Stenotrophomonas maltophilia outbreak in neonatal intensive care unit and outbreak management

Abstract

Objective: Stenotrophomonas maltophilia is a pathogen, which may cause serious outbreak, particularly in neonatal intensive care units, with increasing importance at present. The aim of this study was to assess the epidemiological and clinical features of S. maltophilia epidemic that we encountered in our neonatal intensive care unit and outbreak management.Materials and Methods: Demographic, clinic features, and microbiological findings of the cases who were hospitalized in our neonatal intensive care unit between February 2014 and May 2014 with S. maltophilia was isolated from blood cultures were retrospectively evaluated. Also, the isolation of S. maltophilia in the tracheal aspirate fluid cultures was investigated in the neonatal intensive care unit in the outbreak period and in the previous year. Other patients hospitalized at the same period were considered as the control group. Assessments and measures taken in the outbreak period were studied.Results: S. maltophilia bacteremia was detected in a total of 11 patients in the 4-month epidemic period. The same agent was also isolated from the tracheal aspirate culture in two of these patients. No factor was found to increase the risk of infection in terms of gestational age, birth weight, hospitalization time, and use of carbapenem, umbilical catheter, and total parenteral nutrition compared with the control group (15 patients). Overall mortality rate was found as 36% (4/11) in S. maltophilia cases and 7% (1/15) in the control group. Microorganisms were not isolated from the baticon bottles or medications in the form of ampoules (such as heparin) as well as those sent from the surroundings to find out the source of the outbreak. Source of the outbreak was accepted as cross-contamination among the cases. Baticon bottles were made smaller in volume, and their duration of use was shortened. Daily cleansing of the incubator humidifiers was performed. Training programs regarding the infection control measures for all staff working in the unit were organized.Conclusion: It should be always kept in mind that S. maltophilia causing serious outbreaks may be seen in the neonatal intensive care units. We believe that it would be useful to investigate possible environmental sources, analyze protective measures, and increase personnel awareness in outbreak management.