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We estimated the effectiveness of booster doses of monovalent and bivalent mRNA COVID-19 vaccines against Omicron-associated severe outcomes among adults aged ≥50 years in Ontario, Canada. Monovalent and bivalent mRNA COVID-19 booster doses provided similar strong initial protection against severe outcomes. Uncertainty remains around waning of protection from these vaccines.
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Vacinas contra COVID-19 , COVID-19 , Adulto , Humanos , Ontário/epidemiologia , Vacinas Combinadas , COVID-19/prevenção & controle , Imunização , RNA MensageiroRESUMO
BACKGROUND: Randomized trials conducted in low- and middle-income settings demonstrated efficacy of influenza vaccination during pregnancy against influenza infection among infants <6 months of age. However, vaccine effectiveness (VE) estimates from settings with different population characteristics and influenza seasonality remain limited. METHODS: We conducted a test-negative study in Ontario, Canada. All influenza virus tests among infants <6 months from 2010 to 2019 were identified and linked with health databases to ascertain information on maternal-infant dyads. VE was estimated from the odds ratio for influenza vaccination during pregnancy among cases versus controls, computed using logistic regression with adjustment for potential confounders. RESULTS: Among 23 806 infants tested for influenza, 1783 (7.5%) were positive and 1708 (7.2%) were born to mothers vaccinated against influenza during pregnancy. VE against laboratory-confirmed infant influenza infection was 64% (95% confidence interval [CI], 50%-74%). VE was similar by trimester of vaccination (first/second, 66% [95% CI, 40%-80%]; third, 63% [95% CI, 46%-74%]), infant age at testing (0 to <2 months, 63% [95% CI, 46%-75%]; 2 to <6 months, 64% [95% CI, 36%-79%]), and gestational age at birth (≥37 weeks, 64% [95% CI, 50%-75%]; < 37 weeks, 61% [95% CI, 4%-86%]). VE against influenza hospitalization was 67% (95% CI, 50%-78%). CONCLUSIONS: Influenza vaccination during pregnancy offers effective protection to infants <6 months, for whom vaccines are not currently available.
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Vacinas contra Influenza , Influenza Humana , Vacinação , Eficácia de Vacinas , Humanos , Influenza Humana/prevenção & controle , Influenza Humana/epidemiologia , Feminino , Gravidez , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Ontário/epidemiologia , Lactente , Vacinação/estatística & dados numéricos , Recém-Nascido , Masculino , Adulto , Estações do Ano , Complicações Infecciosas na Gravidez/prevenção & controle , Complicações Infecciosas na Gravidez/virologia , Adulto JovemRESUMO
BackgroundWaning immunity from seasonal influenza vaccination can cause suboptimal protection during peak influenza activity. However, vaccine effectiveness studies assessing waning immunity using vaccinated and unvaccinated individuals are subject to biases.AimWe examined the association between time since vaccination and laboratory-confirmed influenza to assess the change in influenza vaccine protection over time.MethodsUsing linked laboratory and health administrative databases in Ontario, Canada, we identified community-dwelling individuals aged ≥ 6 months who received an influenza vaccine before being tested for influenza by RT-PCR during the 2010/11 to 2018/19 influenza seasons. We estimated the adjusted odds ratio (aOR) for laboratory-confirmed influenza by time since vaccination (categorised into intervals) and for every 28 days.ResultsThere were 53,065 individuals who were vaccinated before testing for influenza, with 10,264 (19%) influenza-positive cases. The odds of influenza increased from 1.05 (95%â¯CI: 0.91-1.22) at 42-69 days after vaccination and peaked at 1.27 (95%â¯CI: 1.04-1.55) at 126-153 days when compared with the reference interval (14-41 days). This corresponded to 1.09-times increased odds of influenza every 28 days (aOR = 1.09; 95%â¯CI: 1.04-1.15). Individuals aged 18-64 years showed the greatest decline in protection against influenza A(H1N1) (aORperâ¯28â¯days = 1.26; 95%â¯CI: 0.97-1.64), whereas for individuals aged ≥ 65 years, it was against influenza A(H3N2) (aORperâ¯28â¯days = 1.20; 95%â¯CI: 1.08-1.33). We did not observe evidence of waning vaccine protection for individuals aged < 18 years.ConclusionsInfluenza vaccine protection wanes during an influenza season. Understanding the optimal timing of vaccination could ensure robust protection during seasonal influenza activity.
