SARS-CoV-2 seroprevalence in Nova Scotia blood donors.

Background: SARS-CoV-2 seroprevalence monitors cumulative infection rates irrespective of case testing protocols. We aimed to describe Nova Scotia blood donor seroprevalence in relation to public health policy and reported data over the course of the COVID-19 pandemic (May 2020 to August 2022). Methods: Monthly random Nova Scotia blood donation samples (24,258 in total) were tested for SARS-CoV-2 infection antibodies (anti-nucleocapsid) from May 2020 to August 2022, and vaccination antibodies (anti-spike) from January 2021 to August 2022. Multivariable logistic regression for infection antibodies and vaccination antibodies separately with month, age, sex, and racialization identified independent predictors. The provincial nucleic acid amplification test (NAAT)-positive case rate over the pandemic was calculated from publicly available data. Results: Anti-N seroprevalence was 3.8% in January 2022, increasing to 50.8% in August 2022. The general population COVID-19 case rate was 3.5% in January 2022, increasing to 12.5% in August 2022. The percentage of NAAT-positive samples in public health laboratories increased from 1% in November 2021 to a peak of 30.7% in April 2022 with decreasing numbers of tests performed. Higher proportions of younger donors as well as Black, Indigenous, and racialized blood donors were more likely to have infection antibodies (p < 0.01). Vaccination antibodies increased to 100% over 2021, initially in older donors (60+ years), and followed by progressively younger age groups. Conclusions: SARS-CoV-2 infection rates were relatively low in Nova Scotia until the more contagious Omicron variant dominated, after which about half of Nova Scotia donors had been infected despite most adults being vaccinated (although severity was much lower in vaccinated individuals). Most COVID-19 cases were detected by NAAT until Omicron arrived. When NAAT testing priorities focused on high-risk individuals, infection rates were better reflected by seroprevalence.

Historique: La séroprévalence du SRAS-CoV-2 permet de surveiller les taux d'infection cumulatifs, quels que soient les protocoles de dépistage des cas. Les chercheurs voulaient décrire la séroprévalence chez les donneurs de sang néo-écossais par rapport aux politiques sanitaires et aux données déclarées tout au long de la pandémie de COVID-19 (mai 2020 à août 2022). Méthodologie: Les chercheurs ont mesuré les anticorps à l'infection par le SRAS-CoV-2 (antinucléocapsidiques) de manière aléatoire tous les mois dans des échantillons de dons de sang de la Nouvelle-Écosse (pour un total de 24 258) entre mai 2020 et août 2022, de même que les anticorps aux vaccins (antispiculaires) (entre janvier 2021 et août 2022). La régression logistique multivariable effectuée séparément pour les anticorps contre l'infection et les anticorps aux vaccins, par rapport au mois, à l'âge, au genre et à la race, ont permis d'établir les prédicteurs indépendants. Les chercheurs ont calculé le taux de cas provinciaux positifs aux tests d'amplification des acides nucléiques (TAAN) à partir des données publiques tout au long de la pandémie. Résultats: La séroprévalence anti-N, qui s'élevait à 3,8 % en janvier 2022, était passée à 50,8 % en août 2022. Le taux de cas de COVID-19 dans la population générale se situait à 3,5 % en janvier 2022 et était monté à 12,5 % en août 2022. Le pourcentage d'échantillons positifs au TAAN dans les laboratoires de santé publique est passé de 1 % en novembre 2021 à un pic de 30,7 % en avril 2022, conjointement à une diminution du nombre de tests effectués. De plus fortes proportions de donneurs plus jeunes et de donneurs noirs, autochtones et racisés étaient susceptibles de posséder des anticorps contre l'infection (p < 0,01). Les anticorps attribuables à la vaccination ont atteint 100 % en 2021, d'abord chez les donneurs plus âgés (de plus de 60 ans), puis dans les tranches d'âges progressivement plus jeunes. Conclusions: Les taux d'infection par le SRAS-CoV-2 sont demeurés relativement faibles en Nouvelle-Écosse jusqu'à la domination du variant Omicron plus contagieux, puis environ la moitié des donneurs néo-écossais ont été infectés, même si la plupart des adultes étaient vaccinés (la gravité de la maladie était toutefois beaucoup plus faible chez les personnes vaccinées). La plupart des cas de COVID-19 ont été dépistés par TAAN jusqu'à l'apparition du variant Omicron. Lorsque les priorités de dépistage par TAAN ont été limitées aux personnes à haut risque, les taux d'infection étaient mieux reflétés par la séroprévalence.

