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131 Cards in this Set
- Front
- Back
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rotavirus:
-family -morphology -genome |
rotavirus:
-reovirus family -naked icosahedral -segmented, dsRNA |
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major worldwide cause of serious gastroenteritis?
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human rotaviruses
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rotavirus seasonality?
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winter in southwestern states to spring in northern and eastern states
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rotaviral gastroenteritis treatment options?
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-ORT (oral rehydration therapy)
-IV |
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what is ORT?
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90 mmol/L Na with glucose, effective and economical alternative to IV
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rare complication of rhesus rotavirus-derived vaccine?
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intussusceptions
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which vaccine did 'post licensure' safety evaluation show to have complications?
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rhesus rotavirus-derived vaccine during first year in 1999
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describe currently licensed pentavalent live-oral vaccine for rotavirus
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reassortant of non-pathogenic bovine rotavirus substituted with dsRNA segment from human rotavirus encoding major serotypes of capsid proteins
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describe recently licensed live-attenuated monovalent vaccine for rotavirus
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monovalent live-attenuated oral human rotavirus with major G1 and P1A[8] serotype
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norovirus:
-family -morphology -genome |
norovirus:
-calcivirus family -naked icosahedral -ss(+)RNA |
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major cause of viral gastroenteritis in older children and adults?
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norovirus
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norovirus transmission?
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contaminated food or water, feces or emesis; not commonly human to human
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major norovirus symptoms?
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vomiting with or without diarrhea
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HAV:
-family -morphology -genome |
HAV:
-picornavirus family -naked icosahedral -(+)ssRNA |
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HBV:
-family -morphology -genome |
HBV:
-hepadnavirus family -lipid enveloped icosahedral -circular DNA, partial ds/partial ss |
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HCV:
-family -morphology -genome |
HCV:
-flavivirus family -lipid enveloped icosahedral -(+)ssRNA |
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HDV:
-family -morphology -genome |
HDV:
-hepatitis D (delta) family -lipid enveloped -(-)ssRNA circular |
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HEV:
-family -morphology -genome |
HEV:
-currently unclassified -naked icosahedral -(+)ssRNA |
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viral antigens of HBV?
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HBsAg, HBcAg, HBeAG
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HBsAg description, clinical measurement, and significance?
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surface antigen, antigen-capture (+) demonstrates active infection
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HBcAg description, clinical measurement, and significance?
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core antigen, IgM-capture ELISA for anti-HBc distinguishes recent versus chronic infection
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HBeAg description, clinical measurement, and significance?
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e antigen related to core protein, PCR or bDNA to determine HBeAg for viral load and infectivity
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HDV requirements for infectivity?
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simultaneous infection with HBV because carries HBsAg and requires it for production of infectious virions
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current viral enzyme targets for hepatitis viruses?
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-reverse transcriptase of HBV
-protease of HCV |
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major route of transmission for HAV?
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fecal oral
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major route of transmission of HBV?
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blood-borne/parenteral, sexual, perinatal
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major route of transmission of HCV?
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blood-borne/parenteral
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major route of transmission of HDV?
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blood-borne/parenteral, sexual, perinatal
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major route of transmission of HEV?
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fecal oral
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serological diagnosis for HAV?
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IgM-capture ELISA positive indicates current or recent infection
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when is anti-HBs IgG useful?
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to insure protective response to vaccine
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preliminary serological diagnosis for HCV?
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anti-HCV ELISA (+)
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confirmatory test for HCV?
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RIBA (recombinant immunoblot assay)
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how is RT-PCR or bDNA used for HCV?
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-blood banking to reduce false (-)
-quantitative for predicting disease progression and monitoring therapy |
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vaccine for HAV?
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IG or inactivated vaccine
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how is the IG for HAV used?
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-individuals traveling to foreign countries with poor sanitation
-non-immune with recent exposure |
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when must IG for HAV be given?
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within two weeks of exposure
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describe vaccine for HBV
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recombinant subunit of HBsAg
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why is administration of HBV vaccine important to infants?
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high rates of chronicity
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protocol for a baby with a HBsAg(+) mother?
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passive immunization with HBIG at one site with dose of HBV vaccine at different site
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vaccine for HDV?
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same as HBV
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preicteric phase of acute viral hepatitis duration and symptoms?
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3-10 days; malaise, anorexia, lethargy, pain in UR quad
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icteric phase of acute viral hepatitis duration and symptoms?
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1-3 weeks; jaundice and dark urine
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convalescent phase of acute viral hepatitis duration and symptoms?
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weeks up to 6 months; malaise and fatigue
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how distinguish different hepatitis viruses?
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serology and epidemiological features
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where is HEV common?
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India, Asia, Africa, parts of Latin America
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serious consequence of HEV infection?
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HEV hepatitis in pregnant women in developing countries has much higher mortality rate of ~20% than in the general population
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consequence of age to development of acute or chronic hepatitis with HBV?
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most newborns become chronic whereas most adults have acute infection
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long term outcomes of chronic hepatitis?
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high risk of developing cirrhosis or primary hepatocellular carcinoma
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therapy for chronic HBV infection?
