Feb 26 2014 - Viral Pathogens, Influenza Flashcards
What are you looking for with an EIA (Enzyme ImmunoAssay)?
Color change, which indicates the presence of an antigen
What is the most sensitive and specific test for identifying a viral infection?
PCR
What drug do you commonly use to treat a herpes virus?
Acylcovir
What does a HSV-1 or HSV-2 vesicle look like?
Clear fluid bubble with red base - painful!
Is initial contact or reactivation the disease-causing part of herpes?
Reactivation - Sx = lesions, fever, anorexia
What is gingivostomatitis?
Herpes lesions/manifestations in the FRONT of the mouth and tongue
What is herpetic whitlow?
Herpes-inoculated finger via contact (healthcare workers)
What is herpes gladiotorum?
Other herpes skin lesions via contact - think ears, neck, etc.
What is the difference between genital herpes lesions, syphilis ulcers, and a chancroid?
genital herpes: very painful, red, ulcerated
syphilis: hard and painless ulcers
chancroid: soft, painful ulcer, with lymph node involvement
What is herpes keratitis?
Dendritic lesions in the cornea (herpes virus reaches cornea from opthalmic br. of CN5)
Why is neonatal herpes an emergency?
Bc lesions in the skin, eyes, and mucous membranes will often lead to CNS issues and Disseminated (lethal) herpes
Can you pass on herpes in an asymptomatic phase?
Yes. Viral shedding happens often even with out Sx’s
How is herpes virus transmitted?
Through contact, sexual or otherwise, and mom to child
How is VZV (Varicella Zoster Virus) transmitted?
Via aerosol droplets or contact
What are some symptoms of initial VZV (Varicella Zoster Virus) infection?
Fever, cough, cropping/itchy rash (chicken pox)
What kind of vaccine is the chicken pox vaccine?
Live, attenuated (VAR), do not give to immunocompromised Pts
Can you pass on VZV (Varicella Zoster Virus) in an asymptomatic phase?
Nope :) There is no asymptomatic shedding
What are some symptoms of reactivated VZV (Varicella Zoster Virus) infection?
Shingles - so intensely painful, dermatomal rashes. Can cause neuralgia
What do you give 60+ y/o Pt’s to boost immune system against VZV?
Zostavax - a vaccine booster to prevent shingles
Is VZV immune response Ab or Tcell mediated?
Tcell mediated
Sx of EBV infection?
Fever, cough, mild HSM, lymphadenopathy
Where is EBV hanging out during a latent period? Is EBV infection curable?
EBV hangs out in B-cell lymphocytes, and once infected, always infected
Proportion of the population that will be infected with EBV by age 40?
90% (believe it. Also, yikes)
What do you look for on histologic slide with EBV?
Large, abundant, basophillic WBC cytoplasm
What does it mean if Pt has EBNA?
Pt had an active EBV a little while ago
How is CMV (Cytomegalovirus) transmitted?
Via contact, blood transfusion, transplant, being pregnant (?)
Which cells are infected with CMV?
epithelial cells, esp. in salivary glands and genital/urinary tract (shed in the urine)
Proportion of the population that will be infected with CMV by age 40?
50-80% will be carriers
Where does latent CMV virus hang out?
In MO, LY
Sx of CMV reactivation?
Asymptomatic unless immunocompromised (gotcha!)
Sx of Congenital CMV Syndrome?
Hearing loss, HSM, jaundice, “blueberry spots”
Which tests Dx CMV?
Serology for IgM and IgG, or PCR, or viral culturing, or direct fluorescence
What do you look for on histologic slide with CMV?
“Owl’s eye” intranuclear inclusion bodies
Tx for CMV?
Gancyclovir
What type of virus is RSV (Respiratory Syncytial Virus)?
enveloped, ssRNA
What do G and F proteins do for RSV (Respiratory Syncytial Virus)?
G protein = virus attachment
F protein = fusion of cells
How is RSV (Respiratory Syncytial Virus) transmitted?
Contact or aerosol
Sx of RSV (Respiratory Syncytial Virus)?
fever, runny nose, involvement of lower resp tract
Sx of Bronchiolitis?
congestion, cough, fever, decreased RR with retractions and pneumonia-like wheezing
Possible Tx for RSV (Respiratory Syncytial Virus)?
Supportive mostly. Also Ribivirin (expensive), Albuterol, or mAb to RSV’s F-protein
What type of virus is Rotavirus?
dsRNA with segmented genome
Sx of Rotavirus infection?
Vomiting, watery diarrhea, fever, abdominal pain for 3-8 days
What does Rotavirus do to the GI tract?
Kills and causes sloughing of microvilli on enterocytes (osmotic diarrhea)
What test to Dx Rotavirus?
ELISA assay on stool samples
Does Rotavirus cross-protect against Norovirus?
Nope. Damn, bc Norovirus is also crazy contagious
When is Influenza season normally?
December - March, with peak in February
What type of virus is influenza?
Segmented RNA virus
Type A influenza
Pandemic proportions - Severe in animals and humans
Type B influenza
Epidemic proportions - Less severe, humans only
Antigenic Drift
Small changes/muts that accumulate over time
Antigenic Shift
One large change, usually due to 2 viral genomes infecting the same host that co-mingle. (Type A Flu)
Influenza drugs that inhibit Neuramidase
Oseltamivir, Zanamivir
Influenza drugs that inhibit Influenza matrix
Amantidine, Rimantadine
Influenza Sx in neonates
high fever, mottling, apnea, GI issues, anorexia
Influenza Sx in adults
High fever, muscle aches, chills
FLAARDS?
Flu Acute Associated Respiratory Distress Syndrome
2009 Swine Flu was which strain?
H1N1
3 criteria for Pandemics?
1) Emergence of new subtype
2) Must infect humans & cause serious illness
3) Sustained transmission w/out interruption in humans
Influenza nasal vaccine is (live, dead) (trivalent, quadravalent)
Live attenuated, Quadravalent
Pt is febrile, with signs of focal process (redness, abscess). Bacterial or viral?
Bacterial (probably)
Pt has a high lymphocyte count. Bacterial or viral?
Viral (probably)
Pt has left-shift with elevated neutrophils. Bacterial or viral?
Bacterial
Pt. has blood-tinged sputum. Bacterial or viral?
Probably bacterial (pneumonia)
