TY - JOUR
T1 - Infection and transmission of SARS-CoV-2 in London care homes reporting no cases or outbreaks of COVID-19
T2 - Prospective observational cohort study, England 2020
AU - Jeffery-Smith, Anna
AU - Dun-Campbell, Kate
AU - Janarthanan, Roshni
AU - Fok, Jonathan
AU - Crawley-Boevey, Emma
AU - Vusirikala, Amoolya
AU - Fernandez Ruiz De Olano, Elena
AU - Sanchez-Perez, Marina
AU - Tang, Suzanne
AU - Rowland, Thomas AJ
AU - Wynne-Evans, Edward
AU - Bell, Anita
AU - Patel, Bharatkumar
AU - Amin-Chowdhury, Zahin
AU - Aiano, Felicity
AU - Paranthaman, Karthikeyan
AU - Ma, Thomas
AU - Saavedra-Campos, Maria
AU - Ellis, Joanna
AU - Lackenby, Angie
AU - Whitaker, Heather
AU - Myers, Richard
AU - Hoschler, Katja
AU - Brown, Kevin
AU - Ramsay, Mary
AU - Shetty, Nandini
AU - Chow, J. Yimmy
AU - Ladhani, Shamez
AU - Zambon, Maria
N1 - Funding Information:
This work was supported by Public Health England.
Publisher Copyright:
© 2021
PY - 2021/4/1
Y1 - 2021/4/1
N2 - Background: Care homes have been disproportionately affected by the COVID-19 pandemic. We investigated the potential role of asymptomatic infection and silent transmission in London care homes that reported no cases of COVID-19 during the first wave of the pandemic. Methods: Five care homes with no cases and two care homes reporting a single case of COVID-19 (non-outbreak homes) were investigated with nasal swabbing for SARS-CoV-2 RT-PCR and serology for SARS-CoV-2 antibodies five weeks later. Whole genome sequencing (WGS) was performed on RT-PCR positive samples. Serology results were compared with those of six care homes with recognised outbreaks. Findings: Across seven non-outbreak homes, 718 (387 staff, 331 residents) individuals had a nasal swab and 651 (386 staff, 265 residents) had follow-up serology. Sixteen individuals (13 residents, 3 staff) in five care homes with no reported cases were RT-PCR positive (care home positivity rates, 0 to 7.6%) compared to 13 individuals (3.0 and 10.8% positivity) in two homes reporting a single case. Seropositivity across these seven homes varied between 10.7-56.5%, with four exceeding community seroprevalence in London (14.8%). Seropositivity rates for staff and residents correlated significantly (rs 0.84, [95% CI 0.51-0.95] p <0.001) across the 13 homes. WGS identified multiple introductions into some homes and silent transmission of a single lineage between staff and residents in one home. Interpretation: We found high rates of asymptomatic infection and transmission even in care homes with no COVID-19 cases. The higher seropositivity rates compared to RT-PCR positivity highlights the true extent of the silent outbreak.
AB - Background: Care homes have been disproportionately affected by the COVID-19 pandemic. We investigated the potential role of asymptomatic infection and silent transmission in London care homes that reported no cases of COVID-19 during the first wave of the pandemic. Methods: Five care homes with no cases and two care homes reporting a single case of COVID-19 (non-outbreak homes) were investigated with nasal swabbing for SARS-CoV-2 RT-PCR and serology for SARS-CoV-2 antibodies five weeks later. Whole genome sequencing (WGS) was performed on RT-PCR positive samples. Serology results were compared with those of six care homes with recognised outbreaks. Findings: Across seven non-outbreak homes, 718 (387 staff, 331 residents) individuals had a nasal swab and 651 (386 staff, 265 residents) had follow-up serology. Sixteen individuals (13 residents, 3 staff) in five care homes with no reported cases were RT-PCR positive (care home positivity rates, 0 to 7.6%) compared to 13 individuals (3.0 and 10.8% positivity) in two homes reporting a single case. Seropositivity across these seven homes varied between 10.7-56.5%, with four exceeding community seroprevalence in London (14.8%). Seropositivity rates for staff and residents correlated significantly (rs 0.84, [95% CI 0.51-0.95] p <0.001) across the 13 homes. WGS identified multiple introductions into some homes and silent transmission of a single lineage between staff and residents in one home. Interpretation: We found high rates of asymptomatic infection and transmission even in care homes with no COVID-19 cases. The higher seropositivity rates compared to RT-PCR positivity highlights the true extent of the silent outbreak.
KW - Asymptomatic transmission
KW - Care home
KW - SARS-CoV-2 outbreak
UR - http://www.scopus.com/inward/record.url?scp=85101494511&partnerID=8YFLogxK
U2 - 10.1016/j.lanepe.2021.100038
DO - 10.1016/j.lanepe.2021.100038
M3 - Article
AN - SCOPUS:85101494511
SN - 2666-7762
VL - 3
JO - The Lancet Regional Health - Europe
JF - The Lancet Regional Health - Europe
M1 - 100038
ER -
