Lecture 7 2/7/24 Flashcards
What are the two main ways of diagnosing an infectious disease?
-detection of agent or its components
-detection of antibodies elicited by an agent
What is sensitivity?
proportion of patients with the disease that test positive; true positives
What is specificity?
proportion of patients without the disease that test negative; true negatives
What is positive predictive value?
proportion of patients testing positive that have the disease
What is the negative predictive value?
proportion of patients testing negative that do not have the disease
What is robustness?
test’s capacity to be unaffected by minor variations in test conditions
What are the characteristics of spIN?
-if a test is highly SPECIFIC, trust the POS result
-used to rule a disease IN
What are the characteristics of snOUT?
if a test is highly SENSITIVE, trust the NEG result
-used to rule a disease OUT
Which type of test is good for screening?
sensitive
Which type of test is good for confirmation?
specific
What are the important factors involved in sampling?
-location specimen is collected from
-timing of collection
-proper transport/storage
What are some examples of send-out tests?
-PCR
-sequencing
-FA
-serum neutralization
-virus isolation/ID
-agar gel immunodiffusion
What are examples of send-out or in-house tests?
virology and serology testing
What is a direct test?
test that looks for the virus directly by identifying protein, nucleic acid, or live virus
What is an indirect test?
test that looks for the virus indirectly by identifying antibody responses