Herpes Viruses Flashcards
What is the structure of the herpes virus?
enveloped
dsDNA
linear
What are the herpes viruses?
HHV1/HSV1-Oral herpes HHV2/HSV2-Genital Herpes VZV EBV CMV HHV6/7 HHV8-Kaposi's Sarcoma HHVECHKO
What are some things that can be caused by HSV1? treatment?
cold sores
temporal lobe encephalitis
keratoconjunctivitis
gingivostomatitis
acyclovir or valacyclovir
Where does HSV1 lie dormant?
sensory neurons, trigeminal ganglion
What does HSV2 cause? treatment?
genital and some oral lesions
get multiple painful vesicles
acyclovir or valacyclovir
What is the transmission of HSV2?
sexual contact
birth vaginal
or in utero if primary infection
**lies dormant in sacral nerve root ganglion
What does HHV3 cause?
VZV
primary: chickenpox-transmitted via resp secretions
secondary shingles. single dermatome, does not cross midline, transmitted via direct contact
What is the treatment for VZV? Where does it lie dormant?
lies dormant in sacral nerve root ganglion
treatment: famicyclovir
What’s the deal with EBV?
mono
increased risk for lymphomas, nasopharyngeal carcinoma, oral hairy leukoplakia
**infects B cells via CD21
What is the usual presentation of EBV?
fever, HSM, pharyngitis (looks like strep, exudative), LAD, esp posterior cervical nodes
What is the important histo feature of EBV?
atypical lymphocytes (T cells)–>Downy cells: foamy w/ basophilic cytoplasm
How do you test for Mono?
monospot test, checks for heterophils antibodies to RBCs of sheep, horse, beef
If mono is misdiagnosed as strep throat, what could happen?
given amoxicillin for strep throat
get maculopapular rash
think allergic to pencillins when NOT
With heterophile - mono, what could it be?
CMV HIV Acute toxoplasmosis viral hepatitis strep throat
How is CMV passed on?
congenitally (TORCH)
sexual contact
saliva, breast milk, urine
transplant
What does CMV do in patients who have received bone marrow transplants?
IN patients with AIDS?
bone marrow transplants: life-threatening pneumonia
AIDS: retinitis, GI ulcers, Candida esophagitis (won’t respond to antifungals)
What is the histo feature w/ CMV?
Owl eye inclusion
Where does CMV remain latent?
in mononuclear and polymorphonuclear cells
What’s the deal with HHV6/7 infections?
Produce Roseola (6th disease)
high fevers
then diffuse macular rash
febrile seizures possible
What’s the deal with HHV8 infection?
Kaposi's sarcoma neoplasm of endothelial cells, spindle cells lining lymphatic and vascular vessels classic: slow growing HIV type immunocompromised, transplant patients dark/violaceous plaques or nodules
**treat w/ HAART, alitretinoin, vinblastine, daunorubicin, doxorubicin
Kaposi’s can also affect which things?
lungs-hemoptysis
GI tract
What is the tzanck smear?
multinucleated giant cells: HSV1, HSV2, VZV
What are the intranuclear inclusions you see w/ HSV?
Intranuclear Eosinophilic Inclusions
Type A Cowdry Bodies
Type 1 Cowdry Inclusions
Describe acyclovir and valacyclovir?
guanosine analog
it is activated inside HSV/VZV thymidine kinase
inhibits viral DNA pol
What does famiciclovir?
used for VZV preferentially, also guanosine analog and is activated by thymidine kinase
Ganciclovir?
guanosine analog
activated by CMV viral kinase
inhibits viral DNA pol
SE: bone marrow suppression and renal toxicity
**Treats CMV infections
Foscarnet?
doesn’t need to be activated
DNApol inhibitor AND HIV reverse transcriptase inhibitor
**good for resistant bugs
**can cause nephrototoxicity, anemia