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pegylated rIFN-alpha and/or lamivudine
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therapy for chronic HCV infection?
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combination ribavirin and pegylated rIFN-alpha
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how is effectiveness of therapy measured for HCV?
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RT-PCR or bDNA
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why is genotyping helpful to therapy in HCV?
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some genotypes have better response to therapy than others
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monitor effectiveness in HBV therapy?
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PCR or bDNA
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monitor effectiveness in HDV therapy
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RT-PCR
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what may help prevent recurrent infection with HBV following a liver transplant?
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immunoprophylaxis with HBIG
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when is a liver transplant indicated?
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for fulminant viral hepatitis or chronic viral hepatitis
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what does HTLV-1 cause?
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adult T-cell leukemia/lymphoma (ATL)
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which viral protein of HTLV-1 enhances cell proliferation?
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Tax protein
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what is the role of the Tax protein in development of cancer?
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transcriptional transactivator of IL-2 receptor and IL-2
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is site of proviral DNA integration important in HTLV-1?
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no, exact site of proviral integration is not important but tumor arises from a single modified cell
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what two cancers are associated with EBV?
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endemic Burkitt's lymphoma and nasopharyngeal carcinoma
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what cell type is associated with endemic Burkitt's lymphoma and what geographic area has the highest incidence?
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B cells; Africa
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what cell type is associated with nasopharyngeal carcinoma and what geographic area has the highest incidence?
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epithelial cells; southern China
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what is the viral etiology of vast majority of worldwide cases of Kaposi's sarcoma?
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infection with HHV-8/KSHV combined with AIDS due to HIV-1 infection
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what are the major causes of worldwide primary hepatocellular carcinoma?
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chronic infection with HBV or HCV
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where is there strong geographical correlation of persistent HBV infection and liver cancer?
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China, Southeast Asia, Sub-Saharan Africa
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which viruses are the cause of the majority of cases of cervical carcinoma?
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HPV-16 and -18
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HPV-16 and -18 are associated with which cancers?
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cervical, penile, vulvar, possibly tonsils, lower tongue, upper throat
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what is the oncogenic mechanism of HPV-16 in cancer?
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E6 and E7 binding of cellular tumor suppressor/anti-oncogene proteins
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what are E6 and E7?
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viral non-structural proteins that bind cellular tumor suppressor/anti-oncogene proteins
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what is mechanism of E7 viral protein?
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bind retinoblastoma gene product (p105-RB) inactivating it to mimick loss of RB1 gene seen in persons with genetic predisposition to retinoblastoma
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what is mechanism of E6 viral protein?
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binds to wild-type p53 protein
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what alters susceptibility to cervical cancer?
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polymorphism in p53 gene sequence resulting in Arg; 7x higher risk in Arg/Arg homozygous
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what viral gene product of HBV is important to oncogenesis?
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X protein = HBx
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what viral gene product of HCV is important oncogenesis?
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C (core) protein
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lymphocytic choriomeningitis, Lassa, Machupo, and Junin viruses are part of what virus family and what distinguishes them?
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arenaviridae; zoonotic using rodents as natural animal reservoir and amplifying host
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what is the geographic distribution and associated syndrome of lymphocytic choriomeningitis virus?
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US and Europe causing meningitis or meningoencephalitis
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what is the geographic distribution and associated syndrome of Lassa virus?
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West Africa causing hemorrhagic fever with hepatitis in severe cases
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which virus has deafness as a major complication in 1/3 of cases?
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Lassa virus
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what is the geographic distribution and associated syndrome of Machupo and Junin viruses?
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South America causing Bolivian and Argentine hemorrhagic fever, respectively
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what family do ebola and marburg viruses belong to?
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filoviridae family
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what disease do ebola and marburg viruses cause?
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hemorrhagic fever with high fatality in humans and primates
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what is the natural reservoir for marburg virus?
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fruit-eating bats
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morphology of filoviruses?
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pleomorphic and sometimes long virions, lipid enveloped with helical nucleocapsids (-)ssRNA
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what was the major route of human-to-human transmission of ebola virus in outbreaks of this viral disease in sub-Saharan Africa?
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contact with blood or blood-contaminated body fluids
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morphology of hantaviruses?
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lipid enveloped, helical nucleocapsid, segmented (-)ssRNA
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what are the natural hosts of hantavirus?
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rodents; exhibit no symptoms from chronic viral infection
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how is hantavirus spread to humans from its natural host?
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inhalation or direct contact with virus shed in rodent excreta
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what disease does hantavirus cause?
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generalized infections with high morbidity and mortality
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what unique clinical syndrome and countray are associated with Hantaan virus?
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HFRS [hemorrhagic fever with renal syndrome] in Korea
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what unique clinical syndrome and country are associated with Sin Nombre virus?
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HPS [hantavirus pulmonary syndrome] in the US from deer mice
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what does HPS manifest as?
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febrile with bilateral interstitial pulmonary infiltrates and respiratory compromise requiring supplemental oxygen developing in previously healthy person
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what specific assays were developed to diagnose Sin Nombre and related viruses in suspected cases of HPS?
