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CATIE

Hepatitis B

Summary

Hepatitis B is a liver infection caused by the hepatitis B virus. Hepatitis B is passed when the virus in bodily fluids such as blood, semen or vaginal fluid from a person with hepatitis B enters the body of another person. Getting vaccinated is one of the best ways to prevent getting hepatitis B. There are many other effective ways to prevent getting or passing hepatitis B. The only way to know if a person has hepatitis B is to get tested.

Without proper care, hepatitis B can lead to serious health problems such as liver failure, liver cancer and early death. Most healthy adults who get hepatitis B clear the virus on their own during the acute infection phase, but this is less likely for infants and children. Once someone has cleared the virus, which is confirmed with a blood test, they have lifelong immunity and cannot pass the virus to another person. If the virus is not cleared during the acute infection phase, the infection becomes chronic. There is currently no cure for hepatitis B, but with proper care, people with hepatitis B can live long and healthy lives.

What is hepatitis B?

Hepatitis B is a viral infection that targets the liver. The liver is a very important organ as it helps the body fight infections, break down substances like food, alcohol and drugs, and more. When the hepatitis B virus enters the body, it uses the liver cells to make copies of itself, leading to inflammation and scarring over time. Without proper care, the ongoing injury to the liver can lead to liver disease, liver cancer and death. 

How is hepatitis B transmitted?

Hepatitis B is passed when the virus in bodily fluids such as blood, semen or vaginal fluid from a person with hepatitis B enters the body of another person. The chance of transmission varies depending on the amount of virus in a person’s blood (viral load). Hepatitis B cannot be transmitted by a person who has cleared the virus. In Canada, many people have been vaccinated against hepatitis B, which means they have immunity and cannot get hepatitis B.

For those who are not immune, here are some ways hepatitis B is passed in Canada:

  • Sexual transmission: Hepatitis B can be passed through condomless sex if the virus in the blood or bodily fluids of a person with hepatitis B comes into contact with another person’s mucous membranes or torn or cut skin. This is especially true for condomless sex that involves potential contact with blood (e.g., rough sex, or contact with menstrual blood, open sores or wounds). 
  • Sharing drug use equipment: Sharing equipment used to inject drugs (e.g., needles, syringes, cookers, filters) can lead to direct blood-to-blood contact, resulting in a high risk of hepatitis B transmission. Sharing equipment used for smoking or snorting drugs (e.g., pipes or straws) can also transmit hepatitis B through cracked, bleeding lips or tiny nosebleeds.
  • Perinatal transmission: Hepatitis B can be passed from parent to child during childbirth. Although this is not a common transmission route in Canada, it may be in other countries where hepatitis B is more common and infants are not consistently vaccinated. The risk of hepatitis B transmission through breastfeeding/chestfeeding is negligible, and it is considered safe to breastfeed/chestfeed infants who receive preventive vaccination starting at birth.
  • Household transmission: Hepatitis B can be passed between household members through direct contact with blood or other bodily fluids (e.g., sharing personal care items like razors, nail clippers and toothbrushes). This is sometimes called horizontal transmission, a broad term describing transmission that falls outside defined routes like perinatal transmission or sexual transmission. It primarily happens in households, either between adults, from adults to unvaccinated children, or between unvaccinated children.
  • Unsterilized tattoo or piercing equipment:Tattooing and piercing can transmit hepatitis B, but the risk depends on the context. When sterile or new equipment is used (like in a professional tattoo or piercing studio), there is no risk for hepatitis B transmission. There is an increased risk for hepatitis B transmission in unregulated settings (e.g., prisons) where tattoo and piercing equipment is shared because there is limited or no access to sterile and single-use equipment. There is also an increased risk in countries where infection control practices for tattooing and piercing are not regulated.
  • Unsafe medical procedures or traditional healing practices: Canada started testing donated blood and tissue for hepatitis B in 1972, eliminating the risk from transfusions or organ donation. The risk of hepatitis B transmission from medical procedures (i.e., the use of unsterilized medical, dental and surgical equipment) and traditional healing practices (e.g., acupuncture) is low to non-existent in Canada because of strict infection control practices. However, the risk of transmission from medical procedures and traditional healing practices may be higher in countries where infection control practices are more limited, or when these procedures and practices are done outside of regulated settings.

