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Hepatitis B: The Basics and Beyond



Hepatitis B: The Basics and Beyond

Maha Al-Jabri, MD
Consultant, Transplant and General Infectious Diseases
Hamad Medical Corporation

July 28 marks the annual World Hepatitis Day, honoring the birth of Baruch Blumberg, who was awarded the Nobel Prize in Medicine in 1976 for his discovery of the hepatitis B virus (HBV). While hepatitis can result from both infectious and non-infectious causes, World Hepatitis Day is dedicated specifically to raising awareness about viral hepatitides, a group of preventable, yet still widespread diseases. This article focuses on hepatitis B, the most common cause of death among viral hepatitides, as it can lead to chronic hepatitis, which may progress to liver fibrosis, cirrhosis, and hepatocellular carcinoma.1,2

In 2019, approximately 1.5 million new HBV infections were reported worldwide, adding to an estimated 296 million people living with chronic HBV infection and resulting in about 820,000 HBV-related deaths globally.3 Regionally, the World Health Organization (WHO) African Region recorded the highest number of new infections at 990,000 in 2019, while the Western Pacific Region reported the highest HBV-related mortality with 470,000 deaths.3 In the WHO Eastern Mediterranean Region, there were 100,000 new HBV infections and 33,000 deaths reported.3 A recent prevalence estimate for hepatitis B in the Gulf Cooperation Council (GCC) region was 1.56% between 2010 and 2020, showing a significant decline compared to 9.38% before 1990, indicating a promising overall trend.4 The WHO global hepatitis strategy aims to reduce viral hepatitis incidence by 90% and mortality by 65% by 2030.

Transmission of HBV can occur both horizontally and vertically. Horizontal transmission involves the transfer of bodily fluids from person to person, including blood transfusions, sexual contact, and non-sexual household contact. Non-sexual household contact is one mode of HBV transmission in regions with moderate to high endemicity, with hepatitis B surface antigen (HBsAg) prevalence reaching as high as 30.6% among household contacts of individuals with chronic hepatitis B (CHB).5,6 This is partly due to HBV’s high environmental stability, as it can retain approximately 90% of its infectivity even after being left at room temperature for 28 days.7 Vertical transmission, or mother-to-child transmission (MTCT), can occur in the antenatal period through placental tears, bleeding, and exposure of the newborn to maternal bodily fluids during delivery. MTCT was a major route of HBV transmission in high-endemic regions, such as China, though with the implementation of effective preventative strategies this has become less common.8 In areas of low endemicity, the primary modes of transmission are intravenous drug use and high-risk sexual activity.

Acute HBV infection is asymptomatic in the majority of patients. Among those who do develop hepatitis, whether icteric or anicteric, fulminant hepatitis may occur, though it is rare. Treatment of acute hepatitis B is primarily supportive. A proportion of HBV-infected individuals progress to CHB, which is defined by persistence of HBsAg for ≥6 months. The age at which HBV infection is acquired is a key prognostic factor in the development of chronic infection: approximately 90% of infants who acquired HBV go on to develop CHB, compared to only 5% of adults.9 CHB can lead to cirrhosis, liver failure, and hepatocellular carcinoma, which together account for a high percentage of HBV-related deaths annually.1-3

Given the high risks associated with acquiring HBV infection during infancy, prevention of MTCT is essential. For pregnant patients who are HBsAg-positive with HBV DNA ≥200,000 IU/mL, or HBsAg-positive alone when HBV DNA testing is unavailable, prophylaxis with tenofovir is recommended, starting from the second trimester until at least delivery.10,11 Further, the timely administration of HBV immunoglobulin and vaccination of the newborn within 24 hours of birth are essential for effective prevention.8  The hepatitis B vaccine is widely available and is included in the routine childhood immunization schedule in Qatar. The first dose is administered within 24 hours of birth, followed by three additional doses typically within the first six months of life.  

