There's a possibility for false-positives. I think there's a type of test that looks for an enzyme that you could have without contracting the virus. I saw an article in HN this morning, but I can't find it anymore.

Also, false positives could happen as a result of bad logistics and management of the specimens.

Some useful sources that seem to validate the occurrence of false positives:

- This research on testing specifically calls out the fact that their method didn't yield false positives in trials: https://www.eurosurveillance.org/content/10.2807/1560-7917.E..., which seems to indicate that it's common for false positives to occur when developing testing methods for new viruses.

- This research talks about false positives in asymptomatic patients: https://www.ncbi.nlm.nih.gov/pubmed/32133832. "In the close contacts of COVID-19 patients, nearly half or even more of the 'asymptomatic infected individuals' reported in the active nucleic acid test screening might be false positives."

- This guy in Egypt is apparently a false-positive, likely due to a mismanaged testing protocol: https://www.livescience.com/matt-swider-stuck-in-egypt-coron...

I imagine with many tests, even at 0.1% eventually you'll get some false positive due to human error, or other things going wrong