A determination of healthcare worker exposure to Mycobacterium tuberculosis in two Californian hospitals.
The US Centers for Disease Control and Prevention (CDC) recommends the prompt and sustained placement of potentially infectious tuberculosis patients in to negative-pressure isolation rooms, to help prevent other patients and workers, who remain outside of the room, from exposure to potential aerosols of Mycobacterium tuberculosis. The purpose of this study was to assess the potential for healthcare worker exposure to such aerosols and, to study compliance with the CDC guidelines. All room locations of culture-positive pulmonary TB patients were identified retrospectively for a one-year period at two hospitals. Placement in a negative-pressure isolation room was delayed for >24h after admission in 30% of 54 patients at hospital 1, and for 56% of nine patients at hospital 2. The median delay in isolation was three days at hospital 1, and five days at hospital 2. At hospital 1, of the 16 patients with delayed or no isolation, 14 (88%) were AFB smear-positive, and 12 (75%) were admitted to the hospital during the winter months. At hospital 2, of five patients with delayed or no isolation, two (40%) were AFB smear-positive, and four (80%) were admitted to the hospital during the winter months. The main reason for non-isolation was failure to initiate and sustain isolation for all suspect tuberculosis patients during the winter. These delays may reflect an insufficient number of isolation rooms to accommodate an increased usage of isolation rooms during the winter months. Delays in suspecting tuberculosis also contributed to non isolation. For 33% of the non-isolated patients, recognition of the diagnosis was delayed for three or more days. Patients were hospitalized on most adult inpatient wards, and virtually every hospital location that had these patients also had, non-isolated sources of mycobacterial aerosol. All workers were at risk of exposure, although the risk varied by hospital location, and should be tuberculosis skin-tested, at least annually. Suspect and known tuberculosis patients should be isolated until they are demonstrated to be non-infectious.
Public Health Institute, California Department of Health Services, Occupational Health Branch, Oakland, California 94612, USA. psutton1@dhs.ca.gov
P M
PM
Sutton
M
M
Mossman
F
F
Reinisch
R J
RJ
Harrison
D000328:Adult; D000336:Aerosols; D000391:Air Microbiology; D002140:California; D002487:Centers for Disease Control and Prevention, U.S. / Q000592:standards; D019983:Guideline Adherence; D006801:Humans; D017758:Infectious Disease Transmission, Patient-to-Professional / Q000517:prevention & control*; D010356:Patient Isolation / Q000592:standards*; D010564:Personnel, Hospital; D012189:Retrospective Studies; D013997:Time Factors; D014376:Tuberculosis / Q000517:prevention & control* / Q000635:transmission*; D014481:United States
D000336:Aerosols