Prevalence of Health Care and Hospital Worker SARS-CoV-2 IgG Antibody in a Pediatric Hospital.

OBJECTIVES: Asymptomatic transmission of coronavirus disease 2019 (COVID-19) in health care settings is not well understood. In this study, we aimed to determine the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) antibodies in health care and hospital workers (HCHWs) and assess how antibody levels change over time. METHODS: Cross-sectional study of employed HCHWs at a freestanding, urban pediatric tertiary care hospital. Employed HCHWs ≥18 years old who were asymptomatic and worked in clinical hospital locations were eligible to participate. Participants completed blood draws and surveys at baseline (between May 4, 2020, and June 2, 2020) and 2 months later (between July 6, 2020, and August 7, 2020). Surveys collected demographic information, SARS-CoV-2 exposures, and previous COVID-19 diagnosis. RESULTS: In total, 530 participants enrolled in and completed baseline study activities. The median age was 37 years (range 19-67 years); 86% identified as female, and 80% identified as white. Two months later, 481 (91%) HCHWs completed another survey and blood draw. Four of 5 (0.9%) seropositive subjects at baseline remained seropositive at 2 months, although 3 had decreasing IgG indices. Five (1.0%) seropositive individuals, including 4 who were previously seropositive and 1 newly seropositive, were detected 2 months later. History of positive SARS-CoV-2 polymerase chain reaction testing results (P < .001) and history of COVID-19 exposure (P < .001) were associated with presence of SARS-CoV-2 antibodies. CONCLUSIONS: SARS-CoV-2 antibodies were detected in 1% of HCHWs in an urban pediatric hospital in a city with moderate SARS-CoV-2 prevalence. Participants with a known previous COVID-19 diagnosis showed a decline or loss of IgG antibodies over 2 months. These results have implications for identifying those with previous exposure and for ongoing public health recommendations for ensuring workplace safety.

Inflammation Induced by Natural Neuronal Death and LPS Regulates Neural Progenitor Cell Proliferation in the Healthy Adult Brain.

Inflammation is typically considered a negative response to injury or insult; however, recent advances demonstrate that inflammatory cells regulate development, plasticity, and homeostasis through anticytotoxic, progenerative responses. Here, we extend analyses of neuroinflammation to natural neurodegenerative and homeostatic states by exploiting seasonal plasticity in cytoarchitecture of the avian telencephalic song control nucleus, high vocal center [HVC (proper name)], in the songbird Gambel's white-crowned sparrow (Zonotrichia leucophrys gambelii). We report that local injection of the endotoxin lipopolysaccharide into HVC of birds in both breeding (high circulating testosterone level) and nonbreeding (low circulating testosterone level) conditions increased neural progenitor cell proliferation in the nearby but distinct ventricular zone. Additionally, we found that oral administration of the anti-inflammatory drug minocycline during seasonal regression of HVC reduced microglia activation in HVC and prevented the normal proliferative response in the ventricular zone to apoptosis in HVC. Our results suggest that local neuroinflammation positively regulates neural progenitor cell proliferation and, in turn, contributes to the previously described repatterning of HVC cytoarchitecture following seasonally induced neuronal loss.