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2.
J Travel Med ; 2022 Feb 23.
Article in English | MEDLINE | ID: covidwho-1722536

ABSTRACT

We identified the U.S. airports and metropolitan areas, particularly New York City, Miami, and Los Angeles, that were the most likely locations of importation and domestic spread of Omicron from South Africa. Vaccination coverage suggested that several cities in Georgia, Texas, and Utah were particularly vulnerable to public health impacts.

3.
JAMA Netw Open ; 5(2): e2146798, 2022 02 01.
Article in English | MEDLINE | ID: covidwho-1694847

ABSTRACT

Importance: The incidence of infection during SARS-CoV-2 viral waves, the factors associated with infection, and the durability of antibody responses to infection among Canadian adults remain undocumented. Objective: To assess the cumulative incidence of SARS-CoV-2 infection during the first 2 viral waves in Canada by measuring seropositivity among adults. Design, Setting, and Participants: The Action to Beat Coronavirus study conducted 2 rounds of an online survey about COVID-19 experience and analyzed immunoglobulin G levels based on participant-collected dried blood spots (DBS) to assess the cumulative incidence of SARS-CoV-2 infection during the first and second viral waves in Canada. A sample of 19 994 Canadian adults (aged ≥18 years) was recruited from established members of the Angus Reid Forum, a public polling organization. The study comprised 2 phases (phase 1 from May 1 to September 30, 2020, and phase 2 from December 1, 2020, to March 31, 2021) that generally corresponded to the first (April 1 to July 31, 2020) and second (October 1, 2020, to March 1, 2021) viral waves. Main Outcomes and Measures: SARS-CoV-2 immunoglobulin G seropositivity (using a chemiluminescence assay) by major geographic and demographic variables and correlation with COVID-19 symptom reporting. Results: Among 19 994 adults who completed the online questionnaire in phase 1, the mean (SD) age was 50.9 (15.4) years, and 10 522 participants (51.9%) were female; 2948 participants (14.5%) had self-identified racial and ethnic minority group status, and 1578 participants (8.2%) were self-identified Indigenous Canadians. Among participants in phase 1, 8967 had DBS testing. In phase 2, 14 621 adults completed online questionnaires, and 7102 of those had DBS testing. Of 19 994 adults who completed the online survey in phase 1, fewer had an educational level of some college or less (4747 individuals [33.1%]) compared with the general population in Canada (45.0%). Survey respondents were otherwise representative of the general population, including in prevalence of known risk factors associated with SARS-CoV-2 infection. The cumulative incidence of SARS-CoV-2 infection among unvaccinated adults increased from 1.9% in phase 1 to 6.5% in phase 2. The seropositivity pattern was demographically and geographically heterogeneous during phase 1 but more homogeneous by phase 2 (with a cumulative incidence ranging from 6.4% to 7.0% in most regions). The exception was the Atlantic region, in which cumulative incidence reached only 3.3% (odds ratio [OR] vs Ontario, 0.46; 95% CI, 0.21-1.02). A total of 47 of 188 adults (25.3%) reporting COVID-19 symptoms during phase 2 were seropositive, and the OR of seropositivity for COVID-19 symptoms was 6.15 (95% CI, 2.02-18.69). In phase 2, 94 of 444 seropositive adults (22.2%) reported having no symptoms. Of 134 seropositive adults in phase 1 who were retested in phase 2, 111 individuals (81.8%) remained seropositive. Participants who had a history of diabetes (OR, 0.58; 95% CI, 0.38-0.90) had lower odds of having detectable antibodies in phase 2. Conclusions and Relevance: The Action to Beat Coronavirus study found that the incidence of SARS-CoV-2 infection in Canada was modest until March 2021, and this incidence was lower than the levels of population immunity required to substantially reduce transmission of the virus. Ongoing vaccination efforts remain central to reducing viral transmission and mortality. Assessment of future infection-induced and vaccine-induced immunity is practicable through the use of serial online surveys and participant-collected DBS.


