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67 Cards in this Set
- Front
- Back
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What are the common features of herpesviruses?
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Enveloped
dsDNA Loves to be latent with recurrent infections during immunosuppression |
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What are the alpha group herpesviruses?
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HSV-1, HSV-2 and VZ
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What are the beta group herpesviruses?
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CMV, HHV-6, and HHV-7
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What are the gamma group herpesviruses?
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EBV and HHV-8
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What is the tropism of each herpesvirus group?
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alpha: neurotropic
gamma: lymphotropic beta: others |
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How do herpesviruses enter the cell?
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Receptor mediated entry
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What transcription products are released by the herpesviruses in immediate early, early, and late stages?
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IE: regulatory
E: enzymes for DNA replication L: structural proteins |
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HSV-1 and HSV-2 infect which cells? Where do they remain latent?
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Infect most cells and are latent in sensory ganglia.
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What unique protein product is made by the HSV-1 and 2?
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Protein which degrades cellular RNA and inhibits splicing
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How is HSV-1 and HSV-2 replication characterized?
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Rolling circle replication
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What allows herpesviruses to create a syncytia?
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Viral proteins expressed in the plasma membrane create a giant cell syncytia. This allows the virus to escape antibodies.
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What is required for herpesviruses resolution?
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Cell mediated immunity
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How is HSV-1 transmitted?
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Orally
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How is HSV-2 transmitted?
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Sexually
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What is more common, HSV-1 or HSV-2?
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HSV-1 (90% in underdeveloped areas have antibodies by age 2)
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Who is at risk for HSV-1 and HSV-2 infections?
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children and the sexually active
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What organs are most at risk with HSV-1 and HSV-2 infections? Who is at risk for complication?
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Eye and brain
Immunocompromised |
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What is the prevalence of the HSV-1 and HSV-2 in the population?
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HSV-1: almost everyone has it
HSV-2: almost half |
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When is HSV infection usually fatal?
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Neonates, transmitted from mom in vaginal tract
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What is the most common presentation of primary herpetic infection?
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Acute gingivostomatitis
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Following a primary oral HSV infection, 45% develop _____.
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Herpes labialis
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What drugs are used to control HSV outbreaks?
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acyclovir
valacyclovir penciclovir famciclovir |
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What disease conditions are caused by varicella-zoster?
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Chicken pox
Shingles |
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Where is VZ mainained in a latent state?
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Neurons
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Even though most are infected as children, what percentage of young adults are susceptible to varicella?
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10%
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What is the site of initial infection of varicella?
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respiratory tract
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Trace the pathogenesis of VZ.
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Respiratory tract to blood stream to lymphatic system to spleen and skin.
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What is important in limiting the spread of VZ?
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Antibody is important to limit viremia
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Who experiences complications of varicella infection?
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adults and immunocompromised could experience viral pneumonia, encephalititis, and hemorrhagic chicken pox.
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When does Herpes Zoster infections occur?
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Could be at any age, but mostly >50.
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What is the risk associated with congenital VZ virus infection?
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pneumonia
Has 3% transmission to fetus: scarring of skin, hypoplasia of limbs, CNS and eye defects, and death in infancy |
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What drugs are available for VZ control?
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Acyclovir, famciclovir, valacyclovir
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Describe the vaccine available for VZ.
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Live attenuated, effective as prophylactic treatment in people even after exposure
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EBV has limited tissue tropism, what receptor on what cell can it bind?
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Binds CD21 on B cells and epithelial cells of the oronasopharynx.
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What are the three outcomes of EBV infection?
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1. replication in B cells or epithelial cells
2. Latent in B cells 3. Transformation of B cells |
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What population is at higher risk for B cell transformation due to EBV?
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Patients with T cell problems (ie HIV)
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What genes are expressed in the lytic cycle of EBV? (4)
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Zta (ZEBRA)
EA: early antigen VCA: viral capsid antigen MA: membrane antigen |
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What EBV antigens have oncogene-like activity?
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EB nuclear antigen-2
Latent membrane proteins |
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What is the function of EBNA-1?
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To maintain the chromosome
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What diseases are caused by EBV?
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Mononucleosis and Burkitt's lymphoma
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Only after lysis of an EBV infected cell, will antibody be formed to which antigen?
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EBNA
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What amount of virus will persist for life after EBV infection?
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1 infected B cell/mL for the rest of your life.
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How is EBV transmitted? What percentage of infected people shed the virus?
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via saliva
>90% of infected shed the virus for life. |
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What is the prevalence of EBV infection in the US?
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70% by age 30
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What population is at risk for Burkitt's due to EBV?
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African children
Those with depressed T function (HIV/AIDS) |
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What is the symptomology associated with mononucleosis?
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[EBV infection]
Fatigue, fever, swollen glands, HSM |
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EBV increases the risk of what carcinoma?
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Nasopharyngeal carcinoma of epithelial origin
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What is the most common cause of congenital defects?
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Cytomegalovirus
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CMV in opportunistic in what patients?
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immunocompromised
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What group is CMV in?
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beta-herpesvirus
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HCMV replicates only in ______.
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human cells
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What cells maintain CMV in latent form?
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Bone marrow stromal cells
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How is CMV transmitted?
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organ transplant, urine, saliva, and semen
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What percentage of CMV infected people show clinical evidence of disease?
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10%
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What is the most common viral cause of mental retardation?
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Congenital CMV
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What disease conditions are caused by CMV?
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Congenital disease
CMV mononucleosis Reactive disease in immunocompromised: retinitis, pneumonitis, disseminated infection, death |
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What CMV infected population is at risk for retinitis? for pneumonitis?
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retinitis: AIDS
pneumonitis: transplant patients |
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What prophylactic drugs can be given to prevent CMV infection following transfusion/transplantation?
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acyclovir/ganciclovir
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HHV-6 and HHV-7 are in what group?
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beta-herpesviruses
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What are some features of HHV-6 and HHV-7?
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dsDNA
Target is T cells, and sometimes B cells Share limited antigenic cross-reactivity |
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How are HHV-6 and HHV-7 transmitted?
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via saliva and breast feeding
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What percentage of the adult population is infected by both viruses HHV-6 and HHV-7?
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90-99%
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What virus is responsible for Roseola Infantum? How is it treated?
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HHV-6: spiking fever and mild rash.
No antiviral treatment. Supportive |
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What disease is associated with HHV-7?
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none
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HHV-8 is in what group?
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gamma-herpesviruses
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Where was HHV-8 originally isolated?
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From Kaposi's sarcoma cells
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What group is at risk for HHV-8 infection?
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HIV/AIDS
Homosexuals |
