tetano
Editor, Senior Moderator
Antimicrob Resist Infect Control
. 2023 Apr 21;12(1):38.
doi: 10.1186/s13756-023-01242-y.
A systematic outbreak investigation of SARS-CoV-2 transmission clusters in a tertiary academic care center
Matthias von Rotz[SUP] 1 [/SUP], Richard Kuehl[SUP] 1 [/SUP], Ana Durovic[SUP] 2 [/SUP], Sandra Zingg[SUP] 3 [/SUP], Anett Apitz[SUP] 4 [/SUP], Fanny Wegner[SUP] 5 6 7 [/SUP], Helena M B Seth-Smith[SUP] 5 6 7 [/SUP], Tim Roloff[SUP] 5 6 7 [/SUP], Karoline Leuzinger[SUP] 8 9 [/SUP], Hans H Hirsch[SUP] 1 8 9 [/SUP], Sabine Kuster[SUP] 1 [/SUP], Manuel Battegay[SUP] 1 [/SUP], Luigi Mariani[SUP] 10 [/SUP], Stefan Schaeren[SUP] 11 [/SUP], Stefano Bassetti[SUP] 12 [/SUP], Florian Banderet-Uglioni[SUP] 4 [/SUP], Adrian Egli[SUP] 5 6 7 [/SUP], Sarah Tschudin-Sutter[SUP] 13 [/SUP]
Affiliations
Abstract
Background: We sought to decipher transmission pathways in healthcare-associated infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within our hospital by epidemiological work-up and complementary whole genome sequencing (WGS). We report the findings of the four largest epidemiologic clusters of SARS-CoV-2 transmission occurring during the second wave of the pandemic from 11/2020 to 12/2020.
Methods: At the University Hospital Basel, Switzerland, systematic outbreak investigation is initiated at detection of any nosocomial case of SARS-CoV-2 infection, as confirmed by polymerase chain reaction, occurring more than five days after admission. Clusters of nosocomial infections, defined as the detection of at least two positive patients and/or healthcare workers (HCWs) within one week with an epidemiological link, were further investigated by WGS on respective strains.
Results: The four epidemiologic clusters included 40 patients and 60 HCWs. Sequencing data was available for 70% of all involved cases (28 patients and 42 HCWs), confirmed epidemiologically suspected in house transmission in 33 cases (47.1% of sequenced cases) and excluded transmission in the remaining 37 cases (52.9%). Among cases with identical strains, epidemiologic work-up suggested transmission mainly through a ward-based exposure (24/33, 72.7%), more commonly affecting HCWs (16/24, 66.7%) than patients (8/24, 33.3%), followed by transmission between patients (6/33, 18.2%), and among HCWs and patients (3/33, 9.1%, respectively two HCWs and one patient).
Conclusions: Phylogenetic analyses revealed important insights into transmission pathways supporting less than 50% of epidemiologically suspected SARS-CoV-2 transmissions. The remainder of cases most likely reflect community-acquired infection randomly detected by outbreak investigation. Notably, most transmissions occurred between HCWs, possibly indicating lower perception of the risk of infection during contacts among HCWs.
Keywords: COVID-19; Epidemiologic cluster; Nosocomial outbreaks; Outbreak investigation; SARS-CoV-2 cluster; Whole genome sequencing.
. 2023 Apr 21;12(1):38.
doi: 10.1186/s13756-023-01242-y.
A systematic outbreak investigation of SARS-CoV-2 transmission clusters in a tertiary academic care center
Matthias von Rotz[SUP] 1 [/SUP], Richard Kuehl[SUP] 1 [/SUP], Ana Durovic[SUP] 2 [/SUP], Sandra Zingg[SUP] 3 [/SUP], Anett Apitz[SUP] 4 [/SUP], Fanny Wegner[SUP] 5 6 7 [/SUP], Helena M B Seth-Smith[SUP] 5 6 7 [/SUP], Tim Roloff[SUP] 5 6 7 [/SUP], Karoline Leuzinger[SUP] 8 9 [/SUP], Hans H Hirsch[SUP] 1 8 9 [/SUP], Sabine Kuster[SUP] 1 [/SUP], Manuel Battegay[SUP] 1 [/SUP], Luigi Mariani[SUP] 10 [/SUP], Stefan Schaeren[SUP] 11 [/SUP], Stefano Bassetti[SUP] 12 [/SUP], Florian Banderet-Uglioni[SUP] 4 [/SUP], Adrian Egli[SUP] 5 6 7 [/SUP], Sarah Tschudin-Sutter[SUP] 13 [/SUP]
Affiliations
- PMID: 37085891
- PMCID: PMC10119817
- DOI: 10.1186/s13756-023-01242-y
Abstract
Background: We sought to decipher transmission pathways in healthcare-associated infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within our hospital by epidemiological work-up and complementary whole genome sequencing (WGS). We report the findings of the four largest epidemiologic clusters of SARS-CoV-2 transmission occurring during the second wave of the pandemic from 11/2020 to 12/2020.
Methods: At the University Hospital Basel, Switzerland, systematic outbreak investigation is initiated at detection of any nosocomial case of SARS-CoV-2 infection, as confirmed by polymerase chain reaction, occurring more than five days after admission. Clusters of nosocomial infections, defined as the detection of at least two positive patients and/or healthcare workers (HCWs) within one week with an epidemiological link, were further investigated by WGS on respective strains.
Results: The four epidemiologic clusters included 40 patients and 60 HCWs. Sequencing data was available for 70% of all involved cases (28 patients and 42 HCWs), confirmed epidemiologically suspected in house transmission in 33 cases (47.1% of sequenced cases) and excluded transmission in the remaining 37 cases (52.9%). Among cases with identical strains, epidemiologic work-up suggested transmission mainly through a ward-based exposure (24/33, 72.7%), more commonly affecting HCWs (16/24, 66.7%) than patients (8/24, 33.3%), followed by transmission between patients (6/33, 18.2%), and among HCWs and patients (3/33, 9.1%, respectively two HCWs and one patient).
Conclusions: Phylogenetic analyses revealed important insights into transmission pathways supporting less than 50% of epidemiologically suspected SARS-CoV-2 transmissions. The remainder of cases most likely reflect community-acquired infection randomly detected by outbreak investigation. Notably, most transmissions occurred between HCWs, possibly indicating lower perception of the risk of infection during contacts among HCWs.
Keywords: COVID-19; Epidemiologic cluster; Nosocomial outbreaks; Outbreak investigation; SARS-CoV-2 cluster; Whole genome sequencing.