Transmission of community- and hospital-acquired SARS-CoV-2 in hospital settings in the UK: A cohort study

Background Nosocomial spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been widely reported, but the transmission pathways among patients and healthcare workers (HCWs) are unclear. Identifying the risk factors and drivers for these nosocomial transmissions is critical for infection prevention and control interventions. The main aim of our study was to quantify the relative importance of different transmission pathways of SARS-CoV-2 in the hospital setting. Methods and findings This is an observational cohort study using data from 4 teaching hospitals in Oxfordshire, United Kingdom, from January to October 2020. Associations between infectious SARS-CoV-2 individuals and infection risk were quantified using logistic, generalised additive and linear mixed models. Cases were classified as community- or hospital-acquired using likely incubation periods of 3 to 7 days. Of 66,184 patients who were hospitalised during the study period, 920 had a positive SARS-CoV-2 PCR test within the same period (1.4%). The mean age was 67.9 (±20.7) years, 49.2% were females, and 68.5% were from the white ethnic group. Out of these, 571 patients had their first positive PCR tests while hospitalised (62.1%), and 97 of these occurred at least 7 days after admission (10.5%). Among the 5,596 HCWs, 615 (11.0%) tested positive during the study period using PCR or serological tests. The mean age was 39.5 (±11.1) years, 78.9% were females, and 49.8% were nurses. For susceptible patients, 1 day in the same ward with another patient with hospital-acquired SARS-CoV-2 was associated with an additional 7.5 infections per 1,000 susceptible patients (95% credible interval (CrI) 5.5 to 9.5/1,000 susceptible patients/day) per day. Exposure to an infectious patient with community-acquired Coronavirus Disease 2019 (COVID-19) or to an infectious HCW was associated with substantially lower infection risks (2.0/1,000 susceptible patients/day, 95% CrI 1.6 to 2.2). As for HCW infections, exposure to an infectious patient with hospital-acquired SARS-CoV-2 or to an infectious HCW were both associated with an additional 0.8 infection per 1,000 susceptible HCWs per day (95% CrI 0.3 to 1.6 and 0.6 to 1.0, respectively). Exposure to an infectious patient with community-acquired SARS-CoV-2 was associated with less than half this risk (0.2/1,000 susceptible HCWs/day, 95% CrI 0.2 to 0.2). These assumptions were tested in sensitivity analysis, which showed broadly similar results. The main limitations were that the symptom onset dates and HCW absence days were not available. Conclusions In this study, we observed that exposure to patients with hospital-acquired SARS-CoV-2 is associated with a substantial infection risk to both HCWs and other hospitalised patients. Infection control measures to limit nosocomial transmission must be optimised to protect both staff and patients from SARS-CoV-2 infection.

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Transmission dynamics of SARS-CoV-2 in the hospital setting

10.1101/2021.04.28.21256245 ◽

2021 ◽

Author(s):

Yin Mo ◽

David W Eyre ◽

Sheila Lumley ◽

Timothy Walker ◽

Robert Shaw ◽

...

Keyword(s):

