SARS-CoV-2 Infection Dynamics in Children and Household Contacts in a Slum in Rio de Janeiro.

OBJECTIVES: To investigate the dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a vulnerable population of children and their household contacts. METHODS: SARS-CoV-2 reverse transcription polymerase chain reaction assays and coronavirus disease 2019 (COVID-19) immunoglobulin G serology tests were performed in children and their household contacts after enrollment during primary health care clinic visits. Participants were followed prospectively with subsequent specimens collected through household visits in Manguinhos, an impoverished urban slum (a favela) in Rio de Janeiro at 1, 2, and 4 weeks and quarterly post study enrollment. RESULTS: Six hundred sixty-seven participants from 259 households were enrolled from May to September 2020. This included 323 children (0-13 years), 54 adolescents (14-19 years), and 290 adults. Forty-five (13.9%) children had positive test results for SARS-CoV-2 polymerase chain reaction. SARS-CoV-2 infection was most frequent in children aged <1 year (25%) and children aged 11 to 13 years (21%). No child had severe COVID-19 symptoms. Asymptomatic infection was more prevalent in children aged <14 years than in those aged ≥14 years (74.3% and 51.1%, respectively). All children (n = 45) diagnosed with SARS-CoV-2 infection had an adult contact with evidence of recent infection. CONCLUSIONS: In our setting, children do not seem to be the source of SARS-CoV-2 infection and most frequently acquire the virus from adults. Our findings suggest that, in settings such as ours, schools and child care potentially may be reopened safely if adequate COVID-19 mitigation measures are in place and staff are appropriately immunized.

Glutamine Therapy Reduces Inflammation and Extracellular Trap Release in Experimental Acute Respiratory Distress Syndrome of Pulmonary Origin.

The innate immune response plays an important role in the pathophysiology of acute respiratory distress syndrome (ARDS). Glutamine (Gln) decreases lung inflammation in experimental ARDS, but its impact on the formation of extracellular traps (ETs) in the lung is unknown. In a mouse model of endotoxin-induced pulmonary ARDS, the effects of Gln treatment on leukocyte counts and ET content in bronchoalveolar lavage fluid (BALF), inflammatory profile in lung tissue, and lung morphofunction were evaluated in vivo. Furthermore, ET formation, reactive oxygen species (ROS) production, glutathione peroxidase (GPx), and glutathione reductase (GR) activities were tested in vitro. Our in vivo results demonstrated that Gln treatment reduced ET release (as indicated by cell-free-DNA content and myeloperoxidase activity), decreased lung inflammation (reductions in interferon-γ and increases in interleukin-10 levels), and improved lung morpho-function (decreased static lung elastance and alveolar collapse) in comparison with ARDS animals treated with saline. Moreover, Gln reduced ET and ROS formation in BALF cells stimulated with lipopolysaccharide in vitro, but it did not alter GPx or GR activity. In this model of endotoxin-induced pulmonary ARDS, treatment with Gln reduced pulmonary functional and morphological impairment, inflammation, and ET release in the lung.