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PurposeClose-contact rates are thought to be a significant driving force behind the dynamics of transmission for many infectious respiratory diseases. Efforts to control such infections typically focus on the practice of strict contact-avoidance measures. Yet, contact rates and their relation to transmission, and the impact of control measures, are seldom quantified. Here, we quantify the response of contact rates, transmission and new cases of COVID-19 to public health contact-restriction orders, and the associations among these three variables, in the Canadian province of British Columbia (BC) and within its two most densely populated regional health authorities: Fraser Health Authority (FHA) and Vancouver Coastal Health Authority (VCHA).MethodsWe obtained time series for self-reported close-contact rates from the BC Mix COVID-19 Survey, new reported cases of COVID-19 from the BC Center for Disease Control, and transmission rates based on dynamic model fits to reported cases. Our study period was from September 13, 2020 to February 19, 2021, during which three public health contact-restriction orders were introduced (October 26, November 7 and November 19, 2020). We used segmented linear regression to quantify impacts of public health orders, Pearson correlation to assess the instantaneous relation between contact rates and transmission, and vector autoregressive modeling to study the lagged relations among the three variables.ResultsOverall, declines in contact rates and transmission occurred concurrently with the announcement of public health orders, whereas declines in new cases showed a reporting delay of roughly two weeks. The impact of the first public health order (October 26, 2020) on contact rates and transmission was more pronounced than that of the other two health orders. Contact rates and transmission on the same day were strongly correlated (correlation coefficients = 0.64, 0.53 and 0.34 for BC, FHA, and VCHA, respectively). Moreover, contact rates were a significant time-series driver of COVID-19 and explained roughly 30% and 18% of the variation in new cases and transmission, respectively. Interestingly, increases in transmission and new cases were followed by reduced rates of contact: overall, average daily cases explained about 10% of the variation in provincial contact rates.ConclusionWe show that close-contact rates were a significant driver of transmission of COVID-19 in British Columbia, Canada and that they varied in response to public health orders. Our results also suggest a possible feedback, by which contact rates respond to recent changes in reported cases. Our findings help to explain and validate the commonly assumed, but rarely measured, response of close contact rates to public health guidelines and their impact on the dynamics of infectious diseases.

This study identified factors associated with hospital admission among people with laboratory-diagnosed COVID-19 cases in British Columbia. The study used data from the BC COVID-19 Cohort, which integrates data on all COVID-19 cases with data on hospitalizations, medical visits, emergency room visits, prescription drugs, chronic conditions and deaths. The analysis included all laboratory-diagnosed COVID-19 cases in British Columbia to 15 January 2021. We evaluated factors associated with hospital admission using multivariable Poisson regression analysis with robust error variance. Of the 56,874 COVID-19 cases included in the analysis, 2298 were hospitalized. Factors associated with increased hospitalization risk were as follows: male sex (adjusted risk ratio (aRR) = 1.27, 95%CI = 1.17–1.37), older age (p-trend &lt, 0.0001 across age groups increasing hospitalization risk with increasing age [aRR 30–39 years = 3.06, 95%CI = 2.32–4.03, to aRR 80+ years = 43.68, 95%CI = 33.41–57.10 compared to 20–29 years-old]), asthma (aRR = 1.15, 95%CI = 1.04–1.26), cancer (aRR = 1.19, 95%CI = 1.09–1.29), chronic kidney disease (aRR = 1.32, 95%CI = 1.19–1.47), diabetes (treated without insulin aRR = 1.13, 95%CI = 1.03–1.25, requiring insulin aRR = 5.05, 95%CI = 4.43–5.76), hypertension (aRR = 1.19, 95%CI = 1.08–1.31), injection drug use (aRR = 2.51, 95%CI = 2.14–2.95), intellectual and developmental disabilities (aRR = 1.67, 95%CI = 1.05–2.66), problematic alcohol use (aRR = 1.63, 95%CI = 1.43–1.85), immunosuppression (aRR = 1.29, 95%CI = 1.09–1.53), and schizophrenia and psychotic disorders (aRR = 1.49, 95%CI = 1.23–1.82). In an analysis restricted to women of reproductive age, pregnancy (aRR = 2.69, 95%CI = 1.42–5.07) was associated with increased risk of hospital admission. Older age, male sex, substance use, intellectual and developmental disability, chronic comorbidities, and pregnancy increase the risk of COVID-19-related hospitalization.

