TY - JOUR

T1 - A major outbreak of covid-19 at a residential care home

AU - Andersen, Christian Østergaard

AU - Buch, Ivana

AU - Castruita, José Alfredo Samaniego

AU - Jacobsen, Nana Gry

AU - Jensen, Christel Barker

AU - Westh, Henrik

AU - Marvig, Rasmus Lykke

AU - Pedersen, Martin Schou

AU - Schønning, Kristian

AU - Pinholt, Mette

N1 - Publisher Copyright: © 2021, Almindelige Danske Laegeforening. All rights reserved.

PY - 2021

Y1 - 2021

N2 - INTRODUCTION SARS-CoV-2 outbreaks at care homes are associated with a high morbidity and mortality. We aimed to study the molecular epidemiology of a major care home outbreak in Denmark. METHODS After a staff member had been tested positive on 16 November 2020, a bundle approach programme was initiated including frequent surveillance screenings of residents and staff, isolation and cohorting procedures. This approach also involved limiting the number of visitors and enhancing the use of personal protective equipment, hand hygiene, and environmental cleaning. Naso/oropharyngeal swabs were tested for SARS-CoV-2 by polymerase chain reaction. Available positive samples were sequenced and phylogenetic relationships between the outbreak and local circulating strains were reconstructed. RESULTS In all, 50% (56/114) of residents and 26% (49/190) of staff members became infected during the 46-day outbreak period. Altogether 16% of the infected residents died within 30 days after becoming infected. A total of 44% (46/105) of the samples with SARS-CoV-2 were sequenced. and phylogenetic analysis demonstrated a dominant outbreak lineage belonging to Global Lineage B.1.1.29 containing the mutation I233V in the S gene. The outbreak lineage was detected in the community 28 days before its introduction into the care home. CONCLUSIONS Introduction of SARS-CoV-2 to care homes is associated with severe outbreaks. Initiation of a bundle approach infection control programme in addition to measures ensuring enhanced herd immunity were successful in controlling the outbreak. Genome sequencing proved to be a powerful tool to describe the relatedness of the various clones and may help focusing outbreak interventions.

AB - INTRODUCTION SARS-CoV-2 outbreaks at care homes are associated with a high morbidity and mortality. We aimed to study the molecular epidemiology of a major care home outbreak in Denmark. METHODS After a staff member had been tested positive on 16 November 2020, a bundle approach programme was initiated including frequent surveillance screenings of residents and staff, isolation and cohorting procedures. This approach also involved limiting the number of visitors and enhancing the use of personal protective equipment, hand hygiene, and environmental cleaning. Naso/oropharyngeal swabs were tested for SARS-CoV-2 by polymerase chain reaction. Available positive samples were sequenced and phylogenetic relationships between the outbreak and local circulating strains were reconstructed. RESULTS In all, 50% (56/114) of residents and 26% (49/190) of staff members became infected during the 46-day outbreak period. Altogether 16% of the infected residents died within 30 days after becoming infected. A total of 44% (46/105) of the samples with SARS-CoV-2 were sequenced. and phylogenetic analysis demonstrated a dominant outbreak lineage belonging to Global Lineage B.1.1.29 containing the mutation I233V in the S gene. The outbreak lineage was detected in the community 28 days before its introduction into the care home. CONCLUSIONS Introduction of SARS-CoV-2 to care homes is associated with severe outbreaks. Initiation of a bundle approach infection control programme in addition to measures ensuring enhanced herd immunity were successful in controlling the outbreak. Genome sequencing proved to be a powerful tool to describe the relatedness of the various clones and may help focusing outbreak interventions.

M3 - Journal article

AN - SCOPUS:85117507647

VL - 68

JO - Danish Medical Journal

JF - Danish Medical Journal

SN - 2245-1919

IS - 10

M1 - A03210227

ER -