Hepatitis B is not passed by hugging, touching or kissing or by sharing utensils with someone who has the virus.

Who can get hepatitis B?

Since hepatitis B can be transmitted when the virus in bodily fluids such as blood, semen and vaginal fluid enters the body of another person, any activity involving such contact poses a risk of transmission. Many factors influence the chance of transmission: the type of activity, how common hepatitis B is in the population, and social and structural factors (e.g., financial insecurity, housing instability or the criminalization of drug use) that influence whether a person knows about and can access prevention strategies. 

Some communities are disproportionately impacted by hepatitis B, including people who use drugs, people with prison experience, immigrants and newcomers from countries where hepatitis B is common, Indigenous peoples, and gay, bisexual and other men having sex with men (gbMSM). While individual behaviours play a role in hepatitis B transmission, a person’s risk is shaped by more than just their own actions. Although being a member of one or more of these communities is not a risk factor for hepatitis B in and of itself, social and structural factors experienced by these communities can limit a person’s ability to protect their health and manage risk. Recognizing how risk is created and reinforced by these social and structural factors can provide insights into why some individuals may be at higher risk for hepatitis B than others.

How can hepatitis B transmission be prevented?

Vaccination

The best way to prevent hepatitis B is to get vaccinated. This provides immunity against hepatitis B, so even if someone is exposed to the virus, they will be protected and will not develop an infection. Anyone who is at risk of hepatitis B should be screened to confirm their immune status; if they don’t have hepatitis B and are not immune to the virus from a past infection or vaccination, they should be offered a hepatitis B vaccine.

In Canada, vaccine programs vary provincially, with some provinces starting the two- or three-part vaccine series at birth or during early infancy, others during childhood and others in adolescence.1 Since the implementation of these programs, the incidence of acute hepatitis B infections has decreased. 

Vaccination is also recommended for specific populations by the Public Health Agency of Canada. According to the Canadian Immunization Guide,1 vaccination is recommended for the following groups if they do not have hepatitis B and are not immune*:

  • immigrants and newcomers from countries where hepatitis B is common, including sub-Saharan Africa, East and South Asia, eastern and southern Europe, the Pacific Islands and parts of Central and South America
  • household contacts (including children) of people who have immigrated from countries where hepatitis B is common
  • people who travel frequently to countries where hepatitis B is common
  • Indigenous peoples
  • people who share or have shared drug use equipment
  • people who have had condomless sex with someone who has hepatitis B or have had multiple sex partners in the past six months
  • men who have sex with men
  • people who are incarcerated
  • people living with HIV
  • frontline healthcare workers or service providers who are at risk of occupational exposure to hepatitis B (e.g., needle-stick injuries, handling blood)
  • people with chronic liver or renal disease, including patients undergoing dialysis
  • people with other health conditions as specified in the Canadian Immunization Guide

*See the Canadian Immunization Guide for the full list of populations for whom vaccination is recommended.

Other ways to prevent transmission

Here are some other ways to prevent hepatitis B transmission:

  • Using new equipment every time someone injects drugs (e.g., needles, syringes, cookers, filters). 
  • Using personal equipment every time someone smokes or snorts drugs (e.g., pipes, straws).
  • Using condoms the right way each time someone has sex.
  • Getting tested for hepatitis B during pregnancy. If a person tests positive for hepatitis B, they should take effective treatment during pregnancy and ensure the infant receives appropriate care, including receiving the full vaccine series, starting at birth. 
  • Individuals recently exposed to hepatitis B who are not already immune should seek medical care to access PEP (post-exposure prophylaxis). This involves receiving a hepatitis B vaccine and hepatitis B immune globulin (HBIG) injection, ideally within 24 hours of exposure. 

How is hepatitis B diagnosed? 

