Objective: We sought to determine the cause and mode of transmission of a cluster of bloodstream infections as a result of Klebsiella pneumoniae.
Design and setting: We conducted a prospective cohort study in a neonatal intensive care department from May 1999 to December 2000.
Methods: We performed surveillance of nosocomial infections, and clinical and environmental investigations.
Results: During an 8-week period, 5 cases of K pneumoniae bloodstream infections were observed, at least 3 of them belonging to the same genotype. Before the second case developed any symptoms of infection, the same strain had also been found in the patient environment. Intervention measures were, therefore, immediately introduced. Further cases, however, occurred in the following weeks. Even after further intervention activities and the end of the outbreak, the same strain was discovered in environmental samples from a stethoscope and a nurse's hand.
Conclusions: Even where there is acute awareness of the problem and a generally high infection control level in a department, it is difficult to change behavior in such a way that further nosocomial infections can be totally excluded.