Oral-only antibiotics for bone and joint infections in children: study protocol for a nationwide randomised open-label non-inferiority trial.

INTRODUCTION: Children with bone and joint infections are traditionally treated with intravenous antibiotics for 3-10 days, followed by oral antibiotics. Oral-only treatment has not been tested in randomised trials. METHODS AND ANALYSIS: Children (3 months to 18 years) will be randomised 1:1 with the experimental group receiving high-dose oral antibiotics and the control group receiving intravenous antibiotics with a shift in both groups to standard oral antibiotics after clinical and paraclinical improvement. Children in need of acute surgery or systemic features requiring intravenous therapy, including septic shock, are excluded. The primary outcome is defined as a normal blinded standardised clinical assessment 6 months after end of treatment. Secondary outcomes are non-acute treatment failure and recurrent infection. Outcomes will be compared by a non-inferiority assumption with an inferiority margin of 5%. ETHICS AND DISSEMINATION: The trial has the potential to reduce unnecessary hospitalisation and use of intravenous antibiotics in children with bone or joint infections. Due to the close follow-up, exclusion of severely ill children and predefined criteria for discontinuation of the allocated therapy, we expect the risk of treatment failure to be minimal. TRIAL REGISTRATION NUMBER: NCT04563325.

Symptoms in the acute phase of SARS-CoV-2 infection among Danish children aged 0-14 years

Objectives This study aimed to investigate the prevalence and burden of proxy-reported acute symptoms in children in the first 4 weeks after detection of a SARS-CoV-2 infection and factors associated with symptom burden. Methods Nationwide cross-sectional survey using parental proxy-report of symptoms associated with SARS-CoV-2 infection. In July 2021, a survey was sent to mothers of all Danish children aged 0-14 years with a positive SARS-CoV-2 PCR during the period January 2020 - July 2021. The survey included 17 acute symptoms associated with SARS-CoV-2 infection and questions about comorbidities. Results Of 38,152 children with a positive SARS-CoV-2 PCR, 10,994 (28.8 %) responded. Median age was 10.2 (range 0.2-16.0) years and 51.8% were male. Among participants 54.2% (n=5,957) reported no symptoms, 43.7 % (n=4,807) reported mild symptoms, and 2.1 % (n=230) reported severe symptoms. Most common symptoms were fever (25.0 %), headaches (22.5 %) and sore throat (18.4 %). Asthma (OR 1.91 (95% CI 1.57;2.32) and 2.11 (1.36;3.28)), allergy (1.31 (1.14;1.52) and 1.70 (1.18;2.46)), eczema (1.43 (1.20;1.71) and 2.03 (1.38;2.97)), and OCD/anxiety/depression (2.06 (1.39;3.06) and 3.79 (1.80;7.97)) were associated with reporting higher symptom burden. Highest prevalence of symptoms was found among children aged 0-2 and 12-14 years. Conclusions Among SARS-CoV-2 positive children aged 0-14 years approximately half reported no acute symptoms within the first four weeks after a positive PCR. Most of symptomatic children reported mild symptoms. Several comorbidities were associated with reporting higher symptom burden.

Risk of body weight changes among Danish children and adolescents during the COVID-19 pandemic.

BACKGROUND: Knowledge of COVID-19 and the pandemic's effects on Danish children's body weight is limited. OBJECTIVE: Objectives were to investigate (I) risk of weight changes among Danish children with and without SARS-CoV-2, (II) associations between weight changes, psychological symptoms, and long COVID symptoms, and (III) weight distribution pre- and post-pandemic. METHODS: A national survey was administered to all Danish children aged 0-18 years, with prior COVID-19 (cases) and matched references including questions on weight, weight changes during the pandemic and long COVID-related symptoms. Descriptive statistics and logistic regression were used. Weight distribution was compared with a pre-pandemic database. RESULTS: In all, 17 627 cases and 54 656 references were included. The 4-18-year-old cases had lower odds of unintended weight gain. The 2-3-year-old cases had higher odds and the 15-18-year-old cases lower odds of weight loss compared to references. Regardless of COVID-19 status, any reported long COVID-related symptom was associated with a change in body weight. No sign of increasing obesity rates was found among Danish children post-pandemic. CONCLUSION: COVID-19 was associated with higher odds of weight loss in 2-3-year-olds and lower odds of unintended weight gain in 4-18-year-olds. Any long COVID-related symptom was associated with higher odds of weight changes regardless of COVID-19 status.