Subject(s)
COVID-19 Serological Testing/statistics & numerical data , COVID-19/epidemiology , Immunoglobulin G/blood , Adolescent , Adult , Aged , COVID-19/immunology , Canada/epidemiology , Female , Humans , Incidence , Male , Middle Aged , Pandemics , SARS-CoV-2 , Surveys and Questionnaires
4.
Ann Intern Med ; 174(2): 283-284, 2021 02.
Article in English | MEDLINE | ID: covidwho-1553980
6.
Chest ; 161(4): 989-998, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1466218

ABSTRACT

Patients admitted to the ICU with critical COVID-19 often require prolonged periods of mechanical ventilation. Difficulty weaning, lack of progress, and clinical deterioration are commonly encountered. These conditions should prompt a thorough evaluation for persistent or untreated manifestations of COVID-19, as well as complications from COVID-19 and its various treatments. Inflammation may persist and lead to fibroproliferative changes in the lungs. Infectious complications may arise including bacterial superinfection in the earlier stages of disease. Use of immunosuppressants may lead to the dissemination of latent infections, and to opportunistic infections. Venous thromboembolic disease is common, as are certain neurologic manifestations of COVID-19 including delirium and stroke. High levels of ventilatory support may lead to ventilator-induced injury to the lungs and diaphragm. We present diagnostic and therapeutic considerations for the mechanically ventilated patient with COVID-19 who shows persistent or worsening signs of critical illness, and we offer an approach to treating this complex but common scenario.


Subject(s)
COVID-19 , Respiration, Artificial , COVID-19/complications , Critical Illness/therapy , Diaphragm , Humans
7.
Lancet Reg Health Am ; 2: 100055, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1373179

ABSTRACT

BACKGROUND: Understanding vaccination intention during early vaccination rollout in Canada can help the government's efforts in vaccination education and outreach. METHOD: Panel members age 18 and over from the nationally representative Angus Reid Forum were invited to complete an online survey about their experience with COVID-19, including their intention to get vaccinated. Respondents were asked "When a vaccine against the coronavirus becomes available to you, will you get vaccinated or not?" Having no intention to vaccinate was defined as choosing "No - I will not get a coronavirus vaccination" as a response. Odds ratios and predicted probabilities are reported for no vaccine intentionality in demographic groups. FINDINGS: 14,621 panel members completed the survey. Having no intention to vaccinate against COVID-19 is relatively low overall (9%) with substantial variation among demographic groups. Being a resident of Alberta (predicted probability = 15%; OR 0.58 [95%CI 0.14-2.24]), aged 40-59 (predicted probability = 12%; OR 0.87 [0.78-0.97]), identifying as a visible minority (predicted probability = 15%; OR 0.56 [0.37-0.84]), having some college level education or lower (predicted probability = 14%) and living in households of at least five members (predicted probability = 13%; OR 0.82 [0.76-0.88]) are related to lower vaccination intention. INTERPRETATION: The study identifies population groups with greater and lesser intention to vaccinate in Canada. As the Canadian COVID-19 vaccination effort continues, policymakers may use this information to focus outreach, education, and other efforts on the latter groups, which also have had higher risks for contracting and dying from COVID-19. FUNDING: Pfizer Global Medical, Unity Health Foundation, Canadian COVID-19 Immunity Task Force.

9.
J Travel Med ; 27(2)2020 03 13.
Article in English | MEDLINE | ID: covidwho-1335914

ABSTRACT

There is currently an outbreak of pneumonia of unknown aetiology in Wuhan, China. Although there are still several unanswered questions about this infection, we evaluate the potential for international dissemination of this disease via commercial air travel should the outbreak continue.


Subject(s)
Air Travel , Betacoronavirus/isolation & purification , Coronavirus Infections/transmission , Pneumonia, Viral/transmission , Animals , Betacoronavirus/genetics , COVID-19 , China/epidemiology , Contact Tracing , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Humans , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Public Health , SARS-CoV-2 , Zoonoses
10.
BMC Infect Dis ; 21(1): 710, 2021 Jul 27.
Article in English | MEDLINE | ID: covidwho-1329108

ABSTRACT

Scientists across disciplines, policymakers, and journalists have voiced frustration at the unprecedented polarization and misinformation around coronavirus disease 2019 (COVID-19) pandemic. Several false dichotomies have been used to polarize debates while oversimplifying complex issues. In this comprehensive narrative review, we deconstruct six common COVID-19 false dichotomies, address the evidence on these topics, identify insights relevant to effective pandemic responses, and highlight knowledge gaps and uncertainties. The topics of this review are: 1) Health and lives vs. economy and livelihoods, 2) Indefinite lockdown vs. unlimited reopening, 3) Symptomatic vs. asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, 4) Droplet vs. aerosol transmission of SARS-CoV-2, 5) Masks for all vs. no masking, and 6) SARS-CoV-2 reinfection vs. no reinfection. We discuss the importance of multidisciplinary integration (health, social, and physical sciences), multilayered approaches to reducing risk ("Emmentaler cheese model"), harm reduction, smart masking, relaxation of interventions, and context-sensitive policymaking for COVID-19 response plans. We also address the challenges in understanding the broad clinical presentation of COVID-19, SARS-CoV-2 transmission, and SARS-CoV-2 reinfection. These key issues of science and public health policy have been presented as false dichotomies during the pandemic. However, they are hardly binary, simple, or uniform, and therefore should not be framed as polar extremes. We urge a nuanced understanding of the science and caution against black-or-white messaging, all-or-nothing guidance, and one-size-fits-all approaches. There is a need for meaningful public health communication and science-informed policies that recognize shades of gray, uncertainties, local context, and social determinants of health.


