Flashcards in Hepatitis & Liver Disease Deck (74)
What is the risk of perinatal transmission of HAV?
0% - There is no perinatal transmission of HAV.
Can pregnant women be vaccinated against HAV?
The inactivated HAV vaccine can be safely used for prevention, including during pregnancy if a patient is at risk for HAV exposure. Two doses IM (Havrix 1 mL [50 U] or Vaqta 1 g [1440 U]), given 6 to 12 months apart, are needed to confer immunity. HA vaccine is also available in combination with HB vaccine. Immunity after vaccination lasts >10 years.
How should pregnant woman with an exposure to HAV be treated?
Exposed pregnant women can receive immune globulin injections, which are >85% effective in preventing HAV infection if given within two weeks of exposure. The standard intramuscular dose of immune globulin IS 0.02 mg/kg. The HAV vaccine series should also be initiated.
What is the therapy for acute HAV infection?
The vast majority of hepatitis A virus (HAV) infections are self-limited. Therapy is supportive.
Symptoms of HAV infection
Fever, malaise, decreased appetite, nausea, abdominal discom- fort, dark urine, jaundice.
How is HAV transmitted?
Fecal/oral contact with infected person or contaminated food/ water; rarely from blood transmission. Most U.S. cases are from person-to-person or sexual contacts or transmission during outbreaks.
Average HAV incubation period?
28 (15-49 days)
What are the complications/chronic sequelae of HAV?
Mortality is <0.3%. Chronic carrier state does not exist.
Diagnosis of HAV
HAV IgM and IgG. HAV IgM is detectable 5 to 10 days before the onset of symptoms and usually decreases to undetectable concentrations within six months after recovery. Consider rest of hepatitis workup. Check AST/ ALT, bilirubin.
Where are the HAV endemic areas?
High: Mexico, South America, Africa, Middle EastIntermediate: Asia
Is breast-feeding permitted in women with HAV?
Who should receive the HAV vaccine?
International travelersChildren in endemic areasIntravenous drug usersIndividuals who have occupational exposure (e.g., workers in a primate laboratory)Residents and staff of chronic care institutions Individuals with liver diseaseHomosexual menIndividuals with clotting factor disorders
What is the vertical transmission rate of HBV in women with HBeAg+?
What is the vertical transmission rate of HBV in women who are HBsAg+ but HBeAg-?
What is the vertical transmission rate of acute HBV in the third trimester?
Without intervention, what percent of newborns infected with HBV develop chronic hepatitis? How many develop complications?
90%, with 25% of chronic HBV carriers eventually dying of complications (cirrhosis, hepatocellular cancer)
What vaccines do newborns born to women with HBV receive? Efficacy?
HBIg, HB vaccine, within 12 hrs of birth, prevents 90% of neonatal HBV infection
Is breastfeeding contraindicated in HBV+ mothers?
Breast-feeding is not contraindicated, as long as the mother is HBeAg- and HIV-, and the newborn receives appropriate immunoprophylaxis.
Labs for serologic diagnosis of acute HBV
HBsAg+, HBcAb+, HBcIgM+, HBsAb‰ÛÒ
Labs for serologic diagnosis of chronic HBV
HBsAg+ >6 months, HBsAb‰ÛÒ
Differential diagnosis of hepatitis
Hepatic A, B, or C virusCytomegalovirus (CMV)Epstein‰ÛÒBarrVaricella (VZV)Coxsackie BHerpes (HSV)RubellaAutoimmune
Diagnosis of newborn HBV
Detection of persistent (e.g., >9 months of age) HBsAg. Only HbsAb is attributable to newborn vaccination: HBcAb arises only as the result of actual HBV infection.
Symptoms of acute HBV
Only 30% to 50% of patients acutely infected have symptoms such as loss of appetite, malaise, nausea, and vomiting. About 10% have jaundice. The onset is usually insidious.
Natural history of HBV infection
One-third of the world‰Ûªs population (two billion people) have been infected with HBV: 90% have complete resolution, while about 10% overall develop chronic HBV infection; but this incidence is 90% in children 5 years old. About 25% of HBV chronic infection patients die of liver disease (4000/yr in the United States, >1 million/yr world-wide‰ÛÓ0.5% mortality)
HBV vaccine efficacy
The vaccine is about 95% effective against HBV.
HBV incubation period
‰ÛÏs‰Û surface‰ÛÓinfected. If present >6 months = chronic HBV infection‰ÛÏc‰Û‰ÛÓcore‰ÛÏe‰Û‰ÛÓinfectious
‰ÛÏs‰Û‰ÛÓimmune‰ÛÏc‰Û‰ÛÓcovers ‰ÛÏwindow‰Û period, and usually precedes HBsAb conversion
Risk of chronic HBV infection
About 5% of HBV infections become chronic. This can lead to cirrhosis, hepatocellular carcinoma, and death.