Hospital admissions and need for mechanical ventilation in children with respiratory syncytial virus before and during the COVID-19 pandemic: a Danish nationwide cohort study.

BACKGROUND: The incidence of respiratory syncytial virus (RSV) increased in several countries after the relaxation of COVID-19 restrictions. We aimed to investigate the age-related risk of RSV-associated hospital admissions and need for mechanical ventilation during the RSV resurgence in summer and autumn 2021 compared with the four RSV seasons preceding the COVID-19 pandemic. We also aimed to describe the clinical complications necessitating mechanical ventilation. METHODS: This population-based cohort study included patients aged 0-17 years admitted to hospital with RSV in Denmark during the RSV resurgence in summer and autumn 2021, and the four pre-COVID-19 RSV seasons (2016-17, 2017-18, 2018-19, and 2019-20). We retrieved data on RSV-associated hospital admissions from the Danish National Patient Registry and demographic and clinical details of children who received mechanical ventilation through prospective real-time data collection in 2021-22 and retrospective data collection for the 2016-17 to 2019-20 RSV seasons from all eight paediatric and neonatal intensive care units in Denmark. Risk factors for severe RSV disease were as defined as age younger than 3 months or severe comorbidities. We calculated the risk of RSV-associated hospital admissions per 100 000 population in each RSV season from week 21 to week 20 of the following year. We also calculated the risk rate of receiving mechanical ventilation per 100 000 population and 1000 RSV-associated hospital admissions during each RSV season from week 21 to week 20 of the following year. We calculated risk ratios (RRs) for hospital admission and mechanical ventilation by dividing the risk rate of hospital admission and mechanical ventilation in 2021-22 by annual mean risk rates in the four pre-COVID-19 RSV epidemics (2016-17 to 2019-20). We compared RRs using Fisher's exact test. We compared complications leading to intubation between children with and without risk factors for severe RSV disease. The study is registered at ClinicalTrials.gov, NCT05186597. FINDINGS: Among 310 423 Danish children aged younger than 5 years, the mean number of RSV-associated hospital admissions increased from 1477 (SD 226) in the 2016-17 to 2019-20 RSV seasons to 3000 in the 2021-22 RSV season (RR 2·0 [95% CI 1·9-2·1]). 54 children with RSV received mechanical ventilation in 2021-22 compared with 15-28 annually in the 2016-17 to 2019-20 RSV seasons (2·3 [1·6-3·3]). The highest increase in hospital admissions and need for mechanical ventilation occurred among children aged 24-59 months (4·1 [3·6-4·7] for hospital admission; 4·6 [1·7-12·6] for mechanical ventilation). Among children admitted to hospital, the risk of mechanical ventilation was similar in 2021-22 and the four pre-COVID-19 seasons (risk rate 14·3 per 1000 RSV-associated hospital admissions [95% CI 10·4-19·3] vs 12·9 [10·1-16·1]; RR 1·1 [95% CI 0·8-1·6]). Across all RSV seasons studied, among children younger than 3 months or those with severe comorbidities, respiratory failure due to bronchiolitis led to mechanical ventilation in 69 (79%) of 87 children. Of 46 children with no risk factors for severe RSV, 40 (87%) received mechanical ventilation due to additional complications, including neurological (n=16; 35%), cardiac (n=1; 2%), and pulmonary complications (n=23; 50%; eg, wheeze responsive to bronchodilator therapy, severe bacterial co-infections, and pneumothorax). INTERPRETATION: In Denmark, RSV disease did not seem to be more severe for the individual child during the RSV resurgence in 2021 following relaxation of COVID-19 restrictions. However, hospital admissions were higher among older children, possibly due to a postponed first RSV infection or no recent reinfection. Older children without risk factors for severe RSV disease had atypical complications that led to intubation. If new RSV-preventive interventions for healthy infants delay first RSV infection, a higher number of older children might be admitted to hospital due to atypical clinical phenotypes, rather than classical bronchiolitis. FUNDING: National Ministry of Higher Education and Science and the Innovation Fund Denmark.

