Epidemic infections in surgical patients

From 1967 to 1977, the Centers for Disease Control investigated 22 epidemics of nosocomial infections among surgical patients. Fifteen of the outbreaks involved operative site infections and were caused by various microorganisms: gram-positive bacteria (47%), gram-negative bacteria (13%), atypical mycobacteria (13%), Aspergillus (7%), and multiple microorganisms (20%). Sources for infecting strains were infected personnel or patients (53%), the operating room environment (20%), and four unknown factors (27%). Control measures included treatment of personnel who were carriers and infected patients, adherence to aseptic techniques, improvements in OR airflow and cleaning procedures, and discontinuation of elective surgery during OR construction. The other seven epidemics were associated with perioperative care and caused by gram-negative bacteria. There were six epidemics of primary bacteremia, four of them associated with arterial pressure transducers. Another bacteremia epidemic was caused by the infusion of contaminated commercially prepared normal serum albumin. The remaining primary bacteremia epidemic was caused by using syringes contaminated by ice to obtain blood samples for blood gas determinations. One epidemic of Salmonella gastroenteritis and secondary bacteremia was traced to a contaminated intermittent-suction machine used for postoperative care. Control measures for these epidemics included judicious use and proper decontamination and sterilization of the transducers, recall of the contaminated product, aseptic procedures for caring for arterial cannulae, and proper decontamination of suction equipment. Suggestions for the evaluation and control of potential epidemics are based on the results of these investigations.