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Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Humanos , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Estações do Ano , Ontário/epidemiologia , Vírus da Influenza A Subtipo H3N2 , VacinaçãoRESUMO
BACKGROUND: Randomized trials conducted in low- and middle-income settings demonstrated efficacy of influenza vaccination during pregnancy against influenza infection among infants <6 months of age. However, vaccine effectiveness (VE) estimates from settings with different population characteristics and influenza seasonality remain limited. METHODS: We conducted a test-negative study in Ontario, Canada. All influenza virus tests among infants <6 months from 2010-2019 were identified and linked with health databases to ascertain information on maternal-infant dyads. VE was estimated from the odds ratio for influenza vaccination during pregnancy among cases versus controls, computed using logistic regression with adjustment for potential confounders. RESULTS: Among 23,806 infants tested for influenza, 1,783 (7.5%) were positive and 1,708 (7.2%) were born to mothers vaccinated against influenza during pregnancy. VE against laboratory-confirmed infant influenza infection was 64% (95% confidence interval [CI]: 50%-74%). VE was similar by trimester of vaccination (1st/2nd: 66%, 40%-80%; 3rd: 63%, 46%-74%), infant age at testing (0-<2 months: 63%, 46%-75%; 2-<6 months: 64%, 36%-79%), and gestational age at birth (≥37 weeks: 64%, 50%-75%; < 37 weeks: 61%, 4%-86%). VE against influenza hospitalization was 67% (95%CI: 50%-78%). CONCLUSIONS: Influenza vaccination during pregnancy offers effective protection to infants <6 months, for whom vaccines are not currently available.
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INTRODUCTION: We assessed protection from COVID-19 vaccines and/or prior SARS-CoV-2 infection against Omicron-associated severe outcomes during successive sublineage-predominant periods. METHODS: We used a test-negative design to estimate protection by vaccines and/or prior infection against hospitalization/death among community-dwelling, PCR-tested adults aged ≥50 years in Ontario, Canada between January 2, 2022 and June 30, 2023. Multivariable logistic regression was used to estimate the relative change in the odds of hospitalization/death with each vaccine dose (2-5) and/or prior PCR-confirmed SARS-CoV-2 infection (compared with unvaccinated, uninfected subjects) up to 15 months since the last vaccination or infection. RESULTS: We included 18,526 cases with Omicron-associated severe outcomes and 90,778 test-negative controls. Vaccine protection was high during BA.1/BA.2 predominance, but was generally <50% during periods of BA.4/BA.5 and BQ/XBB predominance without boosters. A third/fourth dose transiently increased protection during BA.4/BA.5 predominance (third-dose, 6-month: 68%, 95%CI 63%-72%; fourth-dose, 6-month: 80%, 95%CI 77%-83%), but was lower and waned quickly during BQ/XBB predominance (third-dose, 6-month: 59%, 95%CI 48%-67%; 12-month: 49%, 95%CI 41%-56%; fourth-dose, 6-month: 62%, 95%CI 56%-68%, 12-months: 51%, 95%CI 41%-56%). Hybrid immunity conferred nearly 90% protection throughout BA.1/BA.2 and BA.4/BA.5 predominance, but was reduced during BQ/XBB predominance (third-dose, 6-month: 60%, 95%CI 36%-75%; fourth-dose, 6-month: 63%, 95%CI 42%-76%). Protection was restored with a fifth dose (bivalent; 6-month: 91%, 95%CI 79%-96%). Prior infection alone did not confer lasting protection. CONCLUSION: Protection from COVID-19 vaccines and/or prior SARS-CoV-2 infections against severe outcomes is reduced when immune-evasive variants/subvariants emerge and may also wane over time. Our findings support a variant-adapted booster vaccination strategy with periodic review.
