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53 Cards in this Set
- Front
- Back
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What is the virus family of hepatitis A, does it have an envelope, and what is it's genome?
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Hep A is a naked icosohedral picorna virus with a +ssRNA genome
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What is the virus family of hepatitis B, does it have an envelope, and what is it's genome?
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Hep B is a hepadna virus with a lipid envelope and a dsDNA genome
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What is the virus family of hepatitis C, does it have an envelope, and what is it's genome?
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Hep C is a lipid enveloped flavi virus that has a +ssRNA genome
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What is the virus family of hepatitis E, does it have an envelope, and what is it's genome?
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Hep E is a naked calci-like virus with a +ssRNA genome
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Describe the genome of hepatitis D virus
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It has an unusual -ssRNA genome that is circular but base paired with internal "delta antigen"
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Describe the laboratory diagnosis of Hep A infection
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Antibody-capture ELISA to detect serum anti-HAV IgM (current or recent infection) or IgG (past infection, immunization)
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What is the therapy for Hep A?
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Prevention with active immunization with the inactivated virus before 1 year; passive immunization with human Ig for post-exposure protection (also can be used for pre-exposure, travel to endemic areas)
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What is the major mode of transmission for hep A?
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Fecal-oral, including outbreaks associated with food
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What is the major mode of transmission for Hep E?
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Fecal-oral
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Where is the highest prevelance of Hep E?
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Asia, with 10-20% seroprevelence
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What must be done to Hep B virions in order to analyze them via PCR or bDNA?
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They must have their lipid-envelope extracted with a detergent
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What are the most common modes of transmission for Hep B?
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Blood, sexual, and perinatal
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What laboratory findings are seen with a current Hep B infection?
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Antigen capture ELISA of HBsAG (hep B surface antigen)
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What lab findings indicate a chronic Hep B infection?
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Anti-HBc IgG without the presence of IgM if the patient is also positive for surface antigen (HBsAg)
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What is the lab indication of a high level of infectivity in Hep B?
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Presence of serum HBeAg
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What does it mean when a patient is anti-HBs IgG positive but anti-HBc negative?
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They have been immunized against Hep B
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What does it mean when a patient is anti-HBs IgG positive and anti-HBc positive?
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They have previously been infected with Hep B
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What test is used to determine viral load in a person with chronic Hep B?
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Nucleic acid based testing such as PCR or bDNA
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Describe the immunization against Hep B
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It is an active immunization with a recombinant HBsAg (hep B surface antigen) administered IM in 3 doses (1st before 2mo, 2nd one month later and 3rd dose around 6 mo)
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What is given to babies born to HBsAg + mothers?
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Passive immunization with Hep B immune globulin (HBIG)
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What drugs are used to treat Hep C?
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Ribavarin in combination with interferon alpha
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What is used to treat HepB and what does it target?
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Nucleoside DNA polymerase inhibitors such as lamivudine and entecavir; these target the RNA dependant DNA polymerase
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Describe the human Hep D infection
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It occurs as a co-infection with Hep B or a super infection of a person with chronic Hep B (anti-HBs negative)
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How is Hep D diagnosed?
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ELISA to detect the total anti-delta antigen
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Describe the immunization of Hep D
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It is the same used for Hep B alone
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What are the major source of hep C infection?
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Injection drug abuse and sexual
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What is a potential anti-viral target for Hep C infections?
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Protease inhibitors because a polyprotein is generated by the virus
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What are the major viral antigens encoded by the Hep B genome?
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Hep B surface antigen (HBsAg), HBcAg, and HBeAg
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How is Hep C diagnosed?
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Antibody capture ELISA detecting anti-HCV with a confirmatory RIBA (analogous to western blot); RT-PCR used for viral load determination
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Hep D is found only with what other virus?
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Hep B
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Describe the virus-cell interaction of Hep A
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It is a non-cytopathic "steady state" infection
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What is the HBcAg?
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The core antigen of the hep B virus
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What is the HBeAg?
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A secretable soluble protein related the core antigen and indicative of an active replication with high infectivity
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Describe the genome of the Hep B virus
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It is a circular DNA genome that is partially double stranded and partially single-stranded
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What is required for the production of the Hep D particle?
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HBsAg
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Describe the clinical presentation of the majority of hepatitis virus infections?
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The majority of the infections are asymptomatic or mild without jaundice (anicteric)
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Why is serology needed in the diagnosis of hepatitis viral infections?
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There is a large amount in overlap of the symptoms and severity
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What specific labs are obtained when acute viral hepatitis is suspected?
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Serum aminotransferases, serological antibodies (anti-viral IgM), antigen assays for each specific virus, and nucleic acids assays for specific viruses (HBV, HCV)
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What are the phases of acute viral hepatitis?
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Incubation period, preicteric, icteric, and convalescent
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What symptoms are commonly found in the preicteric phase and how long does it last?
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The preicteric phase is generally 3-10 days and shows malaise, weakness, followed by anorexia, nausea, vomiting, and dull pain in the right upper quadrant
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Describe the symptoms of the icteric phase; how long does it usually last?
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The icteric phase generally lasts 1-3 weeks and shows jaundice or dark skin with elevations of aminotransferases
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What complication exists for acute viral hepatitis?
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Fulminant hepatitis
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Describe the convalescent phase of viral hepatitis
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Malaise and weakness persisting for weeks, with relapse or prolonged illness up to 6 months with HAV
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Which hepatitis is a chronic, life-long infection that may progress to liver cirrhosis or cancer?
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Hep C
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Which hepatitis virus has a high mortality rate among pregnant females and what parts of the world is this disease seen?
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Hep E infection of pregnant females leads to a 20% mortality in endemic countries such as India and parts of Africa and Latin America
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What is the definition of chronic hepatitis?
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Abnormality in liver function which persists for greater than 6 months; characteristic of both Hep B and C but NOT A or E
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What is a major factor contributing to the likelihood of a patient infected with Hep B developing a chronic Hep B?
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Age; infants affected at birth are 90% likely to become chronically infected compared to only 10% of children or adults
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What are complications and long-term outcomes seen associated with chronic active hepatitis?
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Cirrhosis and hepatocellular carcinoma
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What is the outcome of Hep B carriers superinfected with Hep D?
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Most (80%) progress to a chronic Hep B/D hepatitis leading to cirrhosis of the liver
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What drugs are used to treat Hep B?
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Lamivudine, pegylated rIFN alpha
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What is the antigen serotype of an asymptomatic carrier of Hep B?
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They will be HBsAg positive, HBeAg negative, and viral DNA negative
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What is a common treatment for patients with chronic Hep C and fulminant liver disease?
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Liver transplantation; hepatitis can recur after the transplantation
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What is the range of symptoms possible for a Hep B infection?
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They can range from asymptomatic to fulminant hepatitis, chronic Hep B with long term outcomes of chronic active hepatitis being cirrhosis and hepatocellular carcinoma
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