Multisystem inflammatory syndrome in children (MIS-C): A nationwide collaborative study in the Greek population.

Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe hyperinflammatory condition that may occur following SARS-CoV-2 infection. This retrospective, descriptive study of children hospitalized with multisystem inflammatory syndrome in children (MIS-C) in 12 tertiary care centers from 3/11/2020 to 12/31/2021. Demographics, clinical and laboratory characteristics, treatment and outcomes are described. Among 145 patients (95 males, median age 8.2 years) included, 123 met the WHO criteria for MIS-C, while 112 (77%) had serological evidence of SARS-CoV-2 infection. Fever was present in 99%, gastrointestinal symptoms in 77%, mucocutaneous involvement in 68% and respiratory symptoms in 28%. Fifty-five patients (38%) developed myocarditis, 29 (20%) pericarditis and 19 (13%) coronary aneurysms. Among the above cases 11/55 (20%), 1/29 (3.4%) and 5/19 (26.3%), respectively, cardiac complications had not fully resolved at discharge. Underlying comorbidities were reported in 18%. Median CRP value was 155 mg/l, ferritin 535 ng/ml, PCT 1.6 ng/ml and WBC 14.2 × 109/mm3. Most patients had elevated troponin (41.3%) and/or NT-pro-BNP (49.6%). Intravenous immunoglobulin plus corticosteroids were used in 117/145 (80.6%), monotherapy with IVIG alone in 13/145 (8.9%) and with corticosteroids alone in 2/145 (1.3%). Anti-IL1 treatment was added in 15 patients (10.3%). Thirty-three patients (23%) were admitted to the PICU, 14% developed shock and 1 required ECMO. Mortality rate was 0.68%. The incidence of MIS-C was estimated at 0.69/1000 SARS-CoV-2 infections. Patients who presented with shock had higher levels of NT-pro-BNP compared to those who did not (p < 0.001). Acute kidney injury and/or myocarditis were associated with higher risk of developing shock. CONCLUSION: MIS-C is a novel, infrequent but serious disease entity. Cardiac manifestations included myocarditis and pericarditis, which resolved in most patients before discharge. Timely initiation of immunomodulatory therapy was shown to be effective. NT-pro-BNP levels may provide a better prediction and monitoring of the disease course. Further research is required to elucidate the pathogenesis, risk factors and optimal management, and long-term outcomes of this clinical entity. WHAT IS KNOWN: • MIS-C is an infrequent but serious disease entity. • Patients with MIS-C present with multi-organ dysfunction, primarily involving the gastrointestinal and cardiovascular systems. WHAT IS NEW: • NT-pro-BNP levels may provide a better prediction and monitoring of the disease course. • Acute kidney injury and/or myocarditis were associated with higher risk of developing shock.

Navigating paediatric virology through the COVID­19 era (Review).

The present review article presents the key messages of the 8th Workshop on Paediatric Virology organised virtually by the Institute of Paediatric Virology based on the island of Euboea in Greece. The major topics covered during the workshop were the following: i) New advances in antiviral agents and vaccines against cytomegalovirus; ii) hantavirus nephropathy in children; iii) human rhinovirus infections in children requiring paediatric intensive care; iv) complications and management of human adenovirus infections; v) challenges of post­coronavirus disease 2019 (COVID­19) syndrome in children and adolescents; and vi) foetal magnetic resonance imaging in viral infections involving the central nervous system. The COVID­19 era requires a more intensive, strategic, global scientific effort in the clinic and in the laboratory, focusing on the diagnosis, management and prevention of viral infections in neonates and children.

Herpes Zoster Ophthalmicus in a Healthy Toddler Fully Immunized Against Varicella-Zoster Virus: A Case Report and Review of Treatment Strategies in Children.

Herpes zoster ophthalmicus (HZO) is a rare presentation of herpes zoster in children; however, it may become chronic and debilitating. The pathophysiology of HZO complications is not completely understood and may include virus virulence, vascular and neural inflammation and immune reactivity. Therefore, clinical experts suggest an antiviral agent combined with topical steroids, but treatment duration and the need for secondary prophylaxis, given the likelihood of recurrence, are not clearly defined. We present a complex case of HZO in a varicella zoster virus (VZV)-vaccinated toddler successfully treated with acyclovir and topical steroids. We also present a review of the relevant literature regarding the therapeutic management and long-term sequelae of HZO in children.