The only way to know if someone has hepatitis B is to get tested. There are often no symptoms until the liver is severely injured and a person experiences significant health problems. Testing for hepatitis B involves taking a blood sample and using that sample to conduct a panel of blood tests. These tests look for hepatitis B antigens and antibodies in the blood. 

The combination of test results can tell:

  • if a person has ever been exposed to the virus
  • if a person has a current infection and whether the infection is acute or chronic 
  • whether someone has immunity to the virus, either from being vaccinated or because they cleared the virus on their own

Contact tracing and partner notification

Hepatitis B is a reportable infection in Canada. This means that when an infection is confirmed by a clinic, healthcare provider or laboratory, it must be reported to public health authorities. When a person has a newly identified hepatitis B infection, a public health nurse or other healthcare provider will ask them to contact or provide contact information for all people who may have been exposed during the period of infection, including sexual partners and people living in the same household. If the person chooses not to contact their sexual partners and/or household contacts, the healthcare provider or public health staff will attempt to contact these individuals and encourage them to be tested. The Public Health Agency of Canada recommends that anyone who has been in contact with a person diagnosed with hepatitis B be tested to assess their immune status and given the vaccine if they are not immune.

Acute hepatitis B infection

An acute hepatitis B infection begins when the body is first exposed to the hepatitis B virus and can last up to six months. Although most people will experience few or no symptoms during the acute infection phase, the virus is highly active and can be passed to others. About 30% to 50% of adults with acute hepatitis B will develop symptoms two to five months after infection. These can include fatigue, loss of appetite, jaundice (yellowing of the whites of the eyes and skin), nausea, vomiting, rash, dark urine, joint discomfort or pain, and abdominal discomfort or pain. Rarely, a person may experience severe acute hepatitis B symptoms — such as bleeding or bruising more easily, brain fog or confusion, and jaundice — that can rapidly progress to acute liver failure and death. 

Most healthy adults (95%) will clear the virus from their body on their own during the acute phase in a process called spontaneous clearance. This is confirmed with a blood test. Once someone has cleared the hepatitis B virus, they have lifelong immunity, meaning they cannot get the virus again. It also means that they cannot pass the virus to another person. 

Chronic hepatitis B infection

If the virus is not cleared within the first six months of infection, the infection becomes chronic. The age of exposure to hepatitis B plays a major role in determining the likelihood that an acute hepatitis B infection becomes chronic. Infants and children, especially those born to a pregnant person with hepatitis B, have a significantly higher likelihood of developing a chronic infection. Without proper preventive care, approximately 90% of infants (exposed from birth up to one year old) and about 20% to 30% of children (exposed between one to five years of age) will develop chronic hepatitis B.

Chronic hepatitis B has several phases, with different levels of immune response to the virus from the body. If a person’s immune system is unable to keep the virus under control on its own, they may need treatment to prevent liver disease. Even for those who don't need treatment right away, regular lifelong monitoring is important to make sure the virus isn't active and causing liver damage. 

What is the treatment for hepatitis B?

Acute hepatitis B 

Treatment is not usually required for an acute infection, as it typically resolves on its own within six months in healthy adults. However, in rare cases where symptoms are severe during acute infection, treatment can be used to relieve the symptoms or interrupt viral replication.

Chronic hepatitis B

Currently, two types of hepatitis B treatments are available for people with a chronic infection: antiviral pills (nucleos(t)ide analogues) that are taken daily and interferon-based treatments that are taken weekly by injection for several months. In Canada, antiviral pills are the preferred treatment. The goal of current treatments for chronic hepatitis B is to control the replication of the virus to prevent and potentially reverse liver injury. 

Not everyone with chronic hepatitis B needs treatment. Treatment is only required when the immune system is unable to control the virus and/or there is ongoing liver damage. Even with treatment, the virus is still present in liver cells, so it can become active again if treatment stops. This means that the virus cannot be completely cured, so those who do take treatment usually require long-term treatment. In some cases, treatment may be stopped under specialist care.

