The Council of Nicea decreed in 325 AD that every city with a cathedral should also establish a hospital, because pilgrims were frequently sick when they arrived. The underlying word for hospital, hospitality, host, hostel, and hotel is "hosp," which is Latin for "traveler." Religious groups staffed hospitals. Priests heard confessions and baptised babies. Hospitals provide care for people who are injured or sick without knowing exactly how they will be treated. A surgeon performs operations to repair or replace organs damaged by disease or injury. A physician treats diseases and symptoms not yet diagnosed by other doctors as well as providing long-term care. These physicians are called "hospitalists" because they manage the medical needs of everyone living within the walls of a large building, such as a hospital or nursing home. In the United States, most hospitals were established due to the need for medical care that was outside the scope of practice of local doctors. In 1847, only two out of every 100 Americans was not exposed to tuberculosis. By 1952, this had reduced to eight cases per 100,000 people. However, by 1978, this rate had increased to 133 cases per 100,000 people. This increase can be attributed to improved diagnosis and treatment options for TB, but it also shows how far modern medicine has come since 1847. Nowadays, hospitals play an important role in treating some types of cancer.