Incidence and clinical phenotype of multisystem inflammatory syndrome in children after infection with the SARS-CoV-2 delta variant by vaccination status: a Danish nationwide prospective cohort study.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) occurs after infection with SARS-CoV-2 and its incidence is likely to depend on multiple factors, including the variant of the preceding SARS-CoV-2 infection and vaccine effectiveness. We aimed to estimate the incidence of MIS-C, and describe the clinical phenotype, following the delta variant of SARS-CoV-2 (B.1.617.2 and sublineages) according to vaccination status. We aimed to compare the incidence and clinical phenotype of MIS-C from our cohort during the pre-delta era. METHODS: This prospective, population-based cohort study included patients aged 0-17 years hospitalised with MIS-C in Denmark, according to the US Centers for Disease Control and Prevention case definition, from Aug 1, 2021, to Feb 1, 2022, a period dominated by the delta variant. We identified MIS-C cases via a nationwide research collaboration involving real-time data collection from all 18 paediatric departments. Aggregated number of SARS-CoV-2 infections by vaccination status was obtained from the Danish COVID-19 surveillance registries. The incidence of MIS-C was calculated using the estimated number of infected individuals by vaccination status. We calculated the incidence of MIS-C per 1 000 000 vaccinated and unvaccinated person-years, and estimated vaccine effectiveness as 1-incidence rate ratio using Poisson regression. Incidence and phenotype of MIS-C were compared with MIS-C cases from the first year of the pandemic. This study is registered at ClinicalTrials.gov, NCT05186597. FINDINGS: We identified 51 MIS-C cases among unvaccinated individuals and one in a fully vaccinated adolescent. The incidence of MIS-C was one in 3400 unvaccinated individuals (95% CI 2600-4600) with the delta variant and one in 9900 vaccinated individuals (95% CI 1800-390 000) with breakthrough infection. The estimated vaccine effectiveness against MIS-C after the delta variant was 94% (95% CI 55-99; p=0·0061) in individuals aged 5-17 years. The clinical phenotype during the delta wave was comparable to the pre-delta era. INTERPRETATION: We found the incidence and phenotype of MIS-C in unvaccinated children during the delta wave to be similar to the incidence during the first year of the pandemic. We found vaccine effectiveness to be high against MIS-C, which we suggest was due to protection from infection and, possibly, a decreased incidence of MIS-C after breakthrough infection. Knowledge of the incidence of MIS-C after different SARS-CoV-2 variants and the effect of vaccination might contribute to the elucidation of the extent to which MIS-C is a vaccine-preventable disease. FUNDING: National Ministry of Higher Education and Science and Innovation Fund Denmark.

Short- and Long-Term Self-Reported Symptoms in Adolescents Aged 12-19 Years after Vaccination against SARS-CoV-2 Compared to Adolescents Not Vaccinated-A Danish Retrospective Cohort Study.

This study investigated self-reported short- and long-term symptoms among adolescents receiving the BNT162b2 (Pfizer/BioNTech) vaccine against SARS-CoV-2 and those who did not. A retrospective cohort study based on Danish national survey (collected between 20 July and 15 September 2021) and register data was conducted. Differences in short-term (<14 days) and long-term (>two months) symptoms were explored using logistic regression adjusted for confounders. A total of 747 vaccinated (first dose n = 326; second dose n = 421) and 6300 unvaccinated adolescents were included in analyses of short-term symptoms and 32 vaccinated and 704 unvaccinated adolescents in long-term symptom analyses. In the first 14 days after the first and second vaccine dose the most reported symptoms included headache and muscle or joint symptoms. In both vaccinated and unvaccinated adolescents, the 15-19-year-olds reported significantly higher proportions of all symptoms compared to the 12-14-year-olds. After the second vaccine dose vaccinated 12-14-year-olds reported significantly more headache in adjusted analyses (OR 2.20 (95% CI 1.24; 3.90)). Among the 15-19-year-olds, significantly more vaccinated adolescents reported gastrointestinal symptoms (1.38 (1.06; 1.81)), headache (1.66 (1.24; 2.22)), and tiredness (1.44 (1.08; 1.93)). No differences were found in long-term symptoms. Vaccinated adolescents reported significantly more short-term symptoms including headache, tiredness, and gastrointestinal symptoms after the second vaccine dose than unvaccinated adolescents. Long-term symptom results should be interpreted with caution due to limited sample size.

