I. Introduction
In January 1992, the CDC Tuberculosis Working Group asked that NIOSH "take the lead" in developing guidelines for appropriate personal respiratory protection, i.e. respirators, to protect workers in health-care facilities from occupational transmission of tuberculosis. In addition to consideration of the complex technical issues of respiratory protection which follow, NIOSH personnel also gave careful thought to our understanding of the current epidemiology and control of tuberculosis, to the directives to NIOSH embodied in the Occupational Safety and Health Act of 1970, and to the operational philosophy of prudent public health practice.
A. Current Epidemiology and Control of Tuberculosis―Summary information on the transmission of tuberculosis was reported by CDC in 1991 (1):
The number of tuberculosis cases reported to CDC has been increasing since 1988, after a long historic decline. In 1990, 25,701 cases were reported, an increase of 9.4% over the 1989 figure and the largest annual increase since 1952. From 1985 to 1990, reported cases increased by 15.8%. Disproportionately greater increases in reported cases occurred among Hispanics, non-Hispanic blacks, and Asians/Pacific Islanders. In contrast, decreases were observed among non-Hispanic whites and American Indians/Alaskan Natives. By age, the largest increase in reported cases occurred in the 25- to 44-year age group; this increase may be largely attributable to rising numbers of tuberculosis cases among persons with human immunodeficiency virus infection or acquired immunodeficiency syndrome. Notable increases also occurred among children.
Snider and Roper later provided the following caution (2):
Events during the past decade have changed the nature and magnitude of the problem of tuberculosis. Much of what many physicians learned in training about this disease is no longer true. In many respects, tuberculosis has become a new entity.
