Respiratory Isolation for Tuberculosis: A Historical Perspective

Although tuberculosis is an ancient disease, recognition of its airborne route of transmission, with implications for respiratory isolation, is only relatively recent. Since the time of Hippocrates, the dogma among health practitioners was that the disease was hereditary or that it could be contracted by inhaling "miasma", or corrupted air. Consequently, isolation of patients was not routine practice, and, in fact, patients with scrofula (morbus regius, or "king's evil) sought to be cured by the "royal touch" throughout the middle ages. The sanatorium, which emerged in the mid-19th century, initially served as a place of healing, where patients could receive the appropriate diet, rest therapy, graduated exercise, and abundant fresh air. Major scientific breakthroughs, including Robert Koch's 1882 discovery of the tubercle bacillus as the disease's etiological agent and early 20th century experimental evidence that the organism could be transmitted via expectorated droplet nuclei, helped to reinforce the important public health role of sanatoria and tuberculosis hospitals in preventing disease transmission through isolation. The advent of highly efficacious and oral antitubercular regimens in the mid-20th century and the concurrent declining incidence of the disease contributed to the closure of tuberculosis sanatoria and hospitals in the US and western Europe. Over the past several decades, tuberculosis treatment in the US has been conducted in the outpatient setting under the supervision of local public health departments. Patients receiving treatment are required to remain in respiratory isolation in the home until they are deemed noninfectious based on multiple sputum samples. This historical review demonstrates that despite changing medical knowledge, drug therapies, and social conditions over time, the role of isolation remains an important topic of debate in the treatment of patients with pulmonary tuberculosis.