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Significance There is growing evidence that preexisting autoantibodies neutralizing type I interferons (IFNs) are strong determinants of life-threatening COVID-19 pneumonia. It is important to estimate their quantitative impact on COVID-19 mortality upon SARS-CoV-2 infection, by age and sex, as both the prevalence of these autoantibodies and the risk of COVID-19 death increase with age and are higher in men. Using an unvaccinated sample of 1,261 deceased patients and 34,159 individuals from the general population, we found that autoantibodies against type I IFNs strongly increased the SARS-CoV-2 infection fatality rate at all ages, in both men and women. Autoantibodies against type I IFNs are strong and common predictors of life-threatening COVID-19. Testing for these autoantibodies should be considered in the general population.

Objectives: The aim of this study is to identify the epidemiological, clinical, and laboratory features of coronavirus disease 2019 (COVID-19) in children.Methods: A retrospective study was conducted by pediatric infectious disease specialists from 32 different hospitals from all over Turkey by case record forms. Pediatric cases who were diagnosed as COVID-19 between March 16, 2020, and June 15, 2020 were included. Case characteristics including age, sex, dates of disease onset and diagnosis, family, and contact information were recorded. Clinical data, including the duration and severity of symptoms, were also collected. Laboratory parameters like biochemical tests and complete blood count, chest X-ray, and chest computed tomography (CT) were determined.Results: There were 1,156 confirmed pediatric COVID-19 cases. In total, male cases constituted 50.3% (n = 582) and females constituted 49.7% (n = 574). The median age of the confirmed cases was 10.75 years (4.5–14.6). Of the total cases, 90 were younger than 1 year of age (7.8%), 108 were 1–3 years of age (9.3%), 148 were 3–6 years of age (12.8%), 298 were 6–12 years of age (25.8%), 233 were 12–15 years of age (20.2%), and 268 cases were older than 15 years of age (23.2%). The most common symptom of the patients at the first visit was fever (50.4%) (n = 583) for a median of 2 days (IQR: 1–3 days). Fever was median at 38.4°C (38.0–38.7°C). The second most common symptom was cough (n = 543, 46.9%). The other common symptoms were sore throat (n = 143, 12.4%), myalgia (n = 141, 12.2%), dyspnea (n = 118, 10.2%), diarrhea (n = 112, 9.7%), stomachache (n = 71, 6.1%), and nasal discharge (n = 63, 5.4%). When patients were classified according to disease severity, 263 (22.7%) patients were asymptomatic, 668 (57.7%) patients had mild disease, 209 (18.1%) had moderate disease, and 16 (1.5%) cases had severe disease. One hundred and forty-nine (12.9%) cases had underlying diseases among the total cases; 56% of the patients who had severe disease had an underlying condition (p < 0.01). The need for hospitalization did not differ between patients who had an underlying condition and those who do not have (p = 0.38), but the need for intensive care was higher in patients who had an underlying condition (p < 0.01). Forty-seven (31.5%) of the cases having underlying conditions had asthma or lung disease (38 of them had asthma).Conclusions: To the best of our knowledge, this is one of the largest pediatric data about confirmed COVID-19 cases. Children from all ages appear to be susceptible to COVID-19, and there is a significant difference in symptomatology and laboratory findings by means of age distribution.

Multisystem inflammatory syndrome in children (MIS-C) is a rare and severe condition that follows benign COVID-19. We report autosomal recessive deficiencies of OAS1 , OAS2 , or RNASEL in five unrelated children with MIS-C. The cytosolic dsRNA-sensing OAS1 and OAS2 generate 2′-5′-linked oligoadenylates (2-5A) that activate the ssRNA-degrading RNase L. Monocytic cell lines and primary myeloid cells with OAS1 , OAS2 , or RNASEL deficiencies produce excessive amounts of inflammatory cytokines upon dsRNA or SARS-CoV-2 stimulation. Exogenous 2-5A suppresses cytokine production in OAS1- but not RNase L-deficient cells. Cytokine production in RNase L-deficient cells is impaired by MDA5 or RIG-I deficiency and abolished by MAVS deficiency. Recessive OAS–RNase L deficiencies in these patients unleash the production of SARS-CoV-2–triggered, MAVS-mediated inflammatory cytokines by mononuclear phagocytes, thereby underlying MIS-C.

