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52 Cards in this Set
- Front
- Back
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What kind of virus is HAV?
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Picornavirus
+ssRNA, naked |
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How is HAV spread?
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Fecal-oral
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What kind of infection is caused by HAV?
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Replicated in liver.
Symptoms similar to HBV. No chronic or carrier state. |
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How is HAV treated?
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No treatment.
Vaccine given routinely in childhood in communities with high rates of HAV hepatitis (Alaska natives and American indians). |
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Who is at risk for HAV infection?
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Travelers to high HAV-endemic countries.
Homosexual and bisexual men. Drug users. Persons with chronic liver disease. |
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What is shown in clinical lab tests for HAV infection?
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Anti-HAV = exposed, vaccinated
Anti-HAV IgM = recently vaccinated Increased ALT in acute infection. |
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What is HBV morphology?
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Hepadnavirus
circular - partial dsDNA - enveloped |
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How is HBV spread?
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Parenteral
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What are the antigens made by HBV genome?
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HBsAg = surface antigen on outer surface envelope
HBcAg = core protein - no labs HBeAg = DNA pol |
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Where is HBV found in the body?
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High - blood
Moderate - semen, vaginal fluid, saliva Low - urine, feces, sweat, breastmilk |
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Where is HBV infection highest?
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Present worldwide.
Found higher in developing countries. 80% of infants born to infected mothers will be infected! |
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What is histology of HBV infection?
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"ground glass" cytoplasm in hepatocytes
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What is used to diagnose HBV with immunostaining?
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HBcAg
HBsAg |
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What non-specific changes are seen with HBV infection?
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hepatocellular necrosis
portal inflammation fibrosis and cirrhosis |
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What does HBsAg indicate? HBeAg?
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HBsAg = active or chronic infection, carrier
HBeAg = highly infectios (virus is active and replicating) |
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What does anti-HBs indicate?
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Immunity due to vaccine or disease.
*anti-HBs is hard to detect. |
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What is present in chronic infection vs. acute infection with recovery?
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HBsAg will be present in chronic infection.
HBsAg is not present after recovery from acute infection; anti-HBc will be present in both. |
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What is the window in HBV acute infection?
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Anti-HBs has not developed and Anti-HBc IgM has disappeared.
--> Must measure total Anti-HBc |
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What correlates with chronic HBV infection?
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Chronic infection is more likely the earlier infection occurs. May be asymptomatic early then develop cirrhosis later in life.
Symptomatic infection more likely later in life. |
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How is HBV treated?
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Vaccine = required infant immunization and for susceptible groups
Treat: IFN alpha then lamivudine then Adefovir |
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What kind of virus is HCV?
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Flavivirus
+ssRNA - enveloped |
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How is HCV spread?
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Parenteral
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What is the likelihood of developing chronic disease from HCV?
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80% of those infected are chronic carriers; cirrhosis occurs in 20%
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What are the symptoms of acute illness with HCV?
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Mild illness - jaundice
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What is the histology of HCV infection?
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Portal dense lymphocytic infiltrate with follicle formation.
Lobar inflammation, Kuppfer cell hyperplasia, fibrosis, cirrhosis |
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What do clinical lab tests look for to diagnose HCV?
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Anti-HCV
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What are two ways to test for anti-HCV?
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ELISA for screening.
RIBA for conformation. Then do PCR to calculate viral load. |
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Is there an antigen test for HCV?
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NO.
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What is present in acute infection of HCV with recovery?
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High titer of anti-HCV
Normal ALT and HCV RNA |
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What is present in chronic infection with HCV?
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High titer of anti-HCV.
High titer of HCV RNA. Elevated ALT. |
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What are some factors that promote progression to chronic infection with HCV?
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Increased alcohol intake.
Age >40 at time of infection. HIV co-infection. Male. Other co-infections such as HBV. |
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What are the risks of aquiring HCV by occupational exposure?
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Inefficiently transmitted by occupational exposure.
Low incidence with needle stick, 10 times lower than HBV, no reports due to skin exposure to blood. |
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What should you do if you are exposed to HCV?
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Test source for HCV.
Test worker immediately to get baseline anti-HCV and ALT and then again 4-6 months later. Confirm all anti-HCV with RIBA. |
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What is the risk of perinatal transmission of HCV?
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Lower risk of transmission than HBV.
Only transmitted if women HCV-RNA positive at delivery. Not associated with method of delivery or breastfeeding. Infected infants tend to do well. |
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What is the risk of transmission of HCV sexually?
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Occurs but has low efficacy.
- no higher risks in MSM - low prevalence in long term partners - male to female is more efficient - accounts for 15-20% of acute and chronic infections probably only because sex is a common behavior. |
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Who is at increased risk for HCV infection?
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IV drug users.
Intranasal cocaine. Clotting factors before 1987. Blood/organs before 1992. Chronic hemodialysis. Evidence of liver disease. |
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How is HCV infection managed?
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Antiviral combination therapy
- IFN alpha, ribavirin Vaccinate against Hep A Counsel to reduce harm to liver, ie limit or abstain from alcohol |
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What can result if chronic hepatitis leads to cirrhosis?
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Hepatocellular carcinoma
Death Stable cirrhosis (50%) |
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There are 6 types of HCV, which is most common?
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Type 1 is most common and the most difficult to treat.
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What is HDV?
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Delta virus is a defective virus.
Requires HBV for replication = can prevent with HBV vaccine! circular ssRNA that has and HBV envelope and HDV core |
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How is HDV spread?
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Parenteral spread.
- illegal IV drug use - sexual contact |
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How does HDV effect HBV infection?
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Makes it worse --> leading to cirrhosis.
Should counsel HBV-infected persons against risky behaviors. |
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What is the difference in timing of HDV infection: at same time as HBV vs. after HBV infection?
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co-infection has severe acute disease but low risk of chronic infection.
Super-infection will usually develop chronic HDV infection and high risk of severe chronic liver disease. |
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How does serology differ in coinfection vs. super-infection?
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Coinfection: high anti-HBs after symptoms end and low or none anti-HDV.
superinfection: elevated ALT, High anti-HDV, HBsAg present. |
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What is HEV?
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Enteric virus in developing countries.
Norovirus (calciviridae) +ssRNA - naked |
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What are the clinical aspects of HEV?
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Similar to HAV.
Transmitted fecal-oral. Present in stool before symptoms occur. Symptoms disappear with appearance of antibody. |
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Who has a high mortality rate if HEV infected?
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Pregnant women.
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What are most outbreaks of HEV due to?
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Drinking fecally contaminated water.
Seen in U.S. if travel to HEV-endemic areas. |
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How do you treat/prevent HEV?
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Avoid drinking water, fruits, uncooked shellfish of unknown purity.
No treatment or vaccine. |
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What is HFV?
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Misnamed virus.
Most likely is HBV. |
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What is HGV?
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Flavivirus.
+ssRNA - enveloped |
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What is HGV similar to?
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Similar to HCV.
Parenteral spread - tattoos! |
