Lower skeletal muscle mass on CT body composition analysis is associated with adverse clinical course and outcome in children with COVID-19.

OBJECTIVES: To assess the association between body composition measures in children with COVID-19 and severity of the disease course and clinical outcome. METHODS: A retrospective study of children (< 19 years) with COVID-19 admitted to the hospital who underwent CT of the chest and/or abdomen was conducted. Data compiled from electronic medical records included demographics, body mass index (BMI), length of stay, ICU admission, invasive mechanical ventilation and death. Waist circumference and perimeters for skeletal muscle mass (abdominal, psoas and paraspinal muscles) were measured on an axial CT image at the level of the twelfth thoracic vertebra or first lumbar vertebra using FIJI software. RESULTS: Fifty-seven subjects were identified (54% male, median age 15.6 years, 61% Hispanic, 23% African-American). 25% (14/57) were admitted to the ICU and 21% (12/57) needed intubation. 9% (5/57) died. Waist circumference ranged between 53.2 and 138.4 cm (mean 86.58 ± 18.74 cm) and skeletal muscle mass ranged between 0.6 and 6.8 cm2 (mean 3.5 ± 1.19 cm2). Lower skeletal muscle mass had a univariate association with ICU admission (odds ratio (OR) 0.4; 95%CI 0.17-0.76; p = 0.01) and mortality (OR 0.22; 95%CI 0.04-0.69; p = 0.01). Multivariate analysis showed similar association after controlling for comorbidities (adjusted OR 0.46; 95%CI 0.19-0.95; p = 0.04 and adjusted OR 0.31; 95%CI 0.06-0.95; p = 0.04, respectively). There was no association between BMI or waist circumference with ICU stay, mechanical ventilation or mortality. CONCLUSION: Lower skeletal muscle mass is associated with an adverse clinical course and outcome in children with COVID-19.

Acute appendicitis and SARS-CoV-2 in children: imaging findings at a tertiary children's hospital during the COVID-19 pandemic.

BACKGROUND: Evidence suggests severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may be associated with appendicitis or clinical symptoms that mimic appendicitis, but it is not clear if the findings or utility of imaging in pediatric patients with suspected appendicitis have changed since the onset of the coronavirus disease 2019 (COVID-19) pandemic. OBJECTIVE: To evaluate for potential differences in SARS-CoV-2 positive and SARS-CoV-2 negative pediatric patients imaged for suspected appendicitis to determine the reliability of the existing medical imaging approach for appendicitis in a population that contains both SARS-CoV-2 positive and SARS-CoV-2 negative pediatric patients. MATERIALS AND METHODS: Patients imaged for suspected appendicitis Apr. 1, 2020, to Dec. 31, 2020, were identified via an electronic medical records search. Differences in ultrasound (US) diagnostic performance, use of computed tomography (CT) following US, rates of appendicitis, imaging findings of appendicitis and perforation were compared between SARS-CoV-2 positive and SARS-CoV-2 negative tested patients, using pathology and surgery as reference standards for appendicitis and perforation, respectively. Fisher exact test and Student's t-test were used for statistical analysis. RESULTS: One thousand, six hundred and ninety-three patients < 18 years old met inclusion criteria, with 46% (772/1,693) female, 11 imaged with only CT and 1,682 with US. Comparing SARS-CoV-2 positive and SARS-CoV-2 negative patients, no statistically significant differences in sensitivity or specificity of US (P = 1 and P = 1, respectively), or in the US (P-values ranging from 0.1 to 1.0) or CT imaging findings (P-values ranging from 0.2 to 1.0) in appendicitis were found. Perforation rates were similar between SARS-CoV-2 positive (20/57, 35.1% perforated) and SARS-CoV-2 negative (359/785, 45.7% perforated) patients with appendicitis (P = 0.13). Use of CT following first-line US was similar, with 7/125 (5.6%) of SARS-CoV-2 positive imaged with CT after US and 127/1,557 (8.2%) of SARS-CoV-2 negative imaged with CT after US (P = 0.39). CONCLUSION: In pediatric patients with suspected appendicitis, no significant difference was found in the diagnostic performance of US, CT usage or perforation rates between SARS-CoV-2 positive and SARS-CoV-2 negative patients.

Population stratification enables modeling effects of reopening policies on mortality and hospitalization rates.

OBJECTIVE: Study the impact of local policies on near-future hospitalization and mortality rates. MATERIALS AND METHODS: We introduce a novel risk-stratified SIR-HCD model that introduces new variables to model the dynamics of low-contact (e.g., work from home) and high-contact (e.g., work on-site) subpopulations while sharing parameters to control their respective R0(t) over time. We test our model on data of daily reported hospitalizations and cumulative mortality of COVID-19 in Harris County, Texas, from May 1, 2020, until October 4, 2020, collected from multiple sources (USA FACTS, U.S. Bureau of Labor Statistics, Southeast Texas Regional Advisory Council COVID-19 report, TMC daily news, and Johns Hopkins University county-level mortality reporting). RESULTS: We evaluated our model's forecasting accuracy in Harris County, TX (the most populated county in the Greater Houston area) during Phase-I and Phase-II reopening. Not only does our model outperform other competing models, but it also supports counterfactual analysis to simulate the impact of future policies in a local setting, which is unique among existing approaches. DISCUSSION: Mortality and hospitalization rates are significantly impacted by local quarantine and reopening policies. Existing models do not directly account for the effect of these policies on infection, hospitalization, and death rates in an explicit and explainable manner. Our work is an attempt to improve prediction of these trends by incorporating this information into the model, thus supporting decision-making. CONCLUSION: Our work is a timely effort to attempt to model the dynamics of pandemics under the influence of local policies.