able showed no cases of patients with active tuberculosis at time of their dental visit. These chart review data were also reported separately in greater detail (64).
The authors conducted a survey of 54 dental schools and received 24 (44 percent) responses. A total of 14/24 (58 percent) had no PPD data available, and 5 (21 percent) had no data available but were planning to start testing. Of five (21 percent) with data, only three shared their results. At one dental clinic on the West Coast, the PPD conversion rate was approximately 1 percent. At another West Coast school, the conversion rate for faculty was 1.6 percent, for students it was 2 percent, and for staff it was 1.8 percent. At the third school, in the Midwest, the only positive PPD results were in foreign-born students.
A 1-year study, completed in July 1995, of student conversions during the 3rd year (the first clinical year) revealed a 10.6 percent conversion rate. It was unclear if students had received two-stage testing for their initial tests.
The control plan for the facility involved a risk analysis, after which the facility was designated very low risk (i.e., tuberculosis in the community but not the facility). The paper speculates that a lot of the skin test conversion may have been community acquired. Administrative controls included obtaining a detailed history from every new patient and an abbreviated history on patient return to screen for tuberculosis; patients with suspicious findings were sent to a designated clinic for more detailed evaluation. HEPA masks were made available and were to be used for high-risk patients. Engineering controls are not required at that risk level, and none were specifically planned.
Although no cases of tuberculosis were found by their chart review, given the high prevalence of tuberculosis in New York City during that time period and given the high rates of PPD conversions in students and faculty, a higher-level risk assessment would seem more appropriate. An argument could be made for implementing more aggressive control measures, especially engineering controls in common areas, and perhaps better personal protective equipment for the staff.
Kellerman and colleagues (65) calculated the costs from 1989 to 1994 of implementing the CDC guidelines at three New York City hospitals (Roosevelt, Cabrini, St. Clare’s) and a Miami hospital (Jackson) that had had nosocomial outbreaks. Also included was one low-risk hospital in Nebraska (Regional West) for comparison. The hospitals provided estimates of nursing time for placing and reading PPD tests, supply costs,