A shift is confirmed only if everyone on it has, as of that day: a clear pre-employment report, a weekly specimen collected within the week, a monthly blood test within the month, the latest report clear, no open stop-work, and a work card that has not expired. Asked as of the shift's own day.
The name on the local work permit card — the name every specimen is labelled with — the card's expiry, and the test dates. Each test is recorded as collected on a date and reported clear or not clear. There is no field for what a report found, which test was positive, or anything else medical.
The next weekly specimen and the next monthly blood test for everyone working, worked out from the last collection. Anything already past its date is red: that worker is off the schedule until it is done and reported clear.
A report that is not clear means stopping work immediately. The stop starts on the day the report came in and stays open until somebody records the day work was allowed again, after a clear report. Nothing here says why — that is between the worker, the clinic and the health authority.