Acute symptoms in SARS-CoV-2 positive adolescents aged 15-18 years - Results from a Danish national cross-sectional survey study.

Background: The purpose of this study was to investigate prevalence of self-reported symptom burden during the acute phase of SARS-CoV-2 infection and associated factors including sex differences. Methods: All Danish adolescents aged 15-18 years with laboratory confirmed SARS-CoV-2 infection between January 2020 and July 2021 were invited to participate. A survey covered the initial four weeks of SARS-CoV-2 infection and included questions regarding 17 symptoms associated with acute COVID-19, symptom burden and medical history. Statistical analyses included descriptive statistics and logistic regression. Findings: A total of 24,315 adolescents with SARS-CoV-2 infection were invited and 6630 (27.3%) completed the questionnaire. The median age was 17.6 years, and 58.4% (n = 3873) were female. No symptoms were reported by 33.8% (n = 2241), mild perceived symptom burden by 57.2%(n = 3775), and severe symptom burden by 9.0 % (n = 594). Two thirds (n = 2999) of the symptomatic participants reported a symptom duration of 1-10 days. The most prevalent symptoms included headaches 39.2% (n = 2597), a reduced sense of smell 36.2% (n = 2398), cough 31.6% (n = 2093), sore throat 31.1% (n = 2063), and a reduced sense of taste 31.1% (n = 2062). Adolescents at the age of 18 years had higher odds of reporting ≥6 symptoms OR1.47 (95%CI, 1.23-1.76), p < 0.0001 and adolescents 18+ years old had higher odds of reporting a severe symptom burden OR1.98 (95%CI, 1.43-2.73) compared to the 15years old adolescents. A history of OCD/anxiety/depression was associated with reporting ≥6 symptoms OR 1.67 (95%CI, 1.34-2.09), p < 0.0001 and a history of allergy and OCD/anxiety/depression reporting severe symptom burden OR 1.64 (95%CI, 1.35-1.99), p < 0.0001 and OR 1.75 (95%CI, 1.28-2.36), p = 0.0004. Females reported more symptoms than males; median of three (IQR 0-6) vs. a median of two (IQR 0-4) symptoms, p < 0.0001. Interpretation: Two in three experienced symptoms and the majority reported mild symptom burden. Headache, a reduced sense of smell and taste, cough and sore throat were most common. Female sex, asthma and previous Epstein-Barr virus were associated with more symptoms and higher symptom burden. Funding: The study was funded by the AP Møller Foundation. The research was investigator initiated. The study funder played no role in the study.

Fatal SARS-CoV-2-Associated Panton-Valentine Leukocidin-producing Staphylococcal Bacteremia: A Nationwide Multicenter Cohort Study.

We reviewed all cases of Panton-Valentine leukocidin-producing Staphylococcus aureus (PVL-SA) bacteremia in Danish children between 2016 and 2021. We found 2 fatal cases with preceding viral prodrome due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Given the usual benign course of SARS-CoV-2 infection in children, awareness of possible superinfection with PVL-SA in a child with rapid deterioration is crucial to ensure adequate treatment, including antimicrobial drugs with antitoxin effect.

Long COVID symptoms in SARS-CoV-2-positive adolescents and matched controls (LongCOVIDKidsDK): a national, cross-sectional study.

