Multidrug-resistant Acinetobacter baumannii outbreak: an investigation of the possible routes of transmission

Abstract Objectives To establish the possible sources and routes of transmission of a multidrug-resistant Acinetobacter baumannii outbreak involving 22 patients. Study design Descriptive, retrospective study. Methods An environmental investigation was undertaken, monitoring surfaces, air and water. Reconstruction of the spread of the infection took several factors into account such as intrahospital movements of patients and healthcare personnel, hospitalization of patients in the same ward and in chronologically compatible periods, and length of stay. A. baumannii clinical samples were typed using the Multilocus Sequence Typing scheme. Results The outbreak originated from a patient admitted to the sub-intensive care unit, and the infection subsequently spread to other wards. The allelic profile proved to be the same for all the clinical isolates. Environmental monitoring yielded negative results for A. baumannii . Conclusions The results suggest that this epidemic spread through cross-transmission involving healthcare workers.