ABSTRACT
BACKGROUND: To assess SARS-CoV-2 seroprevalence in healthcare workers (HCW) with sampling in June and October 2020 and April and November 2021. METHODS: Observational and prospective study in 2455 HCW with serum sampling. Antibodies against SARS-CoV-2 nucleocapsid and occupational, social and health risk factors were assessed at each time point. RESULTS: Seropositivity for SARS-CoV-2 in HCW increased from 11.8% in June 2020 to 28.4% in November 2021. Of those with a positive test in June 2020, 92.1% remained with a positive test, 6.7% had an indeterminate test and 1.1% had a negative test in November 2021. Non-diagnosed carriers represented 28.6% in June 2020 and 14.6% in November 2021. Nurses and nursing assistants showed the highest prevalence of seropositivity. Close contact (at home or in the hospital) with Covid-19 cases without protection and working in the frontline were the main risk factors. A total of 88.8% HCW were vaccinated, all with a positive serological response in April 2021, but levels of antibodies decreased about 65%, and two vaccinated persons presented a negative serological test against spike protein in November 2021. Levels of spike antibodies were higher in those vaccinated with Moderna compared with Pfizer and the percentage of antibody reduction was higher with Pfizer vaccine. CONCLUSIONS: This study shows that seroprevalence of SARS-CoV-2 antibodies among HCW doubled that of the general population and that protection both at the workplace and in the socio-familial field was associated with a lower risk of infection, which stabilized after vaccination.
ABSTRACT
The aim of this study was to detect the presence and degree of impairment of cardiovascular disease (CVD) risk factors, grouped as metabolic cardiovascular syndrome (MCS), in obese prepubertal children. We also assessed the influence of high fasting insulin levels in this pathological status. A cross-sectional study was performed on obese children based on fasting blood samples. Subjects were 61 obese children (aged 6 to 9 years) and an equal number of non-obese children paired by age and sex. The obese children presented the following characteristics in comparison to the non-obese group: significantly high levels of insulin (8.2 +/- 0.52 v 6.12 +/- 0.34 microU/mL), triglycerides (TG) (0.79 +/- 0.04 v 0.60 +/- 0.02 mmol/L), uric acid (0.24 +/- 0.005 v 0.21 +/- 0.004 mmol/L), systolic (SBP) (94.59 +/- 1.06 v 88.85 +/- 1.2 mm Hg) and diastolic (56.49 +/- 1.07 v 52.21 +/- 1.06 mm Hg) blood pressure (DBP), and low levels of high-density lipoprotein cholesterol (HDL-C) (1.30 +/- 0.04 v 1.46 +/- 0.03 mmol/L), and nonesterified fatty acids (0.407 +/- 0.02 v 0.505 +/- 0.02 mmol/L). The hyperinsulinemic obese children showed the same types of differences when compared with the normoinsulinemic group. In the obese group, having adjusted for age, waist/hip ratio (WHR), body mass index (BMI), and sex hormone-binding globulin (SHBG), insulin was an independent prediction factor for triglycerides (P =.0004), apolipoprotein A-I (Apo-AI) (P =.005), and alanine aminotransferase (ALT) (P =.029). BMI was an independent prediction factor for HDL-C (P =.001) and triglycerides (P =.027). However, insulin was an independent prediction factor in the control group for triglycerides (P =.0002) and SBP (P =.012), just as BMI was for HDL-C (P =.011) and uric acid (P =.041). We conclude that the cluster of CVD risk factors associated with MCS and intra-abdominal fat is present in obese prepubertal children. This situation seems to depend, to a large extent, on the insulin basal level. The apparent association between BMI and MCS is due to the correlation between BMI and insulin, and to the fact that insulin associates with MCS. Within the obese group, hyperinsulinemic children present the greatest impairment in the parameters considered to be constituents of MCS.
