Multisystem inflammatory syndrome in children and SARS-CoV-2 variants: a two-year ambispective multicentric cohort study in Catalonia, Spain.

Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe disease temporarily related to SARS-CoV-2. We aimed to describe the epidemiological, clinical, and laboratory findings of all MIS-C cases diagnosed in children < 18 years old in Catalonia (Spain) to study their trend throughout the pandemic. This was a multicenter ambispective observational cohort study (April 2020-April 2022). Data were obtained from the COVID-19 Catalan surveillance system and from all hospitals in Catalonia. We analyzed MIS-C cases regarding SARS-CoV-2 variants for demographics, symptoms, severity, monthly MIS-C incidence, ratio between MIS-C and accumulated COVID-19 cases, and associated rate ratios (RR). Among 555,848 SARS-CoV-2 infections, 152 children were diagnosed with MIS-C. The monthly MIS-C incidence was 4.1 (95% CI: 3.4-4.8) per 1,000,000 people, and 273 (95% CI: 230-316) per 1,000,000 SARS-CoV-2 infections (i.e., one case per 3,700 SARS-CoV-2 infections). During the Omicron period, the MIS-C RR was 8.2 (95% CI: 5.7-11.7) per 1,000,000 SARS-CoV-2 infections, which was significantly lower (p < 0.001) than that for previous variant periods in all age groups. The median [IQR] age of MIS-C was 8 [4-11] years, 62.5% male, and 80.2% without comorbidities. Common symptoms were gastrointestinal findings (88.2%) and fever > 39 °C (81.6%); nearly 40% had an abnormal echocardiography, and 7% had coronary aneurysm. Clinical manifestations and laboratory data were not different throughout the variant periods (p > 0.05).  Conclusion: The RR between MIS-C cases and SARS-CoV-2 infections was significantly lower in the Omicron period for all age groups, including those not vaccinated, suggesting that the variant could be the main factor for this shift in the MISC trend. Regardless of variant type, the patients had similar phenotypes and severity throughout the pandemic. What is Known: • Before our study, only two publications investigated the incidence of MIS-C regarding SARS-CoV-2 variants in Europe, one from Southeast England and another from Denmark. What is New: • To our knowledge, this is the first study investigating MIS-C incidence in Southern Europe, with the ability to recruit all MIS-C cases in a determined area and analyze the rate ratio for MIS-C among SARS-CoV-2 infections throughout variant periods. • We found a lower rate ratio of MISC/infections with SARS-CoV-2 in the Omicron period for all age groups, including those not eligible for vaccination, suggesting that the variant could be the main factor for this shift in the MISC trend.

Characterization of severe asthma in the pediatric population

Introduction and objectives Relationship between the causal mechanisms of pediatric severe asthma and severity of symptoms would be helpful for developing personalized strategies for treatment and prevention. Materials and methods For this study, 698 medical histories of asthmatics between 6 and 18 years of age were reviewed in a period of 2 years. Variables analyzed were: age, sex, ethnicity, perinatological history, allergy history, asthma predictive index (API), exposure to tobacco, heavy traffic or epithelium, lung function, age of onset of symptoms, hospitalization admissions/PICU, systemic corticosteroids, daily symptoms control, device prescribe for daily control, and adherence. Results A total of 86 children with severe asthma were included (12.3%). Mean age 13.3 +/− 1.86 years, sex ratio1:1, mean age of symptom onset 2.765 +/− 3.06 years, mean IgE 1076.18KU / L +/− 1136, mean eosinophils 604c / mcl +/− 511.9, mean of FEV1 93.15% +/− 16.3. Evidently, 70 children (81.4%) had positive API, 68 (79.1%) rhinitis, 34 (39.5%) atopic dermatitis. 73 (83.9%) sensitized to inhalants and 56 (65.1%) to dermatophagoides, 39 (45.3%) passive smokers, 19 (22.1%) exposure to heavy traffic; 55 (64%) showed symptoms with exercise, 35 (40.7%) had audible wheezing. The mean systemic corticosteroid cycles/year was 3.63 +/− 3.23, mean PICU admissions 0.36 +/− 0.83, mean hospital admissions 4.31 +/− 5.3, average emergency room visits/year 19.44 +/− 16.28. 38 (56.7%) had good adherence, 44 (51%) used an MDI device and 39 (45.3%) used dry powder. Conclusions Children with severe asthma meet the following criteria: premature, positive API, rhinitis, atopic dermatitis, high IgE, eosinophilia, passive smokers, exposure to heavy traffic, decreased lung function, and low adherence to controller medication (AU)