Tuberculosis control in health care workers: An algorithmic approach Richard M. Grimes, PhD a, c Deanna E. Grimes, DrPH, RN b, c Edward Graviss, PhD, MPH, CIC d, e Houston, Texas Health care workers have always been at risk for contracting tuberculosis (TB) from patients with active disease. In addition, health care workers who have active TB pose a risk for transmitting TB to patients. As a result, institutions that employ health care professionals must adopt programs to reduce the probability of transmission of TB to their employees or their patients. This article discusses the new guidelines for preventing TB issued by the Centers for Disease Control and Prevention and suggests approaches for adapting the guidelines to the needs of individual institutions. It emphasizes the importance of skin testing for early detection, correct interpretation of the tests, the approaches to determining who should be tested, and the relative frequency with which employees should be tested. It presents algorithms to assist employee health and infection control personnel in screening current and prospective employees, and in responding to positive and negative test results, and the booster effect. (AJIC A m J Infect Control 1996;24:70-7) The Centers for Disease Control and Prevention (CDC) has released its “Guidelines for Preventing the Transmission of A4ycobacterium tuberculosis in Health Care Facilities, 1994.“’ Implementing the recommendations in all institutions and situ- ations presents some challenges. This is particu- larly true for the sections of the guidelines dealing with skin testing of health care workers. Infection control personnel working together with clini- cians, occupational health personnel, and health administrators will have to adapt these guidelines to meet the needs of their organization. The purpose of this article is to assist decision makers in applying the guidelines. At the turn of the century, tuberculosis (TB) was the leading cause of death in this country. TB remained a leading killer until the 1940s when the From the University of Texas-Houston Health Science Center, School of Public Healtha and School of Nursing,!’ AIDS Education and Training Center for Texas and Oklahoma,c the Veterans Administration Medical Center,d and Baylor College of Medicine,e Houston. Supported in part by the Division of Medicine, Bureau of Health Professions, Health Resources and Services Administration, United States Public Health Service under cooperative agreement no. 5 D35 PE 00116-04. Reprint requests: Richard M. Grimes, PhD, University of Texas- Houston Health Science Center, School of Public Health, P.O. Box 20186, Houston, TX 772250186. 17/52/69939 70 first antitubercular chemotherapy became avail- able.* The number of TB cases in the United States steadily declined from 1953, when TB became a universally reportable disease, until 1984 when the number of cases began to plateau. From 1985 to 1993, an estimated 64,000 excess cases of TB occurred, compared with the num- ber of cases that would have been expected by previous trends. 3 This seems to have been a result of several phenomena, including the HIV epidemic4 increased immigration from countries with high TB prevalence,’ and de- clines in economic and living conditions in the u.s.6 Although the increase in TB cases can be attributed to certain phenomena or groups7 it is important to remember that the tubercle bacilli do not select their hosts on the basis of race, sex, place of birth, or social class. This microorganism only needs to find a susceptible person in which to flourish. Anyone who comes into contact with the droplet nuclei-containing bacilli from a person who is coughing is at risk of becoming infected. This has always been the case for health care workers. A classic study conducted in the 1930s showed that, whereas only 28% of 643 student nurses were infected at the start of their training, 48% were infected within 4 months of beginning training, 89% after 1 year in school, and 100% at graduation.’