Healthcare Worker ◽

Healthcare Workers ◽

Hospital Setting ◽

Research Unit ◽

Infection Risk ◽

Control Measures ◽

Nosocomial Transmission ◽

Teaching Hospitals ◽

Serological Tests ◽

Hospital Acquired

Background: SARS-CoV-2 can spread efficiently in hospitals, but the transmission pathways amongst patients and healthcare workers are unclear. Methods: We analysed data from four teaching hospitals in Oxfordshire, UK, from January to October 2020. Associations between infectious SARS-CoV-2 individuals and infection risk were quantified using logistic, generalised additive and linear mixed models. Cases were classified as community- or hospital-acquired using likely incubation periods. Results: Nine-hundred and twenty of 66184 patients who were hospitalised during the study period had a positive SARS-CoV-2 PCR test within the same period (1%). Out of these, 571 patients had their first positive PCR tests while hospitalised (62%), and 97 of these occurred at least seven days after admission (11%). Amongst the 5596 healthcare workers, 615 (11%) tested positive during the study period using PCR or serological tests. For susceptible patients, one day in the same ward with another patient with hospital-acquired SARS-CoV-2 was associated with an additional eight infections per 1000 susceptible patients (95%CrI 6-10). Exposure to an infectious patient with community-acquired COVID-19 or to an infectious healthcare worker was associated with substantially lower infection risks (2/1000 susceptible patients/day, 95%CrI 1-2). As for healthcare worker infections, exposure to an infectious patient with hospital-acquired SARS-CoV-2 or to an infectious healthcare worker were both associated with an additional one infection per 1000 susceptible healthcare workers per day (95%CrI 1-2). Exposure to an infectious patient with community-acquired SARS-CoV-2 was associated with half this risk (0.5/1000 susceptible healthcare workers/day, 95%CrI 0.3-0.7). Interpretation: Exposure to patients with hospital-acquired SARS-CoV-2 poses a substantial infection risk. Infection control measures to limit nosocomial transmission must be optimised to protect both staff and patients from SARS-CoV-2 infection. Funding: National Institute for Health Research Health Protection Research Unit (NIHR HPRU) in Healthcare Associated Infections and Antimicrobial Resistance at Oxford University in partnership with Public Health England (PHE) (NIHR200915). Medical Research Council, Nosocomial transmission of SARS-CoV-2 (MR/V028456/1).

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Eastern Cape Healthcare Workers Acquisition of SARS-CoV-2 (ECHAS): Cross-Sectional (Nested Cohort) Study Protocol

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18010323 ◽

2021 ◽

Vol 18 (1) ◽

pp. 323

Author(s):

Oladele Vincent Adeniyi ◽

David Stead ◽

Mandisa Singata-Madliki ◽

Joanne Batting ◽

Leo Hyera ◽

...

Keyword(s):

Cohort Study ◽

Infection Rate ◽

Healthcare Workers ◽

Health Facilities ◽

Control Measures ◽

Infection Prevention And Control ◽

Eastern Cape ◽

Rt Pcr ◽

Cross Sectional ◽

Increased Risk

Healthcare workers (HCWs) are at increased risk of infection by the virulent severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Though data exist on the positivity rate of the SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) test as well as COVID-19-related deaths amongst HCWs in South Africa, the overall infection rate remains underestimated by these indicators. It is also unclear whether the humoral immune response after SARS-CoV-2 infection offers durable protection against reinfection. This study will assess the SARS-CoV-2 seroprevalence amongst HCWs in the Eastern Cape (EC) and examine the longitudinal changes (rate of decay) in the antibody levels after infection in this cohort. Using a multi-stage cluster sampling of healthcare workers in selected health facilities in the EC, a cross-sectional study of 2250 participants will be recruited. In order to assess the community infection rate, 750 antenatal women in the same settings will be recruited. Relevant demographic and clinical characteristics will be obtained by a self-administered questionnaire. A chemiluminescent microparticle immunoassay (CMIA) will be used for the qualitative detection of IgG antibodies against SARS-CoV-2 nucleocapsid protein. A nested cohort study will be conducted by performing eight-weekly antibody assays (X2) from 201 participants who tested positive for both SARS-CoV-2 RT-PCR and serology. Logistic regression models will be fitted to identify the independent risk factors for SARS-CoV-2 infection. The cumulative SARS-CoV-2 infection rate and infection fatality rate among the frontline HCWs will be estimated. In addition, the study will highlight the overall effectiveness of infection prevention and control measures (IPC) per exposure sites/wards at the selected health facilities. Findings will inform the South African Department of Health’s policies on how to protect HCWs better as the country prepares for the second wave of the SARS-CoV pandemic.

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A 6-Year Review of Carbapenemase-Producing Organisms in Alberta, Canada

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2020.608 ◽

2020 ◽

Vol 41 (S1) ◽

pp. s104-s105

Author(s):

Ye Shen ◽

Jennifer Ellison ◽

Uma Chandran ◽

Sumana Fathima ◽

Jamil Kanji ◽

...