Decreasing Incidence of the Multisystem Inflammatory Syndrome in Children Over 3 Pandemic Waves.

In this nationwide retrospective study, a substantial decline in the incidence of multisystem inflammatory syndrome in children over 3 successive pandemic waves characterized by different severe acute respiratory syndrome coronavirus 2 variants was documented-from 3.4 of 1000 to 1.1 of 1000 and finally to 0.25 of 1000 confirmed severe acute respiratory syndrome coronavirus 2 positive cases (P < 0.0001), respectively, whereas clinical findings and severity did not significantly vary.

Obesity as a risk factor for severe influenza infection in children and adolescents: a systematic review and meta-analysis.

Obesity has been recently identified as a predisposing factor for a worse prognosis in viral illnesses such as SARS-CoV-2; however, its role in children with influenza is not yet clarified. The current systematic review and meta-analysis aims to assess whether obesity is a risk factor for either hospitalization or a worse prognosis when hospitalized among children infected by influenza. We systematically searched the following databases using a structured algorithm: MEDLINE, Clinicaltrials.gov, and Cochrane Central Register of Controlled Trials (CENTRAL). Statistical meta-analysis was performed using the "meta" package in R software, and included studies were evaluated using the Newcastle-Ottawa scale. Among children with influenza, obesity increased the odds of hospitalization with a pooled OR of 1.89 (95% CI [1.23, 2.9], I2 = 0, p = 0.003). When hospitalized, children with obesity were also more likely to have a worse outcome than their healthy-weight counterparts, with a pooled OR of 1.24 (95% Cl [1.02; 1.51], I2 = 11, p = 0.03). In an effort to lower heterogeneity, a leave-one-out meta-analysis was conducted. Publication bias was assessed with the visual inspection of funnel plots and the trim-and-fill method. Certainty assessment was evaluated using the GRADE score. CONCLUSIONS: The findings of our meta-analysis suggest that obesity in children with influenza is associated with a worse prognosis, both hospitalization and ICU admission/death. WHAT IS KNOWN: • Obesity has been identified as a risk factor for non-communicable as well as communicable diseases. • A previous meta-analysis failed to demonstrate a statistically significant association between obesity and influenza infection severity. WHAT IS NEW: • Children with high BMI and influenza infection are more likely to get hospitalized. • Pediatric inpatients with increased BMI and influenza infection may have a worse prognosis.

Initial Seronegative West Nile Virus Encephalitis in an Immunocompromised Child.

We present a case of initial seronegative West Nile virus encephalitis in an immunocompromised child due to B-cell acute lymphoblastic leukemia. Although diagnostic guidelines for West Nile virus infection exist, we highlight that these may not be met in immunocompromised patients who may have a delayed immune response.

Insights in paediatric virology during the COVID-19 era (Review).

The present article provides an overview of the key messages of the topics discussed at the '7th Workshop on Paediatric Virology', which was organised virtually on December 20, 2021 by the Institute of Paediatric Virology, located on the Island of Euboea in Greece. The workshop's plenary lectures were on: i) viral pandemics and epidemics in the ancient Mediterranean; ii) the impact of obesity on the outcome of viral infections in children and adolescents; and iii) COVID-19 and artificial intelligence. Despite the scarcity of evidence from fossils and remnants, viruses have been recognised as significant causes of several epidemics in the ancient Mediterranean. Paediatric obesity, a modifiable critical health risk factor, has been shown to impact on the development, progression and severity of viral infections. Thus, the prevention of paediatric obesity should be included in formulating public health policies and decision-making strategies against emerging global viral threats. During the current COVID-19 pandemic, artificial intelligence has been used to facilitate the identification, monitoring and prevention of SARS-CoV-2. In the future, it will play a fundamental role in the surveillance of epidemic-prone infectious diseases, in the repurposing of older therapies and in the design of novel therapeutic agents against viral infections. The collaboration between different medical specialties and other diverse scientific fields, including archaeology, history, epidemiology, nutritional technologies, mathematics, computer technology, engineering, medical law and ethics is essential for the successful management of paediatric viral infections. The current COVID-19 pandemic has underscored this need, which should be further encouraged in modern medical education.

A toddler diagnosed with severe postinfectious bronchiolitis obliterans and COVID-19 infection.

