Virology Exam 3 (final) Flashcards
(27 cards)
testing precision
- repeating a test will produce same results (hit target every time)
- reproducibility/reliability
testing validity
- who does/doesn’t have the disease
- accuracy
calculate sensitivity
a (true pos)/ a+c (total diseased)
gold standard criterion format
left side: test (pos on top, neg on bottom)
top side: true disease status (diseased on left, not on right)
calculate specificity
d (true neg)/b+d (total not diseased
increase sensitivity of a test…
increase false positives
why choose a high sensitivity test
absolutely don’t want to miss a diseased animal
increase specificity of a test…
increase false negatives
why choose a high specificity test
confirm a diagnosis (do not want to have a false positive)
calculate PPV
a (true pos)/ c + d (total test pos)
calculate NPV
d (true neg)/c + d (total test neg)
benefit of a modified live or attenuated live vacc
get both Ab’s and a cell-mediated IR
benefit of a inactivate or killed vacc
can’t revert to virulence
4 dimensions of test validity
sensitivity
specificity
PPV
NPV
High prevalence = ____
increased PPV, decreased NPV
Bornaviridae
Borna disease
Proventricular dilation disease
Borna disease
- encephalomyelitis
- get intranasally –> CNS
- EQ have prodromal and neuro phase or subclin
Proventricular dilation disease
- avian bornavirus
- psittacines
- macaw wasting dz, proventricular dilation dz
- neuro signs, GI signs, generally fatal
Filoviridae
Ebola hemorrhagic fever
- primates, swine
- reservoir: egyptian fruitbat
- fever, GI signs, red eyes, rash, hemorrhage
- mining and tourists (zoonotic)
Bunyaviridae
- cache valley virus
- rift valley fever
- heartland virus
- crimean-congo hemorrhagic fever
- akabane dz
- schmallenberg virus
- hanta virus
Rift valley fever (africa)
- zoonotic
- culex and aedes transmit, or ingestion of meat
- hepatic and neuronal necrosis, splenomegaly
- acute bloody diarrhea, abortion storms in ewes, cows
Cache valley virus (north america)
- zoonotic (encephalitis)
- fetal defects like akbane dz
- sheep, goats
- res: deer, EQ, cattle
- transmit - anopheline and cluex mosquitos
- neuro, developmental defects or preg loss
Schmallenberg virus (europe)
- orthobunyavirus
- fetal defects, abortion, stillbirth, decreased production
- sheep, goats, cattle
- transmitted by culicoides & arthropods
Heartland Virus (missouri)
- phlebovirus
- blood stuff, pain
- humans
- transmitted by A. americanum