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BACKGROUND: Older adults are recommended to receive influenza vaccination annually, and many use statins. Statins have immunomodulatory properties that might modify influenza vaccine effectiveness (VE) and alter influenza infection risk. METHODS: Using the test-negative design and linked laboratory and health administrative databases in Ontario, Canada, we estimated VE against laboratory-confirmed influenza among community-dwelling statin users and nonusers aged ≥66 years during the 2010-2011 to 2018-2019 influenza seasons. We also estimated the odds ratio for influenza infection comparing statin users and nonusers by vaccination status. RESULTS: Among persons tested for influenza across the 9 seasons, 54 243 had continuous statin exposure before testing and 48 469 were deemed unexposed. The VE against laboratory-confirmed influenza was similar between statin users and nonusers (17% [95% confidence interval, 13%-20%] and 17% [13%-21%] respectively; test for interaction, P = .87). In both vaccinated and unvaccinated persons, statin users had higher odds of laboratory-confirmed influenza than nonusers (odds ratios for vaccinated and unvaccinated persons 1.15 [95% confidence interval, 1.10-1.21] and 1.15 [1.10-1.20], respectively). These findings were consistent by mean daily dose and statin type. VE did not differ between users and nonusers of other cardiovascular drugs, except for ß-blockers. We did not observe that vaccinated and unvaccinated users of these drugs had increased odds of influenza, except for unvaccinated ß-blocker users. CONCLUSIONS: Influenza VE did not differ between statin users and nonusers. Statin use was associated with increased odds of laboratory-confirmed influenza in vaccinated and unvaccinated persons, but these associations might be affected by residual confounding.
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Inibidores de Hidroximetilglutaril-CoA Redutases , Vacinas contra Influenza , Influenza Humana , Humanos , Idoso , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Eficácia de Vacinas , Vacinação , Ontário/epidemiologia , Estações do AnoRESUMO
Designing diagnostic assays to genotype rapidly mutating viruses remains a challenge despite the overall improvements in nucleic acid detection technologies. RT-PCR and next-generation sequencing are unsuitable for genotyping during outbreaks or in point-of-care detection due to their infrastructure requirements and longer turnaround times. We developed a quantum dot barcode multiplexing system to genotype mutated viruses. We designed multiple quantum dot barcodes to target conserved, wildtype, and mutated regions of SARS-CoV-2. We calculated ratios of the signal output from different barcodes that enabled SARS-CoV-2 detection and identified SARS-CoV-2 variant strains from a sample. We detected different sequence types, including conserved genes, nucleotide deletions, and single nucleotide substitutions. Our system detected SARS-CoV-2 patient specimens with 98% sensitivity and 94% specificity across 91 patient samples. Further, we leveraged our barcoding and ratio system to track the emergence of the N501Y SARS-CoV-2 mutation from December 2020 to May 2021 and demonstrated that the more transmissible N501Y mutation started to dominate infections by April 2021. Our barcoding and signal ratio approach can genotype viruses and track the emergence of viral mutations in a single diagnostic test. This technology can be extended to tracking other viruses. Combined with smartphone detection technologies, this assay can be adapted for point-of-care tracking of viral mutations in real time.
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COVID-19 , Ácidos Nucleicos , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Genótipo , Nucleotídeos , MutaçãoRESUMO
A new method for the detection of genomic RNA combines RNA cleavage by the 10-23 DNAzyme and use of the cleavage fragments as primers to initiate rolling circle amplification (RCA). 230 different 10-23 DNAzyme variants were screened to identify those that target accessible RNA sites within the highly structured RNA transcripts of SARS-CoV-2. A total of 28 DNAzymes were identified with >20 % cleavage, 5 with >40 % cleavage and one with >60 % in 10â min. The cleavage fragments from these reactions were then screened for coupling to an RCA reaction, leading to the identification of several cleavage fragments that could efficiently initiate RCA. Using a newly developed quasi-exponential RCA method with a detection limit of 500 aM of RNA, 14 RT-PCR positive and 15 RT-PCR negative patient saliva samples were evaluated for SARS-CoV-2 genomic RNA, achieving a clinical sensitivity of 86 % and specificity of 100 % for detection of the virus in <2.5â h.
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Técnicas Biossensoriais , COVID-19 , DNA Catalítico , Humanos , DNA Catalítico/metabolismo , RNA , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Clivagem do RNA , COVID-19/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/métodos , Genômica , Técnicas Biossensoriais/métodosRESUMO
The Canadian Sentinel Practitioner Surveillance Network estimated vaccine effectiveness (VE) during the unusually early 2022/23 influenza A(H3N2) epidemic. Like vaccine, circulating viruses were clade 3C.2a1b.2a.2, but with genetic diversity affecting haemagglutinin positions 135 and 156, and reassortment such that H156 viruses acquired neuraminidase from clade 3C.2a1b.1a. Vaccine provided substantial protection with A(H3N2) VE of 54% (95% CI: 38 to 66) overall. VE was similar against H156 and vaccine-like S156 viruses, but with potential variation based on diversity at position 135.
