Clinical Course and Severity of COVID-19 in 940 Infants with and without Comorbidities Hospitalized in 2020 and 2021: The Results of the National Multicenter Database SARSTer-PED

COVID-19 among infants: key clinical features and remaining controversies

Infants aged <1 year represent a seemingly more susceptible pediatric subset for infections. Despite this, coronavirus disease 2019 (COVID-19) infection has not been proven as more serious in this age group (outside the very early neonatal period) than in others. Indeed, a considerable number of asymptomatic infections have been recorded, and the symptoms and morbidity associated with COVID- 19 differ minimally from those of other respiratory viral infections. Whether due to an abundance of caution or truly reduced susceptibility, infections in infants have not raised the same profile as those in other age groups. In addition to direct severe acute respiratory syndrome coronavirus 2 diagnostic tests, laboratory markers that differentiate COVID-19 from other viral infections lack specificity in infants. Gastrointestinal presentations are common, and the neurological complications of infection mirror those of other respiratory viral infections. There have been relatively few reports of infant deaths. Under appropriate precautions, breastfeeding in the context of maternal infections has been associated with tangible but infrequent complications. Vaccination during pregnancy provides protection against infection in infants, at least in the early months of life. Multi-inflammatory syndrome in children and multi-inflammatory syndrome in neonates are commonly cited as variants of COVID-19; however, their clinical definitions remain controversial. Similarly, reliable definitions of long COVID in the infant group are controversial. This narrative review examines the key clinical and laboratory features of COVID-19 in infants and identifies several areas of science awaiting further clarification.

Early Outcome of Multisystem Inflammatory Syndrome in Neonates Diagnosed following Prenatal Maternal COVID-19 Infection: A Three-Case Series

BACKGROUND

The aim of this case series report is to evaluate the characteristics of multisystem inflammatory syndrome (MIS) in neonates following prenatal maternal COVID-19 infection.

METHODS

We present a case series of three newborns (≤28 days of age) diagnosed with MIS due to the vertical transmission of SARS-CoV2 infection and admitted from 1 January 2021 to 1 June 2023. The inclusion criteria were negative RT-PCR-SARS-CoV-2 test in infants, initial negative IgM-SARS-CoV-2 in infants followed by the emergence of positive IgG-SARS-CoV-2 antibodies in infants and maternal COVID-19 infection in the third trimester of pregnancy. Patients enrolled in this case series were admitted due to acute febrile illnesses.

RESULTS

All three cases occurred in patients born at a mean gestational age of 39 weeks and who were appropriate for gestational age. The mean age at admission was 18.3 days. Fibrinogen (>400 mg/dL) and ferritin (>120 mg/dL) were elevated above the upper normal limit. Elevated levels of myocardial biomarkers (D-dimers, N-terminal pro b-type natriuretic peptide troponin T and creatine phosphokinase myocardial band) were recorded, with normal heart function evaluated using echocardiography. All three patients were treated with antibiotics; one received intravenous immunoglobulin. A 4-week follow-up was completed in two patients when their myocardial biomarkers and ferritin were still elevated but lower compared with previous examinations. D-dimers levels were normalized in 2/3 patients.

CONCLUSIONS

Subclinical myocarditis was diagnosed as an early outcome in infants with MIS diagnosed postnatally due to the vertical transmission of SARS-CoV2 infection and may represent a new challenge for pediatricians in the pandemic era.

Infection, Dysbiosis and Inflammation Interplay in the COVID Era in Children

For over three years, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children and adolescents has generated repercussions, especially a few weeks after infection, for symptomatic patients who tested positive, for asymptomatic ones, or even just the contacts of an infected person, and evolved from severe forms such as multisystem inflammatory syndrome in children (MIS-C) to multifarious clinical manifestations in long COVID (LC). Referred to under the umbrella term LC, the onset of persistent and highly heterogeneous symptoms such as fatigue, post-exertion malaise, cognitive dysfunction, and others have a major impact on the child's daily quality of life for months. The first aim of this review was to highlight the circumstances of the pathophysiological changes produced by COVID-19 in children and to better understand the hyperinflammation in COVID-19 and how MIS-C, as a life-threatening condition, could have been avoided in some patients. Another goal was to better identify the interplay between infection, dysbiosis, and inflammation at a molecular and cellular level, to better guide scientists, physicians, and pediatricians to advance new lines of medical action to avoid the post-acute sequelae of SARS-CoV-2 infection. The third objective was to identify symptoms and their connection to molecular pathways to recognize LC more easily. The fourth purpose was to connect the triggering factors of LC with related sequelae following acute SARS-CoV-2 injuries to systems and organs, the persistence of the virus, and some of its components in hidden reservoirs, including the gut and the central nervous system. The reactivation of other latent infectious agents in the host's immune environments, the interaction of this virus with the microbiome, immune hyperactivation, and autoimmunity generated by molecular mimicry between viral agents and host proteins, could initiate a targeted and individualized management. New high-tech solutions, molecules, probiotics, and others should be discovered to innovatively solve the interplay between RNA persistent viruses, microbiota, and our immune system.