When we visited the office for the migrant workers they gave us a demonstration of how they explain to the men that no matter what a person looks like or what their profession is they might have HIV. The did this by putting pictures of men on the outside of the different bottles then filling all but one bottle with water and one with vinegar. They put litmus paper in each of them and the litmus paper that changed colors represents the man with HIV. I thought it was a great way to demonstrate it