Hepatitis B is a type of liver infection caused by the hepatitis B virus (HBV). The most common type of hepatitis B infection is acute hepatitis B, meaning the infection lasts less than 6 months. On the other hand, chronic hepatitis B is a type of hepatitis that lasts more than 6 months. People with chronic hepatitis are more likely to develop liver failure, hepatocellular carcinoma (liver cancer), or cirrhosis (scarring of the liver).
Symptoms of hepatitis B infection
Many hepatitis B patients do not exhibit any symptoms. Even without any symptoms, individuals can transmit the hepatitis B virus.
Acute or short-term hepatitis B symptoms include:
• Fever
• Fatigue
• Loss of appetite
• Diarrhea
• Stomach pain
• Jaundice
• Dark urine
• Grey-coloured faeces
If chronic hepatitis B progresses to cirrhosis (when the liver is heavily scarred), patients experience signs and symptoms indicative of liver failure, such as:
• Enlarged spleen
• Fluid retention in the stomach
• Swelling of legs and feet
• Altered mental state (confusion)
• Liver cancer
Transmission of hepatitis B virus
The transmission of hepatitis B virus occurs when a person comes into contact with the body fluids of another person infected with the virus. HBV can survive outside the body for up to seven days and is extremely contagious.
Hepatitis B virus is transmitted in the following ways:
• Having unprotected anal, oral, and vaginal sex with a hepatitis B carrier
• Frequently switching partners and not using condoms during sex
• Using contaminated syringes to inject drugs
• Using contaminated equipment for medical or dental procedures, tattoos, or body piercing
• Being born to an HBV-infected mother
Understanding hepatitis B viral load
Hepatitis B viral load is defined as the amount of hepatitis B virus present in an individual’s blood. The levels of serum HBV DNA or viral load determined by polymerase chain reaction (PCR) are associated with the progression of disease and are used to make decisions for the treatment of hepatitis B infection.
HBV viral load
• 0 to 500 viral load: Harmless, uninfectious trace
• 500 to 5,000 viral load: Unlikely to cause harm or infection
• 5,000 to 250,000 viral load (low risk): Infectious via blood transfusion
• 250,000 to 1 million viral load (medium risk): Infectious via blood transfusion and sexual fluids
• 1 million to 1 billion viral load (high risk): Infectious via blood transfusion and sexual fluids
A high HBV viral load has been linked to a poor prognosis in patients with hepatocellular carcinoma (HCC) due to frequent reoccurrence after HCC treatment and impaired liver function related to HCC progression.
Diagnosis of hepatitis B infection
HBV testing
The purpose of HBV testing is to detect the presence of genetic material, antigens, or antibodies of the HBV. Antigens are substances derived from the hepatitis B virus that stimulate the immune system to produce antibodies, while antibodies are substances produced by the body to identify and neutralize foreign substances (antigens).
A panel of blood tests for HBV testing includes:
• Hepatitis B surface antigen (HBsAg) test: Test results that are "positive" or "reactive" signify that the individual has hepatitis B. The "surface antigen" of the hepatitis B virus is found in the blood sample. If an individual tests "positive," additional testing is required to determine whether the infection is "acute" or "chronic".
• Hepatitis B surface antibody, or anti-HBs (HBsAb) test: Test results that are "positive" or "reactive" show that the individual is immune to the hepatitis B virus. The surface antibody of the hepatitis B virus is found in the blood sample. The hepatitis B vaccine or a full recovery from a prior hepatitis B infection can offer protection against HBV.
• Hepatitis B core antibody, or anti-HBc (HBcAb) test: Test results that are "positive" or "reactive" anti-HBc (or HBcAb) denote a past or present hepatitis B infection. The core antibody of the hepatitis B virus is found in the blood sample. This test is used to detect two types of hepatitis B core antibodies: IgM anti-HBc and IgG anti-HBc.
Vaccination for hepatitis B
Hepatitis B can be prevented with a vaccine. The hepatitis B vaccine should be given to all infants within 24 hours of birth. The second and third doses of the hepatitis B vaccine are usually administered after one and six months, respectively, following the first dose.
Adults who have not been vaccinated as children are recommended to receive a three-dose hepatitis B vaccine regimen. Individuals who have completed a three-dose hepatitis B vaccination series are generally not required to receive booster vaccines.
The Hepatitis B vaccine provides protection from HBV for a minimum of 20 years and likely for your entire life.
Treatment for hepatitis B infection
Treatment for hepatitis B infection depends on the severity of the condition. For example, treatment in the case of:
Hepatitis B virus exposure: HBIG is an antibody that is injected 24 hours after exposure to the hepatitis B virus in individuals who have not been vaccinated against hepatitis B. Since HBIG only provides temporary protection, it is recommended that individuals who have never had the hepatitis B vaccine get vaccinated at the same time as their HBIG treatment.
Acute hepatitis B infection: In acute hepatitis B infection, individuals may not require treatment as the infection will usually resolve naturally. Healthcare providers may recommend rest, adequate nutrition, and hydration to combat the infection. In more severe cases, antiviral medications or hospitalization may be necessary to prevent complications.
Chronic hepatitis B infection: Chronic Hepatitis B is a long-term condition that requires lifelong treatment. The initiation of treatment depends on a variety of factors, including whether the virus is causing liver damage, scarring, or inflammation, and if the patient has other infections such as hepatitis C, or HIV, and if their immune system is weakened by certain medications or medical conditions. Treatment with antiviral agents and interferon injections can reduce the risk of liver disease and slow down the progression of hepatitis B infection.
Hepatitis B virus can be transmitted by direct contact with the body fluids of an infected person.
It is advised to undergo HBV testing for the diagnosis of a hepatitis B infection and for the evaluation of immunity to HBV through prior infection or after vaccination.
At present, there is no definitive cure for hepatitis B infection. Despite having severe symptoms, most adults who develop hepatitis B are able to fully recover. HBV vaccination is associated with suppression of the viral load and production of higher levels of antibodies. Therefore, it is recommended to get vaccinated against the hepatitis B virus to avoid