Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
1.
Lancet Reg Health Eur ; 3: 100038, 2021 Apr.
Article in English | MEDLINE | ID: covidwho-1192394

ABSTRACT

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. FUNDING: PHE.

2.
Age Ageing ; 50(3): 649-656, 2021 05 05.
Article in English | MEDLINE | ID: covidwho-1096485

ABSTRACT

INTRODUCTION: Previous investigations have identified high rates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among residents and staff in care homes reporting an outbreak of coronavirus disease 2019 (COVID-19). We investigated care homes reporting a single suspected or confirmed case to assess whether early mass testing might reduce risk of transmission during the peak of the pandemic in London. METHODS: Between 18 and 27 April 2020, residents and staff in care homes reporting a single case of COVID-19 to Public Health England had a nasal swab to test for SARS-CoV-2 infection by reverse transcription polymerase chain reaction and subsequent whole-genome sequencing. Residents and staff in two care homes were re-tested 8 days later. RESULTS: Four care homes were investigated. SARS-CoV-2 positivity was 20% (65/333) overall, ranging between 3 and 59%. Among residents, positivity ranged between 3 and 76% compared with 3 and 40% in staff. Half of the SARS-CoV-2-positive residents (23/46, 50%) and 63% of staff (12/19) reported symptoms within 14 days before or after testing. Repeat testing 8 days later in two care homes with the highest infection rates identified only two new cases. Genomic analysis demonstrated a small number of introduction of the virus into care homes, and distinct clusters within three of the care homes. CONCLUSIONS: We found extensive but variable rates of SARS-CoV-2 infection among residents and staff in care homes reporting a single case of COVID-19. Although routine whole-home testing has now been adopted into practice, care homes must remain vigilant and should be encouraged to report a single suspected case, which should trigger appropriate outbreak control measures.


Subject(s)
COVID-19/diagnosis , Mass Screening/statistics & numerical data , SARS-CoV-2/isolation & purification , Aged , Aged, 80 and over , COVID-19/epidemiology , COVID-19/transmission , COVID-19 Nucleic Acid Testing , COVID-19 Testing , England , Female , Humans , Infection Control , London/epidemiology , Long-Term Care , Male , Pandemics , Policy , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics , Whole Genome Sequencing
3.
J Public Health (Oxf) ; 43(2): 236-242, 2021 06 07.
Article in English | MEDLINE | ID: covidwho-1020271

ABSTRACT

BACKGROUND: Coronavirus disease (COVID)-secure workplace guidance, including the prompt self-isolation of those with COVID-19 symptoms, is fundamental to disease control in workplaces. Despite guidance, a large number of workplace outbreaks have been observed. This study aimed to identify the proportion of symptomatic staff members attending workplaces after symptom onset or testing, and associated factors. METHODS: This study of symptomatic COVID-19 cases associated with London workplaces used London Coronavirus Response Centre (LCRC) records from routine telephone calls with cases and employers, from 17th July to 10th September. For each case, symptoms, date of onset, date of testing and the last attendance at work were extracted. Univariable logistic regression was performed to investigate whether age, gender or occupation was associated with workplace attendance after the onset of symptoms. RESULTS: Out of 130 symptomatic COVID-19 cases, 42 (32.3%) attended the workplace after their reported date of symptom onset, including 16 (12.3%) with recorded COVID-19 symptoms. Five staff members attended after COVID-19 testing. Males were 66% less likely to attend the workplace after the onset of COVID-19 symptoms compared to females (odds ratio 0.34, P = 0.05). Age and occupation were not predictive for workplace attendance after the onset of symptoms. CONCLUSION: A minority of symptomatic cases attended the workplace after the onset of COVID-19 symptoms, with a smaller proportion attending after testing. Males appeared less likely to attend the workplace after the onset of COVID-19 symptoms. This study highlights the need for ongoing COVID-19 secure workplace practices and prompt self-isolation after COVID-19 symptom onset or testing.


Subject(s)
COVID-19 , Workplace , COVID-19 Testing , Female , Humans , London/epidemiology , Male , Retrospective Studies , SARS-CoV-2
5.
EClinicalMedicine ; 28: 100597, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-912161

