Then you can take a flight, go to a hotel for one night, use a test, and probably find out pretty quickly (I’d guess either within an hour or within a day but I don’t know) whether you’re infected.
I’m going to look into myself, if not, but does anyone happen to know how soon after exposure a test will show positive for COVID?
Another issue to consider is that the test could have a high false negative rate (I have seen reports as high as 15% - e.g. https://www.npr.org/sections/health-shots/2020/04/21/838794281/study-raises-questions-about-false-negatives-from-quick-covid-19-test), and it appears that false positives are more likely for asymptomatic people.
Hm. That seems pretty relevant.
It also matters if (or rather, how much) the false positives correlate. If they are close to being independent samples, then you could take two tests or more tests to increase your confidence.
But if false positive are more likely for asymptomatic people, then the tests must be at least somewhat correlated.
I saw guidelines along the lines of “You can stop self-quarantining if you had two negative tests taken more than 24hrs apart, with first test at least 3 days after an exposure”. I do not know where this came from, but I saw it from an org that I would expect to be fairly sane in making evidence-based decisions.
I am a bit confused what kind of test Ben is referring to here. If this is about smear tests, RKI says that it may be possible to show evidence for an infection about 2-3 days before symptoms begin. However, medical professionals warn that it’s not trivial to take the smear test and that therefore laypeople conclusions may lead to wrong negatives. If it’s about blood antibody tests, there may be false positives because antibodies may those formed against other corona virus infections.
According to Harvard //www.health.harvard.edu/diseases-and-conditions/if-youve-been-exposed-to-the-coronavirus
We also don’t yet know at what point during the course of illness a test becomes positive… you will get a false negative test result [on a swab test] 100% of the time on the day you are exposed to the virus. (There are so few viral particles in your nose or saliva so soon after infection that the test cannot detect them.)… About 40% of the time if you are tested four days after exposure to the virus
So this sounds like, with a smear or swab or saliva test, you’d want to wait up to 4 days after potential exposure, and a false negative remains possible.
I believe I’ve seen elsewhere that the saliva test is comparable to a swab in accuracy, but is more foolproof (because you don’t have to take a sample from your throat).