The liver is the largest organ in the human body, with the function of digesting food, storing energy and removing toxins, always doing its best to be the gatekeeper of health, even when it is sick and inflamed, it is not easy to respond at first time, especially in the case of chronic hepatitis.
What is chronic hepatitis?
Chronic hepatitis refers to inflammation or necrosis of liver tissue lasting more than six months. Common types of liver inflammation include: viral hepatitis, alcoholic hepatitis, autoimmune hepatitis, and drug-induced hepatitis. Of these, viral hepatitis is the most common and is the focus of this article.
Viral hepatitis has caused more than 500 million deaths worldwide, and the number of deaths each year is more than one million; in particular, type B and type C are the leading causes of chronic liver disease for hundreds of millions of people, and are also a common cause of cirrhosis and liver cancer.
What is hepatitis B?
Hepatitis B (HBV) is a viral infection caused by the virus (HBV). The incubation period is usually 1-6 months and can lead to acute or chronic disease, with acute hepatitis lasting a few weeks, which is relatively short-lived, and chronic hepatitis lasting more than six months, with persistent abnormalities of liver function indices.
Hepatitis B symptoms
In general, most patients are not prone to symptoms, but when infected with acute hepatitis B or when there is an acute attack of chronic hepatitis B, symptoms such as yellowing of the skin and eyes (jaundice), tea-colored urine, extreme fatigue, nausea or vomiting, abdominal discomfort, etc. may occur.
On a worldwide average, the number of people who have ever been infected with hepatitis B is about 5%.
Route of infection
The route of infection is mainly divided into vertical and horizontal infection:
Vertical infection, also known as mother-to-child transmission, refers to the transmission of the virus from a carrier mother to her newborn child after delivery, which then continues for generations, and this route of transmission is one of the reasons why hepatitis B is so prevalent in Taiwan.
Another type of infection is horizontal transmission, which refers to blood or body fluids with the virus that enter the skin through wounds or enter the human body through mucous membranes and become infected (especially in the blood). For example, sexual intercourse, blood transfusion, needling, acupuncture, tattooing, ear piercing, sharing toothbrushes or razor blades, and hemodialysis, all these can be the route of infection of hepatitis B. Generally speaking, kissing, sharing utensils, and sharing food are also possible routes of infection.
In general, kissing and sharing utensils do not cause transmission unless there is a wound where the virus has come into contact with the person, entering the bloodstream and spreading.
Pathogenesis
As mentioned above, hepatitis B is mainly caused by viruses, so how does hepatitis B virus destroy liver cells? The immune system of the human body has a small defense soldier, called cytotoxic T cells (a kind of lymphocytes), it normally does not interfere with the operation of normal cells, but once the normal cells are infected by germs, it will kill the infected cells, the purpose is to remove the invading germs.
Hepatitis B virus causes the same reason, when the virus invades, cytotoxic T cells will come forward to kill the virus, but unfortunately, due to the Hepatitis B virus hides in the liver cells, when removing the virus, it also solves the problem of liver cells, which is why the virus leads to the necrosis of liver cells.
Test criteria
In general, it is not possible to distinguish Hepatitis B virus from other viruses by visiting a doctor, so blood tests are very important, the main purpose of which is to detect Hepatitis B surface antigen and antibodies.
How is the test result determined?
A positive Hepatitis B surface antigen (HBsAg) test result indicates that you have been infected with the Hepatitis B virus, and if the positive test result is more than six months old, you are diagnosed with chronic Hepatitis B. If the test result is negative, you are a Hepatitis B carrier.
What is a hepatitis B carrier?
When human body is infected by Hepatitis B virus, the body fails to clear the virus and the virus continues to live in human blood or liver cells, then the Hepatitis B surface antigen (HBsAg) can be detected in the blood continuously, which is known as Hepatitis B carrier.
If the liver index of hepatitis B carriers is normal, the ultrasound examination is normal, and there are no clinical symptoms, they can be called “healthy carriers”.
How is hepatitis B virus infectivity tested?
Another type of indicator is called hepatitis B e antigen (HBeAg), which is designed to detect the degree of active replication of the hepatitis B virus. If the blood is positive for e antigen, it indicates that the hepatitis B virus is replicating vigorously and that the number of viruses is large and the infectivity is high. If the blood is positive for e-antigen, it means that the hepatitis B virus is reproducing vigorously, with a large number of viruses and high infectivity.
Another important predictor of disease is the amount of hepatitis B virus DNA (HBV DNA), which can be used to assess the success of and resistance to drug therapy.
Prevention methods
The hepatitis B vaccine is an excellent tool for preventing infection, and the World Health Organization recommends that all infants and young children should be vaccinated against hepatitis B after birth to reduce the risk of vertical transmission. Globally, the current low incidence of chronic hepatitis B infection in children under 5 years of age can be attributed to the widespread use of the vaccine.
