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1.
CMAJ Open ; 10(2): E400-E408, 2022.
Article in English | MEDLINE | ID: covidwho-1818693

ABSTRACT

BACKGROUND: In Canada, published outcome data for COVID-19 come largely from the first 2 waves of the pandemic. We examined changes in demographics and 30-day outcomes after SARS-CoV-2 infection during the first 3 pandemic waves in Alberta and Ontario; for wave 3, we compared outcomes between those infected with a variant of concern and those infected with the original "wild-type" SARS-CoV-2. METHODS: We conducted a population-based retrospective cohort study using linked health care data sets in Alberta and Ontario. We identified all-cause hospitalizations or deaths within 30 days after a positive result on a reverse transcription polymerase chain reaction test for SARS-CoV-2 in individuals of any age between Mar. 1, 2020, and June 30, 2021, with genomic confirmation of variants of concern. We compared outcomes in wave 3 (February 2021 to June 2021) with outcomes in waves 1 and 2 combined (March 2020 to January 2021) after adjusting for age, sex and Charlson Comorbidity Index score. Using wave 3 data only, we compared outcomes by vaccination status and whether or not the individual was infected with a variant of concern. RESULTS: Compared to those infected with SARS-CoV-2 during waves 1 and 2 (n = 372 070), we found a shift toward a younger and healthier demographic in those infected during wave 3 (n = 359 079). In wave 3, patients were more likely to be hospitalized (adjusted odds ratio [aOR] 1.57, 95% confidence interval [CI] 1.46-1.70) but had a shorter length of hospital stay (median 6 days v. 7 days, p < 0.001) and lower 30-day mortality (aOR 0.73, 95% CI 0.65-0.81). The 217 892 patients in wave 3 who were infected with a variant of concern (83.5% confirmed to have the Alpha variant, 1.7% confirmed to have the Delta variant) had a higher risk of death (Alpha: aOR 1.29, 95% CI 1.16-1.44; Delta: aOR 2.05, 95% CI 1.49-2.82) and hospitalization (Alpha: aOR 1.59, 95% CI 1.53-1.66; Delta: aOR 1.88, 95% CI 1.64-2.15) than those infected with wild-type SARS-CoV-2. INTERPRETATION: We observed a shift among those infected with SARS-CoV-2 toward younger patients with fewer comorbidities, a shorter length of hospital stay and lower mortality risk as the pandemic evolved in Alberta and Ontario; however, infection with a variant of concern was associated with a substantially higher risk of hospitalization or death. As variants of concern emerge, ongoing monitoring of disease expression and outcomes among vaccinated and unvaccinated individuals is important to understand the phenotypes of COVID-19 and the anticipated burdens for the health care system.


Subject(s)
COVID-19 , Alberta/epidemiology , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/prevention & control , Cohort Studies , Demography , Humans , Ontario/epidemiology , Retrospective Studies , SARS-CoV-2/genetics , Vaccination
2.
BMC Health Serv Res ; 22(1): 544, 2022 Apr 23.
Article in English | MEDLINE | ID: covidwho-1799102

ABSTRACT

BACKGROUND: As of November 25th 2021, four SARS-CoV - 2 variants of concern (VOC: Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), and Delta (B.1.617.2)) have been detected. Variable degrees of increased transmissibility of the VOC have been documented, with potential implications for hospital and health system capacity and control measures. This rapid review aimed to provide a synthesis of evidence related to health system responses to the emergence of VOC worldwide. METHODS: Seven databases were searched up to September 27, 2021, for terms related to VOC. Titles, abstracts, and full-text documents were screened independently by two reviewers. Data were extracted independently by two reviewers using a standardized form. Studies were included if they reported on at least one of the VOC and health system outcomes. RESULTS: Of the 4877 articles retrieved, 59 studies were included, which used a wide range of designs and methods. Most of the studies reported on Alpha, and all except two reported on impacts for capacity planning related to hospitalization, intensive care admissions, and mortality. Most studies (73.4%) observed an increase in hospitalization, but findings on increased admission to intensive care units were mixed (50%). Most studies (63.4%) that reported mortality data found an increased risk of death due to VOC, although health system capacity may influence this. No studies reported on screening staff and visitors or cohorting patients based on VOC. CONCLUSION: While the findings should be interpreted with caution as most of the sources identified were preprints, evidence is trending towards an increased risk of hospitalization and, potentially, mortality due to VOC compared to wild-type SARS-CoV - 2. There is little evidence on the need for, and the effect of, changes to health system arrangements in response to VOC transmission.


Subject(s)
COVID-19 , SARS Virus , COVID-19/epidemiology , Hospitalization , Humans , SARS-CoV-2
3.
Ann Intern Med ; 175(1): JC5, 2022 01.
Article in English | MEDLINE | ID: covidwho-1634464

ABSTRACT

SOURCE CITATION: O'Brien MP, Forleo-Neto E, Musser BJ, et al. Subcutaneous REGEN-COV antibody combination to prevent Covid-19. N Engl J Med. 2021;385:1184-95. 34347950.


