What is hepatitis B?
Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus (HBV). Hepatitis B infection can be either acute or chronic. Acute hepatitis B infection is short-term, lasting a few weeks. Chronic hepatitis B infection is lifelong and can cause illnesses like cirrhosis and liver cancer.1,2
Lasting a few weeks
What is the prevalence of hepatitis B?
An estimated 2 billion people worldwide have been infected with HBV, and more than 350 million people have chronic, lifelong HBV infections.3
In the US, an estimated 850,000 people were chronically infected with HBV in 2012. New cases of HBV infection in the US had been decreasing until 2012. In 2016, 3,218 cases of HBV were reported; however, because of low case detection and reporting, the Centers for Disease Control and Prevention (CDC) estimates that there were 20,900 acute cases of HBV infection in 2016. That is an increase of over 5% compared to 2012. This increase in new HBV infections is a very concerning trend that the CDC has determined is linked to the ongoing opioid crisis in the United States.4
What are the signs and symptoms of acute hepatitis B?
Hepatitis B doesn’t always cause symptoms. Infants, children, and approximately 50% of adults who have acute HBV infections are typically asymptomatic; however, they are still capable of infecting others.3
- Yellowing of the skin and eyes (jaundice)
- Dark urine
- Extreme fatigue
- Loss of appetite (anorexia)
- Upper right quadrant abdominal discomfort
Who is at risk for chronic hepatitis B?
The likelihood that infection becomes chronic depends upon the age at which a person becomes infected.2
How serious is hepatitis B?
Although the consequences of acute HBV infection can be severe, most of the serious complications associated with HBV infection are due to chronic infection.3
Chronic infection is responsible for most HBV-related morbidity and mortality, including:
- Chronic hepatitis
- Liver failure
- Hepatocellular carcinoma (liver cancer)
People with chronic hepatitis B infection are at 12 to 300 times higher risk of hepatocellular carcinoma than noncarriers. Approximately 25% of people with chronic hepatitis B infection die prematurely from cirrhosis or liver cancer.3
How is hepatitis B transmitted?
Hepatitis B transmission occurs through infected blood, semen, or other bodily fluid. People can become infected from2:
- Perinatal transmission, where an infected mother passes the infection to her baby during birth
- Sex with an infected partner
- Sharing needles, syringes, or drug-preparation equipment
- Sharing items such as toothbrushes, razors, or medical equipment with an infected person
- Direct contact with blood or open sores of an infected person
- Exposure to blood from needlesticks or other sharp instruments of an infected person
How does hepatitis B transmission NOT occur?
How is hepatitis B diagnosed?
Diagnosis is based on clinical, laboratory, and epidemiologic findings. HBV infection cannot be differentiated on the basis of clinical symptoms alone, and definitive diagnosis depends on the results of serologic testing. Serologic markers of HBV infection vary depending on whether the infection is acute or chronic.3
How is hepatitis B treated?
Acute Hepatitis B Treatment
There is no specific treatment for acute hepatitis B. Instead, care is aimed at maintaining comfort and nutritional balance, including replacement of fluids lost from vomiting and diarrhea.1
Chronic Hepatitis B Treatment
Chronic hepatitis B infection can be treated with medicines to slow the progression of cirrhosis, reduce incidence of liver cancer, and improve long-term survival.1
However, treatment does not cure hepatitis B in most people. It only suppresses viral replication. Therefore, most people who start treatment must continue it for life.1
CDC Disease Information
DISCLAIMER: By clicking on the link below, you will be directed away from MerckVaccines.com to another website. Merck does not review or control the content of the site to which the hyperlink connects; therefore, the hyperlink does not constitute an endorsement by Merck.
CDC=Centers for Disease Control and Prevention; HBV=hepatitis B virus.