PCR tests can come back positive for several months post-infection, so there may be no point in testing people in that post-infection period, because it will come back with too many false positives to be useful. 180 days sounds long for that, but people do test positive for months sometimes.
The reason you can test positive for so long is that it takes time for remnant RNA from the virus to totally leave your system, and even though it's not replicating (you aren't infected or infectious), the PCR test is just detecting the RNA.
The reason you can test positive for so long is that it takes time for remnant RNA from the virus to totally leave your system, and even though it's not replicating (you aren't infected or infectious), the PCR test is just detecting the RNA.