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21 Cards in this Set
- Front
- Back
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What are the physiological manifestations of VZV? How is this virus transmitted?
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Chicken pox and Shingles (reemerging disease)
Disease is transmitted by coughing + sneezing (only herpes virus transmitted this way) |
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VZV infects the ________ and ________?
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Skin and mucosa of the respiratory tract and progresses through the blood + lymphatic system to the cells of the reticulo-endothelial system.
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What is the 1st sign of chicken pox? What happens after a primary VZV infection?
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Exanthematous rash
After a primary VZV infection, the virus will remain latent in the dorsal root ganglion |
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How does one get shingles? What population is most vulnerable to getting shingles?
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Shingles is a reactivation of the VZV virus that has been latent in the dorsal root ganglion.
The onset is more common and severe in the immunocompromised. |
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What is the clinical picture of Shingles? What population is most vulnerable to shingles?
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Vesicular rash that follows a nerve on one side of the body
Those with HIV or the immunocompromised |
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How are shingles contracted?
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Shingles can ONLY be contracted as a reemergence of VZV, it cannot be transmitted to someone who has shingles OR someone who hasn't had an initial VZV infection.
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What drugs can be prescribed for herpes viruses? How is it administered? What is it used for?
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-Acyclovir (GUANOSINE analog)
-oral, IV, or topically -treatment or prophylaxis |
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What is the mechanism of action acyclovir?
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It is a chain terminator: it works by adding a monophosphate to acyclovir (AC) which is then converted to AC-GTP + is incorporated into viral DNA and acts as a chain terminator + inhibits DNA polymerase so that there can be no further addition of nucleotides to viral DNA.
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What are the unanticipated results of the VZV vaccine?
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MILD, breakthrough varicella
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What are the differences and similarities in the clinical picture of HSV1 + HSV2?
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-both HSV-1 + HSV-2 lesion look the same, both cause latent infections, both affect the mouth, pharynx, + genitals
HSV-1: above the waist HSV-2: below the waist |
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What diseases do HSV-1 cause?
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-Cold sores on mouth, lip, eye (keratinitis), gladatorium (from wrestling), rugbeiorum (seen in contact sports like rugby), causes genital herpes in 10% of cases.
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What can cause HSV-1 reactivation?
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-immune suppression by cytotoxic drugs
-sexual transmission -physical/emotional stress -temp changes (hot or cold)/too much UV menstration/lactation/malnutrition -excessive fatigue |
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Explain the process of viral replication + latency of an HSV? What cells are infected? What is the latency site?
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Viral replication is initially lytic replication inside epithelial cells --> then they move into sensory neurons and move in a retrograde fashion up the axon to the ganglia where it is stored latently.
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What gene transcripts are involved with latency? When do they become activated?
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LATS: become activated when a source of stress presents itself --> the virus returns back to the lytic phase --> then there is an infection of the initial site of infection
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What is the role of the glycoproteins on herpes viruses?
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They are used for molecular mimicry + to help evade the host immune system
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What type of DNA is found in herpes viruses? What causes the autoimmune type reaction seen in herpes viruses?
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-Linear dsDNA
-Because of the cellular proteins that they take with them when they invade cells, and when you respond you will have an autoimmune type response |
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What is the function of the amorphus proteinaceous tegument?
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functions as a glue that holds the envelope in close contact
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How are herpes viruses transmitted?
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Either by direct contact with mucous membranes or secretions of an infected person (lips, genitals).
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What is the major goal of the viral genome? How are these goals acheived?
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To increase the number of nucleotides in a cell to continue to replicate the viral genome. --> GOOD TARGETS FOR ANTIVIRAL DRUGS!
50% of HSV genes encode regulatory proteins involved in latency + evading host immunity. |
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How do herpes viruses infect cells?
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-the virus attaches to cells of the epidermis or dermis + bind to receptors and proteins located on the surface of the virion
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Which viral proteins participate in entry of the virus into cells?
What receptors aid in the entry of the herpes virus? |
gB, gC, gD, gH, and gL
HVEM: usually binds TNF, but glycoprotein D binding here can also facilitate its entry. Usually on lymphoid cells. Nectin 1+2: usually for immune cell defenses, but can bind herpes virus. On skin, brain, + spinal cord. |