Subject(s)
COVID-19 , Antibodies, Monoclonal, Humanized , Antibodies, Neutralizing , Drug Combinations , Humans , SARS-CoV-2
4.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-294641

ABSTRACT

Objectives This is an update of a previous report that examined literature published up to March 11th, 2021. Sixteen additional studies have been included in this update. The objective of this report is to identify comparative observational studies and randomized controlled trials (RCTs) evaluating the efficacy and effectiveness of COVID-19 vaccination in reducing forward transmission from vaccinated people, and studies examining the biological plausibility of vaccination-induced transmission reduction. Method A search of databases, MEDLINE, Embase, L-OVE and the Cochrane Central Register of Controlled Trials was conducted to identify RCTs or comparative observational studies evaluating the efficacy and effectiveness of COVID-19 vaccination in the prevention of transmission, asymptomatic infections and transmissibility of COVID-19 among vaccinated persons. An additional search of grey literature was conducted. This search is current to May 4th, 2021. Results In this update, 16 additional studies, including 9 human and 7 animal studies, were included. Therefore, this review examines a total of 33 included studies: 21 human studies and 12 preclinical animal studies. Evidence from two large household surveillance studies from the UK suggests that a single or full dose of AstraZeneca (AZ) and Pfizer-BioNtech (PfBnT) vaccines may prevent household transmission of COVID-19 after 14 days of vaccination by up to 54%. The AZ vaccine trials in the general population suggest that an initial low dose followed by a standard dose may provide up to 59% protection against asymptomatic or unknown infection, although efficacy against these outcomes was not demonstrated following two standard doses. PfBnT vaccine observational studies in the general population suggest up to 90% effectiveness against asymptomatic infection after seven or more days of full dose vaccination. Up to 75% effectiveness against asymptomatic infection was reported after full- dose in healthcare workers. Across RCTs examining asymptomatic infection in the general population, one dose of Moderna was shown to provide an efficacy of 61.4% against asymptomatic infection 21 days after the first dose;in another trial, the J&J vaccine had an efficacy of 74% 28 days after the first dose. Lastly, seven of eight studies found significantly increased cycle threshold, suggestive of lower viral load, in PfBnT or AZ vaccinated individuals compared with those who were unvaccinated. Conclusion The AZ and PfBnT vaccines may prevent household transmission of COVID-19 after 14 days of vaccination. More studies have found the vaccines to significantly reduce the risk of asymptomatic infection and significantly increase cycle threshold, suggestive of lower viral load. Further research is needed to evaluate post-vaccination infectivity and transmission of both the wild type COVID-19 virus and the variants of concern from other jurisdictions.

5.
BMJ Open ; 11(12): e055781, 2021 12 02.
Article in English | MEDLINE | ID: covidwho-1550965

ABSTRACT

OBJECTIVES: The four SARS-CoV-2 variants of concern (VOC; Alpha, Beta, Gamma and Delta) identified by May 2021 are highly transmissible, yet little is known about their impact on public health measures. We aimed to synthesise evidence related to public health measures and VOC. DESIGN: A rapid scoping review. DATA SOURCES: On 11 May 2021, seven databases (MEDLINE, Embase, the Cochrane Database of Systematic Reviews, Central Register of Controlled Trials, Epistemonikos' L-OVE on COVID-19, medRxiv, bioRxiv) were searched for terms related to VOC, public health measures, transmission and health systems. No limit was placed on date of publication. ELIGIBILITY CRITERIA: Studies were included if they reported on any of the four VOCs and public health measures, and were available in English. Only studies reporting on data collected after October 2020, when the first VOC was reported, were included. DATA EXTRACTION AND SYNTHESIS: Titles, abstracts and full-text articles were screened by two independent reviewers. Data extraction was completed by two independent reviewers using a standardised form. Data synthesis and reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. RESULTS: Of the 37 included studies, the majority assessed the impact of Alpha (n=32) and were conducted in Europe (n=12) or the UK (n=9). Most were modelling studies (n=28) and preprints (n=28). The majority of studies reported on infection control measures (n=17), followed by modifying approaches to vaccines (n=13), physical distancing (n=6) and either mask wearing, testing or hand washing (n=2). Findings suggest an accelerated vaccine rollout is needed to mitigate the spread of VOC. CONCLUSIONS: The increased severity of VOC requires proactive public health measures to control their spread. Further research is needed to strengthen the evidence for continued implementation of public health measures in conjunction with vaccine rollout. With no studies reporting on Delta, there is a need for further research on this and other emerging VOC on public health measures.


