Digital acoustic surveillance for early detection of respiratory disease outbreaks in Spain: a protocol for an observational study.

INTRODUCTION: Cough is a common symptom of COVID-19 and other respiratory illnesses. However, objectively measuring its frequency and evolution is hindered by the lack of reliable and scalable monitoring systems. This can be overcome by newly developed artificial intelligence models that exploit the portability of smartphones. In the context of the ongoing COVID-19 pandemic, cough detection for respiratory disease syndromic surveillance represents a simple means for early outbreak detection and disease surveillance. In this protocol, we evaluate the ability of population-based digital cough surveillance to predict the incidence of respiratory diseases at population level in Navarra, Spain, while assessing individual determinants of uptake of these platforms. METHODS AND ANALYSIS: Participants in the Cendea de Cizur, Zizur Mayor or attending the local University of Navarra (Pamplona) will be invited to monitor their night-time cough using the smartphone app Hyfe Cough Tracker. Detected coughs will be aggregated in time and space. Incidence of COVID-19 and other diagnosed respiratory diseases within the participants cohort, and the study area and population will be collected from local health facilities and used to carry out an autoregressive moving average analysis on those independent time series. In a mixed-methods design, we will explore barriers and facilitators of continuous digital cough monitoring by evaluating participation patterns and sociodemographic characteristics. Participants will fill an acceptability questionnaire and a subgroup will participate in focus group discussions. ETHICS AND DISSEMINATION: Ethics approval was obtained from the ethics committee of the Centre Hospitalier de l'Université de Montréal, Canada and the Medical Research Ethics Committee of Navarre, Spain. Preliminary findings will be shared with civil and health authorities and reported to individual participants. Results will be submitted for publication in peer-reviewed scientific journals and international conferences. TRIAL REGISTRATION NUMBER: NCT04762693.

[Lithium and water metabolism]. / Lithium et métabolisme de l'eau.

Interaction between lithium+ and water balance was studied in nine patients suffering manic-depressive trouble. Nephrogenic diabetes insipidus with polyuria and polydipsia was induced by Li+ in one case only. No trouble was apparent in eight cases. However, the applied method of investigation by lacking, and next, excess of water, vasopressin and ADH tests, measurements of urinary osmolarity and clearances, showed up a trouble of concentration in four cases, improved by ADH. The Li+ frequently (50%) induces a trouble of urinary concentration, without polyuria; it is brought to light only by biological investigations. Its origin is double, nephrogenic, which is the most important, and central by a pituitary component. In the other hand, the change in water metabolism, studied by the same tests, showed us a decrease of the clearance Li+ after lacking of water (deshydratation), and an increase after water surcharge. That result is not concordant, chiefly in regards to the water surcharge, with former experiments. It appears that our method (division by horary periods for measurement of clearance, study of circadian cycle of urinary Li+) permits some observations more precise than global gathering and measurement of clearances. That method also allows to make evident a circadian cycle of renal clearance of Li+, according to, for some part, with the renal movement of water. That remark would also have some consequence on lithium-therapy practice.