Характеристика COVID-19 у детей: первый опыт работы в стационаре Санкт-Петербурга

Objective: to identify the clinical, laboratory and epidemiological features of the new coronavirus (CV) infection in the provision of specialized medical care to children in the megalopolis of the Russian Federation. Methods: 674 cases of hospitalization of patients from birth to 17 years old inclusive with confirmed COVID-19 in the period from March 26 to June 26, 2020 in a children’s multidisciplinary hospital in St. Petersburg. Diagnostics of SARS-COV-2 in upper respiratory tract (URT) smears was carried out by PCR (a set of reagents for detecting RNA of coronavirus 2019-nCoV by PCR with hybridization-fluorescence detection “Vector-PCRRV-2019-nCoV-RG”). Patients underwent 4 (3; 5) repeated examinations depending on the diagnosis of the referral, as well as the duration of the convalescent virus carriage. The analysis of the severity of the course of the disease, the main clinical manifestations and their relationship with the development of pneumonia, as well as the epidemiological features of COVID-19 in children. The duration of inpatient treatment, outcomes and the need for intensive care are described. Changes in a number of laboratory parameters on analyzers made in the USA were assessed: a clinical blood test on a hematological one - Coulter UniCel (Beckman Coulter), a biochemical blood test on a biochemical one - Uni Cel DxC (Beckman Coulter), a coagulogram on a hemostasis analyzer (Instrumentation Laboratory). Results: Overall, there was a favorable course of COVID-19 in children. Intensive therapy was required only in 3.6% of cases with a total mortality rate of 0.15%, Kawasakilike syndrome was recorded in 0.3% of cases. In 1/3 of patients, prolonged viral shedding from the upper respiratory tract was detected. In children, intrafamilial infection from adults was in the lead; schoolchildren accounted for half of all hospitalizations. A distinctive feature of the new infection was mild clinical symptoms with fever and catarrhal symptoms up to 4/5 of cases, gastrointestinal symptoms - in every third patient. There were no significant differences in the severity of the disease by age. Pneumonia, diagnosed in ¾ cases by computed tomography, complicated the course in 13.1% of cases. The defeat of the lungs was accompanied by fever and dry cough, and in a more severe course: desaturation, chest pains, a feeling of insufficiency of inspiration. The age peaks of the incidence of pneumonia were revealed: at 4, 9, 12 years old and at the age of 17 years, the maximum (in 1/3 of cases). Laboratory changes were insignificant and quickly reversible. Conclusion: the course of COVID-19 in children in the megalopolis of Russia is comparable with foreign information. However, taking into account the experience of “Spanish ‘flu”, it is possible that in pediatric practice the number of severe forms and unfavorable outcomes may change in the near future, especially due to the difficulty of diagnosing Kawasaki-like syndrome and the need for a multidisciplinary approach to the treatment of such patients. Currently, the most vulnerable to the new CV are children with severe oncological, neurological and cardiovascular pathology, who have a rapid decompensation of the underlying disease against the background of COVID-19.Цель: выявить клинико-лабораторные и эпидемиологические особенности новой коронавирусной инфекции при оказании специализированной медицинской помощи детям в мегаполисе Российской Федерации. Материалы и методы: 674 случая госпитализации пациентов от рождения до 17 лет включительно с подтвержденным COVID-19 в период с 26 марта по 26 июня 2020 г. в детский многопрофильный стационар СанктПетербурга. Диагностика SARS-COV-2 в мазках из верхних дыхательных путей проводилась методом ПЦР (набор реагентов для выявления РНК коронавируса 2019- nCoV методом ПЦР с гибридизационно-флуоресцентной детекцией «Вектор-ПЦРРВ-2019-nCoV–RG»). Пациентам выполнено 4 (3; 5) повторных исследования в зависимости от диагноза направления, а также длительности реконвалесцентного вирусоносительства. Проведен анализ тяжести течения заболевания, основных клинических проявлений и их взаимосвязи с развитием пневмонии, а также эпидемиологических особенностей COVID-19 у детей. Описана продолжительность стационарного лечения, исходы и потребность в интенсивной терапии. Оценены изменения ряда лабораторных показателей на анализаторах производства США: клинический анализ крови на гематологическом – Coulter UniCel (Beckman Coulter), биохимический анализ крови на биохимическом – Uni Cel DxC (Beckman Coulter), коагулограмма на анализаторе гемостаза (Instrumentation Laboratory). Результаты: в целом, отмечено благоприятное течение COVID-19 у детей. Интенсивная терапия потребовалась лишь в 3,6% случаев с общей летальностью 0,15%, Кавасаки-подобный синдром зафиксирован в 0,3% случаев. У 1/3 пациентов выявлено затяжное вирусовыделение из верхних дыхательных путей. У детей лидировало внутрисемейное заражение от взрослых, школьники составили половину всех случаев госпитализации. Отличительной чертой новой инфекции была неяркая клиническая симптоматика с лихорадкой и катаральными симптомами до 4/5 случаев, желудочно-кишечными симптомами – у каждого третьего пациента. Значимых различий в тяжести заболевания по возрастам выявлено не было. Пневмония, диагностированная в ¾ случаев с помощью компьютерной томографии, осложняла течение в 13,1% случаев. Поражение легких сопровождалось лихорадкой и сухим кашлем, а при более тяжелом течении – десатурацией, болями в грудной клетке, чувством неполноценности вдоха. Выявлены возрастные пики заболеваемости пневмонией: в 4, 9, 12 лет и в возрасте 17 лет максимальный (в 1/3 случаев). Изменения лабораторных показателей были несущественными и быстро обратимыми. Заключение: течение COVID-19 у детей в мегаполисе России сопоставимо с зарубежными данными. Однако, учитывая опыт испанки, не исключено, что в педиатрической практике число тяжелых форм и неблагоприятных исходов может измениться в ближайшем будущем, особенно по причине сложности диагностики Кавасакиподобного синдрома и необходимости мультидисциплинарного подхода к терапии таких пациентов. В настоящее время наиболее уязвимыми в отношении нового коронавируса являются дети с тяжелой онкологической, неврологической и сердечно-сосудистой патологией, у которых происходит быстрая декомпенсация основного заболевания на фоне COVID-19

