The University of Padua salivary-based SARS-CoV-2 surveillance program minimized viral transmission during the second and third pandemic wave.

BACKGROUND: The active surveillance of students is proposed as an effective strategy to contain SARS-CoV-2 spread and prevent schools' closure. Saliva for molecular testing is as sensitive as naso-pharyngeal swab (NPS), self-collected and well accepted by participants. This prospective study aimed to verify whether the active surveillance of the Padua University employees by molecular testing of self-collected saliva is an effective and affordable strategy for limiting SARS-CoV-2 spread. METHODS: A surveillance program based on self-collection of saliva every 2 weeks (October 2020-June 2021) was conducted. Among 8183 employees of the Padua University, a total of 6284 subjects voluntarily took part in the program. Eight collection points guaranteed the daily distribution and collection of barcoded salivary collection devices, which were delivered to the laboratory by a transport service for molecular testing. Quarantine of positive cases and contact tracing were promptly activated. RESULTS: Among 6284 subjects, 206 individuals were SARS-CoV-2 positive (99 by salivary testing; 107 by NPS performed for contact tracing or symptoms). The cumulative SARS-CoV-2 incidence in this cohort was 3.1%, significantly lower than that of employees not in surveillance (8.0%), in Padua (7.1%) and in the Veneto region (7.2%). Employees with positive saliva results were asymptomatic or had mild symptoms. The levels of serum antibodies after 3 months from the infection were correlated with age and Ct values, being higher in older subjects with greater viral loads. CONCLUSIONS: Salivary-based surveillance with contact tracing effectively allowed to limit SARS-CoV-2 contagion, also in a population with a high incidence.

Effects of sample transportation on commonly requested laboratory tests.

BACKGROUND: Little evidence is available in literature on the effects of sample transportation. The aim of the present study was to evaluate the effects of an integrated system for sample transportation on the quality of six laboratory parameters considered representative of the quality of all tests requested and performed. METHODS: The values of alanine aminotransferase (ALT), calcium (Ca), potassium (K), activated prothrombin time (APTT), prostate specific antigen (PSA), and hemoglobin (Hb) obtained in samples collected in peripheral centers in 2007 were compared with those obtained in 2011, following the introduction of the integrated transportation system entailing a tertiary and a secondary container, a data-logger for registering time and temperature, a mission starter and a system manager. RESULTS: In 2007, for ALT, APTT and K, there were significant variations between findings for samples transported from long-term and those from short-term peripheral centers; following the introduction of the transportation system, no such variations were found. CONCLUSIONS: Improvement in the quality of sample transportation has been achieved, particularly for three of the six parameters evaluated, following the introduction of the integrated system described in the present study.

High sodium intake, glomerular hyperfiltration, and protein catabolism in patients with essential hypertension.

AIMS: A blood pressure (BP)-independent metabolic shift towards a catabolic state upon high sodium (Na+) diet, ultimately favouring body fluid preservation, has recently been described in pre-clinical controlled settings. We sought to investigate the real-life impact of high Na+ intake on measures of renal Na+/water handling and metabolic signatures, as surrogates for cardiovascular risk, in hypertensive patients. METHODS AND RESULTS: We analysed clinical and biochemical data from 766 consecutive patients with essential hypertension, collected at the time of screening for secondary causes. The systematic screening protocol included 24 h urine (24 h-u-) collection on usual diet and avoidance of renin-angiotensin-aldosterone system-confounding medications. Urinary 24 h-Na+ excretion, used to define classes of Na+ intake (low ≤2.3 g/day; medium 2.3-5 g/day; high >5 g/day), was an independent predictor of glomerular filtration rate after correction for age, sex, BP, BMI, aldosterone, and potassium excretion [P = 0.001; low: 94.1 (69.9-118.8) vs. high: 127.5 (108.3-147.8) mL/min/1.73 m2]. Renal Na+ and water handling diverged, with higher fractional excretion of Na+ and lower fractional excretion of water in those with evidence of high Na+ intake [FENa: low 0.39% (0.30-0.47) vs. high 0.81% (0.73-0.98), P < 0.001; FEwater: low 1.13% (0.73-1.72) vs. high 0.89% (0.69-1.12), P = 0.015]. Despite higher FENa, these patients showed higher absolute 24 h Na+ reabsorption and higher associated tubular energy expenditure, estimated by tubular Na+/ATP stoichiometry, accordingly [Δhigh-low = 18 (12-24) kcal/day, P < 0.001]. At non-targeted liquid chromatography/mass spectrometry plasma metabolomics in an unselected subcohort (n = 67), metabolites which were more abundant in high versus low Na+ intake (P < 0.05) mostly entailed intermediates or end products of protein catabolism/urea cycle. CONCLUSION: When exposed to high Na+ intake, kidneys dissociate Na+ and water handling. In hypertensive patients, this comes at the cost of higher glomerular filtration rate, increased tubular energy expenditure, and protein catabolism from endogenous (muscle) or excess exogenous (dietary) sources. Glomerular hyperfiltration and the metabolic shift may have broad implications on global cardiovascular risk independent of BP.