Keyword(s):

Acute Care ◽

Management Practices ◽

Hospital Setting ◽

Data Sources ◽

Infection Prevention And Control ◽

Term Care ◽

Carbapenemase Gene ◽

Care Facilities ◽

Hospital Acquired ◽

Alberta Health

Background: This review describes the epidemiology of carbapenemase-producing organisms (CPO) in both the community and hospitalized populations in the province of Alberta. Methods: Newly identified CPO-positive individuals from April 1, 2013, to March 31, 2018, were retrospectively reviewed from 3 data sources, which shared a common provincial CPO case definition: (1) positive CPO results from the Provincial Laboratory for Public Health, which provides all referral and confirmatory CPO testing, (2) CPO cases reported to Alberta Health, and (3) CPO surveillance from Alberta Health Services Infection Prevention and Control (IPC). The 3 data sources were collated, and initial CPO cases were classified according to their likely location of acquisition: hospital-acquired, hospital-identified, on admission, and community-identified. Risk factors and adverse outcomes were obtained from linkage to administrative data. Results: In total, 171 unique individuals were newly identified with a first-time CPO case. Also, 15% (25 of 171) were hospital-acquired (HA), 21% (36 of 171) were hospital-identified (HI), 33% (57 of 171) were on admission, and 31% (53 of 171) were community identified. Overall, 9% (5 of 171) resided in long-term care facilities. Of all patients in acute-care facilities, 30% (35 of 118) had infections and 70% were colonized. Overall, 38% (65 of 171) had an acute-care admission in the 1 year prior to CPO identification; 59% (63 of 106) of those who did not have a previous admission had received healthcare outside Alberta. A large proportion of on-admission cases (81%, 46 of 57) and community-identified (66%, 33 of 53) cases did not have any acute-care admissions in Alberta in the previous year. Overall, 10% (14 of 171) had ICU admissions in Alberta within 30 days of CPO identification, and 5% (8 of 171) died within 30 days. The most common carbapenemase gene identified was NDM-1 (53%, 90 of 171). Conclusions: These findings highlight the robust nature of Alberta’s provincial CPO surveillance network. We reviewed 3 different databases (laboratory, health ministry, IPC) to obtain comprehensive data to better understand the epidemiology of CPO in both the community and hospital settings. More than half of the individuals with CPO were initially identified in the community or on admission. Most had received healthcare outside Alberta, and no acute-care admissions occurred in Alberta in the previous year. It is important to be aware of the growing reservoir of CPO outside the hospital setting because it could impact future screening and management practices.Funding: NoneDisclosures: None

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The contribution of hospital-acquired infections to the COVID-19 epidemic in England in the first half of 2020

10.1101/2021.09.02.21262480 ◽

2021 ◽

Author(s):

Gwenan M. Knight ◽

Thi Mui Pham ◽

James Stimson ◽

Sebastian Funk ◽

Yalda Jafari ◽

...

Keyword(s):

