I would like to add to the discussion that at some point a disease vector will enter the general population via a homeless source - in San Diego it was and is Hepatitis ---- and 'we' will all of a sudden have to really deal with the issue.  Instead of sit-lie bans and demonization, and bathroom closures ---- 'we' will have to be smarter and more humane than that.  I hope that 'we' will do better.  Our current "leadership" does not do well with forecasting ANYTHING......(http://www.cnn.com/2017/09/14/health/hepatitis-a-outbreak-san-diego-county/index.html)