BackgroundThis study identified factors associated with hospital admission among people with laboratory-diagnosed COVID-19 cases in British Columbia.MethodsThis study was performed using the BC COVID-19 Cohort, which integrates data on all COVID-19 cases, hospitalizations, medical visits, emergency room visits, prescription drugs, chronic conditions and deaths. The analysis included all laboratory-diagnosed COVID-19 cases in British Columbia as of January 15th, 2021. We evaluated factors associated with hospital admission using multivariable Poisson regression analysis with robust error variance.FindingsFrom 56,874 COVID-19 cases included in the analyses, 2,298 were hospitalized. Models showed significant association of the following factors with increased hospitalization risk: male sex (adjusted risk ratio (aRR)=1.27; 95%CI=1.17-1.37), older age (p-trend InterpretationOlder age, male sex, substance use, intellectual and developmental disability, chronic comorbidities, and pregnancy increase the risk of COVID-19-related hospitalization.FundingBC Centre for Disease Control, Canadian Institutes of Health Research.Research in contextEvidence before this studyFactors such as older age, social inequities and chronic health conditions have been associated to severe COVID-19 illness. Most of the evidence comes from studies that don’t include all COVID-19 diagnoses in a jurisdiction), focusing on in-hospital mortality. In addition, mental illness and substance use were not evaluated in these studies. This study assessed factors associated with hospital admission among people with laboratory-diagnosed COVID-19 cases in British Columbia.Added value of this studyIn this population-based cohort study that included 56,874 laboratory-confirmed COVID-19 cases, older age, male sex, injection drug use, problematic alcohol use, intellectual and developmental disability, schizophrenia and psychotic disorders, chronic comorbidities and pregnancy were associated with the risk of hospitalization. Insulin-dependent diabetes was associated with higher risk of hospitalization, especially in the subpopulation younger than 40 years. To the best of our knowledge this is the first study reporting this finding, (insulin use and increased risk of COVID-19-related death has been described previously).Implications of all the available evidencePrioritization of vaccination in population groups with the above mentioned risk factors could reduce COVID-19 serious outcomes. The findings indicate the presence of the syndemic of substance use, mental illness and COVID-19, which deserve special public health considerations.

The Marajo Archipelago, located in the rural area of ​​the state of Para (Amazon region of Brazil), is the region with the lowest index of human development in the country, presenting poor health services, which makes adequate epidemiological surveillance of HIV-1 infection difficult. After a serological screening enrolling 1,877 samples, three samples were diagnosed with HIV-1 and the pro gene was sequenced to evaluate the presence of resistance mutations to protease inhibitors. Molecular analyses revealed, for the first time in the region of Marajo Island, the occurrence of HIV-1 subtypes B and D, as well as the presence of transmitted high and intermediate protease inhibitors resistance mutations. The results emphasize the importance of ongoing molecular epidemiological surveillance studies in the Brazilian Amazon region because antiretroviral (ARV) resistance mutations may limit treatment options, and the presence of certain subtypes seems to influence the progression to AIDS, particularly in areas where the entry and spread of the virus can be facilitated by socio-demographic problems that expose the population to sexually transmitted infections.

International audience; Private forests are widespread in Europe providing a range of ecosystem services of significant value to society, and there are calls for novel policies to enhance their provision and to face the challenges of environmental changes. Such policies need to acknowledge the importance of private forests, and importantly they need to be based on a deep understanding of how property rights held by private forest owners vary across Europe. We collected and analysed data on the content of property rights based on formal legal requirements existing in 31 European jurisdictions. To allow a comparison across jurisdictions, we constructed an original Property Rights Index for Forestry encompassing five rights domains (access, withdrawal, management, exclusion and alienation). We documented substantial variation of the private forest owners' rights, and notably to i) make decisions in operational management and the formulation of management goals, ii) withdraw timber resources from their forest, and iii) exclude others from the use of forest resources. We identified broad relations between the scope for decision making of private forest owners and jurisdictions' former socio-political background and geographical distribution. The variation in the content of property rights has implications for the implementation of international environmental policies, and stresses the need for tailored policy instruments, when addressing European society's rural development, the bioeconomy, climate change mitigation measures and nature protection strategies.