BACKGROUND: Many adolescents have been affected by the COVID-19 pandemic either directly by being infected with the virus or indirectly by lockdowns and restrictions influencing normal living. We aimed to investigate health, including symptoms of long COVID, in adolescents (aged 15-18 years) who tested positive for SARS-CoV-2 compared with a control group. METHODS: LongCOVIDKidsDK was a national, cross-sectional study carried out in Denmark, which included SARS-CoV-2-positive adolescents and matched controls. All Danish adolescents aged 15-18 years with a positive SARS-CoV-2 test during the period Jan 1, 2020, to July 12, 2021, and a control group matched (1:4) by age and sex were sent a survey from July 20, 2021. Participants had until Sept 15, 2021, to respond. Symptoms associated with COVID-19, school attendance, and health-related quality of life were investigated using ancillary questions and validated questionnaires (Paediatric Quality of Life Inventory [PedsQL] and Children's Somatic Symptoms Inventory-24 [CSSI-24]). Statistical analyses included descriptive statistics and logistic regression. This study is registered at ClinicalTrials.gov, NCT04786353. FINDINGS: 24 315 adolescents with a positive SARS-CoV-2 test (case group) and 97 257 matched controls were invited to participate. 3013 matched controls were excluded because of suspected SARS-CoV-2 infection. 6630 (27·3%) responded in the case group and 21 640 (22·3%) responded and were eligible to participate in the control group. Across both groups, median age was 17·6 years (IQR 16·4-18·5), 16 277 (57·6%) of 28 270 responders were female, and 11 993 (42·4%) were male. Participants in the case group had greater odds of having at least one long COVID symptom lasting at least 2 months compared with the control group (3159 [61·9%] vs 12 340 [57·0%], odds ratio 1·22 [95% CI 1·15-1·30]; p<0·0001). Participants in the case group reported significantly lower symptom scores (ie, less somatic distress) on the CSSI-24 than in the control group: mean 10·7 (SD 11·4, median 7·0 [IQR 2·0-15·0]) versus 11·9 (10·6, 9·0 [4·0-17·0]; p<0·0001). Participants in the case group had better quality of life scores on the PedsQL than in the control group: physical functioning mean score 88·7 (SD 13·9, median 93·8 [IQR 84·4-100·0]) versus 86·5 (14·3, 90·6 [81·3-96·9]; p<0·0001); emotional functioning 77·1 (20·3, 80·0 [65·0-95·0]) versus 71·7 (21·4, 75·0 [60·0-90·0]; p<0·0001); social functioning 93·1 (12·5, 100·0 [90·0-100·0]) versus 88·4 (16·2, 95·0 [80·0-100·0]; p<0·0001); and school functioning 66·9 (22·5, 65·0 [60·0-85·0]) versus 62·9 (22·1, 65·0 [50·0-80·0]; p<0·0001). More participants in the case group than in the control group reported 16 or more sick days (1205 [18·2%] vs 2518 [11·6%]; p<0·0001) and 16 or more days of school absence (695 [10·5%] vs 1777 [8·2%]; p<0·0001). INTERPRETATION: Participants with SARS-CoV-2-positive tests had more long-lasting symptoms and sick leave, whereas participants in the control group had more short-lasting symptoms and worse quality of life. Knowledge of long COVID in adolescents is important to guide clinical recognition and management of this condition. FUNDING: AP Møller and Chastine McKinney Møller Foundation.

Left ventricular thrombus in multisystem inflammatory syndrome in children associated with COVID-19.

A 17-year-old adolescent with severe multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease-2019 developed reduced left ventricular function and left ventricular thrombus. With treatment, his condition improved and the thrombus was dissolved. This case illustrates the risk of severe intra-cardiac thrombotic complications in patients with MIS-C.

Population-based Incidence of Myopericarditis After COVID-19 Vaccination in Danish Adolescents.

In this prospective nationwide multicenter study from Denmark, myopericarditis after Pfizer-BioNTech mRNA COVID-19 vaccination was identified in 13 males and 2 females between May 15 and September 15, 2021, among 133,477 vaccinated males and 127,857 vaccinated females 12-17 years of age, equaling 97 males and 16 females per million. In conclusion, the incidence of myopericarditis after COVID-19 vaccination among males appears higher than reports from the United States.

Response to letter in response to “saliva is inferior to nose and throat swabs for SARS-CoV-2 detection in children”

Abstract We thank Chu and Hale for their important comments on the findings of our study investigating the use of saliva for detecting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children.1 Our study followed 20 children and found that in week one and two after diagnosis SARS-CoV-2 was detected in 29% and 11% of saliva samples, 86% and 50% of nasal swabs and 58% and 40% of throat swabs, respectively.2 Chu and Hale got the impression that all saliva samples were taken by a parent, except for the first sample