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22 Cards in this Set
- Front
- Back
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What virus causes roseola? What family does this virus belong to?
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*human herpes virus 6 (HHV-6)
*herpes viruses |
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What is the clinical presentation of roseola?
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*rapid onset of high fever and red rash which resolves in 3-5 days
*many cases may be asymptomatic |
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What is the structure of the roseola virion and genome?
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*icosahedral capsid with an envelope
*genome is dsDNA |
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What complications often arise from reactivation of latent roseola?
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In fact, there is no pathogenesis associated with reactivation of the latent form.
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How is roseola transmitted? Where does the initial infection and replication occur?
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*it is transmitted by salivary droplets, so close contact is required
*initial infection and replication is in the oropharynx |
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How common is infection with roseola?
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Nearly universal - the vast majority of infants are seropositive by 13 months, though most primary infections are subclinical or asymptomatic.
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How is roseola treated? What prevention is available?
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Treatment is usually unwarranted, but ganciclovir or acyclovir can be used in immunosuppressed patients. There is no vaccine.
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What is the causative agent of 5th disease? What is the structure of the virion and genome of this virus?
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*parvovirus B19
*naked icosahedral capsid surrounding one molecule of (+) or (-) ssDNA |
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Where does the virus that causes 5th disease replicate? What does its replication depend on?
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It replicates in the nucleus and must use the host cell's machinery...for this reason, viral replication occurs only when the host cell is in S phase.
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What is the childhood presentation of 5th disease? What symptoms might adults show? What happens with in utero infection?
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*peds have characteristic rash on face (and possibly trunk) and low-grade fever
*adults may have arthalgia due to deposition of Ag-Ab complexes following flu-like illness *in utero infections may cause spontaneous aboortion, though surving fetuses are usually unaffected |
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What population of patients are at risk for serious disease with infection by the virus that causes 5th disease? What condition is likely to occur?
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Parvovirus B19 can cause an aplastic crisis in patients with hemolytic disorders.
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The virus that causes 5th disease is specifically cytotoxic to what cells?
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Erythropoetic cells in the bone marrow, fetal heart and liver.
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How is the virus that causes 5th disease spread?
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Respiratory droplets.
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What family does coxsackie virus belog to? how many serogroups and serotypes of this virus exist?
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*picornavirus
*30 serotypes divided between 2 serogroups |
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Which serogroup of coxsackie virus generally causes more severe disease?
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*infections with serogroup B are more serious than those with serogroup A
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What is the viral and genomic structure of the coxsackie virus? Where in the host celll does this virus replicate?
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*naked, icosahedral capsid
*genome is one mole cule of (+) ssRNA *viral replication occurs in the cytoplasm |
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How is coxsackie virus transmitted?
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It can be transmitted by either the fecal-oral or repiratory route.
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What are some of the clinical presentations of infection with serogroup A of coxsackie virus?
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*herpangina
*hand, foot and mouth disease *aseptic meningitis (typically mild) *infantile diarrhea *usually less severe than group B |
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What are some of the clinical presentations of infection with serogroup B coxsackie virus?
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*myocarditis/pericarditis
*pleurodynia *respiratory or cardiac disease in neonates *typically more severe than group A |
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With what chronic disease has coxsackie virus been associated?
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Juvenile (type 1) diabetes mellitus.
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How does infection with coxsackie virus affect the development of immunity to other agents?
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Infection with coxsackie virus can interfere with the development of antibodies to other picornaviruses, most notably polio.
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What is the difference between a serotype and a serogroup?
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*members of a serotype will be neutrallized by the same antibody
*members of a serogroup will react to, but not be neutralized bby, the same antibody |
