Smear negative TB patients are thought to be much less contagious than smear positive patients, but how much so? In this retrospective analysis from the Netherlands using a national DNA fingerprint database, researchers determined 13% of secondary TB cases were attributable to smear negative patients, and that the relative transmission of smear negative, compared to smear positive, patients was 0.24. This study implies that the “no-isolation needed” hospital standard for smear negative TB patients needs to be re-visited, and that the risk of transmission of smear negative patients is less than smear positive, but certainly not insubstantial (abstract)
Dr. Scheurer is a clinical hospitalist and the Medical Director of Quality and Safety at the Medical University of South Carolina in Charleston, South Carolina, and is Assistant Professor of Medicine. She is a graduate of the University of Tennessee College of Medicine, completed her residency at Duke University, and completed her Masters in Clinical Research at the Medical University of South Carolina. She also serves as the Web Editor and Physician Advisor for the Society of Hospital Medicine.