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Vacinas contra Influenza , Influenza Humana , Humanos , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Vírus da Influenza A Subtipo H3N2 , Estações do Ano , Eficácia de Vacinas , Canadá/epidemiologia , Variação GenéticaRESUMO
BACKGROUND: The influenza A(H3N2) vaccine was updated from clade 3C.3a in 2015-2016 to 3C.2a for 2016-2017 and 2017-2018. Circulating 3C.2a viruses showed considerable hemagglutinin glycoprotein diversification and the egg-adapted vaccine also bore mutations. METHODS: Vaccine effectiveness (VE) in 2016-2017 and 2017-2018 was assessed by test-negative design, explored by A(H3N2) phylogenetic subcluster and prior season's vaccination history. RESULTS: In 2016-2017, A(H3N2) VE was 36% (95% confidence interval [CI], 18%-50%), comparable with (43%; 95% CI, 24%-58%) or without (33%; 95% CI, -21% to 62%) prior season's vaccination. In 2017-2018, VE was 14% (95% CI, -8% to 31%), lower with (9%; 95% CI, -18% to 30%) versus without (45%; 95% CI, -7% to 71%) prior season's vaccination. In 2016-2017, VE against predominant clade 3C.2a1 viruses was 33% (95% CI, 11%-50%): 18% (95% CI, -40% to 52%) for 3C.2a1a defined by a pivotal T135K loss of glycosylation; 60% (95% CI, 19%-81%) for 3C.2a1b (without T135K); and 31% (95% CI, 2%-51%) for other 3C.2a1 variants (with/without T135K). VE against 3C.2a2 viruses was 45% (95% CI, 2%-70%) in 2016-2017 but 15% (95% CI, -7% to 33%) in 2017-2018 when 3C.2a2 predominated. VE against 3C.2a1b in 2017-2018 was 37% (95% CI, -57% to 75%), lower at 12% (95% CI, -129% to 67%) for a new 3C.2a1b subcluster (n = 28) also bearing T135K. CONCLUSIONS: Exploring VE by phylogenetic subcluster and prior vaccination history reveals informative heterogeneity. Pivotal mutations affecting glycosylation sites, and repeat vaccination using unchanged antigen, may reduce VE.
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Epidemias , Vacinas contra Influenza , Influenza Humana , Humanos , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Vírus da Influenza A Subtipo H3N2 , Filogenia , Eficácia de Vacinas , Vacinação , Canadá/epidemiologia , Estações do AnoRESUMO
Our previously discovered monomeric aptamer for SARS-CoV-2 (MSA52) possesses a universal affinity for COVID-19 spike protein variants but is ultimately limited by its ability to bind only one subunit of the spike protein. The symmetrical shape of the homotrimeric SARS-CoV-2 spike protein presents the opportunity to create a matching homotrimeric molecular recognition element that is perfectly complementary to its structural scaffold, causing enhanced binding affinity. Here, we describe a branched homotrimeric aptamer with three-fold rotational symmetry, named TMSA52, that not only possesses excellent binding affinity but is also capable of binding several SARS-CoV-2 spike protein variants with picomolar affinity, as well as pseudotyped lentiviruses expressing SARS-CoV-2 spike protein variants with femtomolar affinity. Using Pd-Ir nanocubes as nanozymes in an enzyme-linked aptamer binding assay (ELABA), TMSA52 was capable of sensitively detecting diverse pseudotyped lentiviruses in pooled human saliva with a limit of detection as low as 6.3 × 103 copies/mL. The ELABA was also used to test 50 SARS-CoV-2-positive and 60 SARS-CoV-2-negative patient saliva samples, providing sensitivity and specificity values of 84.0 and 98.3%, respectively, thus highlighting the potential of TMSA52 for the development of future rapid tests.