Retrospective validation of a rapid Lyme fluorescent immunoassay in differentiating Lyme arthritis from other musculoskeletal presentations in children in a Lyme-endemic region.

Lyme arthritis can present similarly to other causes of joint pain and swelling including septic arthritis and other acute and chronic arthropathies of childhood. Septic arthritis, although rare, constitutes an orthopedic emergency and requires early surgical intervention to reduce the risk of permanent joint damage. Currently, results of standard serologic tests to diagnose Lyme disease take days to weeks, which is unhelpful in acute clinical decision-making. Thus, some children with Lyme arthritis are treated empirically for septic arthritis undergoing unnecessary invasive procedures and hospital admission while on inappropriate antibiotic therapy. We retrospectively validated the Quidel Sofia Lyme Fluorescent Immunoassay, a rapid serologic assay that can detect IgG and/or IgM antibodies to Borrelia burgdorferi in 10 minutes, in residual serum samples collected from 51 children who had Lyme arthritis and 55 children with musculoskeletal presentations who were Lyme negative. The sensitivity and specificity of the Sofia IgG to identify cases of Lyme arthritis in children were 100% (95% confidence interval [CI] of 93.0%-100%) and 96.4% (95% CI: 87.5%-99.6%), respectively. The positive likelihood ratio (LR) was 27.5 (95% CI 7-107), and the negative LR was 0.00 (95% LR 0.00-0.15). We propose that the Sofia IgG, a rapid method for identifying Lyme arthritis, may be useful in differentiating Lyme arthritis from other forms of arthritis. Used in conjunction with readily available clinical and laboratory variables, it could help to rapidly identify children who are at low risk of septic arthritis in Lyme-endemic regions. IMPORTANCE: Lyme arthritis is a common manifestation of Lyme disease in children, with clinical features overlapping with other causes of acute and chronic joint pain/swelling in children. We have demonstrated that the Sofia IgG is a reliable test to rule in and rule out the diagnosis of Lyme arthritis in children with musculoskeletal presentations in a Lyme-endemic region. When used in conjunction with clinical and laboratory variables routinely considered when differentiating Lyme arthritis from other diagnoses, the Sofia IgG has the potential to fill an important gap in care, especially when acute decision-making is necessary. The Sofia IgG should be included in prospective research studies examining clinical prediction tools to identify children at low risk of septic arthritis.

Taqman PACMAN: a simple molecular approach for positive rapid antigen test confirmation during periods of low prevalence.

Antigen-based rapid diagnostic tests (Ag-RDTs) were widely deployed to enhance SARS-CoV-2 testing capacity during the COVID-19 pandemic. Consistent with national guidance for low prevalence settings, positive Ag-RDTs were confirmed using nucleic acid amplification tests (NAATs) to avoid false positive results. However, increasing demands for positive Ag-RDT confirmation competed with other testing priorities in clinical laboratories. This work hypothesized that real-time RT-PCR without nucleic acid extraction (NAE) would be sufficiently sensitive to support positive Ag-RDT confirmation. Ag-RDT and NAAT results from community-based asymptomatic testing sites prior to the omicron variant wave were compared to calculate the weekly false positive rate (FPR) and false detection rate (FDR). Real-time RT-PCR was compared with and without NAE using 752 specimens previously tested positive for SARS-CoV-2 using commercial NAATs and 344 specimens from Ag-RDT-positive individuals. The impact of SARS-CoV-2 prevalence on laboratory resources required to sustain Ag-RDT confirmation was modeled for the RT-PCR with and without NAE. Overall, FPR was low [0.07% (222/330,763)] in asymptomatic testing sites, but FDR was high [30.7% (222/724)]. When RT-PCR was compared with and without NAE, 100% concordance was obtained with NAAT-positive specimens, including those from Ag-RDT-positive individuals. NAE-free RT-PCR significantly reduced time to results, human resources, and overall costs. A 30.7% FDR reaffirms the need for NAAT-based confirmation of positive Ag-RDT results during low SARS-CoV-2 prevalence. NAE-free RT-PCR was shown to be a simple and cost-sparing NAAT-based solution for positive Ag-RDT confirmation, and its implementation supported data-driven broader Ag-RDT deployment into communities, workplaces, and households. IMPORTANCE: Rapid antigen testing for SARS-CoV-2 was widely deployed during the COVID-19 pandemic. In settings of low prevalence, national guidance recommends that positive antigen test results be confirmed with molecular testing. Given the high testing burden on clinical laboratories during the COVID-19 pandemic, the high volume of positive antigen tests submitted for confirmatory testing posed challenges for laboratory workflow. This study demonstrated that a simple PCR method without prior nucleic acid purification is an accurate and cost-effective solution for positive rapid antigen test confirmation. Implementing this method allowed molecular confirmatory testing for positive antigen tests to be sustained as antigen testing was expanded into large populations such as workplaces, schools, and households.