В статье рассматриваются вихри Гертлера в пограничном слое жидкости применительно к характерным диапазонам изменения длины волны вихрей. Формулируется краевая задача для характерного коротковолнового режима. Развитие вихрей Гертлера в сжимаемых, в частности гиперзвуковых, потоках привлекает в настоящее время значительный интерес в связи с разработкой новых технологий, а именно с созданием новых сверхзвуковых малотурбулентных аэродинамических труб и с проектированием гиперзвуковых летательных аппаратов, для которых определение положения ламинарно-турбулентного перехода и нахождение распределений и пиковых величин тепловых потоков являются ключевыми элементами. В настоящей статье сформулирована математическая модель, описывающая нелинейную фазу развития возмущений в сжимаемом пограничном слое в поле центробежных сил при больших, но докритических значениях чисел Рейнольдса и Гертлера. Эта модель предназначена для описания как развития вихрей Гертлера, так и возмущенных течений около локальных или периодических в трансверсальном направлении неровностей или других пространственных возмущенных течений. При малых амплитудах возмущений нелинейные краевые задачи сводятся к линейным задачам теории устойчивости, которая к настоящему времени разработана лишь фрагментарно. На основе метода сращиваемых асимптотических разложений исследованы некоторые линейные режимы развития возмущений в поле центробежных сил. В частности, выявлена роль переходного температурного слоя в развитии возмущений в гиперзвуковых потоках. В то же время имеющиеся экспериментальные исследования свидетельствуют о возникновении других возможных форм возмущенного вихревого движения газа, что требует проведения дальнейших исследований The article deals with Gertler vortices in the boundary layer of fluid applied typical range of variation of the wavelength of the vortices. Formulated boundary problem for the typical shortwavelength regime. The development of vortices Gertler in compressible, especially hypersonic flows, attracted by now considerable interest in the development of new technologies, namely the creation of new supersonic little turbulent wind tunnel and the design of hypersonic aircraft, which detect the position of the laminar-turbulent transition and finding the distributions and peak values of the heat flows are key elements. In this article the mathematical model describing the nonlinear stage of development of disturbances in compressible boundary layer in the field of centrifugal forces at large, but subcritical Reynolds numbers and Gertler. This model is designed for the description of the vortices Gertler, and to describe the perturbed flows about local or periodic irregularities in the transverse direction or the other spatial disturbed flow. For small amplitudes of perturbations of nonlinear boundary value problems are reduced to linear problems of the theory of stability, which so far developed only in fragments. Based on the method of matched asymptotic expansions we studied some linear modes of perturbations in the field of centrifugal forces. In particular, The role of the transition temperature layer in the development of disturbances in hypersonic flows. At the same time, the experimental studies suggest the occurrence of other possible forms of perturbed vortex movement of gas that requires further research

In January 2004, an increase in gastrointestinal illness following oyster consumption was reported in British Columbia. An investigation was initiated to explore the association between norovirus infection and consumption of British Columbia oysters and to identify the source of oyster contamination.The outbreak investigation included active surveillance for human cases, two cohort studies, trace-back of oysters, and laboratory testing of oysters and human stools.Enhanced surveillance identified 26 confirmed and 53 clinical cases over 3 months. Oyster consumption was associated with illness in one cohort and suggestive in the other. Oysters were traced to 14 geographically dispersed harvest sites, 18 suppliers, and 45 points of purchase. Norovirus BCCDC03-028 (genotype I.2) was detected in 50% of human specimens. Experimental methods detected norovirus in 12 oyster samples. Sequencing identified mixed clonal patterns in the oysters with one direct sequence match between an oyster sample and the associated human specimen.The consumption of raw oysters led to norovirus infection. The source of oyster contamination remained unidentified. The geographical dispersion of implicated harvest sites was unusual.This outbreak is unlike most shellfish outbreaks that can be traced back to a common source and challenges conventional thinking that all oyster-related norovirus outbreaks of are a result of point source contamination.

Two major outbreaks of invasive meningococcal disease serogroup C (IMD-C) were identified in British Columbia between 2000 and 2004. Pulsed-field gel electrophoresis (PFGE) andporAgene sequencing of all retained IMD-C isolates were used to assess correlations between genotypes and epidemiological patterns. PFGE patterns of IMD-C genotypes correlated with epidemiological patterns between 2000 and 2004 in British Columbia, and demonstrated that PFGE can identify outbreak-related cases. Both IMD-C outbreaks correlated with a respective PFGE pattern. PFGE analysis demonstrated that the 2004 British Columbia outbreak strain in men who have sex with men was closely related to the 2001 Abbotsford outbreak strain.PorAsequencing data indicated low diversity of class 1 outer membrane proteins in British Columbia, and did not correlate with epidemiological trends. There was a trend for outbreak-associated PFGE types to demonstrate higher case fatality rates.

