ORAggieFan said:
bigtruckguy3500 said:
You got tested too soon. High chance of a negative test any sooner than 7 days prior to last exposure, unless you have symptoms. In my opinion a test 4 days post exposure is meaningless. Urgent care should have told you this.
You disagree with the CDC. They say 7 days with a negative test within 48 hours of day 7 is good to go.
Maybe I'm misunderstanding the CDC or this situation, but this is how I understand it:
-The OP was exposed Saturday night, and was tested this morning - that's maybe 3.5 days. (most important point, I think)
-14 days is still the standard, however exceptions can be made under certain circumstances when other factors are considered, such as pretest probability, availability of resources, and community considerations
-You're considered contagious 48 hours prior to symptom onset (this number may drop, but I haven't seen it drop yet)
-There is a high likelihood of a false negative test prior to 7 days from last contact with an infectious individual
-The minimum recommendation is 10 days quarantine, or 7 days plus a negative test administered within 48 hours of discontinuation of quarantine
-The closer to the day 7 discontinuation of quarantine the test is done, the greater risk reduction is seen in transmission (CDC cites a study that states 24 hours)
- Considering incubation period is 2-14 days, with a median of about 5 days, and a test sensitivity of about 80% (or less, depending on the test used), if we assume 40% will show symptoms by day 3.5 (and symptomatic patients are equally detectable by PCR as asymptomatic) with 80% sensitivity, that's a 32% chance of detecting the virus (I'm sure that's not perfect statistics)
It's certainly a data point, and if positive would be meaningful. But I still think a negative test prior to 7 days isn't as meaningful as people want it to be.
A couple of the quoted articles from the CDC:
Quilty and Clifford
et al. - "They estimated that 14 days of quarantine without testing was approximately equivalent to 7 days of quarantine when a
specimen collected on the last quarantine day tests negative by RT-PCR."
Wells
et al. - "
testing performed within 24 hours prior to the date quarantine was discontinued."
"At community prevalences of 1%, 3% and 5%, the post-quarantine transmission risk at Day 7 of quarantine were 0.25%, 0.84%, and 1.38%, respectively, with a
diagnostic test that had 90% sensitivity."
Not sure how many diagnostic tests out there in the community have a 90% sensitivity.