Aim Multisystem inflammatory syndrome in children (MIS‐C) may cause shock and even death in children. The aim of this study is to describe the clinical features, laboratory characteristics and outcome of children diagnosed with MIS‐C in 25 different hospitals in Turkey. Methods The retrospective study was conducted between 8 April and 28 October 2020 in 25 different hospitals from 17 cities. Data were collected from patients' medical records using a standardised form. Clinical and laboratory characteristics and outcomes according to different age groups, gender and body mass index percentiles were compared using multivariate logistic regression analysis. Results The study comprised 101 patients, median age 7 years (interquartile range (IQR) 4.6–9.3); 51 (50.5%) were boys. Reverse‐transcriptase polymerase chain reaction (PCR) assay was positive in 21/100 (21%) patients; 62/83 (74.6%) patients had positive serology for SARS‐CoV‐2. The predominant complaints were fever (100%), fatigue ( n = 90, 89.1%), and gastrointestinal symptoms ( n = 81, 80.2%). Serum C‐reactive protein (in 101 patients, median 165 mg/L; range 112–228), erythrocyte sedimentation rate (73/84, median 53 mm/s; IQR 30–84) and procalcitonin levels (86/89, median 5 μg/L; IQR 0.58–20.2) were elevated. Thirty‐eight patients (37.6%) required admission to intensive care. Kawasaki disease (KD) was diagnosed in 70 (69.3%) patients, 40 of whom had classical KD. Most patients were treated with intravenous immunoglobulin ( n = 92, 91%) and glucocorticoids ( n = 59, 58.4%). Seven patients (6.9%) died. Conclusion The clinical spectrum of MIS‐C is broad, but clinicians should consider MIS‐C in the differential diagnosis when persistent fever, fatigue and gastrointestinal symptoms are prominent. Most patients diagnosed with MIS‐C were previously healthy. Immunomodulatory treatment and supportive intensive care are important in the management of cases with MIS‐C. Glucocorticoids and intravenous immunoglobulins are the most common immunomodulatory treatment options for MIS‐C. Prompt diagnosis and prompt treatment are essential for optimal management.

Pneumonia is a significant cause of death for children, particularly those in developing countries. The records of children who were hospitalized because of pneumonia between January 2003 and December 2015 were retrospectively reviewed, and patients who met the recurrent pneumonia criteria were included in this study. During this 13-year period, 1395 patients were hospitalized with pneumonia; of these, 129 (9.2%) met the criteria for recurrent pneumonia. Underlying diseases were detected in 95 (73.6%) patients, with aspiration syndrome (21.7%) being the most common. Rhinovirus (30.5%), adenovirus (17.2%) and respiratory syncytial virus (13.9%) were the most frequent infectious agents. These results demonstrate that underlying diseases can cause recurrent pneumonia in children. Viruses are also commonly seen in recurrent pneumonia. Appropriate treatments should be chosen based on an analysis of the underlying disease, the patient's clinical condition and the laboratory and radiological data.

IntroductionBloodstream infections (BSIs) are the main cause of morbidity, prolonged hospitalization, increased cost, and mortality in patients [1,2]. Underlying diseases, applied chemotherapy protocols, central venous catheter (CVC), radiation therapy, surgical procedures, and mucositis may predispose patients to infections [3]. Today, more than 80% of pediatric patients receiving cancer treatment have long-term CVCs [4]. The majority of BSIs are related to the use of these catheters in children.Early diagnosis and empirical antibiotic treatment may help improve the prognosis of BSIs. However, the choice of empirical antibiotic treatment must be based on the patient's clinical status, frequently detected isolates, and their antimicrobial susceptibility patterns in the region [5]. In some hospitals, treatment of BSIs caused by multiresistant bacteria is an important problem because of increasing antibiotic resistance [6].Until the 1990s gram-positive microorganisms were the pathogens most often responsible for BSIs; today gram-negative pathogens are frequently isolated in many centers [7]. It is very important to know the local prevalence of responsible microorganisms for appropriate management. For this purpose, in our study we aimed to identify the microorganisms that were isolated from blood culture during the febrile period in pediatric hematology and oncology patients, their antimicrobial susceptibility patterns, and clinical outcomes. Materials and methods Study populationsThis was a cross-sectional study that included febrile patients with hematological and/or oncological diseases Background/aim: Bloodstream infections are the major cause of morbidity, increased cost, prolonged hospitalization, and mortality in pediatric patients. Identifying the predominant microorganisms and antimicrobial susceptibilities in centers helps to select effective empirical antimicrobials which leads to positive clinical outcomes. We aimed to identify the causative microorganisms and their antimicrobial susceptibilities in patients with bloodstream infections.Materials and methods: Data belonging to patients with hematological and/or oncological diseases admitted to our hospital with fever between January 2010 and November 2015 were analyzed.Results: In total, 71 patients who had 111 bloodstream infection episodes were included. Responsible pathogens were detected as follows: 35.1% gram-positive microorganisms, 60.5% gram-negative bacteria, and 4.4% fungi. The most common causative gram-negative pathogen was Escherichia coli and the most commonly isolated gram-positive microorganism was coagulase-negative staphylococci. Conclusion:Gram-negative microorganisms were predominant pathogens in bloodstream infections. Escherichia coli and coagulasenegative staphylococci were the most commonly isolated responsible pathogens. Beta-lactam/lactamase inhibitors were suitable for empirical treatment. However, in critical cases, colistin could have been used for empirical treatment until the culture results were available. Routine glycopep...

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