Characterizing and controlling sources of bioaerosols in health care facilities was discussed. Controlling the spread of airborne infections in health care facilities has received little attention until the reemergence of tuberculosis as a public health problem. It has been found that the specific knowledge base in this area is very weak and that control programs in many health care facilities are less than ideal. Attempts to improve infection control procedures in health care facilities have usually been based on extrapolation from other areas, particularly traditional industrial hygiene practices, rather than studies specifically tailored to the health care setting. Problems also arise because the major source of an infectious exposure in health care facilities is usually a person, typically a patient. Because the person moves around instead of remaining fixed in one place, as in an industrial setting, the source of infective exposure becomes very dynamic and the level of production of infectious aerosols varies unpredictably. This is in contrast to industrial sources which are usually relatively fixed and constant. The current state of knowledge of airborne infections in health care facilities was reviewed, including disease identification, the patient as a source of infection, evaluation of patient infectivity, miscellaneous sources of infection, and environmental sources of airborne infection. Droplet nuclei exhaled from infective patients are the major source of airborne infection, while exposure may also result from direct contact with patient wounds or abscesses. Effective control methods are based on identifying the source and controlling it. Source control starts with prompt identification of infectious individuals, usually based on clinical signs and symptoms, followed by confirmation by clinical and laboratory tests. Examples of source control methods include having patients cover their mouths when coughing and keeping infected patients in isolation areas. Immunization and screening of health care workers can also protect against being infected. Major issues and research gaps in identifying and controlling bioaerosols in health care facilities were discussed.
Proceedings of the Workshop on Engineering Controls for Preventing Airborne Infections in Workers in Health Care and Related Facilities, July 14-16, 1993, Cincinnati, Ohio