Subject(s)
COVID-19 , SARS-CoV-2 , Communicable Disease Control , Humans , Public Health , Reinfection
12.
BMC Public Health ; 21(1): 990, 2021 05 26.
Article in English | MEDLINE | ID: covidwho-1244918

ABSTRACT

BACKGROUND: Aggressive non-pharmaceutical interventions (NPIs) may reduce transmission of SARS-CoV-2. The extent to which these interventions are successful in stopping the spread have not been characterized in countries with distinct socioeconomic groups. We compared the effects of a partial lockdown on disease transmission among Kuwaitis (P1) and non-Kuwaitis (P2) living in Kuwait. METHODS: We fit a modified metapopulation SEIR transmission model to reported cases stratified by two groups to estimate the impact of a partial lockdown on the effective reproduction number ([Formula: see text]). We estimated the basic reproduction number ([Formula: see text]) for the transmission in each group and simulated the potential trajectories of an outbreak from the first recorded case of community transmission until 12 days after the partial lockdown. We estimated [Formula: see text] values of both groups before and after the partial curfew, simulated the effect of these values on the epidemic curves and explored a range of cross-transmission scenarios. RESULTS: We estimate [Formula: see text] at 1·08 (95% CI: 1·00-1·26) for P1 and 2·36 (2·03-2·71) for P2. On March 22nd, [Formula: see text] for P1 and P2 are estimated at 1·19 (1·04-1·34) and 1·75 (1·26-2·11) respectively. After the partial curfew had taken effect, [Formula: see text] for P1 dropped modestly to 1·05 (0·82-1·26) but almost doubled for P2 to 2·89 (2·30-3·70). Our simulated epidemic trajectories show that the partial curfew measure greatly reduced and delayed the height of the peak in P1, yet significantly elevated and hastened the peak in P2. Modest cross-transmission between P1 and P2 greatly elevated the height of the peak in P1 and brought it forward in time closer to the peak of P2. CONCLUSION: Our results indicate and quantify how the same lockdown intervention can accentuate disease transmission in some subpopulations while potentially controlling it in others. Any such control may further become compromised in the presence of cross-transmission between subpopulations. Future interventions and policies need to be sensitive to socioeconomic and health disparities.


Subject(s)
COVID-19 , SARS-CoV-2 , Communicable Disease Control , Humans , Kuwait/epidemiology , Socioeconomic Factors
13.
Crit Care Med ; 49(9): 1558-1566, 2021 09 01.
Article in English | MEDLINE | ID: covidwho-1191495

ABSTRACT

OBJECTIVES: Severe acute respiratory syndrome-related coronavirus-2 binds and inhibits angiotensin-converting enzyme-2. The frequency of acute cardiac injury in patients with coronavirus disease 2019 is unknown. The objective was to compare the rates of cardiac injury by angiotensin-converting enzyme-2-binding viruses from viruses that do not bind to angiotensin-converting enzyme-2. DATA SOURCES: We performed a systematic review of coronavirus disease 2019 literature on PubMed and EMBASE. STUDY SELECTION: We included studies with ten or more hospitalized adults with confirmed coronavirus disease 2019 or other viral pathogens that described the occurrence of acute cardiac injury. This was defined by the original publication authors or by: 1) myocardial ischemia, 2) new cardiac arrhythmia on echocardiogram, or 3) new or worsening heart failure on echocardiogram. DATA EXTRACTION: We compared the rates of cardiac injury among patients with respiratory infections with viruses that down-regulate angiotensin-converting enzyme-2, including H1N1, H5N1, H7N9, and severe acute respiratory syndrome-related coronavirus-1, to those with respiratory infections from other influenza viruses that do not bind angiotensin-converting enzyme-2, including Influenza H3N2 and influenza B. DATA SYNTHESIS: Of 57 studies including 34,072 patients, acute cardiac injury occurred in 50% (95% CI, 44-57%) of critically ill patients with coronavirus disease 2019. The overall risk of acute cardiac injury was 21% (95% CI, 18-26%) among hospitalized patients with coronavirus disease 2019. In comparison, 37% (95% CI, 26-49%) of critically ill patients with other respiratory viruses that bind angiotensin-converting enzyme-2 (p = 0.061) and 12% (95% CI, 7-22%) of critically ill patients with other respiratory viruses that do not bind angiotensin-converting enzyme-2 (p < 0.001) experienced a cardiac injury. CONCLUSIONS: Acute cardiac injury may be associated with whether the virus binds angiotensin-converting enzyme-2. Acute cardiac injury occurs in half of critically ill coronavirus disease 2019 patients, but only 12% of patients infected by viruses that do not bind to angiotensin-converting enzyme-2.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Angiotensin-Converting Enzyme Inhibitors , COVID-19/complications , Heart Failure/etiology , Influenza, Human/complications , Myocardial Ischemia/etiology , SARS-CoV-2/metabolism , Acute Disease , Arrhythmias, Cardiac/etiology , Down-Regulation , Humans , Influenza A virus/metabolism , Influenza B virus/metabolism
14.
Clin Microbiol Infect ; 27(4): 511-519, 2021 Apr.
Article in English | MEDLINE | ID: covidwho-1174178

