Open Access Research article

Prolonged outbreak of Serratia marcescens in Tartu University Hospital: a case–control study

Vivika Adamson1*, Piret Mitt1, Heti Pisarev2, Tuuli Metsvaht3, Kaidi Telling1, Paul Naaber4 and Matti Maimets15

Author Affiliations

1 Department of Infection Control, Tartu University Hospital, Puusepa 1a, 50406, Tartu, Estonia

2 Department of Public Health, University of Tartu, Tartu, Estonia

3 Pediatric Intensive Care Unit, Intensive Care Clinic, Tartu University Hospital, Tartu, Estonia

4 Department of Medical Microbiology, Stavanger University Hospital, Stavanger, Norway

5 Department of Internal Medicine, Tartu University Hospital, Tartu, Estonia

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BMC Infectious Diseases 2012, 12:281  doi:10.1186/1471-2334-12-281

Published: 31 October 2012



The aim of our study was to investigate and control an outbreak and identify risk factors for colonization and infection with Serratia marcescens in two departments in Tartu University Hospital.


The retrospective case–control study was conducted from July 2005 to December 2006. Molecular typing by pulsed field gel electrophoresis was used to confirm the relatedness of Serratia marcescens strains. Samples from the environment and from the hands of personnel were cultured.


The outbreak involved 210 patients, 61 (29%) developed an infection, among them 16 were invasive infections. Multivariate analysis identified gestational age, arterial catheter use and antibiotic treatment as independent risk factors for colonization and infection with Serratia marcescens. Molecular typing was performed on 83 Serratia marcescens strains, 81 of them were identical and 2 strains were different.


Given the occasionally severe consequences of Serratia marcescens in infants, early implementation of aggressive infection control measures involving patients and mothers as well as the personnel is of utmost importance.