made available. Automatic door closers were installed. HEPA filters were used for recirculated air. A protocol for rapid identification of patients with possible tuberculosis was instituted. Surgical masks were replaced with submicron masks. Strict adherence to tuberculosis isolation precautions was promoted with patient education and incentives. Booths were used for aerosolized pentamidine administration and sputum induction. An annual PPD program for health care workers was implemented, with testing of high-risk health care workers every six months. The impact of the policies on health care worker PPD conversion is noted in Table D-3.

The reason for such small numbers of respiratory therapist conversions was not noted in the abstract. The authors noted that the rate of compliance with PPD testing in 1991 and 1992 was <75 percent; in 1993 it was 95 percent, so the reduction may have been even greater than documented. Unfortunately, rates are not provided, but overall the data are suggestive.

Grant (21) presented the results of a review of all tuberculosis cases at Parkland Memorial Hospital, Dallas, in 1994 and 1995. A variety of enhancements to the tuberculosis control policies were made from April to December 1994, including certification of PPD placement, an algorithm for tuberculosis isolation room assignment in times of low availability, standing orders for patients with suspected tuberculosis, increased UV in waiting areas, a fit testing program, increased employee PPD frequency (depending on job category), and notification of infection control by radiology of suspicious CXRs. Previously, an increase in health care worker PPD conversions had led to improvements in engineering controls, with 64 tuberculosis isolation rooms being made available.

Over the 2 years, 253 tuberculosis patients were admitted, 85 percent of whom had pulmonary disease. In 1994, all AFB smears were processed within 24 hours. Nontuberculous mycobacteria (NTM) were found in 193/ 407 (47 percent) patients with a positive AFB smear. Further results are presented in Table D-4.

The authors report that the data gathered each year were released along with information about the importance of compliance with the tuberculosis control protocols. They suggest that the high rate of NTM made the diagnosis of true tuberculosis more difficult. They also suggest that

TABLE D-3. PPD Conversions in Health Care Workers at BIMC


No. of Conversions


House Staff



All Other

















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