Getting the hepatitis B vaccine is the only way to prevent the disease. Learn about transmission, diagnosis, and treatment
Hepatitis B is caused by HBV, or the hepatitis B virus. Most HBV infections resolve within 1-2 months even without active treatment. If the infection lasts longer than 6 months, it can progress to chronic HBV, which can lead to serious complications including liver cirrhosis, liver failure, liver cancer and even death.
How does hepatitis B spread?
HBV can be transmitted when a person comes in direct contact with blood infected by the virus via sharing needles, razors, tattoo equipment, glucometers, and toothbrushes. The virus can enter the body through small cuts or sores on the skin.
Having multiple blood transfusions or receiving blood products treatment for conditions such as hemophilia increases the risk of hepatitis B. Rarely, HBV can be transmitted through organ transplantation in the case of inadequate testing of the donor.
Vertical transmission is the transmission of a disease or disease-causing agent from mother to baby at birth, meaning that a mother with hepatitis B can spread the virus to her baby during birth.
HBV can be spread in healthcare settings through contaminated needles, syringes, and other instruments.
How is hepatitis B diagnosed?
Your doctor will conduct a physical examination, ask questions about your symptoms, and take a complete medical history. In order to a confirm a diagnosis of HBV, the following tests may be ordered:
- Blood tests: Blood tests are done to diagnose hepatitis B and monitor its impact on the liver:
- Routine liver function tests
- Serological assays for:
- Hepatitis B antigens (HBsAg and HBeAg)
- Antibodies (anti-HBs, anti-HBc, and anti-HBe)
- Hepatitis B virus DNA in serum, which indicates the suitability of antiviral medication and response to treatment
- Liver biopsy: A liver biopsy could be required in chronic cases to detect inflammatory changes in the liver.
What is the difference between acute and chronic HBV?
Acute hepatitis B infection
Symptoms of acute hepatitis B virus infection include:
Acute hepatitis B virus infection usually lasts between 2-4 months. Approximately 30%-50% of children over 5 and most adults are symptomatic. Newborns, children under 5, and immunocompromised adults have a high chance of being asymptomatic.
Approximately 95% of acute infections in people with healthy immune systems are self-limiting. Less than 5% of people with acute hepatitis B infection develop chronic infection. Nearly 1% of people develop acute hepatic failure and die or require immediate liver transplantation.
Chronic hepatitis B infection
When hepatitis B infection lasts for more than 6 months, it is classified as chronic. Chronic hepatitis B is negatively associated with age; the younger the patient, the higher the chances of chronic infection. Chronic infection develops in about:
- 90% of infected babies
- 30% of children under 5
- Less than 5% in others
Usually, people with chronic infections do not show any symptoms. However, some may experience loss of appetite and fatigue.
All people who fit the criteria for chronic hepatitis B should be treated. People with chronic hepatitis B, who are not immune to hepatitis A, should have two doses of hepatitis A vaccination at least 6 months apart.
What are the phases of chronic hepatitis B?
Chronic hepatitis B virus infection can progress through four phases, each of which impacts the treatment regimen:
- Active phase: Blood work shows high levels of liver enzyme, alanine transaminase (ALT), and hepatitis B virus DNA (viral load), which is higher than 20,000 IU/mL. If the person is in the active phase, the infection must be treated right away. Usually, a liver biopsy is done during this phase.
- Inactive phase: Blood work shows low levels of ALT and hepatitis B virus DNA, which is less than 20,000 IU/mL. Active treatment or liver biopsy are not indicated during the inactive phase. The person may be recommended to undergo half-yearly or annual monitoring to check for reactivation of the infection.
- Gray zone phase: Both ALT and hepatitis B virus DNA levels are inconsistent during the gray zone phase of chronic hepatitis B. A liver biopsy may be done to determine the existence of an underlying hepatic disease and helps with the deciding necessary treatment.
- Immune tolerant phase: HBeAg (antigen of hepatitis virus) is positive and hepatitis B virus DNA levels are higher than 20,000 IU/mL, but ALT levels are normal. There is minimal inflammation or fibrosis at this stage; thus, active treatment is usually not necessary. The person must be evaluated every 6 months with ultrasonography and serum alpha-fetoprotein levels because there is a direct association between hepatitis B virus DNA levels and the risk of hepatocellular carcinoma. The person should be checked for reactivation every 6-12 months. If the person transitions to the active form, they must be treated.
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What are treatment options for hepatitis B?
Medications can suppress the hepatitis B virus, which helps minimize the chance of developing more serious liver disease.
Most people will require long-term therapy to keep the infection under control. Antiviral drugs used to treat HBV include:
- Tenofovir: Tenofovir is recommended for people who have received antiviral therapy previously or never received oral antivirals for hepatitis B. Tenofovir comes in two formulations: tenofovir disoproxil fumarate and tenofovir alafenamide. Tenofovir suppresses the hepatitis B virus that is resistant to other antiviral medications, such as lamivudine, telbivudine, adefovir, or entecavir. There is no documentation for tenofovir resistance.
- Entecavir: Entecavir is recommended for people who have never had oral antiviral therapy. Although entecavir resistance is uncommon in people who have never had antiviral medication, it can increase the chances of resistance in up to 50% of people who are treated earlier with the antiviral drug lamivudine for hepatitis B.
Immune modulators are interferon-type medications that help the immune system fight the hepatitis B virus. They are administered as injections over 6-12 months.
People with chronic hepatitis B who have detectable viral activity, continuous liver inflammation, and no cirrhosis should get pegylated interferon-alfa. It may be considered for young individuals who do not have severe liver disease and do not want to be on long-term medication. It is not recommended for people with cirrhosis, liver failure, or recurrence of hepatitis after a liver transplant.
Pegylated interferon is an injection that is administered once a week for one year. Interferon drug resistance has not been documented. The main drawback of pegylated interferon-alpha is that it causes several adverse effects.
For those with severe cirrhosis, liver transplantation may be the only treatment option. However, the procedure is complex, requiring considerable screening to confirm that a person is a good candidate. Not all people with cirrhosis are eligible for a liver transplant.
People with severe cirrhosis or early-stage liver cancer and are in generally favorable medical and socioeconomic situations will be added to the transplant waiting list. Due to donor scarcity, not all people on the transplant waiting list will be able to obtain a liver transplant.
Can hepatitis B be prevented?
- Children must receive hepatitis B immunizations. The immunization regimen consists of three injections administered over 6 months. All three injections are to be administered without fail for complete protection.
- All pregnant women must be screened for hepatitis B before childbirth. If the mother is found to be positive, then the infant should receive the hepatitis B immune globulin injection and the first dose of hepatitis B vaccination within 12 hours after delivery. The infant should receive the second dose of hepatitis B vaccination at the age of 2 months, and the third dose should be administered at 6 months. The infant should then get a blood test between 9-15 months.
- Eat a balanced diet
- Exercise regularly
- Maintain a healthy weight
- Avoid smoking (smoking increases the risk of cancer in hepatitis B)
- Avoid alcohol (alcohol damages the liver)
- Take precautions with prescription and nonprescription medications, including herbal medications
Reduce the risk of transmission
- Discuss your condition with your sexual partners and use a latex condom
- Never share razors, toothbrushes, or other anything that may have blood on them
- Cover exposed wounds or cuts
- Do not donate blood, organs, other tissues, or sperm
- Immediate family members, household members, and regular sexual partners should be screen for hepatitis B
- Anyone who is at risk of contracting hepatitis B should be vaccinated