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COVID-19 , SARS-CoV-2 , Humanos , COVID-19/diagnóstico , Glicoproteína da Espícula de Coronavírus , Bioensaio , OligonucleotídeosRESUMO
A global monkeypox outbreak began in May 2022. Limited data exist on specimen type performance in associated molecular diagnostics. Consequently, a diverse range of specimen sources were collected in the initial weeks of the outbreak in Ontario, Canada. Our clinical evaluation identified skin lesions as the optimal diagnostic specimen source.
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Mpox , Humanos , Mpox/diagnóstico , Mpox/epidemiologia , Monkeypox virus/genética , Ontário/epidemiologiaRESUMO
A surge in hematopoietic stem cell transplantation (HSCT) human adenovirus A31 (HAdV-A31) infections was initially observed in late 2014/2015 at SickKids (SK) Hospital, Toronto, Canada. In response, enhanced laboratory monitoring for all adenovirus infections was conducted. Positive samples underwent genotyping, viral culture, and, in selected cases, whole-genome sequencing (WGS). HAdV-A31 specimens/DNA obtained from four international pediatric HSCT centers also underwent WGS. During the SK outbreak period (27 October 2014 to 31 October 2018), 17/20 HAdV-A31 isolates formed a distinct clade with 0 to 8 mutations between the closest neighbors. Surveillance before and after the outbreak detected six additional HAdV-A31 HSCT cases; three of the four sequenced cases clustered within the outbreak clade. Two SK outbreak isolates were identical to sequences from two patients in an outbreak in England. Three SK non-outbreak sequences also had high sequence similarity to strains from three international centers. Environmental PCR testing of the HSCT ward showed significant adenovirus contamination. Despite intense infection control efforts, we observed re-occurrence of infection with the outbreak strain. Severe but nonfatal infection was observed more commonly with HAdV-A31 compared to other genotypes, except HAdV-C1. Our findings strongly implicate nosocomial spread of HAdV-A31 over 10 years on a HSCT unit and demonstrate the value of WGS in defining and mapping the outbreak. Close linkages among strains in different countries suggest international dissemination, though the mechanism is undetermined. This large, extended outbreak emphasizes the pre-eminent role of HAdV-A31 in causing intractable pediatric HSCT outbreaks of severe illness worldwide.
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Infecções por Adenoviridae , Infecções por Adenovirus Humanos , Adenovírus Humanos , Transplante de Células-Tronco Hematopoéticas , Humanos , Criança , Infecções por Adenovirus Humanos/epidemiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Sequenciamento Completo do Genoma , Hospitais , FilogeniaRESUMO
BACKGROUND: Invasive pneumococcal disease is a major cause of infant morbidity and death worldwide. Vitamin D promotes anti-pneumococcal immune responses in vitro, but whether improvements in infant vitamin D status modify risks of nasal pneumococcal acquisition in early life is not known. METHODS: This is a secondary analysis of data collected in a trial cohort in Dhaka, Bangladesh. Acute respiratory infection (ARI) surveillance was conducted from 0 to 6 months of age among 1060 infants of women randomized to one of four pre/post-partum vitamin D dose combinations or placebo. Nasal swab samples were collected based on standardized ARI criteria, and pneumococcal DNA quantified by qPCR. Hazards ratios of pneumococcal acquisition and carriage dynamics were estimated using interval-censored survival and multi-state modelling. RESULTS: Pneumococcal carriage was detected at least once in 90% of infants by 6 months of age; overall, 69% of swabs were positive (2616/3792). There were no differences between any vitamin D group and placebo in the hazards of pneumococcal acquisition, carriage dynamics, or carriage density (p > 0.05 for all comparisons). CONCLUSION: Despite in vitro data suggesting that vitamin D promoted immune responses against pneumococcus, improvements in postnatal vitamin D status did not reduce the rate, alter age of onset, or change dynamics of nasal pneumococcal colonization in early infancy. Trial registration Registered in ClinicalTrials.gov with the registration number of NCT02388516 and first posted on March 17, 2015.