Subject(s)
COVID-19 , SARS-CoV-2 , Hand Disinfection , Humans , Public Health
6.
Sci Rep ; 11(1): 17787, 2021 09 07.
Article in English | MEDLINE | ID: covidwho-1397899

ABSTRACT

Despite COVID-19's significant morbidity and mortality, considering cost-effectiveness of pharmacologic treatment strategies for hospitalized patients remains critical to support healthcare resource decisions within budgetary constraints. As such, we calculated the cost-effectiveness of using remdesivir and dexamethasone for moderate to severe COVID-19 respiratory infections using the United States health care system as a representative model. A decision analytic model modelled a base case scenario of a 60-year-old patient admitted to hospital with COVID-19. Patients requiring oxygen were considered moderate severity, and patients with severe COVID-19 required intubation with intensive care. Strategies modelled included giving remdesivir to all patients, remdesivir in only moderate and only severe infections, dexamethasone to all patients, dexamethasone in severe infections, remdesivir in moderate/dexamethasone in severe infections, and best supportive care. Data for the model came from the published literature. The time horizon was 1 year; no discounting was performed due to the short duration. The perspective was of the payer in the United States health care system. Supportive care for moderate/severe COVID-19 cost $11,112.98 with 0.7155 quality adjusted life-year (QALY) obtained. Using dexamethasone for all patients was the most-cost effective with an incremental cost-effectiveness ratio of $980.84/QALY; all remdesivir strategies were more costly and less effective. Probabilistic sensitivity analyses showed dexamethasone for all patients was most cost-effective in 98.3% of scenarios. Dexamethasone for moderate-severe COVID-19 infections was the most cost-effective strategy and would have minimal budget impact. Based on current data, remdesivir is unlikely to be a cost-effective treatment for COVID-19.


Subject(s)
COVID-19/drug therapy , COVID-19/therapy , Health Care Costs/statistics & numerical data , Health Care Rationing/economics , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/economics , Adenosine Monophosphate/therapeutic use , Alanine/analogs & derivatives , Alanine/economics , Alanine/therapeutic use , COVID-19/diagnosis , COVID-19/economics , COVID-19/mortality , COVID-19/virology , Clinical Decision-Making/methods , Computer Simulation , Cost-Benefit Analysis , Dexamethasone/economics , Dexamethasone/therapeutic use , Health Care Rationing/organization & administration , Humans , Intensive Care Units/economics , Intensive Care Units/statistics & numerical data , Middle Aged , Oxygen/administration & dosage , Oxygen/economics , Quality-Adjusted Life Years , Respiration, Artificial/economics , SARS-CoV-2 , Severity of Illness Index , Treatment Outcome , United States/epidemiology
9.
CMAJ Open ; 8(4): E887-E894, 2020.
Article in English | MEDLINE | ID: covidwho-1000597

ABSTRACT

BACKGROUND: The prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among asymptomatic patients admitted to hospital has implications for personal protective equipment use, testing strategy and confidence in the safety of acute care services. Our aim was to estimate the positivity rate of reverse transcription polymerase chain reaction (RT-PCR) testing among people admitted to hospital without symptoms of coronavirus disease 2019 (COVID-19) in Alberta, Canada. METHODS: Between Apr. 9 and May 24, 2020, we screened for COVID-19 symptoms and tested for SARS-CoV-2 infection in all consecutive adult patients (≥ 18 yr) admitted via emergency department to 3 Alberta hospitals. We summarized the parameters of the epidemic curve and assessed the performance of symptom screening versus RT-PCR results on nasopharyngeal or oropharyngeal swab samples. RESULTS: The study period encompassed Alberta's initial epidemic curve, with peak active cases per 100 000 of 71.4 (0.07%) on Apr. 30, 2020, and 14.7 and 14.6 at the beginning (Apr. 9, 2020) and end (May 24, 2020), respectively. Testing for SARS-CoV-2 infection (64.9% throat and 35.1% nasopharyngeal swabs) was done on 3375 adults (mean age 51, standard deviation 21, yr; 51.5% men). None of the asymptomatic patients (n = 1814) tested positive, and 71 of those with symptoms tested positive (n = 1561; 4.5%, 95% confidence interval [CI] 3.6%-5.7%). Sensitivity of symptom screening (v. RT-PCR) was 100% (95% CI 95%-100%), and specificity was 55% (95% CI 53%-57%). Posttest probabilities for prevalence of SARS-CoV-2 infection ranging from 1.5 to 14 times the peak prevalence of active cases during the study did not change when we assumed lower sensitivity (92%). INTERPRETATION: In a region with low disease prevalence where protocolized symptom assessment was in place during the admission process, we did not identify people admitted to hospital without COVID-19 symptoms who were RT-PCR positive. There may not be additive benefit to universal testing of asymptomatic patients on hospital admission in a setting of low pretest probability and strong public health containment.


Subject(s)
Asymptomatic Diseases/epidemiology , COVID-19/epidemiology , Clinical Laboratory Techniques/standards , Emergency Service, Hospital/statistics & numerical data , Mass Screening/methods , Quality Improvement , Alberta/epidemiology , COVID-19/diagnosis , Comorbidity , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , SARS-CoV-2
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