
- Drug injection on the street (i.e. using the same needle to inject heroin or cocaine)
- Ingestion of a drug through the nasal canal (i.e. intranasal cocaine)
- In some parts of the world, Hep C is transmitted via unsterilized medical/dental devices.
- In many cases the way a patient became infected with hep C is unknown
Although Hep B and Human Immunodeficiency Virus (HIV) are often transmitted during sex or child delivery from mother to child, these means of transmission are a lot less common for Hep C.
In terms of risk factors that quickens the onset of cirrhosis, alcohol is definitely one of the factors that need to be repeatedly emphasized. Even a small amount of alcohol is enough to contribute towards promoting the development of cirrhosis. Patients should abstaining from drinking alcohol or reduce it to an absolute minimum. Infection of other virus, especially HIV and Hep B, are widely believed to accelerate the natural development of Hep C. Another important point to remember is that Hep C virus not only affects the liver, it may also cause other complications including cryoglobulinemia, and this condition may lead to kidney inflammation and failure, arthritis, and skin ulcers. Non-Hodgkin’s lymphoma (a type of malignant lymphoid tumor) and adult onset diabetes are also related to hep C.
Many people have heard of the term “fatty liver” but may not know exactly what it is. The liver is located in the upper right quadrant of your abdomen within the ribcage. The liver is the second largest organ in the human body (after the skin) and weighs approximately 1400 grams. The liver becomes a fatty liver when 5% or more of it is fat rather than liver tissue.
How does fat travel into the liver? There are two main pathways:
- Due to the close proximity of liver and intestine, fat cells may enter the liver from the intestine.
- Liver cells degeneration: liver cells are broken down and turned into fat cells
Some of the main functions of liver cells are:
- Store glycogen (the main storage form of glucose in the body)
- Produce essential body material
- Eliminate metabolic waste
- Store vitamins
- Store minerals like iron and copper- (these are essential building block of red blood cell)
- Make proteins that are important for blood clotting
- Eliminate waste like alcohol, certain drugs (e.g. Tylenols, Warfarin, Amiodarone) and other toxic substances
- Produce bile (stored in the gallbladder) for fat digestion