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Infecções Pneumocócicas , Streptococcus pneumoniae , Bangladesh/epidemiologia , Portador Sadio/epidemiologia , Suplementos Nutricionais , Feminino , Humanos , Lactente , Nasofaringe , Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas , Vitamina D , VitaminasRESUMO
Influenza virus circulation virtually ceased in Canada during the COVID-19 pandemic, re-emerging with the relaxation of restrictions in spring 2022. Using a test-negative design, the Canadian Sentinel Practitioner Surveillance Network reports 2021/22 vaccine effectiveness of 36% (95%â¯CI: -38 to 71) against late-season illness due to influenza A(H3N2) clade 3C.2a1b.2a.2 viruses, considered antigenically distinct from the 3C.2a1b.2a.1 vaccine strain. Findings reinforce the World Health Organization's decision to update the 2022/23 northern hemisphere vaccine to a more representative A(H3N2) clade 3C.2a1b.2a.2 strain.
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COVID-19 , Vacinas contra Influenza , Influenza Humana , Canadá/epidemiologia , Humanos , Vírus da Influenza A Subtipo H3N2 , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Pandemias/prevenção & controle , Eficácia de VacinasRESUMO
The ability to rapidly diagnose, track, and disseminate information for SARS-CoV-2 is critical to minimize its spread. Here, we engineered a portable smartphone-based quantum barcode serological assay device for real-time surveillance of patients infected with SARS-CoV-2. Our device achieved a clinical sensitivity of 90% and specificity of 100% for SARS-CoV-2, as compared to 34% and 100%, respectively, for lateral flow assays in a head-to-head comparison. The lateral flow assay misdiagnosed â¼2 out of 3 SARS-CoV-2 positive patients. Our quantum dot barcode device has â¼3 times greater clinical sensitivity because it is â¼140 times more analytically sensitive than lateral flow assays. Our device can diagnose SARS-CoV-2 at different sampling dates and infectious severity. We developed a databasing app to provide instantaneous results to inform patients, physicians, and public health agencies. This assay and device enable real-time surveillance of SARS-CoV-2 seroprevalence and potential immunity.
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COVID-19 , Pontos Quânticos , Humanos , Imunoensaio , SARS-CoV-2 , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , SmartphoneRESUMO
BACKGROUND: Older adults are at increased risk of mortality from influenza infections. We estimated influenza vaccine effectiveness (VE) against mortality following laboratory-confirmed influenza. METHODS: Using a test-negative design study and linked laboratory and health administrative databases in Ontario, Canada, we estimated VE against all-cause mortality following laboratory-confirmed influenza for community-dwelling adults aged >65 years during the 2010-2011 to 2015-2016 influenza seasons. RESULTS: Among 54 116 older adults tested for influenza across the 6 seasons, 6837 died within 30 days of specimen collection. Thirteen percent (925 individuals) tested positive for influenza, and 50.6% were considered vaccinated for that season. Only 23.2% of influenza test-positive cases had influenza recorded as their underlying cause of death. Before and after multivariable adjustment, we estimated VE against all-cause mortality following laboratory-confirmed influenza to be 20% (95% confidence interval [CI], 8%-30%) and 20% (95% CI, 7%-30%), respectively. This estimate increased to 34% after correcting for influenza vaccination exposure misclassification. We observed significant VE against deaths following influenza confirmation during 2014-2015 (VEâ =â 26% [95% CI, 5%-42%]). We also observed significant VE against deaths following confirmation of influenza A/H1N1 and A/H3N2, and against deaths with COPD as the underlying cause. CONCLUSIONS: These results support the importance of influenza vaccination in older adults, who account for most influenza-associated deaths annually.
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Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Idoso , Estudos de Casos e Controles , Humanos , Vírus da Influenza A Subtipo H3N2 , Vírus da Influenza B , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Laboratórios , Ontário/epidemiologia , Estações do Ano , VacinaçãoRESUMO
BACKGROUND: Acute myocardial infarction can be triggered by acute respiratory infections. Previous studies have suggested an association between influenza and acute myocardial infarction, but those studies used nonspecific measures of influenza infection or study designs that were susceptible to bias. We evaluated the association between laboratory-confirmed influenza infection and acute myocardial infarction. METHODS: We used the self-controlled case-series design to evaluate the association between laboratory-confirmed influenza infection and hospitalization for acute myocardial infarction. We used various high-specificity laboratory methods to confirm influenza infection in respiratory specimens, and we ascertained hospitalization for acute myocardial infarction from administrative data. We defined the "risk interval" as the first 7 days after respiratory specimen collection and the "control interval" as 1 year before and 1 year after the risk interval. RESULTS: We identified 364 hospitalizations for acute myocardial infarction that occurred within 1 year before and 1 year after a positive test result for influenza. Of these, 20 (20.0 admissions per week) occurred during the risk interval and 344 (3.3 admissions per week) occurred during the control interval. The incidence ratio of an admission for acute myocardial infarction during the risk interval as compared with the control interval was 6.05 (95% confidence interval [CI], 3.86 to 9.50). No increased incidence was observed after day 7. Incidence ratios for acute myocardial infarction within 7 days after detection of influenza B, influenza A, respiratory syncytial virus, and other viruses were 10.11 (95% CI, 4.37 to 23.38), 5.17 (95% CI, 3.02 to 8.84), 3.51 (95% CI, 1.11 to 11.12), and 2.77 (95% CI, 1.23 to 6.24), respectively. CONCLUSIONS: We found a significant association between respiratory infections, especially influenza, and acute myocardial infarction. (Funded by the Canadian Institutes of Health Research and others.).
