The average charge per patient due to nosocomial infection for 215 nosocomial infections in 183 study patients was $693. These costs, however, were concentrated in very few patients; 5% of patients accounted for nearly one-third of total charges. The 10% of patients with highest nosocomial infection costs were patients on Medical or Surgical services; these services were utilized in 71% of patients with nosocomial infection and accounted for 86% of the attributable charges. Among the 22 most costly infections, 17 occurred in surgical wounds and lower respiratory tract. Although these sites accounted for 46% of the infections, they resulted in 77% of the total nosocomial infection charges. Patients with a primary diagnosis of injury had particularly costly infections. Combined analysis of these variables revealed two groups for whom nosocomial infections were especially costly: surgical patients who acquired wound infections after injuries, and medical patients with lower respiratory infections.

Six employees of the emergency department at Parkland Memorial Hospital developed active tuberculosis in 1983-1984. Five of the cases occurred four to 12 months after exposure to the index case, a patient with severe cavitary tuberculosis seen in the emergency department in April 1983. One resident physician developed cavitary disease after exposure to this patient. An additional employee case may have resulted from transmission from one of the initial employee cases. One immunocompromised patient may have acquired tuberculosis as a result of exposure to the index case. In addition, the tuberculin skin tests of at least 47 employees exposed to the index case converted from negative to positive. Of 112 previously tuberculin-negative emergency department employees who were tested in October 1983, 16 developed positive skin tests, including the 5 employees with active disease. Fifteen of these new positives had worked on April 7, 1983, while the index case was in the emergency department (x2 = 20.6, P <0.00l). Factors related to the genesis of the epidemic included the disease characteristics in the index case and the recirculation of air in the emergency department. This investigation indicates that city-county hospital emergency department employees should be screened at least twice a year for evidence of tuberculosis and that the employee health services of such hospitals should regard the surveillance of tuberculous infection among personnel at a high-priority level.

A statistical algorithm was used to identify potentially important clusters among nosocomial infections reported each month by 7 community hospitals. Epidemiologic review and on-site investigations distinguished outbreaks of clinical disease from factitious clusters. In 1 year, 8 outbreaks were confirmed. They involved 82 patients—approximately 2% of patients with nosocomial infections and 0.09% of all discharges. One true outbreak occurred for every 12,000 discharges—at least 1 outbreak per year for the average community hospital. Five (63%) outbreaks were recognized independently by the hospitals' infection control personnel. Four (50%) resolved spontaneously; the hospitals' own control measures were necessary in 2; and 2 resolved only after an outside investigation. Organized surveillance appears necessary to detect some outbreaks, and control measures are needed to stop many. Since, however, outbreaks account for such a small proportion of nosocomial infections, infection control programs should be sufficiently staffed and managed so that most of the effort is directed toward the surveillance and control of endemic infection problems, but with adequate resources remaining to respond to outbreaks when they occur.

As part of the first two phases of the SENIC Project (Study on the Efficacy of Nosocomial Infection Control), information was collected from the heads of the infection surveillance and control programs (ISCPs) in U.S. hospitals. The data were analyzed to describe these respondents and to determine whether differences among them were related to their areas of professional training or to characteristics of the hospitals where they were located. The findings indicate that the ISCP heads constitute a very heterogeneous group, with substantial differences in age, professional training (40% are pathologists), characteristics of their medical practices, memberships in professional organizations related to infection control, time spent in ISCP activities, approach to epidemiologic problems, and opinions on the preventability of nosocomial infections and the seriousness of infection problems in their hospitals. These differences are related strongly to the ISCP heads' professional training, size of hospital, and, to a lesser extent, medical school affiliation, but there is little evidence that the differences are related to regional or urban-rural location or type of ownership of the hospitals. The average ISCP head estimates that about half of all nosocomial infections are preventable, but these estimates vary inversely with tenure in the position and the tendency to approach a clinical problem epidemiologically.