Acute hepatitis B

Acute hepatitis B is an infectious disease of the liver caused by the hepatitis B virus (HBV), a member of the hepadnavirus family. It is classified under viral hepatitis and represents the initial phase of HBV infection lasting less than six months. The virus is an enveloped particle measuring 30-42 nm in diameter, featuring an icosahedral nucleocapsid containing DNA with reverse transcriptase activity. ICD-10 classification B16 and ICD-11 classification 1E50.1 apply to this condition.

Acute hepatitis B presents with a highly variable clinical spectrum, ranging from completely asymptomatic infection to fulminant hepatic failure. When symptomatic, the incubation period ranges from 30 to 180 days following exposure. Initial manifestations include rapid onset of nausea, vomiting, jaundice (yellowish skin), fatigue, dark urine, and abdominal pain. The symptomatic phase typically lasts several weeks, though some individuals may experience illness for up to six months. While deaths from acute HBV infection are rare, a small proportion of patients develop severe liver disease requiring intensive care. The infection may go unrecognized in asymptomatic cases, which constitute a substantial proportion of exposures.

Hepatitis B exhibits a global distribution with marked variation in prevalence patterns across regions. In areas where the disease is endemic, infection acquired around the time of birth or through childhood exposure to contaminated blood represents the predominant transmission pattern. The likelihood of developing chronic hepatitis B is strongly age-dependent: approximately 90% of those infected during or shortly after birth progress to chronic infection, whereas fewer than 10% of individuals infected after age five develop chronic disease. Among those with chronic HBV infection, approximately 25% eventually develop cirrhosis or liver cancer, though most chronic carriers remain asymptomatic for extended periods.

HBV is transmitted through exposure to infectious blood or body fluids containing blood, with the virus demonstrating infectivity 50 to 100 times greater than HIV. Vertical transmission from mother to child during childbirth represents a major route, with a 20% risk of transmission from HBsAg-positive mothers rising to 90% when the mother is also HBeAg-positive. Horizontal transmission occurs through contact with infected blood or secretions, including bites, lesions, and certain sanitary practices. In low-prevalence regions, transmission patterns differ from endemic areas, though the source snippets do not provide detailed geographic-specific transmission dynamics.

Infants infected around the time of birth or shortly thereafter face the highest risk of chronic hepatitis B development. Individuals exposed to infectious blood or body fluids through occupational, medical, or personal contact remain at elevated risk for acute infection. The source snippets indicate that age at infection is the primary determinant of chronicity risk, with young children demonstrating substantially higher rates of persistent infection compared to older children and adults.

Source-backed detail on specific prevention measures for acute hepatitis B is not yet available in the provided source material. General public health measures for HBV prevention typically include vaccination, safe injection practices, blood screening, and prevention of mother-to-child transmission, though these details require verification from additional sources.

Surveillance for acute hepatitis B relies primarily on serological testing, with hepatitis B surface antigen (HBsAg) serving as the principal screening marker for detecting HBV infection. HBsAg represents the first detectable viral antigen during infection, though interpretation of serological assays is complex due to the dynamic nature of antigen and antibody patterns throughout the disease course. Acute infection is distinguished from chronic infection by duration exceeding six months, which has implications for case classification and reporting. The asymptomatic nature of many infections presents challenges for passive surveillance systems.

1. 1 Wikidata. Acute hepatitis B virus infection: relation of age to the clinical expression of disease and subsequent development of the carrier state.
2. 2 Wikipedia. Hepatitis B - Wikipedia.

ICD-10

B16

ICD-11

1E50.1

Total cases

5K

Peak month

2000-07

Coverage

1 reporting countries · 2000-01-01 → 2026-05-01