UPDATE: Okay, a page or two further explains that the guards possibly missed the transfer of five folk from one ward to the other, but it doesn't explain why the five meals for the original six. Unless…knowing there is one man who is critically ill makes it all right to not provide him food. But this is speculation–good for the reader to do.
I'm notorious for overlooking details despite my close reading of a story, but one thing caught my eye.
There were originally six people confined in the afflicted ward, then in the morning, five more people that had been in the "possibly contaminated" ward and were thrown out to join the afflicted. That makes eleven total. Yet the accommodations of food left are for five people. Not six, as for the original group, nor had that group already eaten.
Things like this bug me.