During the COVID-19 pandemic, management of SARS-CoV-2 infection in children with underlying chronic lung disease has been challenging. There are limited studies in children with respiratory comorbidities, apart from asthma, presumably due to low morbidity of SARS-CoV-2 infection in the general pediatric population along with the low incidence of certain pulmonary conditions. Compassionate use of remdesivir has been shown to reduce time to clinical improvement in adults and has been retrospectively studied in small pediatric cohorts with promising results. Whether children with underlying respiratory conditions may benefit from antiviral treatment in the context of different pathophysiologic backgrounds and unknown drug safety and efficacy needs to be further evaluated. We present a case of COVID-19 infection in a 3-year old toddler with severe postinfectious bronchiolitis obliterans, who received compassionate treatment with 5-day-course of remdesivir, and recovered with favourable outcome.

Clinical and immunological features in a cohort of patients with partial DiGeorge syndrome followed at a single center.

DiGeorge syndrome (DGS) is a primary immunodeficiency characterized by various degrees of T-cell deficiency. In partial DGS (pDGS), other risk factors could predispose to recurrent infections, autoimmunity, and allergy. The aim of this study was to assess the effect of different factors in the development of infections, autoimmunity, and/or allergy in patients with pDGS. We studied 467 pDGS patients in follow-up at Great Ormond Street Hospital. Using a multivariate approach, we observed that palatal anomalies represent a risk factor for the development of recurrent otitis media with effusion. Gastroesophageal reflux/dysphagia and asthma/rhinitis represent a risk factor for the development of recurrent upper respiratory tract infections. Allergy and autoimmunity were associated with persistently low immunoglobulin M levels and lymphopenia, respectively. Patients with autoimmunity showed lower levels of CD3+, CD3+CD4+, and naïve CD4+CD45RA+CD27+ T lymphocytes compared with pDGS patients without autoimmunity. We also observed that the physiological age-related decline of the T-cell number was slower in pDGS patients compared with age-matched controls. The age-related recovery of the T-cell number depended on a homeostatic peripheral proliferation of T cells, as suggested by an accelerated decline of the naïve T lymphocytes in pDGS as well as a more skewed T-cell repertoire in older pDGS patients. These evidences suggest that premature CD4+ T-cell aging and lymphopenia induced spontaneous peripheral T-cell proliferation might contribute to the pathogenesis of autoimmunity in patients with pDGS. Infections in these patients represent, in most of the cases, a complication of anatomical or gastroenterological anomalies rather than a feature of the underlying immunodeficiency.

Clinical features, risk factors, and complications among pediatric patients with pandemic influenza A (H1N1).

OBJECTIVE: The authors aimed to describe the epidemiological characteristics, clinical features, risk factors for severe disease, and complications in children with laboratory-confirmed pandemic influenza A (H1N1). METHODS: H1N1 was confirmed by performing reverse-transcriptase polymerase chain reaction (RT-PCR) assay on oropharyngeal swab specimens. The medical charts of a subset of the evaluated patients were reviewed retrospectively; another subset was enrolled prospectively. RESULTS: A total of 51 patients (44 [86%] > 5 years) were identified to have laboratory-confirmed H1N1. Fever was the most common presenting symptom (92%). Of the 15 hospitalized patients, 4 had asthma, and 5 were overweight or obese. All but 1 of these 9 patients developed influenza-related complications. Overall, 10 of the 15 hospitalized patients (67%) developed an influenza-related complication (6 bronchitis and 4 pneumonia). CONCLUSION: In this cohort, most children with confirmed H1N1 infection experience an uncomplicated viral illness. Nevertheless, underlying asthma and obesity may aggravate their clinical course.

Effectiveness and safety of neuraminidase inhibitors in reducing influenza complications: a meta-analysis of randomized controlled trials.