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Hospitalização/estatística & dados numéricos , Influenza Humana/complicações , Infarto do Miocárdio/etiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Incidência , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/diagnóstico , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Ontário/epidemiologia , RiscoRESUMO
BACKGROUND: The implementation of outbreak management measures has decreased the frequency and severity of SARS-CoV-2 outbreaks in Ontario long-term care homes. We describe the epidemiological and laboratory data from one of the first such outbreaks in Ontario to assess factors associated with its severity, and the impact of progressive interventions for infection control over the course of the outbreak. METHODS: We obtained line list and outbreak data from the public health unit to describe resident and staff cases, severity and distribution of cases over time and within the outbreak facility. Where available, we obtained data on laboratory specimens from the Public Health Ontario Laboratory and performed whole genome sequencing and phylogenetic analysis of viral specimens from the outbreak. RESULTS: Among 65 residents of the long-term care home, 61 (94%) contracted SARS-CoV-2, with a case fatality rate of 45% (28/61). Among 67 initial staff, 34 (51%) contracted the virus and none died. When the outbreak was declared, 12 staff, 2 visitors and 9 residents had symptoms. Resident cases were located in 3 of 4 areas of the home. Phylogenetic analysis showed tight clustering of cases, with only 1 additional strain of genetically distinct SARS-CoV-2 identified from a staff case in the third week of the outbreak. No cases were identified among 26 new staff brought into the home after full outbreak measures were implemented. INTERPRETATION: Rapid and undetected viral spread in a long-term care home led to high rates of infection among residents and staff. Progressive implementation of outbreak measures after the peak of cases prevented subsequent staff cases and are now part of long-term care outbreak policy in Ontario.
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COVID-19/epidemiologia , Assistência de Longa Duração , Casas de Saúde , COVID-19/mortalidade , COVID-19/prevenção & controle , COVID-19/virologia , Humanos , Controle de Infecções , Ontário/epidemiologia , Pandemias , Filogenia , SARS-CoV-2/genéticaRESUMO
BACKGROUND: Annual influenza immunization is recommended for people with chronic obstructive pulmonary disease (COPD) by all major COPD clinical practice guidelines. We sought to determine the seasonal influenza vaccine effectiveness (VE) against laboratory-confirmed influenza-associated hospitalizations among older adults with COPD. METHODS: We conducted a test-negative study of influenza VE in community-dwelling older adults with COPD in Ontario, Canada using health administrative data and respiratory specimens collected from patients tested for influenza during the 2010-11 to 2015-16 influenza seasons. Influenza vaccination was ascertained from physician and pharmacist billing claims. Multivariable logistic regression was used to estimate the adjusted odds ratio of influenza vaccination in people with, compared to those without, laboratory-confirmed influenza. RESULTS: Receipt of seasonal influenza vaccine was associated with an adjusted 22% (95% confidence interval [CI], 15%-27%) reduction in laboratory-confirmed influenza-associated hospitalization. Adjustment for potential misclassification of vaccination status increased this to 43% (95% CI, 35%-52%). Vaccine effectiveness was not found to vary by patient- or influenza-related variables. CONCLUSIONS: During the studied influenza seasons, influenza vaccination was at least modestly effective in reducing laboratory-confirmed influenza-associated hospitalizations in people with COPD. The imperfect effectiveness emphasizes the need for better influenza vaccines and other preventive strategies.