ABSTRACT

BACKGROUND: Reports suggest that asymptomatic individuals (those with no symptoms at all throughout infection) with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are infectious, but the extent of transmission based on symptom status requires further study. PURPOSE: This living review aims to critically appraise available data about secondary attack rates from people with asymptomatic, pre-symptomatic and symptomatic SARS-CoV-2 infection. DATA SOURCES: Medline, EMBASE, China Academic Journals full-text database (CNKI), and pre-print servers were searched from 30 December 2019 to 3 July 2020 using relevant MESH terms. STUDY SELECTION: Studies that report on contact tracing of index cases with SARS-CoV-2 infection in either English or Chinese were included. DATA EXTRACTION: Two authors independently extracted data and assessed study quality and risk of bias. We calculated the secondary attack rate as the number of contacts with SARS-CoV-2, divided by the number of contacts tested. DATA SYNTHESIS: Of 927 studies identified, 80 were included. Summary secondary attack rate estimates were 1% (95% CI 0%-2%) with a prediction interval of 0%-10% for asymptomatic index cases in ten studies, 7% (95% CI 3%-11%) with a prediction interval of 1%-40% for pre-symptomatic cases in 11 studies and 6% (95% CI 5%-8%) with a prediction interval of 5%-38% for symptomatic index cases in 40 studies. The highest secondary attack rates were found in contacts who lived in the same household as the index case. Other activities associated with transmission were group activities such as sharing meals or playing board games with the index case, regardless of the disease status of the index case. LIMITATIONS: We excluded some studies because the index case or number of contacts were unclear. CONCLUSION: Asymptomatic patients can transmit SARS-CoV-2 to others, but our findings indicate that such individuals are responsible for fewer secondary infections than people with symptoms. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020188168.


Subject(s)
Asymptomatic Infections/epidemiology , COVID-19/transmission , COVID-19/epidemiology , Contact Tracing , Family Characteristics , Humans , Incidence
17.
JAMA Cardiol ; 6(7): 745-752, 2021 07 01.
Article in English | MEDLINE | ID: covidwho-1116911

ABSTRACT

Importance: The major North American professional sports leagues were among the first to return to full-scale sport activity during the coronavirus disease 2019 (COVID-19) pandemic. Given the unknown incidence of adverse cardiac sequelae after COVID-19 infection in athletes, these leagues implemented a conservative return-to-play (RTP) cardiac testing program aligned with American College of Cardiology recommendations for all athletes testing positive for COVID-19. Objective: To assess the prevalence of detectable inflammatory heart disease in professional athletes with prior COVID-19 infection, using current RTP screening recommendations. Design, Setting, and Participants: This cross-sectional study reviewed RTP cardiac testing performed between May and October 2020 on professional athletes who had tested positive for COVID-19. The professional sports leagues (Major League Soccer, Major League Baseball, National Hockey League, National Football League, and the men's and women's National Basketball Association) implemented mandatory cardiac screening requirements for all players who had tested positive for COVID-19 prior to resumption of team-organized sports activities. Exposures: Troponin testing, electrocardiography (ECG), and resting echocardiography were performed after a positive COVID-19 test result. Interleague, deidentified cardiac data were pooled for collective analysis. Those with abnormal screening test results were referred for additional testing, including cardiac magnetic resonance imaging and/or stress echocardiography. Main Outcomes and Measures: The prevalence of abnormal RTP test results potentially representing COVID-19-associated cardiac injury, and results and outcomes of additional testing generated by the initial screening process. Results: The study included 789 professional athletes (mean [SD] age, 25 [3] years; 777 men [98.5%]). A total of 460 athletes (58.3%) had prior symptomatic COVID-19 illness, and 329 (41.7%) were asymptomatic or paucisymptomatic (minimally symptomatic). Testing was performed a mean (SD) of 19 (17) days (range, 3-156 days) after a positive test result. Abnormal screening results were identified in 30 athletes (3.8%; troponin, 6 athletes [0.8%]; ECG, 10 athletes [1.3%]; echocardiography, 20 athletes [2.5%]), necessitating additional testing; 5 athletes (0.6%) ultimately had cardiac magnetic resonance imaging findings suggesting inflammatory heart disease (myocarditis, 3; pericarditis, 2) that resulted in restriction from play. No adverse cardiac events occurred in athletes who underwent cardiac screening and resumed professional sport participation. Conclusions and Relevance: This study provides large-scale data assessing the prevalence of relevant COVID-19-associated cardiac pathology with implementation of current RTP screening recommendations. While long-term follow-up is ongoing, few cases of inflammatory heart disease have been detected, and a safe return to professional sports activity has thus far been achieved.