Medical Research ◽

Symptom Onset ◽

Research Council ◽

Medical Research Council ◽

National Level ◽

Hospital Setting ◽

Hospital Acquired Infections ◽

Hospitalised Patients ◽

Total Burden ◽

Hospital Acquired

AbstractBackgroundSARS-CoV-2 spreads in hospitals, but the contribution of these settings to the overall COVID-19 burden at a national level is unknown.MethodsWe used comprehensive national English datasets and simulation modelling to determine the total burden (identified and unidentified) of symptomatic hospital-acquired infections. Those unidentified would either be 1) discharged before symptom onset (“missed”), or 2) have symptom onset 7 days or fewer from admission (“misclassified”). We estimated the contribution of “misclassified” cases and transmission from “missed” symptomatic infections to the English epidemic before 31st July 2020.FindingsIn our dataset of hospitalised COVID-19 patients in acute English Trusts with a recorded symptom onset date (n = 65,028), 7% were classified as hospital-acquired (with symptom onset 8 or more days after admission and before discharge). We estimated that only 30% (range across weeks and 200 simulations: 20-41%) of symptomatic hospital-acquired infections would be identified. Misclassified cases and onward transmission from missed infections could account for 15% (mean, 95% range over 200 simulations: 14·1%-15·8%) of cases currently classified as community-acquired COVID-19.From this, we estimated that 26,600 (25,900 to 27,700) individuals acquired a symptomatic SARS-CoV-2 infection in an acute Trust in England before 31st July 2020, resulting in 15,900 (15,200-16,400) or 20.1% (19.2%-20.7%) of all identified hospitalised COVID-19 cases.ConclusionsTransmission of SARS-CoV-2 to hospitalised patients likely caused approximately a fifth of identified cases of hospitalised COVID-19 in the “first wave”, but fewer than 1% of all SARS-CoV-2 infections in England. Using symptom onset as a detection method for hospital-acquired SARS-CoV-2 likely misses a substantial proportion (>60%) of hospital-acquired infections.FundingNational Institute for Health Research, UK Medical Research Council, Society for Laboratory Automation and Screening, UKRI, Wellcome Trust, Singapore National Medical Research Council.Research in contextEvidence before this studyWe searched PubMed with the terms “((national OR country) AND (contribution OR burden OR estimates) AND (“hospital-acquired” OR “hospital-associated” OR “nosocomial”)) AND Covid-19” for articles published in English up to July 1st 2021. This identified 42 studies, with no studies that had aimed to produce comprehensive national estimates of the contribution of hospital settings to the COVID-19 pandemic. Most studies focused on estimating seroprevalence or levels of infection in healthcare workers only, which were not our focus. Removing the initial national/country terms identified 120 studies, with no country level estimates. Several single hospital setting estimates exist for England and other countries, but the percentage of hospital-associated infections reported relies on identified cases in the absence of universal testing.Added value of this studyThis study provides the first national-level estimates of all symptomatic hospital-acquired infections with SARS-CoV-2 in England up to the 31st July 2020. Using comprehensive data, we calculate how many infections would be unidentified and hence can generate a total burden, impossible from just notification data. Moreover, our burden estimates for onward transmission suggest the contribution of hospitals to the overall infection burden.Implications of all the available evidenceLarge numbers of patients may become infected with SARS-CoV-2 in hospitals though only a small proportion of such infections are identified. Further work is needed to better understand how interventions can reduce such transmission and to better understand the contributions of hospital transmission to mortality.

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No Spread of SARS-CoV-2 From Infected Symptomatic Children to Parents: A Prospective Cohort Study in a Controlled Hospital Setting

Frontiers in Pediatrics ◽

10.3389/fped.2021.720084 ◽

2021 ◽

Vol 9 ◽

Author(s):

Francesco Nunziata ◽

Marco Poeta ◽

Edoardo Vassallo ◽

Grazia Isabella Continisio ◽

Andrea Lo Vecchio ◽

...

Keyword(s):

Cohort Study ◽

Prolonged Exposure ◽

Index Case ◽

Close Contact ◽

Hospital Setting ◽

Experimental Conditions ◽

Transmission Rates ◽

Hospitalization Period ◽

Quasi Experimental ◽

The Mean

Introduction: The transmission rates severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from children to adults are unclear due to a lack of controlled conditions.Materials and Methods: We investigated the occurrence of SARS-CoV-2 transmission among 12 discordant child-parent pairs in our ward. In each hospital isolation room, caregivers and children lived in close contact during the entire hospitalization period.Results: A total of 136 swab-positive children (mean age, 3.6 ± 4.9 median age, 1; IQR 0–6.2, range 0.1–17) attended by their caregivers were hospitalized. Of those, 12/136 (8.8%, mean age, 6.1 ± 5.3 median age, 4.5) were attended by caregivers who were swab and serology negative at admission despite previous close contact with positive children at home. Three children were completely dependent on their mothers, one of whom was being breastfed. The mean duration of overall exposure to the index case was 20.5 ± 8.2 days.Conclusion: None of the infected children transmitted SARS-CoV-2 infection to their caregivers, raising the hypothesis of a cluster of resistant mothers or of limited transmission from children to adults despite prolonged exposure and close contact. These data might provide reassurance regarding school openings and offer the chance of investigating SARS-CoV-2 variants in the future under the same quasi-experimental conditions.