ABSTRACT

BACKGROUND: We investigated six London care homes experiencing a COVID-19 outbreak and found high rates of SARS-CoV-2 infection among residents and staff. Here we report follow-up investigations including antibody testing in the same care homes five weeks later. METHODS: Residents and staff in the initial investigation had a repeat nasal swab for SARS-CoV-2 RT-PCR and a blood test for SARS CoV-2 antibodies using ELISA based on SARS-CoV-2 native viral antigens derived from infected cells and virus neutralisation. FINDINGS: Of the 518 residents and staff in the initial investigation, 186/241 (77.2%) surviving residents and 208/254 (81.9%) staff underwent serological testing. Almost all SARS-CoV-2 RT-PCR positive residents and staff were seropositive five weeks later, whether symptomatic (residents 35/35, 100%; staff, 22/22, 100%) or asymptomatic (residents 32/33, 97.0%; staff 21/22, 95.5%). Symptomatic but SARS-CoV-2 RT-PCR negative residents and staff also had high seropositivity rates (residents 23/27, 85.2%; staff 18/21, 85.7%), as did asymptomatic RT-PCR negative individuals (residents 61/91, 67.0%; staff 95/143, 66.4%). Neutralising antibody was detected in 118/132 (89.4%) seropositive individuals and was not associated with age or symptoms. Ten residents (10/79 re-tested, 12.7%) remained RT-PCR positive but with higher RT-PCR cycle threshold values; 7/10 had serological testing and all were seropositive. New infections were detected in three residents and one staff. INTERPRETATION: RT-PCR provides a point prevalence of SARS-CoV-2 infection but significantly underestimates total exposure in outbreak settings. In care homes experiencing large COVID-19 outbreaks, most residents and staff had neutralising SARS-CoV-2 antibodies, which was not associated with age or symptoms. FUNDING: PHE.

6.
J Infect ; 81(4): 621-624, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-801950

ABSTRACT

BACKGROUND: Care homes have been disproportionately affected by the COVID-19 pandemic and continue to suffer large outbreaks even when community infection rates are declining, thus representing important pockets of transmission. We assessed occupational risk factors for SARS-CoV-2 infection among staff in six care homes experiencing a COVID-19 outbreak during the peak of the pandemic in London, England. METHODS: Care home staff were tested for SARS-COV-2 infection by RT-PCR and asked to report any symptoms, their contact with residents and if they worked in different care homes. Whole genome sequencing (WGS) was performed on RT-PCR positive samples. RESULTS: In total, 53 (21%) of 254 staff were SARS-CoV-2 positive but only 12/53 (23%) were symptomatic. Among staff working in a single care home, SARS-CoV-2 positivity was 15% (2/13), 16% (7/45) and 18% (30/169) in those reporting no, occasional and regular contact with residents. In contrast, staff working across different care homes (14/27, 52%) had a 3.0-fold (95% CI, 1.9-4.8; P<0.001) higher risk of SARS-CoV-2 positivity than staff working in single care homes (39/227, 17%). WGS identified SARS-CoV-2 clusters involving staff only, including some that included staff working across different care homes. CONCLUSIONS: SARS-CoV-2 positivity was significantly higher among staff working across different care homes than those who were working in the same care home. We found local clusters of SARS-CoV-2 infection between staff only, including those with minimal resident contact. Infection control should be extended for all contact, including those between staff, whilst on care home premises.


Subject(s)
Coronavirus Infections/epidemiology , Homes for the Aged/statistics & numerical data , Medical Staff/statistics & numerical data , Nursing Homes/statistics & numerical data , Occupational Exposure/adverse effects , Pneumonia, Viral/epidemiology , Betacoronavirus/genetics , COVID-19 , Coronavirus Infections/transmission , England/epidemiology , Genome, Viral/genetics , Humans , Infection Control/methods , London/epidemiology , Pandemics , Pneumonia, Viral/transmission , SARS-CoV-2 , Whole Genome Sequencing
7.
EClinicalMedicine ; 26: 100533, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-753678

ABSTRACT

BACKGROUND: Care homes are experiencing large outbreaks of COVID-19 associated with high case-fatality rates. We conducted detailed investigations in six London care homes reporting suspected COVID-19 outbreaks during April 2020. METHODS: Residents and staff had nasal swabs for SARS CoV-2 testing using RT-PCR and were followed-up for 14 days. They were categorized as symptomatic, post-symptomatic or pre-symptomatic if they had symptoms at the time of testing, in the two weeks before or two weeks after testing, respectively, or asymptomatic throughout. Virus isolation and whole genome sequencing (WGS) was also performed. FINDINGS: Across the six care homes, 105/264 (39.8%) residents were SARS CoV-2 positive, including 28 (26.7%) symptomatic, 10 (9.5%) post-symptomatic, 21 (20.0%) pre-symptomatic and 46 (43.8%) who remained asymptomatic. Case-fatality at 14-day follow-up was highest among symptomatic SARS-CoV-2 positive residents (10/28, 35.7%) compared to asymptomatic (2/46, 4.3%), post-symptomatic (2/10, 20.0%) or pre-symptomatic (3/21,14.3%) residents. Among staff, 53/254 (20.9%) were SARS-CoV-2 positive and 26/53 (49.1%) remained asymptomatic. RT-PCR cycle-thresholds and live-virus recovery were similar between symptomatic/asymptomatic residents/staff. Higher RT-PCR cycle threshold values (lower virus load) samples were associated with exponentially decreasing ability to recover infectious virus (P<0.001). WGS identified multiple (up to 9) separate introductions of different SARS-CoV-2 strains into individual care homes. INTERPRETATION: A high prevalence of SARS-CoV-2 positivity was found in care homes residents and staff, half of whom were asymptomatic and potential reservoirs for on-going transmission. A third of symptomatic SARS-CoV-2 residents died within 14 days. Symptom-based screening alone is not sufficient for outbreak control. FUNDING: None.

SELECTION OF CITATIONS
SEARCH DETAIL