Characteristics of CoVID-19 in children: the first experience in the hospital of st. Petersburg

Objective: to identify the clinical, laboratory and epidemiological features of the new coronavirus (CV) infection in the provision of specialized medical care to children in the megalopolis of the Russian Federation. Methods: 674 cases of hospitalization of patients from birth to 17 years old inclusive with confirmed COVID-19 in the period from March 26 to June 26, 2020 in a children’s multidisciplinary hospital in St. Petersburg. Diagnostics of SARS-COV-2 in upper respiratory tract (URT) smears was carried out by PCR (a set of reagents for detecting RNA of coronavirus 2019-nCoV by PCR with hybridization-fluorescence detection “Vector-PCRRV-2019-nCoV-RG”). Patients underwent 4 (3; 5) repeated examinations depending on the diagnosis of the referral, as well as the duration of the convalescent virus carriage. The analysis of the severity of the course of the disease, the main clinical manifestations and their relationship with the development of pneumonia, as well as the epidemiological features of COVID-19 in children. The duration of inpatient treatment, outcomes and the need for intensive care are described. Changes in a number of laboratory parameters on analyzers made in the USA were assessed: a clinical blood test on a hematological one - Coulter UniCel (Beckman Coulter), a biochemical blood test on a biochemical one - Uni Cel DxC (Beckman Coulter), a coagulogram on a hemostasis analyzer (Instrumentation Laboratory). Results: Overall, there was a favorable course of COVID-19 in children. Intensive therapy was required only in 3.6% of cases with a total mortality rate of 0.15%, Kawasakilike syndrome was recorded in 0.3% of cases. In 1/3 of patients, prolonged viral shedding from the upper respiratory tract was detected. In children, intrafamilial infection from adults was in the lead; schoolchildren accounted for half of all hospitalizations. A distinctive feature of the new infection was mild clinical symptoms with fever and catarrhal symptoms up to 4/5 of cases, gastrointestinal symptoms - in every third patient. There were no significant differences in the severity of the disease by age. Pneumonia, diagnosed in ¾ cases by computed tomography, complicated the course in 13.1% of cases. The defeat of the lungs was accompanied by fever and dry cough, and in a more severe course: desaturation, chest pains, a feeling of insufficiency of inspiration. The age peaks of the incidence of pneumonia were revealed: at 4, 9, 12 years old and at the age of 17 years, the maximum (in 1/3 of cases). Laboratory changes were insignificant and quickly reversible. Conclusion: the course of COVID-19 in children in the megalopolis of Russia is comparable with foreign information. However, taking into account the experience of “Spanish ‘flu”, it is possible that in pediatric practice the number of severe forms and unfavorable outcomes may change in the near future, especially due to the difficulty of diagnosing Kawasaki-like syndrome and the need for a multidisciplinary approach to the treatment of such patients. Currently, the most vulnerable to the new CV are children with severe oncological, neurological and cardiovascular pathology, who have a rapid decompensation of the underlying disease against the background of COVID-19

Spectra of Two-Dimensional Models for Thin Plates with Sharp Edges

We investigate the spectrum of the two-dimensional model for a thin plate with a sharp edge. The model yields an elliptic $3\times3$ Agmon–Douglis–Nirenberg system on a planar domain with coefficients degenerating at the boundary. We prove that in the case of a degeneration rate $\alpha<2$, the spectrum is discrete, but, for $\alpha\geq2$, there appears a nontrivial essential spectrum. A first result for the degenerating scalar fourth order plate equation is due to Mikhlin. We also study the positive definiteness of the quadratic energy form and the necessity to impose stable boundary conditions. These results differ from the ones that Mikhlin published.Delft Institute of Applied MathematicsElectrical Engineering, Mathematics and Computer Scienc