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Whole-genome Sequencing to Track Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Transmission in Nosocomial Outbreaks

Clinical Infectious Diseases ◽

10.1093/cid/ciaa1433 ◽

2020 ◽

Cited By ~ 6

Author(s):

Mary Lucey ◽

Guerrino Macori ◽

Niamh Mullane ◽

Una Sutton-Fitzpatrick ◽

Gabriel Gonzalez ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Genome Sequencing ◽

Close Contact ◽

Clinical Care ◽

Virus Genome ◽

Control Measures ◽

Infection Prevention And Control ◽

Route Of Transmission ◽

Hospital Acquired ◽

And Control

Abstract Background During the first wave of the coronavirus disease 2019 (COVID-19) pandemic, outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in healthcare institutions posed a significant problem. Due to limited evidence, guidance on appropriate infection prevention and control (IPC) measures such as the wearing of face masks varied. Here, we applied whole virus genome sequencing (WvGS) to analyze transmission routes of SARS-CoV-2 in hospital-acquired (HA) COVID-19. Methods An investigation was undertaken for all HA cases of COVID-19 from March to April 2020. Fifty SARS-CoV-2 samples were analysed by WvGS and their phylogenetic relationship established. Results WvGS identified transmission events previously undetected by epidemiological analysis and provided evidence for SARS-CoV-2 transmission between healthcare workers (HCW) and patients and among HCW themselves. The majority of HA COVID-19 cases occurred in patients highly dependent on nursing care, suggesting the likely route of transmission was by close contact or droplet, rather than aerosol, transmission. Mortality among HA COVID-19 infections was recorded as 33%. Conclusions This study provides evidence that SARS-CoV-2 transmission occurs from symptomatic and asymptomatic HCWs to patients. Interventions including comprehensive screening of HCWs for COVID-19 symptoms, PCR testing of asymptomatic HCWs upon identification of HA cases and implementation of universal use of surgical masks for all clinical care is indicated to prevent viral transmission. Our study highlights the importance of close collaboration between guidance bodies and frontline IPC experts for developing control measures in an emergency pandemic situation caused by a virus with undefined transmission modus.

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Nosocomial Transmission of Coronavirus Disease 2019: A Retrospective Study of 66 Hospital-acquired Cases in a London Teaching Hospital

Clinical Infectious Diseases ◽

10.1093/cid/ciaa816 ◽

2020 ◽

Cited By ~ 18

Author(s):

Hannah M Rickman ◽

Tommy Rampling ◽

Karen Shaw ◽

Gema Martinez-Garcia ◽

Leila Hail ◽

...

Keyword(s):

Teaching Hospital ◽

Infection Prevention ◽

Case Fatality ◽

Control Measures ◽

Infection Prevention And Control ◽

Infection Rates ◽

Prevention And Control Measures ◽

Healthcare Associated ◽

Hospital Acquired ◽

And Control

Abstract Coronavirus disease 2019 (COVID-19) can cause deadly healthcare-associated outbreaks. In a major London teaching hospital, 66 of 435 (15%) COVID-19 inpatient cases between 2 March and 12 April 2020 were definitely or probably hospital-acquired, through varied transmission routes. The case fatality was 36%. Nosocomial infection rates fell following comprehensive infection prevention and control measures.