Case Series of Jamestown Canyon Virus Infections with Neurologic Outcomes, Canada, 2011-2016.

Jamestown Canyon virus (JCV) is a mosquitoborne orthobunyavirus in the California serogroup that circulates throughout Canada and the United States. Most JCV exposures result in asymptomatic infection or a mild febrile illness, but JCV can also cause neurologic diseases, such as meningitis and encephalitis. We describe a case series of confirmed JCV-mediated neuroinvasive disease among persons from the provinces of British Columbia, Alberta, Quebec, and Nova Scotia, Canada, during 2011-2016. We highlight the case definitions, epidemiology, unique features and clinical manifestations, disease seasonality, and outcomes for those cases. Two of the patients (from Quebec and Nova Scotia) might have acquired JCV infections during travel to the northeastern region of the United States. This case series collectively demonstrates JCV's wide distribution and indicates the need for increased awareness of JCV as the underlying cause of meningitis/meningoencephalitis during mosquito season.

Clinical features and outcomes of influenza and RSV coinfections: a report from Canadian immunization research network serious outcomes surveillance network.

BACKGROUND: Influenza and RSV coinfections are not commonly seen but are concerning as they can lead to serious illness and adverse clinical outcomes among vulnerable populations. Here we describe the clinical features and outcomes of influenza and RSV coinfections in hospitalized adults. METHODS: A cohort study was performed with pooled active surveillance in hospitalized adults ≥ 50 years from the Serious Outcomes Surveillance Network of the Canadian Immunization Research Network (CIRN SOS) during the 2012/13, 2013/14, and 2014/15 influenza seasons. Descriptive statistics summarized the characteristics of influenza/RSV coinfections. Kaplan-Meier estimated the probability of survival over the first 30 days of hospitalization. RESULTS: Over three influenza seasons, we identified 33 cases of RSV and influenza coinfection, accounting for 2.39 cases per 1,000 hospitalizations of patients with acute respiratory illnesses. Adults aged 50 + years commonly reported cough (81.8%), shortness of breath (66.7%), sputum production (45.5%), weakness (33.3%), fever (27.3%), and nasal congestion (24.2%) as constitutional and lower respiratory tract infection symptoms. The mortality rate was substantial (12.1%), and age, comorbidity burden, and frailty were associated with a higher risk for adverse clinical outcomes. CONCLUSIONS: Older adults are at higher risk for complications from influenza and RSV coinfections, especially those over 65 with a high comorbidity burden and frailty.

Highly pathogenic avian influenza: Unprecedented outbreaks in Canadian wildlife and domestic poultry.

Canada experienced a wave of HPAI H5N1 outbreaks in the spring of 2022 with millions of wild and farmed birds being infected. Seabird mortalities in Canada have been particularly severe on the Atlantic Coast over the summer of 2022. Over 7 million birds have been culled in Canada, and outbreaks continue to profoundly affect commercial bird farms across the world. This new H5N1 virus can and has infected multiple mammalian species, including skunks, foxes, bears, mink, seals, porpoises, sea lions, and dolphins. Viruses with mammalian adaptations such as the mutations PB2-E627K, E627V, and D701N were found in the brain of various carnivores in Europe and Canada. To date this specific clade of H5N1 virus has been identified in less than 10 humans. At the ground level, awareness should be raised among frontline practitioners most likely to encounter patients with HPAI.

