Flashcards in L35_DNA Viruses 2 Deck (66):
Name some infections that herpesviruses cause?
Chickenpox, mononucleosis, Birth Defects, Cancer
How many human herpes viruses are there?
What strain is genital herpes, above the waist?
HSV 2 (genital)
HSV 1 (above waist)
describe the genome of herpes virus
How does herpes virus enter the cell?
It binds to surface proteins and fuses or is endocytosed.
Where does herpes virus capsid uncoat?
The nuclear pore
What happens to the herpesvirus genome when it enters the nucleus?
Describe the stages of transcription of herpersvirus
Immediate Early (Transcription factors), Early (replication proteins), Late (capsid proteins)
Where is the capsid formed for new herpes virus virions?
In the nucleus
What polymerase is used for replication of herpesvirus?
The viral DNA polymerase
How does Herpesvirus egress?
Do all herpesviruses have the same tissue tropism?
Where does herpesvirus get its envelope?
First from nuclear membrane, then it gets its tegument, then gets a second envelope from the trans golgi network.
Is the cell killed in the production of herpesvirus?
Not necessarily, cells can shed virions without being killed
What is the definition of latency
The genome is present in a cell but infectious virions are absent.
When does latency occur?
Immediately upon infection, before any symptoms present, this is why we can get rid of it once its there.
How is HSV1 spread?
Spread by close contact with active lesions or asymptomatic shedding
What type of infection usually occurs in children with HSV1?
Gingivostomatitis (lesions on mouth, face, nose, and eyes)
What cells does herpes virus become latent for life for both HSV1 and HSV2?
Neurons (terminal non-differentiated)
What is the prodrome of recurrent HSV1?
Tingling and itching
What can trigger an HSV1 recurrent outbreak?
Fever, sunlight, hormones, stress, physical trauma, etc.
Where do recurrent mouth lesions originate from?
What part of brain to HSV viruses tend to target?
The temporal lobe
What type of neurological infections can HSV cause in primary and secondary infections?
Primary- meningitis (stiff neck and headache)
Secondary- Encephalitis (Fever and Neurological symptoms)
How is HSV2 spread?
Spread by close contact between mucous membranes (genital and/or oral)
What are the symptoms of HSV2
many lesions, pain, itching, fever, malaise, headache (usually but not always below waist
Are double infections with HSV1 and 2 common?
How can you distinguish between HSV 1 and 2 in the lab?
Serology or PCR
Is there a way to control outbreaks?
Yes you can decrease or suppress outbreaks, many drug is Valtrex
Is there a vaccine for herpes simplex?
How can you prevent HSV spread.
Safe Sex, Avoid contact with clear outbreaks, use valtrex and famvir to prevent outbreaks
What disease can be a reoccurrence of varicella at a later age?
Shingles (Herpes Zooster)
What does VZV stand for?
Varicella Zooster Virus
How is VZV spread?
Aerosol transmission (highly contagious)
Where does VZV establish latency and when?
Dorsal root ganglion before rash appearance
What patterns do recurrent Herpes Zooster outbreaks follow?
Along the dermatome of the affected DRG.
Do opiates help with shingles?
NO because the nerve itself is affected
What are some complications of Shingles
Bell's Palsy, Postherpetic Neuralgia, retinitis
What are some complications of Chicken Pox?
Hepatitis, Encephalitis, Pneumonitis, Bacterial infection.
How is VZV diagnosed?
Clinical signs are distinctive, PCR, antigen, serology kits.
How are VZV and Zoster treated?
No treatment required for uncomplicated VZV. Zoster treatment only effective during first 3 days of outbreak
How can Varicella be prevented?
2 dose Varicella Vaccine. Can give a booster to patients over 50 to prevent Zoster.
How is Epstein Barr Virus transmitted?
What type of cells does Epstein Barr Virus infect?
Oral epithelial and B-cells in tonsils
Where does EBV stay latent?
In B-cells in tonsils
What is the most typical manifestation of EBV
What are the symptoms of mono
Fever, fatigue, sore throat, swollen lymph nodes, enlarged spleen
Who is must susceptible to recurrence of EBV
What type of sequelae does recurrent EBV cause?
malignancies, Oral Hairy Leokoplakia
How do you treat EBV?
You treat the symptoms because there are no antivirals for this virus
How do you test for EBV?
Clinical signs, serology for heterophile (react non specifically) antibodies, blood smears for elevated WBC and atypical lymphocytes
What does CMV stand for?
How does CMV enter body?
Many ways, just about all you can think of, its everywhere in the body
How does CMV manifest in most people?
50-95% are asymtomatic
People who do have CMV symptoms show what signs?
Looks a lot like mono but without sore throat. (Fever, Jaundice, diffuse lymphadenopathy, hepatosplenomegaly, rash)
What is one of the primary causes of deafness?
in utero CMV during gestation
What is the highest risk population for CMV
Pregnant women who have not had CMV before, leads to congenital CMV
Is there a vaccine for CMV?
Are there drugs that can be taken for CMV?
Yes but they are very toxic
What cells does CMV infect?
Immune, T-cells, macrophages
Where is Roseola latent
How is Roseola transmitted?
How does roseola present?
3 days high fever, followed by a faint rash on the trunk
is roseola rash contagious?
Is Herpes virus enveloped?