Contact tracing has been a cornerstone of public health for much of the past century, even before the novel coronavirus.

The history of contact tracing

Contact tracing has been in the news lately because of the important role it can play in slowing the spread of the novel coronavirus, but it has been a cornerstone of public health for much of the past century. In 1937, then-U.S. Surgeon General Thomas Parran wrote a book about syphilis control (melodramatically titled Shadow on the Land), in which he described contact tracing in detail. The practice has been a valuable tool ever since — for combating the spread of sexually transmitted infections as well as vaccine-preventable diseases such as measles and tuberculosis. Smallpox was defeated not by vaccinating entire populations, but by finding and vaccinating anyone who had been in contact with people who had the disease. Contact tracing has also played a part in the progress we’ve made against polio.