Le Canada a vécu un vague d'éclosions de grippe aviaire de souche H5N1 hautement pathogène au printemps 2022 lorsque des millions d'oiseaux sauvages et d'oiseaux d'élevage ont été infectés. La mortalité des oiseaux marins au Canada a été particulièrement marquée sur la côte Atlantique pendant l'été 2022. Plus de sept millions d'oiseaux ont été abattus au Canada, et les éclosions continuent de nuire profondément aux élevages commerciaux d'oiseaux dans le monde. Ce nouveau virus H5N1 peut infecter de multiples espèces de mammifères, y compris des mouffettes, des renards, des ours, des visons, des phoques, des marsouins, des otaries et des dauphins. Les virus adaptés aux mammifères et porteurs des mutations PB2-E627K, E627V et D701N, ont été observés dans le cerveau de divers carnivores de l'Europe et du Canada. Jusqu'à présent, ce clade du virus H5N1 a été dépisté chez moins de dix humains. Sur le terrain, il est important de sensibiliser les praticiens de première ligne qui sont plus susceptibles de voir des patients atteints de la grippe aviaire de souche hautement pathogène.

Epidemiology and clinical manifestations of reported Lyme disease cases: Data from the Canadian Lyme disease enhanced surveillance system.

Lyme disease cases reported in seven Canadian provinces from 2009 to 2019 through the Lyme Disease Enhanced Surveillance System are described herein by demographic, geography, time and season. The proportion of males was greater than females. Bimodal peaks in incidence were observed in children and older adults (≥60 years of age) for all clinical signs except cardiac manifestations, which were more evenly distributed across age groups. Proportions of disease stages varied between provinces: Atlantic provinces reported mainly early Lyme disease, while Ontario reported equal proportions of early and late-stage Lyme disease. Early Lyme disease cases were mainly reported between May through November, whereas late Lyme disease were reported in December through April. Increased awareness over time may have contributed to a decrease in the proportion of cases reporting late disseminated Lyme disease. These analyses help better describe clinical features of reported Lyme disease cases in Canada.

Maternal varicella antibodies in children aged less than one year: Assessment of antibody decay.

OBJECTIVES: To investigate maternal antibody levels to varicella in infants <12 months of age in Ontario, Canada. STUDY DESIGN: In this study, we included specimens from infants <12 months of age, born at ≥37 weeks gestational age, who had sera collected at The Hospital for Sick Children (Toronto, Canada) between 2014-2016. We tested sera using a glycoprotein-based enzyme-linked immunosorbent assay (gpELISA). We measured varicella susceptibility (antibody concentration <150mIU/mL) and mean varicella antibody concentration, and assessed the probability of susceptibility and concentration between one and 11 months of age using multivariable logistic regression and Poisson regression. RESULTS: We found that 32% of 196 included specimens represented infants susceptible to varicella at one month of age, increasing to nearly 80% at three months of age. At six months of age, all infants were susceptible to varicella and the predicted mean varicella antibody concentration declined to 62 mIU/mL (95% confidence interval 40, 84), well below the threshold of protection. CONCLUSIONS: We found that varicella maternal antibody levels wane rapidly in infants, leaving most infants susceptible by four months of age. Our findings have implications for the timing of first dose of varicella-containing vaccine, infection control measures, and infant post-exposure prophylaxis recommendations.

Real-world evaluation of the Lucira Check-It COVID-19 loop-mediated amplification (LAMP) test.

IMPORTANCE: In hospitals during the COVID-19 pandemic, laboratory testing was important to reduce SARS-CoV-2 transmissions, while facilitating patient flow in the emergency department and pre-operative settings, and allowing for the safe return to work of exposed healthcare workers. Delayed test results from laboratory nucleic acid amplification tests (NAATs) posed a barrier to maximizing efficient patient flow and minimizing staffing shortages. This quality improvement project sought to evaluate the analytical and clinical performance of the Lucira Check-It COVID-19 Test, a point-of-care test that used NAAT technology, in the perioperative setting, emergency department, and community testing sites. We found the Lucira Check-It to have comparable performance to laboratory NAATs. It can be employed with little training for specimen collection, processing, and interpretation, and at a cost justifiable from the resources saved from avoiding sample transport and laboratory testing.

Protocol for a longitudinal cohort study of Lyme disease with physical, mental and immunological assessment.

