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Hepatitis B: A Review

Author/s: 
Wen-Juei Jeng, Terry Cheuk-Fung Yip, Anna S. Lok

Importance: Hepatitis B virus (HBV) infection affects an estimated 254 million people worldwide and causes approximately 1.1 million deaths annually. In 2022, there were approximately 1.2 million new HBV infections worldwide and 14 000 in the US.

Observations: HBV is a DNA virus transmitted through percutaneous or mucosal exposure to infected blood, semen, or body fluids. Mother-to-child transmission, which is the principal cause of chronic HBV infection globally, occurs in 70% to 90% of infants born to mothers who are hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) positive and in 5% to 20% of those born to HBsAg-positive/HBeAg-negative mothers. However, HBV vaccination and administration of hepatitis B immune globulin within 12 to 24 hours of birth prevent approximately 94% of perinatal infections, and adding antiviral therapy in pregnant women with high HBV DNA reduces transmission to less than 1%. Although universal birth-dose HBV vaccination is the most effective strategy for eliminating HBV infection, global birth-dose HBV vaccine coverage was only 45% in 2024. The risk of developing chronic infection (HBsAg positive for more than 6 months) is 90% if HBV infection occurs during infancy, 30% in children aged 1 to 5 years, and less than or equal to 5% in immunocompetent adolescents and adults. HBV infection is diagnosed by serologic testing: HBsAg indicates ongoing infection, antibody to HBsAg indicates immunity, and antibody to hepatitis B core antigen indicates ongoing or past infection. Serum HBV DNA levels quantify virus-replication activity. Assessment of liver inflammation and fibrosis with alanine aminotransferase (ALT) and noninvasive tests such as Fibrosis-4 index and liver elastography guide treatment decisions. Chronic HBV infection may progress to cirrhosis and hepatocellular carcinoma (HCC); the 5-year cumulative risk of cirrhosis is 8% to 15% in untreated chronic HBV infection, and annual HCC incidence is 3% to 5% among patients with cirrhosis. Antiviral therapies-pegylated interferon alfa and nucleos(t)ide analogues (entecavir or tenofovir)-suppress HBV DNA replication and reduce the risk of HCC by approximately 50%. Antiviral treatment is recommended for all patients with chronic HBV and cirrhosis and for those without cirrhosis who have high HBV DNA with elevated ALT or significant inflammation/fibrosis. Patients at high risk of HCC should undergo surveillance with ultrasonography and alpha-fetoprotein testing every 6 months.

Conclusions and relevance: HBV infection causes approximately 1.1 million deaths annually worldwide. Universal HBV vaccination, particularly birth-dose administration, is the most effective strategy to prevent HBV infection. Among patients with HBV infection, antiviral therapy decreases progression to cirrhosis and liver failure and reduces the risk of HCC.

Keywords 
hepatitis hepatitis B Hepatitis B Core Antigens Hepatitis B Surface Antigens Antiviral Agents Liver Failure vaccination

Hepatitis B Management: Guidance for the Primary Care Provider

Author/s: 
Tang, AS, Thornton, K, HBV Primary Care Working Group

The purpose of this document is to provide simplified, up-to-date, and readily accessible guidance for primary care medical providers related to the prevention, diagnosis, and management of hepatitis B virus (HBV) infection, including hepatocellular carcinoma surveillance.

Keywords 
hepatitis B alogrithm counseling treatment management

Final Update Summary: Hepatitis B Virus Infection in Pregnant Women: Screening

Importance

Screening for HBV infection during pregnancy identifies women whose infants are at risk of perinatal transmission. Data from a nationally representative sample showed a prevalence of maternal HBV infection of 85.8 cases per 100,000 deliveries from 1998 to 2011 (0.09% of live-born singleton deliveries in the United States).1, 2 Although there are guidelines for universal infant HBV vaccination, rates of maternal HBV infection have increased annually by 5.5% since 1998.1, 2 Persons infected with HBV during infancy or childhood are more likely to develop chronic infection. Chronic HBV infection increases long-term morbidity and mortality by predisposing infected persons to cirrhosis of the liver and liver cancer.

Reaffirmation

In 2009, the USPSTF reviewed the evidence for screening for HBV infection in pregnant women and issued an A recommendation.3 The USPSTF has decided to use a reaffirmation deliberation process to update this recommendation. The USPSTF uses the reaffirmation process for well-established, evidence-based standards of practice in current primary care practice for which only a very high level of evidence would justify a change in the grade of the recommendation.4 In its deliberation of the evidence, the USPSTF considers whether the new evidence is of sufficient strength and quality to change its previous conclusions about the evidence.

Detection

The USPSTF previously reviewed the evidence on serologic testing for HBV (hepatitis B surface antigen [HBsAg]) in pregnancy and found adequate evidence of its accuracy (sensitivity and specificity both >98%).

Benefits of Early Detection and Interventions

The USPSTF found convincing evidence that universal prenatal screening for HBV infection substantially reduces perinatal transmission of HBV and the subsequent development of chronic HBV infection. The USPSTF found adequate evidence that vaccination of all infants against HBV infection and providing postexposure prophylaxis with hepatitis B immune globulin (HBIG) at birth to infants of mothers infected with HBV substantially reduce the risk for acquisition of HBV infection in infants.

Harms of Screening and Interventions

The USPSTF found limited evidence on the harms of screening for HBV infection in pregnant women but bounded the potential harms of screening as no greater than small based on the high accuracy of screening and the low likelihood of harms from preventive interventions.

USPSTF Assessment

Using a reaffirmation process, the USPSTF concludes with high certainty that the net benefit of screening for HBV infection in pregnant women is substantial.

Keywords 
hepatitis B Pregnancy
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