The WHO hepatitis B treatment guidelines updated in March 2024 recommend treating adults and adolescents with CHB who meet any of the following criteria: 1) significant fibrosis or cirrhosis regardless of ALT or HBV DNA level; 2) HBV DNA >2,000 IU/mL combined with ALT elevation above upper limit of normal; 3) presence of certain conditions such as HIV co-infection, family history of liver cancer, immunosuppression, or extrahepatic manifestations; or 4) persistently elevated ALT levels alone, particularly in healthcare settings where HBV DNA testing is not feasible.11 The primary goal of treatment is long-term viral suppression, as complete cure is not currently achievable with available therapies. First-line therapy consists of nucleos(t)ide analogues with a high genetic barrier to resistance, such as entecavir or tenofovir formulations.

In conclusion, HBV infection remains a major cause of morbidity and mortality worldwide. Significant progress has been made in preventing HBV transmission, especially MTCT, resulting in a reduction in the incidence of HBV infection among children. Vaccination remains the most effective measure for preventing all modes of HBV transmission, and continued efforts are needed to expand vaccine access, particularly for children.

Reference List

  1. Mendy EM, Welzel T, Lesi AO, et al. Hepatitis B Viral Load and Risk for Liver Cirrhosis and Hepatocellular Carcinoma in The Gambia, West Africa. Journal of Viral Hepatitis. 2010;17(2):115-122. doi:10.1111/j.1365-2893.2009.01168.x
  2. Iloeje HU, Yang HI, Su J, Jen CL, You SL, Chen CJ. Predicting Cirrhosis Risk Based on the Level of Circulating Hepatitis B Viral Load. Gastroenterology. 2006;130(3):678-686. doi:10.1053/j.gastro.2005.11.016
  3. WHO. Global Progress Report on HIV, Viral Hepatitis and Sexually Transmitted Infections, 2021. Accessed June 30, 2025. https://iris.who.int/bitstream/handle/10665/341412/9789240027077-eng.pdf?sequence=1
  4. Alali AA, Abo-Shehada NM. Prevalence of Hepatitis B Virus Infection in The Gulf Cooperation Council: a Systematic Review and Meta-analysis. BMC Infectious Diseases. 2022;22(1):doi:10.1186/s12879-022-07806-4
  5. Gupta S, Gupta R, Joshi YK, Singh S. Role of Horizontal Transmission in Hepatitis B Virus Spread among Household Contacts in North India. Intervirology. 2008;51(1):7-13. doi:10.1159/000118790
  6. Sabeena S, Ravishankar N. Horizontal Modes of Transmission of Hepatitis B Virus (HBV): A Systematic Review and Meta-Analysis. Iranian Journal of Public Health. 2022;doi:10.18502/ijph.v51i10.10977
  7. Than TT, Jo E, Todt D, et al. High Environmental Stability of Hepatitis B Virus and Inactivation Requirements for Chemical Biocides. The Journal of Infectious Diseases. 2019;219(7):1044-1048. doi:10.1093/infdis/jiy620
  8. Tang L, Li L, Huang L, et al. A Multi-Regional Epidemiological Evaluation on Post-vaccination Serological Testing in Prevention of Vertical Transmission of Hepatitis B Virus — 10 Counties, 5 Provinces, China, 2019–2024. China CDC Weekly. 2025;7(19):658-664. doi:10.46234/ccdcw2025.108
  9. WHO. Hepatitis B. Updated April 9, 2024. Accessed June 29, 2025. https://www.who.int/news-room/fact-sheets/detail/hepatitis-b
  10. Pan QC, Dai E, Mo Z, et al. Tenofovir and Hepatitis B Virus Transmission During Pregnancy. JAMA. 2025;333(5):390. doi:10.1001/jama.2024.22952
  11. WHO. Guidelines for the Prevention, Diagnosis, Care and Treatment for People With Chronic Hepatitis B Infection. World Health Organization. Updated March 29, 2024. Accessed June 29, 2025. https://iris.who.int/bitstream/handle/10665/376353/9789240090903-eng.pdf?sequence=1