INTRODUCTION: There are limited data on the longitudinal impact of Lyme disease. Predictors of recovery have not been fully established using validated data collection instruments. There are sparse data on the immunological response to infection over time. METHODS AND ANALYSIS: This study is a longitudinal cohort study that will recruit 120 participants with Lyme disease in Ontario and Nova Scotia, Canada, with follow-up for up to 24 months. Data will be collected using the Short-Form 36 physical and mental component summaries, Depression and Anxiety Severity Scale Questionnaire, Fatigue Severity Scale and a battery of neuropsychological tests. Mononuclear cells, gene expression and cytokine profiling from blood samples will be used to assess immunological response. Analyses will include the use of non-linear mixed-effects modelling and proportional hazards models. ETHICS AND DISSEMINATION: Ethics approval has been obtained from ethics boards at McMaster University (Hamilton Integrated Research Ethics Board) (7564), Queens University (EMD 315-20) and Nova Scotia Health Research Ethics Board (1027173), and the study is enrolling participants. Written informed consent is obtained from all participants. The results will be disseminated by publication in a peer-reviewed journal and presented at a relevant conference. A brief report will be provided to decision-makers and patient groups.

Uptake of pertussis immunization in pregnancy and determinants of vaccination in Toronto, Canada.

INTRODUCTION: Pertussis causes significant morbidity and mortality in infants aged <6 months. Maternal pertussis vaccination during pregnancy has been recommended in Canada since 2018 to reduce these negative outcomes. In the absence of routine immunization coverage data, our objective was to evaluate uptake in Toronto, Canada. METHODS: We recruited mother-infant pairs at The Hospital for Sick Children, Toronto, between 2018 and 2020. We performed logistic regression to examine associations between demographics and self-reported pertussis vaccination. RESULTS: 76/243 mothers (31.3 %) reported receiving pertussis vaccination during their most recent pregnancy. Odds of receiving vaccination more than doubled with each 1-year increase in year of pregnancy (aOR: 2.2; 95 % CI: 1.3, 3.6; p < 0.01) and among those born in Canada as compared to those not (aOR: 2.0; 95 % CI: 1.1, 3.6; p = 0.02) CONCLUSION: Uptake of pertussis vaccination during pregnancy in Ontario has increased in recent years, however coverage remains lower than desirable.

Immunity of Canadians and risk of epidemics workshop - Conference report.

On November 18-19, 2019, the Immunity of Canadians and Risk of Epidemics (iCARE) Network convened a workshop in Toronto, Ontario, Canada. The objectives of the workshop were to raise the profile of sero-epidemiology in Canada, discuss best practice and methodological innovations, and strategize on the future direction of sero-epidemiology work in Canada. In this conference report, we describe the presentations and discussions from the workshop, and comment on the impact of the COVID-19 pandemic on serosurveillance initiatives, both in Canada and abroad.

Vaccine Effectiveness of non-adjuvanted and adjuvanted trivalent inactivated influenza vaccines in the prevention of influenza-related hospitalization in older adults: A pooled analysis from the Serious Outcomes Surveillance (SOS) Network of the Canadian Immunization Research Network (CIRN).

BACKGROUND: Influenza vaccines prevent influenza-related morbidity and mortality; however, suboptimal vaccine effectiveness (VE) of non-adjuvanted trivalent inactivated influenza vaccine (naTIV) or quadrivalent formulations in older adults prompted the use of enhanced products such as adjuvanted TIV (aTIV). Here, the VE of aTIV is compared to naTIV for preventing influenza-associated hospitalization among older adults. METHODS: A test-negative design study was used with pooled data from the 2012 to 2015 influenza seasons. An inverse probability of treatment (IPT)-weighted logistic regression estimated the Odds Ratio (OR) for laboratory-confirmed influenza-associated hospitalization. VE was calculated as (1-OR)*100% with accompanying 95% confidence intervals (CI). RESULTS: Of 7,101 adults aged ≥ 65, 3,364 received naTIV and 526 received aTIV. The overall VE against influenza hospitalization was 45.9% (95% CI: 40.2%-51.1%) for naTIV and 53.5% (42.8%-62.3%) for aTIV. No statistically significant differences in VE were found between aTIV and naTIV by age group or influenza season, though a trend favoring aTIV over naTIV was noted. Frailty may have impacted VE in aTIV recipients compared to those receiving naTIV, according to an exploratory analysis; VE adjusted by frailty was 59.1% (49.6%-66.8%) for aTIV and 44.8% (39.1%-50.0%) for naTIV. The overall relative VE of aTIV to naTIV against laboratory-confirmed influenza hospital admission was 25% (OR 0.75; 0.61-0.92), demonstrating statistically significant benefit favoring aTIV. CONCLUSIONS: Adjusting for frailty, aTIV showed statistically significantly better protection than naTIV against influenza-associated hospitalizations in older adults. In future studies, it is important to consider frailty as a significant confounder of VE.

