Seventeen birds will need a MUCH bigger coop and run, especially if there are roosters. Otherwise the hens' quality of life will be real low....
I have a 70 sq. ft coop and that's far too small for my 18 birds. But they have an 800+ sq ft run plus the snake fence, and that's ok in summer. In winter, much less so...
If the birds are carrying a low grade infection all the time, the laying will not be so good...
I'd also wonder about eating birds with low grade infections...
I'll add bars in the coop, but they don't spend any time there except to sleep. So far, all the birds sleep together on one of the three bars. The official run is 3000 square feet, but they range past that pretty often.
Everything I've read says the rate of lay will likely be affected and that it's not spread to humans.