Around the world, special health workers are playing a part in efforts to prevent the spread of the coronavirus. They are serving as contact tracers. Contact tracing involves investigative and nursing skills, among others. Tracers seek information from COVID-19 patients about their contacts with other people. The goal is to create a map of every place an infected person has been and who they have met. Some countries have developed national systems. In the United States, programs are created by the states.