Leveraging Influenza Virus Surveillance From 2012 to 2015 to Characterize the Burden of Respiratory Syncytial Virus Disease in Canadian Adults ≥50 Years of Age Hospitalized With Acute Respiratory Illness.

Background: Respiratory syncytial virus (RSV) disease in older adults is undercharacterized. To help inform future immunization policies, this study aimed to describe the disease burden in Canadian adults aged ≥50 years hospitalized with RSV. Methods: Using administrative data and nasopharyngeal swabs collected from active surveillance among adults aged ≥50 years hospitalized with an acute respiratory illness (ARI) during the 2012-2013, 2013-2014, and 2014-2015 influenza seasons, RSV was identified using a respiratory virus multiplex polymerase chain reaction test to describe the associated disease burden, incidence, and healthcare costs. Results: Of 7797 patients tested, 371 (4.8%) were RSV positive (2.2% RSV-A and 2.6% RSV-B). RSV prevalence varied by season from 4.2% to 6.2%. Respiratory virus coinfection was observed in 11.6% (43/371) of RSV cases, with influenza A being the most common. RSV hospitalization rates varied between seasons and increased with age, from 8-12 per 100 000 population in adults aged 50-59 years to 174-487 per 100 000 in adults aged ≥80 years. The median age of RSV cases was 74.9 years, 63.7% were female, and 98.1% of cases had ≥1 comorbidity. Among RSV cases, the mean length of hospital stay was 10.6 days, 13.7% were admitted to the intensive care unit, 6.4% required mechanical ventilation, and 6.1% died. The mean cost per RSV case was $13 602 (Canadian dollars) but varied by age and Canadian province. Conclusions: This study adds to the growing literature on adult RSV burden by showing considerable morbidity, mortality, and healthcare costs in hospitalized adults aged ≥50 years with ARIs such as influenza.

Hunting for mpox (monkeypox) mimickers: Use of the Biofire meningitis/encephalitis panel on lesion swabs to support alternative viral diagnoses.

BACKGROUND: Mpox (formerly monkeypox) is an emerging zoonotic disease of public health concern that presents as a rash mimicking other common viral exanthems. Unlike traditional testing algorithms relying on several assays, the BioFire FilmArray meningitis/encephalitis (ME) panel simultaneously detects common viruses causing rashes; however, Biofire ME is only licensed for testing on cerebral spinal fluid. OBJECTIVES: This study evaluated use of the Biofire ME panel for detection and discrimination of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV), human herpesviruses type 6 (HHV-6), enteroviruses (EVs), and human paraechoviruses (HPeVs) from a dermal or mucocutaneous swabs collected in universal transport media (UTM). STUDY DESIGN: Results of the BioFire ME panel were compared against methods used during clinical testing. Ten-fold serial dilutions in UTM of cultured viruses were used to compare analytical sensitivity, and analytical specificity was assessed using panels of microorganisms in UTM. Clinical sensitivity and specificity were assessed using 20 positive specimens each for HHV-1, HHV-2, HHV-6, VZV, EVs, and HPeV, as well as 35 known negative specimens that included 15 mpox-positive specimens. RESULTS: Biofire ME was as sensitive as comparator methods, and correctly discriminated all HSV-1, HSV-2, VZV, HHV-6, EVs, and HPeVs from mpox and mpox-mimickers. Cross-reaction between EV and rhinoviruses A, B, and C were noted in the specificity panel. CONCLUSIONS: Swabs in UTM collected for mpox testing are suitable for use on the Biofire ME panel, allowing more streamlined diagnostic testing for viral exanthems in patients under investigation for mpox infection.

