I am surprised that you continue to maintain the stance of the locked gates at the in-between, for the truth of this situation is now, redundant, stupid, and merely hampers communication and travel between upper and lower.
The plague has already reached upper residential zones, it has already infected a number of people, a brisk walk there will show you that I am right.
The maintaining of the quarantine will only cost the lives of would be heroes, adventurers that this town so desperately rely upon when traveling via the dangerous route of the gate road.
One might argue you can use the Dunwarren lift, but I am sure there are some in the government who find this route uncomfortable, so it is with many citizens.
If you insist on maintaining the quarantine, post some guards who are given a description of the sick, and they can keep the sick out of upper sanctuary. Allow free travel once more.
May the truth of my words get through-
Truth Bringer Thrisa, Priestess of Savras.