Is Hepatitis B Contagious?

Medically Reviewed on 3/28/2023
How Does Hepatitis B Spread?
Persons infected with hepatitis B can pass the virus to others through blood or body fluids. In the U.S., the most common way of becoming infected is through unprotected sex, although sharing an infected person's needles to inject illicit drugs also is quite common.

The disease, hepatitis B, is contagious. HBV, the viral cause of hepatitis B, is transmitted person-to-person by the following:

  • blood,
  • semen, or
  • any other body fluid from the infected person.

Moreover, hepatitis B can be transferred through sexual contact, sharing needles, or from mother to baby at the time of birth.

What is hepatitis B?

Hepatitis B virus
Hepatitis B infection is transmitted through sexual contact, contact with contaminated blood (for example, through shared needles used for illicit, intravenous drugs), and from mother to child.
  • Hepatitis B is a liver infection caused by the Hepatitis B virus (HBV). To avoid confusion, the term hepatitis B will be used to indicate liver disease and HBV will be used to designate the infecting virus.
  • Hepatitis B can occur as an acute or short-term illness; in other individuals, it may become a chronic infection.
  • Chronic infections occur mainly in infected infants (about 90%) while only about 2%-6% of adults become chronically infected; chronic infections may lead to cirrhosis or liver cancer.

How will I know if I'm infected with hepatitis B?

Hepatitis B Symptoms
A majority of adults who contract hepatitis B have no to mild symptoms, and then the virus resolves spontaneously; however, about 5% of people are not able to eliminate the hepatitis B virus and develop chronic infection.

The signs and symptoms of hepatitis B vary with age; most children under 5 and immunosuppressed adults do not show symptoms with initial infection. However, individuals about 5 years and older have a 30%-50% chance of having initial signs and symptoms of the infection that may include the following:

The incubation period (from the time of exposure to HBV to symptom development) is long for hepatitis B - the average time to onset of symptoms is about 90, days but may range from 60-150 days. Acute hepatitis B symptoms may last from several weeks up to about 6 months. Your physician can confirm hepatitis B infection by studies of the blood; hepatitis B antigens (HBsAg) can be detected as well as antibodies (anti-HBs) that are developed against hepatitis B antigens. Other similar tests are used to determine the individual's infection status.


Is Hepatitis B Contagious? See a medical image of Hepatitis B along with other sexually transmitted diseases (STDs) See Images

Can hepatitis B be transmitted from one person to another?

Hepatitis B is spread person-to-person by methods that usually involve skin puncture or mucosal contact with the blood or body fluids of an infected person. For example:

  • Semen, saliva, sharing needles or syringes, and contact with open sores of an infected person can all facilitate person-to-person spread.
  • Indirect spread from items such as razors, toothbrushes, or other items may cause hepatitis B. Unfortunately, HBV is very stable and can remain infective on items like razors or toothbrushes for about one week.
  • An infected mother can transfer hepatitis B to her newborn during birth.

Fortunately, HBV is not spread through food or beverages, breastfeeding, casual contact like hugging or handholding, or sneezing (as long as no blood from an infected person accompanies these activities).

How will I know if an individual is cured of hepatitis B?

Not all patients with hepatitis B require treatment, which is generally used in more advanced diseases. There are multiple anti-viral agents currently available that are effective in controlling the infection. Your physician will determine if you are a candidate for treatment, and if so, with which agent. Although a commercially available drug is not yet available to cure hepatitis B, researchers in Australia are currently studying an anticancer drug, birinapant. The drug is in clinical trials to determine its potential ability to cure hepatitis B.

However, vaccines against HBV are available; they contain no live virus and can be given to infants, children, and pregnant females; the vaccines can protect most individuals from getting HBV infection.

Individuals that get infected with HBV and do not remain chronically infected can become HBsAg-negative about 15 weeks after the onset of symptoms. However, patients are advised to consult their physician to interpret the results of HBV blood tests. The majority of adults recover from hepatitis B; after several months they become non-contagious and are considered to be cured. Unfortunately, about 2% of adults and more than 90% of children under age 1 do not clear the infection and develop chronic hepatitis B infection. For this reason, the HBV vaccine is urged for all infants and for individuals that are exposed to hepatitis B and have not been vaccinated.

When should I contact a healthcare professional about hepatitis B?

Any infant, child, or adult that has not been vaccinated against HBV should be vaccinated; especially if they have had any close association with HBV-infected individuals.

An individual with chronic hepatitis B infection is advised to do the following:

  • have follow-ups every 6-12 months to maximize their health,
  • get an annual flu shot (influenza vaccination),
  • get vaccinated against hepatitis A, and

Discuss diet, lifestyle changes, and ways to prevent transmission of their disease to others with your healthcare professional.

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Medically Reviewed on 3/28/2023

Viral Hepatitis - Hepatitis B Information. Centers for Disease Control and Prevention. May 31, 2015.

Cancer drug shows promise as cure for hepatitis B. Walter+Eliza Hall; Institute of Medical Research. April 21, 2015

Samji, N. MD. "Viral Hepatitis." Medscape. Updated: Jun 12, 2017.