Carbapenemase Producing Enterobacteriaceae - screening and contact tracing in Region Stockholm in comparison with two other Swedish regions

Sammanfattning: Background: Carbapenemase Producing Enterobacteriaceae (CPE) is a growing problem all around the world. Sweden is relatively spared and there are very seldom outbreaks within the health care sector. Region Stockholm does contact tracing on all new and known carriers of CPE in health care institutions while other regions test only those who share room and toilet. Aim: Is the CPE contact tracing strategy in Region Stockholm more effective in finding patients with a nosocomial spread than in Region Västra Götaland and Region Skåne who has less meticulous contact tracing strategies? Materials and methods: Contact tracing and screening data were collected from the Karolinska University Laboratory for the years 2018 – 2020 and corresponding data were asked for from Region Västra Götaland and Region Skåne. Descriptive data were analyzed in Excel. Results: During the study period the Karolinska University Laboratory handled 23,862 contact tracing tests. Of 288 samples from 169 patients who turned out positive for CPE in screening, bacterial culture and contact tracing altogether, 65 samples (49 patients) turned out positive from contact tracing. Four patients were traced to have the same strain as the index and were considered infected within the health care sector. Region Västra Götaland discovered 6 patients and Skåne 2 patients, respectively, who were infected within the health care sector during the same time. Conclusions: There was an enormous number of contact tracing tests for CPE performed in Region Stockholm. Only four patients turned out to be infected within the health care sector. They would have been discovered by using the close contact tracing and screening in the same way as they do in Region Västra Götaland and Region Skåne. Implications: Based on the findings it could be argued that it would be enough to perform contact tracing on patients who have shared the same room or toilet with a newly diagnosed CPE carrier. There seem to be no reason to test patients when a known carrier is admitted to a ward since the index will have a single room and staff will be aware of the situation.