Raskit Lachmann1, Sven Halbedel2, Marlen Adler3, Natalie Becker4, Franz Allerberger5, Alexandra Holzer6, Idesbald Boone6, Gerhard Falkenhorst6, Sylvia Kleta3, Sascha Al Dahouk3, Klaus Stark6, Petra Luber4, Antje Flieger2, Hendrik Wilking6. 1. FG35 Division of Gastrointestinal Infections, Zoonoses and Tropical Infections, Robert Koch Institute, Berlin, Germany. Electronic address: LachmannR@rki.de. 2. FG11 Division of Enteropathogenic Bacteria and Legionella, Consultant Laboratory for Listeria, Robert Koch Institute, Wernigerode, Germany. 3. German Federal Institute for Risk Assessment, Berlin, Germany. 4. Federal Office of Consumer Protection and Food Safety, Berlin, Germany. 5. Austrian Agency for Health and Food Safety, Vienna, Austria. 6. FG35 Division of Gastrointestinal Infections, Zoonoses and Tropical Infections, Robert Koch Institute, Berlin, Germany.
Abstract
OBJECTIVES: Invasive listeriosis is a severe foodborne infection caused by Listeria(L.)monocytogenes. The aim of this investigation was to verify and describe a molecular cluster of listeriosis patients and identify factors leading to this outbreak. METHODS: Whole genome sequencing and core genome multilocus sequence typing were used for subtyping L. monocytogenes isolates from listeriosis cases and food samples in Germany. Patient interviews and investigational tracing of foodstuffs offered in health-care facilities (HCF), where some of the cases occurred, were conducted. RESULTS: We identified a German-wide listeriosis outbreak with 39 genetically related cases occurring between 2014 and 2019. Three patients died as a result of listeriosis. After identification of HCF in different regions of Germany for at least 13 cases as places of exposure, investigational tracing of food supplies in six prioritized HCF revealed meat products from one company (X) as a commonality. Subsequently the outbreak strain was analysed in six isolates from ready-to-eat meat products and one isolate from the production environment of company X. No further Sigma1 cases were detected after recall of the meat products from the market and closure of company X (as of August 2020). CONCLUSIONS: Interdisciplinary efforts including whole genome sequencing, epidemiological investigations in patients and investigational tracing of foods were essential to identify the source of infections, and thereby prevent further illnesses and deaths. This outbreak underlines the vulnerability of hospitalized patients for foodborne diseases, such as listeriosis. Food producers and HCF should minimize the risk of microbiological hazards when producing, selecting and preparing food for patients.
OBJECTIVES: Invasive listeriosis is a severe foodborne infection caused by Listeria(L.)monocytogenes. The aim of this investigation was to verify and describe a molecular cluster of listeriosis patients and identify factors leading to this outbreak. METHODS: Whole genome sequencing and core genome multilocus sequence typing were used for subtyping L. monocytogenes isolates from listeriosis cases and food samples in Germany. Patient interviews and investigational tracing of foodstuffs offered in health-care facilities (HCF), where some of the cases occurred, were conducted. RESULTS: We identified a German-wide listeriosis outbreak with 39 genetically related cases occurring between 2014 and 2019. Three patientsdied as a result of listeriosis. After identification of HCF in different regions of Germany for at least 13 cases as places of exposure, investigational tracing of food supplies in six prioritized HCF revealed meat products from one company (X) as a commonality. Subsequently the outbreak strain was analysed in six isolates from ready-to-eat meat products and one isolate from the production environment of company X. No further Sigma1 cases were detected after recall of the meat products from the market and closure of company X (as of August 2020). CONCLUSIONS: Interdisciplinary efforts including whole genome sequencing, epidemiological investigations in patients and investigational tracing of foods were essential to identify the source of infections, and thereby prevent further illnesses and deaths. This outbreak underlines the vulnerability of hospitalized patients for foodborne diseases, such as listeriosis. Food producers and HCF should minimize the risk of microbiological hazards when producing, selecting and preparing food for patients.
Authors: Valeria Russini; Martina Spaziante; Tiziana Zottola; Anna Giovanna Fermani; Gina Di Giampietro; Giovanni Blanco; Paolo Fabietti; Riccardo Marrone; Roberta Parisella; Sergio Parrocchia; Teresa Bossù; Stefano Bilei; Maria Laura De Marchis Journal: Pathogens Date: 2021-05-12