It is also important to be aware of the possibility of horizontal infection, such as blood transfusions, sharing needles, acupuncture, ear piercing, tattooing, eyebrow tattooing, sharing toothbrushes or razors, etc. Gloves should be worn when handling blood and condoms when having sexual intercourse.
In particular, hepatitis B is not transmitted through saliva or food, but through blood or wounds, so intentionally using non-washable plates or separating dishes from the patient’s plates is not an effective method of prevention.
Treatment Modalities
The two main types of treatment are injectable interferon and oral antiviral drugs.
Interferon does not destroy the virus, but reduces its activity to minimize damage to liver cells. It is important to note that injectable interferon can cause flu-like side effects: fever, chills, tiredness, headache, muscle aches and pains.
Oral antiviral medications have fewer side effects. Although they cannot cure hepatitis B, they can effectively inhibit the growth of the virus and reduce the risk of liver damage and complications.
What is hepatitis C?
Hepatitis C, or hepatitis C for short, is a viral infection caused by the virus (HCV). The incubation period is usually 6-9 weeks, and about 70-80% of infected patients will develop chronic hepatitis, which is more likely to progress to cirrhosis or liver cancer.
Symptoms of hepatitis C
The onset of the disease is usually not obvious and symptoms occur mainly after acute infection. About 20% of patients experience symptoms such as fever, fatigue, nausea or vomiting, yellowing of the skin or eyes (jaundice), etc. The symptoms are more similar to those of hepatitis B. The symptoms of hepatitis C are similar to those of hepatitis B. The symptoms of hepatitis B are not obvious.
Route of infection
Hepatitis C virus enters the body mainly through blood or body fluids (e.g. wounds), e.g. sharing needles, importing contaminated blood, having sex with infected people, importing untested blood bags, sharing hygiene products (razors, toothbrushes, nail clippers), etc.
Causative factors
Hepatitis C virus (HCV) is a 30 to 50 nm diameter, lipid-coated RNA virus with 6 major genotypes and approximately 100 minor genotypes. HCV is highly mutable, associated with cytotoxic T cells and helper T cells, and tends to become chronic after infection, resulting in repeated infection of hepatocytes or severe damage to hepatocytes. This leads to recurrent infection of liver cells or severe damage to liver cells.
Test Criteria
Since Hepatitis C is primarily caused by the Hepatitis C Virus (HCV), Anti-HCV is used to test for Hepatitis C. A positive reaction for Anti-HCV means that one has been infected with Hepatitis C or is currently infected with Hepatitis C. It does not fully determine whether the infection is ongoing or has been cured and must be referred to HCV-RNA.
Patients infected with hepatitis C may develop antibodies within 1-5 months, and a small number of people may take longer. Therefore, those who are negative for anti-HCV cannot completely rule out the possibility of hepatitis C infection.
In addition to antibody testing, HCV RNA testing is required to confirm the diagnosis of hepatitis C. The diagnosis of hepatitis C is confirmed when the HCV RNA exceeds the reference level.
Hepatitis C Prevention
Although there is no vaccine to prevent hepatitis C, unlike hepatitis B, hepatitis C is curable with long-term medication. Effective prevention is to reduce the chance of horizontal infection by avoiding unnecessary injections or blood transfusions, avoiding the sharing of hygienic utensils (e.g. toothbrushes, razors, nail clippers), avoiding highly infectious behaviors (e.g. acupuncture, tattoos, eyebrow tattoos, ear piercings), and engaging in sexual behaviors that require protection, etc.
Treatment Options
Currently, the standard treatment for hepatitis C is pegylated interferon in combination with ribavirin. The mechanism of action of peginterferon is to stimulate the immune system, cause T-cell proliferation and prevent necrosis, increase the ability to fight the hepatitis C virus, and inhibit the replication of viral RNA.
Ribavirin works by regulating the immune system, inducing mutations in viral RNA that prevent further synthesis and increase the effect of inhibiting viral replication. This drug is not very effective on its own, but it can have a multiplying effect when combined with interferon.
It can also be used in combination with antiviral drugs, but its use should follow the doctor’s instructions.
What should people with hepatitis B and C be aware of?
A regular lifestyle is an important way to maintain liver health. Do not drink alcohol, stay up late at night, or take drugs of unknown origin to reduce liver stress.
Because hepatitis B and C carriers have a higher risk of developing cirrhosis and liver cancer than the general population, they should see a doctor regularly to monitor their condition. If there are any signs of hepatitis or an abnormal increase in the liver index, they should see a doctor as soon as possible, and early treatment will have a significant effect on stabilizing their condition.