The good news is that with ongoing monitoring and proper care, people with hepatitis B can live long and healthy lives. A healthcare provider will recommend the care plan that is best for an individual on the basis of several factors, such as the amount of liver injury, the level of immune control, other coinfections and the person’s capacity to take lifelong treatment. Some people with chronic hepatitis B will also require regular ultrasound screening for liver cancer.

In a very small number of people on treatment, the virus becomes undetectable in the blood, which means the virus is no longer active or causing liver damage. When this happens, it is called a functional cure for hepatitis B and treatment can be stopped. With a functional cure, the risk of transmission becomes extremely low, and the risk of liver cancer is reduced. Ongoing monitoring may still be recommended for some individuals. A functional cure specifically refers to the loss of hepatitis B surface antigen (HBsAg) confirmed by a blood test. 

What about coinfection with other viruses?

Hepatitis B shares common transmission routes with other viral infections, like hepatitis C, D and HIV. People who are diagnosed with chronic hepatitis B should also be screened for these viruses. 

Hepatitis B and C coinfection

Hepatitis B and C both affect the liver, and one virus (usually the hepatitis C virus) dominates the other. Unlike hepatitis B, there are highly effective direct-acting antiviral (DAA) treatments that cure hepatitis C. If a person has both viruses and is cured of hepatitis C, the hepatitis B virus may flare up. In this situation, hepatitis B treatment may be considered in advance of hepatitis C treatment to prevent this from happening. Because of the risk of reactivation following DAA treatment, ongoing hepatitis B monitoring is also required. People with hepatitis B and C coinfection should discuss their treatment options with a healthcare provider.

Hepatitis B and D coinfection

Hepatitis D is transmitted in the same ways as hepatitis B, but the hepatitis D virus can only survive when hepatitis B is present. Because of this, hepatitis D infections only happen in people who already have hepatitis B (superinfection) or when both viruses are acquired at the same time (coinfection). Hepatitis D leads to a more severe form of liver disease than hepatitis B on its own. There is currently no cure for hepatitis D, but treatment options are available to prevent worsening of liver disease. Hepatitis B and D coinfection is uncommon. People who have this coinfection should discuss their treatment options with a healthcare provider. 

Hepatitis B and HIV coinfection

HIV is a virus that weakens the immune system; some people with HIV who were vaccinated against hepatitis B virus in the past can lose their immunity to hepatitis B. Hepatitis B also progresses faster and causes more liver-related health problems among people with HIV than among people without HIV. While hepatitis B infection does not speed up the progression of HIV or affect the response to HIV treatment, some individuals with both viruses have a higher risk of developing severe liver injury when they start HIV treatment than people with HIV who don’t have hepatitis B. 

How can people with chronic hepatitis B infection live well?

Chronic hepatitis B is a lifelong condition, so maintaining liver health is crucial to prevent further liver injury. Many wellness strategies that promote a person’s overall health can also promote liver health. Although these strategies are not feasible or realistic for everyone, a person should be supported to take care of their health and their liver however they can. 

Getting vaccinated for hepatitis A — if a person is not already vaccinated — and screened for hepatitis C and D can promote liver health by preventing a person from getting further infections that injure their liver. Since liver disease affects the digestion, metabolism, absorption and storage of nutrients, eating well gives people energy and nutrients, which supports their immune function and helps their liver to regenerate or maintain itself. Light to moderate exercise can boost energy, reduce stress and prevent steatosis (fat buildup around the liver) so that liver problems do not worsen. 

People with advanced liver damage (cirrhosis) may also want to avoid or reduce behaviours that can cause further liver injury. Alcohol use can increase liver injury and the likelihood of developing liver cancer. Stopping or reducing alcohol use will reduce the risk of further liver injury and health complications. Prescription or non-prescription drugs or herbal supplements should only be taken in consultation with a healthcare provider, as some medications and supplements can have toxic effects on the liver.

Acknowledgement

We thank Hemant Shah, MD, MScCH HTPE, for expert review.

Author: Madison K

Published 2026

Reference

Government of Canada. Hepatitis B vaccines. In Canadian Immunization Guide: Part 4. Immunizing agents. 2024. Available from: https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-4-active-vaccines/page-7-hepatitis-b-vaccine.html