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RT-PCR or immunohistochemistry of lung tissue and ELISA to detect anti-hantavirus IgM or IgG in serum
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why do arboviruses require reservoirs and amplifying hosts?
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humans are dead-end hosts for most arboviruses
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what is the major worldwide cause of arboviral disease in humans?
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mosquito-borne dengue virus type 1-4
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what family do dengue virus type 1-4 belong to?
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flaviviridae
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what is the danger of immunity against one serotype of dengue virus?
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immune-mediated, antibody-dependent enhancement resulting in more fatal dengue hemorrhagic fever of dengue shock syndrome
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what is the pathogenesis of immune-mediated, antibody-dependent enhancement in the subsequent infection with a different dengue serotype?
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cross reacting antibodies to the new serotype (that do not neutralize it) form complexes binding Fc receptors on macrophages are consequently endocytosed and introduced into a cell that would normally not be infected to cause more serious disease
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what family does the yellow fever virus belong to?
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flaviviridae
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what clinical conditions are associated with yellow fever virus infection?
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hemorrhagic fever, hepatitis, and nephritis
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what is the jungle cycle of YFV?
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monkey-mosquito-monkey
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what is the urban cycle of YFV?
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human-mosquito-human
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what are the symptoms of arboviral encephalitis?
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neurological disease with same symptoms of meningitis progressing with lethargy, confusion, seizures, paralysis, prior to coma and death in most serious cases; often non-fatal have residual neuropsychiatric sequelae
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who has the highest risk of clinical CNS disease following infection with arbovirus causing encephalitis?
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elderly
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what are the reservoirs/amplifying hosts of mosquito-borne arboviral encephalitis in the US?
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avian species?
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what family does west nile virus belong to?
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flaviviridae
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what are the major causes of arboviral encephalitis in the US?
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west nile virus, california serogroup/la crosse virus, st. louis encephalitis, eastern and western equine encephalitis viruses
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what family does the california serogroup/la crosse virus belong to?
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bunyaviridae
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what family does st. louis encephalitis virus belong to?
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flaviviridae
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what family do eastern and western equine encephalitis viruses belong to?
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togaviridae
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what family does Japanese encephalitis virus belong to?
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flaviviridae
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what is the major cause of arboviral encephalitis in Asia?
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japanese encephalitis virus
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what are animals serve as reservoirs for the japanesse encephalitis virus?
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pigs and avian species
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what vaccine is recommended for travel to YFV areas?
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live attenuated YFV vaccine
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what is recommended for those planning on residing in Asia for one month or longer to prevent against JEV?
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new version of inactive JEV vaccine produced in cell culture rather than mouse brain
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what is useful in predicting where specific arboviruses will be a significant problem in humans?
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serological assays of sentinel birds to detect antviral antibody is used in surveillance
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what does it mean that recombinant viral vectors are infectious but replication defective viruses?
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all replicative gene have been removed and replaced by a transgene --> recombinant virions are able to enter the cell but do not encode the machinery to replicate
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what are packaging cell lines?
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recombinant plasmids containing transgene are packaged by cell lines that constitutively produce genes for replication but lack sigma so cannot themselves be packaged
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what is the major advantage of retroviral vectors?
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efficient integration of genome DNA into chromosomal DNA
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what are the essential viral sequences which must be present in plasmids used in construction of retroviral vectors?
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upstream and downstream LTR sequences, and sigma RNA packaging sequence
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morphology of flaviviruses?
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lipid enveloped, icosahedral capsid (+)ssRNA
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morphology of togaviruses?
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lipid enveloped, icosahedral capsid (+)ssRNA
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morphology of bunyaviruses?
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lipid enveloped, helical containing 3 segments of (-)ssRNA
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what is the advantage of the newer lentivirus vectors as compared to murine retrovirus derived vectors?
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integration of proviral DNA in non-dividing and dividing cells versus only dividing cells for murine viruses
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what is the advantage of newer 'pseudotyped' retroviruses as compared to murine viruses with amphotropic env protein?
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increased virion stability and extended host range with the rhabdovirus envelope glycoprotein replacing the retrovirus env protein
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what is a biosafety risk of retro/lentivirus vectors?
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insertional mutagenesis
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what are the major differences between adenoviral and retro/lentiviral vectors for gene therapy?
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lack of integration of adenoviral DNA into chromosomes and increased capacity for larger cDNA/transgene sequences in recombinant adenoviral genomes
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what is a clinical disadvantage of first-generation, E1 gene-adenoviral vector?
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leakiness of viral gene expression which allowed development of cellular immune response (anti-viral CTLs), thereby eliminating cells containing the recombinant adenoviral genomes
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what is the major advantage of recombinant parvovirus vectors derived from adeno-associated viruses (AAVs)?
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viral DNA persistence in nucleus and/or integration into chromosomal DNA in absence of adenoviral help
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what is the major disadvantage of recombinant parvovirus vectors derived from adeno-associated viruses (AAVs)?
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small size of genome limits size of cDNA/transgene
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