Формулируется краевая задача обтекания вогнутой поверхности потоком вязкой несжимаемой жидкости, для решения которой принимается метод сращивания асимптотических разложений. Этому методу свойственна потеря граничных условий. Нельзя ожидать, что внешнее разложение будет удовлетворять условиям, которые наложены во внутренней области, и обратно – внутреннее разложение в общем случае не будет удовлетворять условиям в удаленной области. Но потеря условий восполняется сращиванием. Сращивание представляет собой основную черту метода. Возможность сращивания основана на существовании области перекрытия, в которой пригодно как внутреннее, так и внешнее разложение. Используя это перекрытие, можно получить точное соотношение между конечными частными суммами. Реализация этой возможности осуществима только для возмущения параметра, которое неоднородно в координатах, или для возмущения координаты, которое неоднородно по другим координатам. Нельзя срастить два различных параметрических разложения, таких как разложение для больших и малых значений числа Рейнольдса или числа Маха; невозможно срастить два различных координатных разложения, таких как разложение для малых и больших значений времени или расстояния. Такие ряды могут перекрываться в том смысле, что они имеют общую область сходимости, но процесс аналитического продолжения дает только приближенное соотношение для некоторого конечного числа членов. Существование области перекрытия означает, что внутреннее разложение внешнего разложения должно с точностью до соответствующего порядка согласовываться с внешним разложением внутреннего разложения. Этот принцип распространяется на приближения высшего порядка при сохранении дальнейших членов в асимптотических разложениях. Можно допустить, что число членов может быть различно во внутреннем и внешнем разложениях, поскольку нормальный порядок сращивания требует разницы на единицу при четных шагах Formulated boundary problem of flow around the concave surface of a viscous incompressible fluid, the solution of which is accepted method of matched asymptotic expansions. The method of matched asymptotic expansions characterized by the loss of boundary conditions. One can not expect that the outer expansion will satisfy the conditions imposed are in the inner region, and conversely, the inner expansion generally will not satisfy the conditions in a remote area. But the loss is compensated splicing conditions. Splicing is the main feature of the method. The possibility of matching based on the existence of the overlap region, which are suitable both internal and external expansion. Using this overlap, you can get the exact relationship between the finite partial sums. The implementation of this option is only feasible for the perturbation parameter, which is inhomogeneous in the coordinates, and the coordinates for the disturbance, which is inhomogeneous in other coordinates. You can not splice two different parametric decomposition, such as the expansion for large and small values of the Reynolds number and Mach number; it is impossible to splice two different coordinate expansions, such as the expansion of small and large values of time or distance. Such rows can overlap in the sense that they have a common domain of convergence, but the process of analytic continuation gives only approximate relation to a finite number of members. The existence of a region of overlap means that the internal expansion external expansion should be up to the relevant procedure in line with the outer expansion of internal expansion. This principle applies to higher-order approximation, while maintaining further terms in the asymptotic expansion. We can assume that the number of members may be different for internal and external expansions as the normal order of splicing requires margin per unit for even steps

BACKGROUND: To address the increasing age of pertussis cases, Yukon replaced the Grade 9 tetanus/diphtheria/inactivated polio booster with diphtheria/tetanus/acellular pertussis (dTap) and implemented a dTap catch-up program for Grade 12 students. The program began in June 2004, making Yukon one of the first Canadian jurisdictions to introduce dTap within five years of a tetanus booster. We implemented enhanced surveillance to monitor adverse events following immunization (AEFI) to determine whether students receiving dTap =3 to

Background The objective of this evaluation was to determine whether reports of dead corvid sightings and submissions of dead corvids for West Nile virus testing were representative of true corvid mortality in British Columbia in 2004, a year with no West Nile virus activity, in order to ensure the system was accurately describing corvid mortality rather than reflecting regional differences in surveillance methods. Results Local Health Areas reported 0–159 (median = 3) dead corvid sightings and 0–209 (median = 5) submissions for West Nile virus testing. The expected numbers of dead corvid sightings and submissions for testing from each Local Health Area were 0–232 (median = 3) and 0–258 (median = 4), respectively. Twelve Local Health Areas reported significantly fewer sightings than expected; 21 reported significantly more. Eleven Local Health Areas submitted significantly fewer corvids than expected; 26 submitted significantly more. Conclusion Some Local Health Areas were over-represented and others under-represented in terms of corvid West Nile virus surveillance indicators. Recommendations were made to improve the representativeness of corvid surveillance data. Geographic analysis can be used to evaluate the representativeness of surveillance systems and result in improvements to surveillance.

The objective of this evaluation was to determine whether reports of dead corvid sightings and submissions of dead corvids for West Nile virus testing were representative of true corvid mortality in British Columbia in 2004, a year with no West Nile virus activity, in order to ensure the system was accurately describing corvid mortality rather than reflecting regional differences in surveillance methods. Local Health Areas reported 0–159 (median = 3) dead corvid sightings and 0–209 (median = 5) submissions for West Nile virus testing. The expected numbers of dead corvid sightings and submissions for testing from each Local Health Area were 0–232 (median = 3) and 0–258 (median = 4), respectively. Twelve Local Health Areas reported significantly fewer sightings than expected; 21 reported significantly more. Eleven Local Health Areas submitted significantly fewer corvids than expected; 26 submitted significantly more. Some Local Health Areas were over-represented and others under-represented in terms of corvid West Nile virus surveillance indicators. Recommendations were made to improve the representativeness of corvid surveillance data. Geographic analysis can be used to evaluate the representativeness of surveillance systems and result in improvements to surveillance.