Using Serum Specimens for Real-Time PCR-Based Diagnosis of Human Granulocytic Anaplasmosis, Canada.

Whole blood is the optimal specimen for anaplasmosis diagnosis but might not be available in all cases. We PCR tested serum samples collected in Canada for Anaplasma serology and found 84.8%-95.8% sensitivity and 2.8 average cycle threshold elevation. Serum can be acceptable for detecting Anaplasma spp. when whole blood is unavailable.

2021-2022 AMMI Canada guidance on the use of antiviral drugs for influenza in the COVID-19 pandemic setting in Canada.

We provide an update to the Association of Medical Microbiology and Infectious Disease Canada seasonal influenza foundation guideline on the use of antiviral drugs for influenza for the upcoming 2021-2022 influenza season in Canada. Peramivir and baloxavir marboxil were licensed in Canada in 2017 and 2020, respectively, but neither is currently marketed. Thus, this guidance continues to focus on further optimizing the use of oseltamivir and zanamivir. Important issues for this year include the implications of co-circulation of severe acute respiratory syndrome coronavirus 2 and influenza viruses; the role of diagnostic testing in relation to impact on patient management; and dosing and administration recommendations for neuraminidase inhibitors for various at-risk age groups.

Une mise à jour des lignes directrices de base d'AMMI Canada sur l'utilisation de médicaments antiviraux contre l'influenza au cours de la saison grippale 2021-2022 au Canada est présentée. Le péramivir et le baloxavir marboxil ont été homologués au Canada en 2017 et en 2020, respectivement, mais ni l'un ni l'autre n'est encore commercialisé. Les lignes directrices continuent donc d'être axées sur l'optimisation de l'oseltamivir et du zanamivir. Les enjeux importants cette année incluent les effets de la cocirculation du coronavirus 2 du syndrome respiratoire aigu sévère et des virus de l'influenza, le rôle des tests diagnostiques sur la prise en charge des patients, de même que les recommandations en matière de posologie et d'administration des inhibiteurs de la neuraminidase dans divers groupes d'âge à risque.

Impact of respiratory viral infections on mortality and critical illness among hospitalized patients with chronic obstructive pulmonary disease.

BACKGROUND: Seasonal respiratory viral infections are associated with exacerbations and morbidity among patients with COPD. The real-world clinical outcomes associated with seasonal viral infections are less well established among hospitalized patients. RESEARCH QUESTION: To estimate the association between seasonal respiratory viral infections, 30-day mortality, and intensive care unit (ICU) admission among hospitalized COPD patients. STUDY DESIGN AND METHODS: We conducted an analysis of a national prospective multicenter cohort of COPD patients hospitalized with acute respiratory illness during winter seasons (2011-2015) in Canada. Nasopharyngeal swabs were performed on all patients at the onset of hospital admission for diagnosis of viral infection. Primary outcomes were 30-day mortality and ICU admissions. Secondary outcomes included invasive/non-invasive ventilation use. RESULTS: Among 3931 hospitalized patients with COPD, 28.5% (1122/3931) were diagnosed with seasonal respiratory viral infection. Viral infection was associated with increased admission to ICU (OR 1.5, 95% CI 1.2-1.9) and need for mechanical ventilation (OR 1.9, 95% CI 1.4-2.5), but was not associated with mortality (OR 1.1, 95% CI 0.8-1.4). Patients with respiratory syncytial virus (RSV) were equally likely to require ICU admission (OR 1.09, 95% CI 0.67-1.78), and more likely to need non-invasive ventilation (OR 3.1; 95% CI 1.8-5.1) compared to patients with influenza. INTERPRETATION: Our results suggest COPD patients requiring hospitalization for respiratory symptoms should routinely receive viral testing at admission, especially for RSV and influenza, to inform prognosis, clinical management, and infection control practices during winter seasons. Patients with COPD will be an important target population for newly developed RSV therapeutics. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT01517191.

Modified Two-Tiered Testing Enzyme Immunoassay Algorithm for Serologic Diagnosis of Lyme Disease.

The modified 2-tier testing algorithm (MTTT) for Lyme disease (LD) has been approved by the US Food and Drug Administration. In this study, we show that the MTTT detected 28% more cases of early infection compared with the standard 2-tier algorithm while retaining high specificity in a region with a high incidence of LD.