Subject(s)
Athletes/statistics & numerical data , COVID-19/epidemiology , Heart Diseases/epidemiology , Mass Screening/methods , Adult , Comorbidity , Cross-Sectional Studies , Female , Humans , Male , Prevalence , Return to Sport , SARS-CoV-2 , United States/epidemiology , Young Adult
19.
Science ; 371(6530): 708-712, 2021 02 12.
Article in English | MEDLINE | ID: covidwho-1066806

ABSTRACT

The United Kingdom's COVID-19 epidemic during early 2020 was one of world's largest and was unusually well represented by virus genomic sampling. We determined the fine-scale genetic lineage structure of this epidemic through analysis of 50,887 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes, including 26,181 from the UK sampled throughout the country's first wave of infection. Using large-scale phylogenetic analyses combined with epidemiological and travel data, we quantified the size, spatiotemporal origins, and persistence of genetically distinct UK transmission lineages. Rapid fluctuations in virus importation rates resulted in >1000 lineages; those introduced prior to national lockdown tended to be larger and more dispersed. Lineage importation and regional lineage diversity declined after lockdown, whereas lineage elimination was size-dependent. We discuss the implications of our genetic perspective on transmission dynamics for COVID-19 epidemiology and control.


Subject(s)
COVID-19/epidemiology , COVID-19/virology , Genome, Viral , SARS-CoV-2/genetics , COVID-19/prevention & control , COVID-19/transmission , Chain of Infection , Communicable Disease Control , Communicable Diseases, Imported/epidemiology , Communicable Diseases, Imported/virology , Epidemics , Humans , Phylogeny , Travel , United Kingdom/epidemiology
20.
J Am Med Dir Assoc ; 22(3): 494-497, 2021 03.
Article in English | MEDLINE | ID: covidwho-1065277

ABSTRACT

OBJECTIVES: To assess changes in the mobility of staff between nursing homes in Ontario, Canada, before and after enactment of public policy restricting staff from working at multiple homes. DESIGN: Pre-post observational study. SETTING AND PARTICIPANTS: 623 nursing homes in Ontario, Canada, between March 2020 and June 2020. METHODS: We used GPS location data from mobile devices to approximate connectivity between all 623 nursing homes in Ontario during the 7 weeks before (March 1-April 21) and after (April 22-June 13) the policy restricting staff movement was implemented. We constructed a network diagram visualizing connectivity between nursing homes in Ontario and calculated the number of homes that had a connection with another nursing home and the average number of connections per home in each period. We calculated the relative difference in these mobility metrics between the 2 time periods and compared within-home changes using McNemar test and the Wilcoxon rank-sum test. RESULTS: In the period preceding restrictions, 266 (42.7%) nursing homes had a connection with at least 1 other home, compared with 79 (12.7%) homes during the period after restrictions, a drop of 70.3% (P < .001). Including all homes, the average number of connections in the before period was 3.90 compared to 0.77 in the after period, a drop of 80.3% (P < .001). In both periods, mobility between nursing homes was higher in homes located in larger communities, those with higher bed counts, and those part of a large chain. CONCLUSIONS AND IMPLICATIONS: Mobility between nursing homes in Ontario fell sharply after an emergency order by the Ontario government limiting long-term care staff to a single home, though some mobility persisted. Reducing this residual mobility should be a focus of efforts to reduce risk within the long-term care sector during the COVID-19 pandemic.


Subject(s)
COVID-19/prevention & control , Nursing Homes , Nursing Staff/organization & administration , Public Policy , Communicable Disease Control/organization & administration , Female , Humans , Male , Ontario , Pandemics , SARS-CoV-2
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