Definition and etiology

“The presence of HBsAg establishes the diagnosis of hepatitis B. Chronic vs acute infection is defined by the presence of HBsAg for at least 6 months.” (opens the original PMC page at this quote in a new tab)View highlighted excerpt for this quoteCopyFlag

“The presence of HBsAg for at least 6 months establishes the chronicity of infection.” (opens the original PMC page at this quote in a new tab)View highlighted excerpt for this quoteCopyFlag

“Hepatitis B is caused by infection with HBV. HBV is a 40–42-nanometer enveloped virus classified in the Hepadnaviridae family. HBV contains a circular, partially double-stranded DNA genome that is 3.2 kb in length. After a susceptible person is exposed, the virus enters the liver via the bloodstream. The liver is the primary site of HBV replication.” (opens the source at this quote in a new tab)CopyFlag

“Is classified by serologic subtype and genotype, which vary geographically.” (opens the source at this quote in a new tab)CopyFlag

“Is infectious for at least 7 days on surfaces.” (opens the source at this quote in a new tab)CopyFlag

“HBV is highly infectious and transmitted when blood, semen or other body fluids from a person infected with the virus enters the body of someone who is uninfected.” (opens the source at this quote in a new tab)CopyFlag

“In highly endemic areas, hepatitis B is most commonly spread from mother to child at birth (perinatal transmission) or horizontal transmission through person-to-person contact in the presence of open cuts and sores, especially from an infected child to an uninfected child during the first 5 years of life.” (opens the source at this quote in a new tab)CopyFlag

“Hepatitis B is also spread by needlestick injury, tattooing, piercing and exposure to infected blood and body fluids, such as saliva and menstrual, vaginal and seminal fluids. Transmission of the virus may also occur through the sharing or reuse of contaminated needles and syringes or sharp objects either in health care settings, in the community or among persons who inject drugs. Sexual transmission is more prevalent in unvaccinated persons with multiple sexual partners.” (opens the source at this quote in a new tab)CopyFlag

“In regions with high endemicity, vertical transmission from mother to child during childbirth or through close personal contact contributes significantly to the prevalence of HBV infection. However, HBV can be transmitted through various routes, including perinatal transmission, sexual contact, sharing of contaminated needles or other injection equipment, and exposure to infected blood.” (opens the source at this quote in a new tab)CopyFlag

“The risk for chronic infection varies according to the age at infection and is greatest among young children. Approximately 90% of infected infants and 30% of children infected between 1–5 years will remain chronically infected with HBV. By contrast, approximately 95% of infected adults recover completely from acute HBV infection and do not become chronically infected.” (opens the source at this quote in a new tab)CopyFlag

“The average incubation period for HBV is 60 days (range: 40–90 days) from exposure to onset of abnormal serum alanine aminotransferase (ALT) levels and 90 days (range: 60–150 days) from exposure to onset of signs and symptoms.” (opens the source at this quote in a new tab)CopyFlag

“Hepatitis B infection acquired in adulthood leads to chronic hepatitis in less than 5% of cases, whereas infection in infancy and early childhood leads to chronic hepatitis in about 95% of cases.” (opens the source at this quote in a new tab)CopyFlag

“Ten genotypes of HBV have been identified labeled A through J (103, 104). The prevalence of HBV genotypes varies geographically. HBV genotypes A through H have been found in the United States, with genotypes A, B, and C being most prevalent (26). HBV genotypes may play an important role in the progression of HBV-related liver disease as well as response to interferon (IFN) therapy (103, 105).” (opens the original PMC page at this quote in a new tab)View highlighted excerpt for this quoteCopyFlag

“Studies from Asia found that HBV genotype B is associated with HBeAg seroconversion at an earlier age, more sustained remission after HBeAg seroconversion, less active hepatic necroinflammation, a slower rate of progression to cirrhosis, and a lower rate of HCC development compared with genotype C (103).” (opens the original PMC page at this quote in a new tab)View highlighted excerpt for this quoteCopyFlag

“In terms of genotype, genotype C has been associated with a higher risk of HCC than genotype B in individuals with chronic HBV infection in Asia.105,196 In individuals from Africa (e.g. The Gambia), HBV genotype A has been identified as a risk factor for liver fibrosis202 and HCC199 compared with genotype E. In Alaska, genotype F was associated with the highest HCC risk.197” (opens the source at this quote in a new tab)CopyFlag

“In an optimal setting, liver fibrosis is assessed using LSM, with defined cut-off values for VCTE indicating significant fibrosis (7.2-7.9 kPa), advanced fibrosis (8.8-9.4 kPa) and cirrhosis (≥11.7-12.2 kPa), as shown in two systematic reviews and meta-analyses focused on individuals with HBV infection.” (opens the source at this quote in a new tab)CopyFlag

“The most recent meta-analysis, focused exclusively on individuals with HBV infection, proposes thresholds of 6.0–8.0 kPa for significant fibrosis (with a cut-off of >7.0 kPa identifying most cases), >8.0–11.0 kPa for advanced fibrosis, and >11.0–14.0 kPa for cirrhosis.” (opens the source at this quote in a new tab)CopyFlag

“The Baveno VI consensus introduced the term “compensated advanced chronic liver disease (cACLD)” to describe patients with advanced fibrosis or early cirrhosis who remain asymptomatic but are at risk of developing clinically significant portal hypertension (CSPH) and disease progression.80 Liver stiffness values <10 kPa were proposed as a safe cut-off for excluding cACLD and values >15 kPa as highly suggestive of cACLD.” (opens the source at this quote in a new tab)CopyFlag

“The recommended endpoint of novel therapy is functional cure defined as HBsAg loss using a conventional assay for detection of HBsAg (limit of detection 0.05 IU/mL) and HBV DNA below the lower limit of quantification (i.e. < 10 IU/ml) at 24 weeks off-therapy.” (opens the original PMC page at this quote in a new tab)View highlighted excerpt for this quoteCopyFlag

“Loss of HBsAg with acquisition of anti-HBs has been termed functional cure. This is distinguished from true cure, in which HBsAg and covalently closed circular DNA are eliminated.” (opens the original PMC page at this quote in a new tab)View highlighted excerpt for this quoteCopyFlag