Covid question, couldn't find answer to. How soon can you

[Laura PourMeADrink]

Test someone after exposure?

My dad had to go to hospital with back issues this past Wed. Doctor called my mom and said, " Well, we had him next a patient who got symptoms and tested positive. We moved your husband and will test him, results tomorrow"

Results were negative, he's home, but my mom still worried. Yet I can't find information where it says at what point a test picks up the virus.

IOW, if I am next to someone and pick it up, will a test show that 5 min after exposure and infection?

[TreasonousBastard]

1. I keep hearing that two weeks is the incubation period. This may change as they come up with...

newer techniques.

It also depends upon which test is used. And antibody test would have to wait until the virus takes hold.

[janterry]

2. The testing hasn't been particulary accurate

up to 30% (from what I see).

So, if I were him - I'd still isolate.

[hlthe2b]

3. No. There is incubation period before one would expect to show signs of infection &/orshedding virus

and thus positive on any antigen test.. Incubation time is variable, especially based on viral load, but median of 5.5 days, average 5.7 days and up to range 2-14 days. So the test COULD be positive anywhere from 2-14 days in someone truly exposed and then infected. The incubation period is the time when the virus is replicating and thus sufficient to be detected.

People like to say that PCR is so accurate it can detect the smallest amount of nucleic acid signaling a particular virus if it is there. IF IT IS THERE is the catch. Like saying we can detect a needle in a haystack if it is there. True as it goes, but you first have to locate (sample) the right section of hay where the needle exists. If the needle (virus in this case) were replicating, you'd have a much better chance of sampling the virus for confirmation and in the case of COVID-19 having sufficient viral load to trigger your body to react/produce symptoms as well.

[Laura PourMeADrink]

7. So you are equating incubation period to test efficacy.? If true

Then it wouldn't make sense to test until 14 days post exposure. To know incubation didn't occur.

[hlthe2b]

8. No. that is NOT AT ALL what I am saying. One could test positive as early as two days or as late

as 14 for some. That is the incubation period and the time when virus is replicating. Median is 5.5 days, average 5.7 days. That is why CDC recommends two repeated negative tests 7 days AFTER untreated fever breaks before considering one to have cleared the virus AND a full 14 day quarantine period for someone exposed.

A shortened incubation period of two days has been documented for some. Most likely that reflects a high dose exposure, but likewise differences in immune response within the individual.

If you experimentally inoculated someone with the virus and tested them IMMEDIATELY--without having had a prior exposure-- they should and would test negative unless the sampler accidentally picked up contamination from the environment).

[Laura PourMeADrink]

12. Thanks. What is odd to me is that there doesn't seem to be guidance on

the optimum time to test. Everyone talks about incubation periods but not "time to test" an exposed person. Obviously their hospital didn't. Or they would have isolated him for AT LEAST five days (median) and then performed the test.

Now he, my mom, and my two sisters are in the path.

Many suffer. And that includes those who live away from home and can't fly up to help.

[lapfog_1]

4. anywhere from 2 to 5 days

from exposure to positive antigen tests.

However that number is, at best, educated guesswork based on contact tracing.

If you doctor had your father sit next to another person ( symptomatic or not ), then you should sue for malpractice.

The doctor's office should ASSUME that every person walking through the door is a carrier, social distancing should be enforced... masks required ( and, if possible, provided ), wipes provided for every surface you might touch with instructions to clean before touching and as you leave the waiting area or exam room.

They started doing drive through tests for a reason... and wasn't just because it was fast and convenient.

[Laura PourMeADrink]

6. So if they tested him the day of or day after exposure it was

Too soon?

[Igel]

9. Almost certainly.

Possible after a couple of days.

Incubation is different when when you'd test positive. You can test positive and never show symptoms; incubation is from exposure to symptom onset. But one day is too soon, probably not enough virus load to show up in tests. (Viral growth in a body is also exponential.)

[Laura PourMeADrink]

10. Well that's devastating news. I just hope and pray he

And my mom don't get it. Cruel beyond words.

[Mike 03]

5. Kick and Rec for info. nt

[LisaL]

11. Incubation period is 2 to 14 days.

So the test that was done on your father is not going to be positive if taken right after exposure.
Doctor has to know that, did he not tell that to your father?
If you could test somebody right away and get valuable results, there would be no reason for people to quarantine for 14 days.

[Laura PourMeADrink]

13. My dad's 98 and has had dementia for the last, maybe

Five years, really bad the last couple months compared to when I saw him at xmas. No visitors allowed at hospital. So there was zero info. Doctor didn't even call my mom for 3 days.

Doctor that called said they tested him and if he was positive he would have to go straight to a nursing home. Of course, they are all fucked up now too. Every nursing home in CT has numerous cases.