hepatitis%20a%20-and-%20e
HEPATITIS A & E

Hepatitis A route of transmission is through oral-fecal route. While in hepatitis E, aside from the oral-fecal route, it is also transmitted through blood transfusion in endemic areas.

Hepatitis A incubation period is 15-50 days and hepatitis E incubation period is 21-60 days.

Hepatitis A & E viruses cause epidemics.

 

History

Important points in the clinical history of patients w/ suspected viral hepatitis

  • Contacts w/ jaundiced patients
  • IV drug use
  • History of blood transfusion
  • Surgery or hospitalizations
  • Family history of chronic liver disease
  • Occupation
  • Food & water sources

Laboratory Tests

Serological Tests for Viral Hepatitis

Hepatitis A

  • Anti-hepatitis A virus IgM has high sensitivity & specificity & is a marker of acute infection
    • This test remains positive for ≥6 months
  • Anti-hepatitis A virus should be tested in patients <50 years

Hepatitis B

  • Usually characterized by the presence of hepatitis B surface antigen (HBsAg) which suggests infectivity
    • Anti-HBs is produced following a resolved infection & is the only HBV antibody marker present after immunization
  • Anti-HBc (anti-core antibody) is the first antibody to appear in the serum & is a marker of natural immunity
    • Presence of anti-HBc IgM is diagnostic for acute hepatitis B virus (HBV) infection but may occur during a flare of chronic hepatitis B
    • Its presence indicates an immune response against HBV within liver cells & is a specific marker of acute hepatitis B infection
  • Hepatitis B e antigen (HBeAg) is a marker of active viral replication
    • This may be negative at the time that the patient is evaluated for acute hepatitis B since viral replication may have already ceased
  • Patients w/ chronic hepatitis B should also be tested for co-infection w/ hepatitis C virus (HCV), hepatitis D virus (HDV) & human immunodeficiency virus (HIV), if they are at risk for these infections
  • Depending on local health services, the following groups should be tested for chronic HBV infection:
    • Persons born in hyperendemic areas, men who have sex w/ men (MSM), IV drug users, dialysis patients, HIV-positive individuals, pregnant women & family members, household members & sexual contacts of HBV-infected persons, blood or organ donors, healthcare workers, patients needing chemotherapy
      • Individuals who are seronegative should be vaccinated against HBV
      • HBsAg-positive patients should be evaluated to assess progression of liver disease & need for antiviral therapy
      • Anti-HBs-positive patients have developed natural immunity & do not need to be vaccinated

Hepatitis C

  • Anti-HCV antibodies are the first-line diagnostic test
  • Acute hepatitis C cannot be reliably diagnosed by antibody tests since these often do not become positive until 3 months after infection
    • If the clinical suspicion is high, the patient should be tested for HCV RNA to establish the diagnosis
    • HCV RNA is used to determine acute or chronic infection
  • Chronic hepatitis C should be confirmed w/ anti-HCV antibodies & HCV RNA
  • Recombinant immunoblot assay (RIBA) may be used to establish the cause of a positive anti-HCV test in a person w/ undetectable HCV RNA
    • A negative RIBA indicates that a positive anti-HCV immunoassay result showed a false-positive result & no further testing is necessary
    • A positive RIBA & ≥2 subsequent tests in which HCV RNA cannot be detected suggest that HCV infection has resolved & no further testing is indicated
    • A positive anti-HCV & negative HCV RNA indicate no active HCV infection but should have HCV RNA retesting after 3 months to document recovery
  • HCV RNA quantitative testing to determine baseline viral load is recommended before starting antiviral therapy
    • End of therapy is indicated by undetectable HCV RNA in a sensitive assay (<15 IU/mL) 12 & 24 weeks after therapy
  • HCV genotype, including subtyping of genotype 1a/1b, should be determined, if possible, in all HCV-infected persons prior to treatment to determine type & duration of therapy & chances of response; predominant genotypes in Asia are:
    • Genotypes 1b & 2: East Asia (China, Taiwan, South Korea, Japan)
    • Genotype 3: South Asia (India & Pakistan)
      • Genotype 3 is considered difficult to treat & is associated w/ a poor prognosis
    • Genotypes 1 & 6: Southeast Asia (Vietnam, Cambodia, Laos, Indonesia, Myanmar, Malaysia, Philippines, Thailand)
  • Liver biopsy may be done if it is thought that the results will influence clinical decision, but biopsy is not mandatory to start therapy in patients w/ genotypes 2 & 3
    • Liver biopsy may be obtained to provide prognostic information
  • Depending on local health services, the following groups should be tested for chronic HCV infection:
    • Persons who have in the recent or remote past used illicit IV drugs
    • Persons w/ conditions associated w/ high prevalence of HCV infection
      • Positive HIV, hemophiliacs who received clotting factor prior to 1987, history of hemodialysis, persons who received blood/blood products or organ transplants prior to 1995, children born to HCV-infected mothers, healthcare workers after needle stick injury or mucosal exposure to HCV-positive blood, current sexual partners of HCV-infected persons

Hepatitis D

  • Confirmed by positive anti-HDV antibody or HDV RNA test
  • Hepatitis D occurs as a co-infection w/ Hepatitis B

Hepatitis E

  • IgM anti-HEV, IgG anti-HEV & hepatitis E virus (HEV) RNA indicate acute hepatitis E infection
    • HEV RNA is detected from serum & stool of infected patients by PCR

Other lab tests that are recommended in patients suspected to have viral hepatitis:

  • Liver function tests (LFTs)
    • Aspartate aminotransferase (AST) & alanine aminotransferase (ALT)
    • Serum bilirubin, alkaline phosphatase (ALP)
  • Prothrombin time, international normalized ratio (INR)
  • Noninvasive tests such as the aminotransferase/platelet ratio index (APRI) or FIB4 may be used to assess the degree of hepatic fibrosis when resources are limited prior to initiating HCV therapy
    • Transient elastography may be an option for patients w/ contraindications to liver biopsy

Evaluation

Features of Hepatic Decompensation

  • Mental dullness, hepatic encephalopathy, bilateral asterixis, ascites, clinical deterioration
  • Serum bilirubin >2.5x upper limit of normal, PT is 3 seconds longer than control or INR >1.5
Digital Edition
Asia's trusted medical magazine for healthcare professionals. Get your MIMS Gastroenterology - Malaysia digital copy today!
Sign In To Download
Editor's Recommendations
Most Read Articles
4 days ago
Children with high dental anxiety are more likely to develop dental diseases, which, in turn, negatively affect the family’s quality of life, a recent study has found.
2 days ago
Exposure to corticosteroids in patients with autoimmune hepatitis (AIH) appears to contribute to increased risks of cataract, diabetes and bone fractures, a study has found. Notably, the fracture risk is elevated at low doses, while the risk of adverse events overall is dose-dependent and is reversible.
14 Nov 2019
In patients with atrial fibrillation (AF) and stable coronary artery disease (CAD), rivaroxaban monotherapy is noninferior to combination treatment with an antiplatelet therapy in terms of cutting the risk of cardiovascular events and mortality, according to data from the AFIRE trial.
3 days ago
Supplementation with oral nano vitamin D appears to moderate disease activity and severity grade of patients with active ulcerative colitis (UC), suggests a study, adding that this association is more evident in those achieving a target vitamin D level of 40 ng/mL.