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29 Cards in this Set
- Front
- Back
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Describe the structure of parvovirus B19. |
SSDNA Linear Non-enveloped |
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What is the target cell for parvovirus B19? |
RBC precursor in bone marrow Endothelium Placenta Fetal myocardium |
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Which virus causes erythema infectiosum/Fifth Disease/Slapped Cheek disease? |
Parvovirus B19 |
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What is the clinical presentation of Parvovirus B19? |
Viremia: fever, URI (coryza, pharyngitis), myalgias, reticulocytopenia, anemia Immune clearance: erythema infectiousum rash, arthralgia, resolution anemia |
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Describe the rash associated with parvovirus B19. |
Slapped cheek rash SpreadsWh from face to trunk and extremities Lacy reticular appearance |
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What are two possible complications associated with parvovirus B19? |
Aplastic crisis --> severe anemia in pts with underlying hemolytic disorder Chronic infections in immunosuppressed |
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What are the complications associated with fetal parvovirus? |
Hydrops fetalis myocarditis severe anemia |
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How is parvovirus diagnosed? |
PCR |
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What is the treatment for parvovirus, mumps and the measles? |
Supportive care |
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Describe the structure of measles and mumps. |
Paramyxovirus SSRNA, negative sense Enveloped nonsegmented |
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What is the clinical presentation of the measles? |
Prodrome (2-4 days) Sudden onset high fever with cough, coryza, conjunctivitis Koplik spots precede rash by 2-3 days Rash starts around face/hairline and moves down to trunk then extremities |
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How does measles infection lead to induced immunosuppression? |
Lymphopenia due to direct killing of lymphocytes and thymic stroma. Impaired Th1 differentiation and enhanced Th2 production. Cytokine release leads to apoptosis of T cells |
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What is the most common complication of the measles? |
otitis media |
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What are the most common causes of mortality in measles infections? |
PNA Encephalitis |
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How is the measles diagnosed? |
Clinical diagnosis Positive IgM or increase in IgG between acute/convalescent titers |
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Why is Vitamin A given to patients infected with the measles? |
Measles lead to depletion of Vitamin A stores, which is required with regeneration of epithelial and other cells. |
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What is an important immunogen in mumps? |
Envelope that contains hemagglutinin |
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What is the clinical presentation of mumps? |
Prodrome fever Mild URI (33%) Parotid swelling (70%) Headache Abdominal discomfort Morbilliform rash |
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What are common complications from mumps? |
Orchitis CNS involvement (meningitis, encephalitis) Oophoritis Pancreatitis Arthritis Myocarditis |
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Describe the structure of Rubella. |
Togavirus SSRNA, positive sense Non-segmented Envelope |
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What is the clinical presentation of Rubella? |
Asymptomatic (50%) Prodrome (1-3 days): fever, eye pain/redness, sore throat, GI symptoms, arthralgia Rash: begins on face, spreads to cover entire body Adenopathy (suboccipital) Arthralgia/arthritis Rare encephalitis |
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What is the clinical presentation of congenital rubella? |
Blueberry muffin rash Deafness Jaundice Cataracts Microcephaly Hepatosplenomegaly Miscarriage Lymphadenopathy |
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Why is MMR not given to pregnant women or women planning to conceive within next 3 months? |
Risk of congenital rubella infection |
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Describe the structure of HPV |
dsDNA circular non-enveloped |
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Which oncogenic HPV type accounts for 50% of cervical cancer? |
HPV 16 |
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How does E6 lead to degradation of tumor suppressor gene p53? |
E6 associated protein (E6-AP) forms trimer with p53 and E6, which causes ubiquitin to bind, leading to degradation of the trimer complex |
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What is the function of E2? |
It regulates E6/7 expression |
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Why is E2 function lost once the virus enters the host? |
HPV has circular DNA, which must break to linearize and enter host DNA. Virus typically breaks in E2 region, rendering it nonfunctional |
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What is the immunogen in HPV vaccine? |
Capsid proteins |
