Doing everything you can to avoid spreading disease is among the most basic requirements of membership in a civil society. It has been for millennia.
Trying to prevent the transmission of pathogens explains the laws in Leviticus, the development of modern sewer systems and the use of quarantine to stem epidemics.
Throughout history, a person’s duty to prevent the spread of disease to his neighbors has been so fundamental that it has been largely uncontroversial. Then came modern America, which is in the middle of an entirely preventable measles outbreak.