Salmonellosis in a Premature Nursery Unaccompanied by Diarrheal Disease

Introduction into a large premature nursery of six apparently normal infants, who were later found to be infected with S. tennessee, led to epidemic spread of the infection over a 4-month period. No infant was ill at any time. Original source of the infection could not be determined. Feedings, contact with other patients, and infected animals could be eliminated as modes of spread. Rectal-swab cultures of nurses and attendants were all negative. Infection of air was demonstrated and positive cultures were obtained from bedside tables and recently changed cribs. A positive culture was obtained from hands of one nurse immediately after washing. Evidence was found that increase in spread was associated with decrease in amount of nursing care. It is inferred that defective nursing techniques, particularly handwashing, was the chief mode of spread.