Cross-sectional prevalence of SARS-CoV-2 antibodies in healthcare workers in paediatric facilities in eight countries.

BACKGROUND: Healthcare workers (HCWs) have been disproportionately affected by coronavirus disease 2019 (COVID-19), which may be driven, in part, by nosocomial exposure. If HCW exposure is predominantly nosocomial, HCWs in paediatric facilities, where few patients are admitted with COVID-19, may lack antibodies to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and be at increased risk during the current resurgence. AIM: To compare the seroprevalence of SARS-CoV-2 amongst HCWs in paediatric facilities in seven European countries and South Africa (N=8). METHODS: All categories of paediatric HCWs were invited to participate in the study, irrespective of previous symptoms. A single blood sample was taken and data about previous symptoms were documented. Serum was shipped to a central laboratory in London where SARS-CoV-2 immunoglobulin G was measured. FINDINGS: In total, 4114 HCWs were recruited between 1st May and mid-July 2020. The range of seroprevalence was 0-16.93%. The highest seroprevalence was found in London (16.93%), followed by Cape Town, South Africa (10.36%). There were no positive HCWs in the Austrian, Estonian and Latvian cohorts; 2/300 [0.66%, 95% confidence interval (CI) 0.18-2.4] HCWs tested positive in Lithuania; 1/124 (0.81%, 95% CI 0.14-4.3) HCWs tested positive in Romania; and 1/76 (1.3%, 95% CI 0.23-7.0) HCWs tested positive in Greece. CONCLUSION: Overall seroprevalence amongst paediatric HCWs is similar to their national populations and linked to the national COVID-19 burden. Staff working in paediatric facilities in low-burden countries have very low seroprevalence rates and thus are likely to be susceptible to COVID-19. Their susceptibility to infection may affect their ability to provide care in the face of increasing cases of COVID-19, and this highlights the need for appropriate preventative strategies in paediatric healthcare settings.

Demethylation of the hypoxia induction factor 1 binding site of GPX3 at excess blood ammonia in propionic acidemia.

OBJECTIVES: Elevated levels of metabolites such as ammonia and propionylcarnitine in propionic acidemia (PA) lead to an increased reactive oxygen species (ROS) production which could activate and stabilize the epigenetic regulated hypoxia-inducible factor-1α (HIF-1α). In order to evaluate the DNA methylation status of the HIF-1α binding site in PA, we investigated the antioxidant gluthatione peroxidase 3 gene (GPX3) promoter region. DESIGN AND METHODS: Using leukocyte DNA extracted from bloodspots collected 2-4 days after birth from diet free newborns, the cytosine phosphodiester bond guanine (CpG) dinucleotides of a HIF-1α binding site (CGTTTTTTACG) in the promoter region of GPX3 was retrospectively analysed. Patients included 7 PA. and 7 healthy controls (KO) respectively. RESULTS: A demethylated TGTTTTTTATG allele was detected in 3 PA patients with blood ammonia (NH3) concentrations of 500, 595, and 987 umol/L respectively; a demethylated/partial methylated TGTTTTTTAC/TG allele in 4 PA patients (2 PA with blood NH3 = 213, 271 umol/L respectively); a partial methylated C/TGTTTTTTAC/TG allele in 5 healthy controls respectively; a partial methylated/methylated C/TGTTTTTTACG allele in 2 healthy controls. CONCLUSION: Our results suggest that at excess NH3, the DNA methylation status of the HIF-1α binding site of GPX3 in newborns with PA is demethylated (TGTTTTTTATG allele). However, the demethylated allele has to be confirmed as a statistically significant change in more patients.