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Comparing the epidemiology of hospital-acquired methicillin-resistant Staphylococcus aureus clone groups in Alberta, Canada

Epidemiology and Infection ◽

10.1017/s0950268816000376 ◽

2016 ◽

Vol 144 (10) ◽

pp. 2184-2190 ◽

Cited By ~ 1

Author(s):

S. BRUZZESE ◽

K. BUSH ◽

J. LEAL ◽

J. KIM ◽

D. M. VICKERS ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Acute Care ◽

Infection Prevention ◽

Care Setting ◽

Hospital Setting ◽

Community Setting ◽

Infection Prevention And Control ◽

Methicillin Resistant ◽

Hospital Acquired ◽

And Control

SUMMARYPatients with methicillin-resistant Staphylococcus aureus (MRSA) clones, which were traditionally seen in the community setting (USA400/CMRSA7 and USA300/CMRSA10), are often identified as hospital-acquired (HA) infections using Infection Prevention and Control (IPC) surveillance definitions. This study examined the demographics and healthcare risk factors of patients with HA-MRSA to help understand if community MRSA clones are from a source internal or external to the hospital setting. Despite USA300/CMRSA10 being the predominant clone in Alberta, hospital clones (USA100/CMRSA2) still dominated in the acute care setting. In the Alberta hospitalized population, patients with USA400/CMRSA7 and USA300/CMRSA10 clones were significantly younger, had fewer comorbidities, and a greater proportion had none or ambulatory care-only healthcare exposure. These findings suggest that there are two distinct populations of HA-MRSA patients, and the patients with USA400/CMRSA7 and USA300/CMRSA10 clones identified in hospital more greatly resemble patients affected by those clones in the community. It is possible that epidemiological assessment overidentifies HA acquisition of MRSA in patients unscreened for MRSA on admission to acute care.

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112 Outbreak of Carbapenemase-Producing Enterobacteriaceae in a Regional Burn Centre

Journal of Burn Care & Research ◽

10.1093/jbcr/irab032.116 ◽

2021 ◽

Vol 42 (Supplement_1) ◽

pp. S75-S75

Author(s):

Sarah Rehou ◽

Sydney Rotman ◽

Melisa Avaness ◽

Marc G Jeschke ◽

Shahriar Shahrokhi

Keyword(s):

Infection Control ◽

Total Body Surface Area ◽

Skin Barrier ◽

Control Measures ◽

Infection Prevention And Control ◽

Environmental Cleaning ◽

Infection Control Measures ◽

Potential Source ◽

Total Body ◽

Hospital Acquired

Abstract Introduction Antimicrobial resistance is an increasing problem in hospitals worldwide, though the prevalence of carbapenemase-producing Enterobacteriaceae (CPE) in our region is low. Burn patients are among the most vulnerable to infection because of the loss of the protective skin barrier. Because of this, burn centres prioritize infection prevention and control with measures like additional precautions, enhanced environmental cleaning, dedicated facilities, and mandatory use of personal protective equipment (PPE). Methods This report describes a CPE outbreak in a regional burn centre. We hypothesized that contamination of in-room hand hygiene sinks with CPE was a potential source of transmission. In a period of 2.5 months, four nosocomial cases of CPE were identified, three containing the KPC gene and one VIM gene. There was more than one month between the first and second KPC case, with no overlap in patient stay or rooms. Results The first two cases were identified while there was no CPE patient source on the unit. CPE KPC gene was isolated in sink drains of three different rooms. In addition to the rigorous infection control practices already in place due to the unique patient population, additional outbreak control measures were implemented. The burn centre restricted admissions to complex burns or burns >10% total body surface area, in consultation with the attending surgeon. No elective admissions were permitted. To avoid CPE exposure to new patients, initial admissions were rerouted to the emergency department and, if possible, the patient was admitted to another unit. Patient cohorting was implemented through nursing team separation for CPE positive and negative patients and geographical separation of CPE positive cases to one side of the unit. Conclusions Despite aggressive infection control measures already in place at our burn centre, there was hospital acquired CPE colonization/infection. Given there was CPE acquisition when there was no positive patients on the unit and CPE contaminated sinks of the same enzyme were identified, it suggests that hospital sink drains can become a potential source of CPE.

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