"Phthisiophobia": The difficult recognition of transmission of tuberculosis to health care workers

Even if the contagious nature of tuberculosis was universally accepted during the nineteenth century, its transmission to health care workers (HCWs) was initially denied by the scientific community. Working among TB patients was not considered dangerous for healthy adults, so the potential risks for HCWs were branded as unwarranted "phthisiophobia" (fear of contracting tuberculosis). Objectives: This study aims at analyzing the problem of tuberculosis transmission among health care workers from an historical perspective, particularly highlighting the contribution made by the Italian Occupational Medicine community. Methods: Scientific literature and historical sources on different theories regarding tuberculosis transmission were investigated, specially focusing on the period at the turn of the 19th and 20th centuries. Results: At the beginning of the twentieth century, Luigi Devoto (1864-1936), an Italian pioneer in the field of Occupational Medicine, was one of the first scientists to conduct research on the transmission of tuberculosis among nurses. Since the 1920s several studies, conducted mainly on medical and nursing students, confirmed the risk for HCWs. However an international consensus on this issue was only achieved during the 1950s, when the institution of mandatory chest radiographs on admission for all patients significantly decreased the cases of tuberculosis among HCWs. Conclusions: Devoto was one of the first scholars who postulated the transmission of tuberculosis to HCWs. He also theorized that hospital personnel with active disease could also be a source of contagion to patients. Nowadays, "third party risk" and latent tuberculosis infection pose a new challenge for occupational physicians in hospitals.