BACKGROUND: Several studies suggest that neuraminidase inhibitors (NIs) can reduce the duration of influenza symptoms. However, data regarding their effectiveness in reducing influenza complications are scarce. METHODS: We evaluated the effectiveness of NIs in reducing influenza complications and mortality of patients with seasonal influenza, by performing a meta-analysis of randomized controlled trials (RCTs), retrieved from PubMed, Cochrane Central Register of Controlled Trials and Scopus databases, comparing NIs with placebo. RESULTS: Eleven RCTs (10 double-blind) were included; 8 involved adults/adolescents. In total, 5315 patients were included; 3491 (65.7%) with confirmed infection. Total influenza-related complications were significantly less likely in otherwise healthy patients with confirmed influenza infection that were treated with NIs versus placebo [7 RCTs, 2621 patients, risk ratio (RR) = 0.74, 95% confidence interval (CI) = 0.58-0.95] This finding was more pronounced in high-risk patients [4 RCTs, 475 patients, RR = 0.37, 95% CI = 0.24-0.59]; P < 0.01 for the chi(2) test for subgroup differences. In the comparisons regarding individual complications, a trend in favour of NIs was observed. Acute otitis media was significantly less likely in patients with confirmed influenza infection treated with NIs versus placebo (3 RCTs, 1124 patients, RR = 0.50, 95% CI = 0.30-0.85). No differences were found in the comparisons regarding the safety outcomes. No deaths were observed in trials that reported on mortality. CONCLUSIONS: NIs seem to be effective in reducing total influenza-related complications in otherwise healthy and high-risk patients, and have an acceptable safety profile. However, RCTs providing separate data for mild to serious complications and detailed reporting of adverse events and mortality are needed.

Exposure to quinolones is associated with carbapenem resistance among colistin-susceptible Acinetobacter baumannii blood isolates.

In this study, we explored risk factors associated with bacteraemia caused by colistin-susceptible/carbapenem-resistant (Co(S)/Ca(R)) Acinetobacter baumannii. A retrospective cohort study of hospitalised patients with A. baumannii bacteraemia was performed at a tertiary care hospital over a 44-month period. Thirty-nine patients with bacteraemia due to A. baumannii (35 Intensive Care Unit and 4 ward patients) were included in the analysis. Twenty-five patients (64%) had bacteraemia due to Co(S)/Ca(R)A. baumannii and 14 patients (36%) had bacteraemia due to colistin-susceptible/carbapenem-susceptible A. baumannii. Mortality was 56% (14/25) and 35.7% (5/14) for patients in the two groups, respectively (P=0.22). Bivariate analysis showed that prior exposure to fluoroquinolones (P=0.01) and antipseudomonal penicillins (P=0.004) as well as a higher number of antibiotics in use on the day of bacteraemia (P=0.02) were associated with isolation of a Co(S)/Ca(R) strain among patients with A. baumannii bacteraemia. Multivariate analysis using a backward logistic regression model showed that only exposure to fluoroquinolones was associated with development of Co(S)/Ca(R)A. baumannii bacteraemia (odds ratio=11.6; 95% confidence interval 2.4-55.9; P=0.02). The appearance of Co(S)/Ca(R)A. baumannii infections represents a major threat to critically ill hospitalised patients. Exposure to fluoroquinolones is an independent risk factor for development of Co(S)/Ca(R)A. baumannii bacteraemia.

The diversity of definitions of multidrug-resistant (MDR) and pandrug-resistant (PDR) Acinetobacter baumannii and Pseudomonas aeruginosa.

Different definitions of the terms multidrug-resistant (MDR) and pandrug-resistant (PDR) Acinetobacter baumannii and Pseudomonas aeruginosa have been used in the biomedical literature. The authors searched for relevant studies indexed in the PubMed database (01/2000-09/2005) to systematically examine the various definitions of MDR and PDR for these bacteria. Initially 107 retrieved relevant studies were reviewed. Ninety-two studies were further analysed, 50 of which focused on A. baumannii and 42 on P. aeruginosa. A considerable diversity of definitions of the terms MDR and PDR A. baumannii and P. aeruginosa was found. Of note, the term PDR was inappropriately used in all five studies that used it. The review reveals that various definitions have been used for the terms MDR and PDR A. baumannii and P. aeruginosa, a fact that causes confusion to researchers and clinicians. The authors believe that at least a widely accepted definition for PDR A. baumannii and P. aeruginosa should be uniformly used worldwide.

Risk factors for isolation of strains susceptible only to polymyxin among patients with Pseudomonas aeruginosa bacteremia.

We conducted a case-control study to identify risk factors associated with the isolation of Pseudomonas aeruginosa strains susceptible only to polymyxin from blood by comparing data between 16 patients with blood isolates that were susceptible only to polymyxins and 40 patients with blood isolates that were susceptible to carbapenems. The multivariable analysis showed that exposure to carbapenems was associated with the development of P. aeruginosa bacteremia susceptible only to polymyxin (odds ratio, 9.0; 95% confidence interval, 2.4 to 34.3; P = 0.001).