Prevalence and risk factors of SARS-CoV-2 antibody responses among healthcare workers (June 2020-November 2021).

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.

A Systematic and Universal Artificial Intelligence Screening Method for Oropharyngeal Dysphagia: Improving Diagnosis Through Risk Management.

Oropharyngeal dysphagia (OD) is underdiagnosed and current screening is costly. We aimed: (a) to develop an expert system (ES) based on machine learning that calculates the risk of OD from the electronic health records (EHR) of all hospitalized older patients during admission, and (b) to implement the ES in a general hospital. In an observational, retrospective study, EHR and swallowing assessment using the volume-viscosity swallow test for OD were captured over 24 months in patients > 70 yr admitted to Mataró Hospital. We studied the predictive power for OD of 25,000 variables. ES was obtained using feature selection, the final prediction model was built with non-linear methods (Random Forest). The database included 2809 older patients (mean age 82.47 ± 9.33 yr), severely dependent (Barthel Index 47.68 ± 31.90), with multiple readmissions (4.06 ± 7.52); 75.76% had OD. The psychometrics of the ES built with a non-linear model were: Area under the ROC Curve of 0.840; sensitivity 0.940; specificity, 0.416; Positive Predictive Value 0.834; Negative Predictive Value 0.690; positive likelihood ratio (LH), 1.61 and negative LH, 0.146. The ES screens in 6 s all patients admitted to a 419-bed hospital, identifies patients at greater risk of OD, and shows the risk for OD in the clinician's workstation. It is currently in use at our institution. Our ES provides accurate, systematic and universal screening for OD in real time during hospital admission of older patients, allowing the most appropriate diagnostic and therapeutic strategies to be selected for each patient.

Metabolic cardiovascular syndrome in obese prepubertal children: the role of high fasting insulin levels.

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.

Elevated plasma total homocysteine levels in hyperinsulinemic obese subjects.

Homocysteine has been associated with the oxidative stress in the pathogenesis of atherosclerosis. Oxidative stress caused by triglycerides and free fatty acids is known to cause insulin resistance and hyperinsulinemia. On the other hand, insulin resistance may increase homocysteine levels. Since obesity is associated with insulin resistance and hyperinsulinemia, we aimed to study the possible association of homocysteine with hyperinsulinemia in obese subjects. 20 obese male subjects (body mass index >29), aged 33--55 (mean 45 years old) were studied. A fasting blood sample was obtained for the study and the subjects undertook an oral glucose tolerance test with samples taken at 1 and 2 h after glucose. Subjects were divided in two groups according to the fasting insulin levels, < 9 &mgr;U/ml or normoinsulinemic (group 1) and >9 &mgr;U/ml or hyperinsulinemic (group 2). Glucose, insulin, homocysteine, folate, B(12,) total cholesterol, HDL-cholesterol and triglycerides levels were determined in fasting blood samples. In oral glucose tolerance test, glucose, insulin and homocysteine levels were measured. Hyperinsulinemic obese subjects (group 2) had higher levels of insulin and glucose at 1 h and 2 h postglucose, compared with group 1. Fasting total homocysteine and triglyceride levels were also increased in this group, whereas folate and B(12) levels were similar in both groups. Fasting homocysteine significantly correlated with fasting insulin (r = 0.6, p <0.01). Homocysteine levels slightly but significantly decreased after glucose loading in normoinsulinemic but not in hyperinsulinemic obese subjects. These results show that higher homocysteine levels are observed in the hyperinsulinemic obese subjects and suggest that homocysteine could play a role in the higher risk of cardiovascular disease in obesity.