Search

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first appeared in December 2019 in Wuhan, China, and has rapidly led to a global pandemic (1). Globally, accurate figures on deaths caused [...]

Introduction As of 25 May 2020, 347 697 deaths resulting from 5 392 654 laboratory-confirmed infectious cases of coronavirus disease (COVID-19) had been reported. (1,2) Global travel contributed to the [...], Objective To estimate the effect of airline travel restrictions on the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) importation. Methods We extracted passenger volume data for the entire global airline network, as well as the dates of the implementation of travel restrictions and the observation of the first case of coronavirus disease (COVID-19) in each country or territory, from publicly available sources. We calculated effective distance between every airport and the city of Wuhan, China. We modelled the risk of SARS-CoV-2 importation by estimating survival probability, expressing median time of importation as a function of effective distance. We calculated the relative change in importation risk under three different hypothetical scenarios that all resulted in different passenger volumes. Findings We identified 28 countries with imported cases of COVID-19 as at 26 February 2020. The arrival time of the virus at these countries ranged from 39 to 80 days since identification of the first case in Wuhan. Our analysis of relative change in risk indicated that strategies of reducing global passenger volume and imposing travel restrictions at a further 10 hub airports would be equally effective in reducing the risk of importation of SARS-CoV-2; however, this reduction is very limited with a close-to-zero median relative change in risk. Conclusion The hypothetical variations in observed travel restrictions were not sufficient to prevent the global spread of SARS-CoV-2; further research should also consider travel by land and sea. Our study highlights the importance of strengthening local capacities for disease monitoring and control. [phrase omitted] [phrase omitted] Objectif Evaluer les effets des restrictions de voyage par voie aerienne sur le risque d'importer le coronavirus 2 du syndrome respiratoire aigu severe (SARS-CoV-2). Methodes Nous avons preleve les donnees sur le volume de passagers pour l'ensemble du reseau aerien dans le monde, ainsi que les dates de mise en reuvre des restrictions de voyage et l'observation du premier cas de maladie a coronavirus (COVID-19) dans chaque pays ou territoire, a partir de sources accessibles au public. Nous avons calcule la distance reelle entre chaque aeroport et la ville de Wuhan, en Chine. Nous avons modelise le risque d'importation du SARS-CoV-2 en estimant sa probabilite de survie, la periode mediane d'importation etant exprimee en fonction de la distance reelle. Nous avons determine l'evolution relative du risque d'importation selon trois scenarios hypothetiques, qui ont tous debouche sur differents volumes de passagers. Resultats Nous avons identifie 28 pays ayant importe des cas de COVID-19 au 26 fevrier 2020. La date d'arrivee du virus dans ces pays s'est etalee sur une periode de 39 a 80 jours depuis la detection du premier cas a Wuhan. Notre analyse de l'evolution relative du risque a indique que les strategies de reduction du nombre global de passagers et de restriction des voyages dans 10 aeroports de premiere categorie auraient eu le meme niveau d'efficacite dans la diminution du risque d'importation du SARS-CoV-2. Neanmoins, cette diminution est tres limitee, avec une evolution relative mediane du risque proche de zero. Conclusion Les variations hypothetiques presentes dans les restrictions de voyage observees n'etaient pas suffisantes pour eviter la propagation du SARS-CoV-2 aux quatre coins de la planete. Les futures recherches a ce propos devraient egalement tenir compte des deplacements par voie terrestre et maritime. Notre etude souligne l'importance de renforcer les capacites locales de surveillance et de controle des maladies. [phrase omitted] Objetivo Estimar el efecto de las restricciones a los viajes en avion sobre el riesgo de importacion del coronavirus tipo 2 del sindrome respiratorio agudo grave (SARS-CoV-2). Metodos Se obtuvieron los datos sobre el volumen de pasajeros de toda la red global de aerolineas, asi como las fechas en las que se implementaron las restricciones de viaje y la observacion del primer caso de la enfermedad del coronavirus (COVID-19) en cada pais o territorio, a partir de fuentes a disposicion del publico. Se calculo la distancia efectiva entre cada aeropuerto y la ciudad de Wuhan, China. Se diseno un modelo del riesgo de importacion del SARS-CoV-2 al estimar la probabilidad de supervivencia, que indica el tiempo medio de importacion en funcion de la distancia efectiva. Se calculo el cambio relativo en el riesgo de importacion bajo tres escenarios hipoteticos diferentes que arrojaron valores distintos sobre el volumen de pasajeros. Resultados Se identificaron 28 paises con casos importados de la COVID-19 al 26 de febrero de 2020. El tiempo de llegada del virus a estos paises oscilo entre 39 y 80 dias desde la identificacion del primer caso en Wuhan. El analisis que se expone aqui sobre el cambio relativo del riesgo indico que las estrategias orientadas a reducir el volumen de pasajeros a nivel mundial y a imponer restricciones a los viajes en otros 10 aeropuertos centrales serian igualmente efectivas para reducir el riesgo de importacion del SARS-CoV-2; sin embargo, esta reduccion es muy limitada si se tiene en cuenta que el cambio relativo medio del riesgo es casi nulo. Conclusion Las variaciones hipoteticas de las restricciones de viaje que se observaron no fueron suficientes para impedir la propagacion global del SRAS-CoV-2; ademas, se deberia analizar la posibilidad de viajar por tierra y por mar en las investigaciones futuras. Este estudio destaca la importancia de fortalecer la capacidad local para monitorear y controlar la enfermedad.

The homeostatic regulation of sleep is characterized by rebound sleep after prolonged wakefulness, but the molecular and cellular mechanisms underlying this regulation are still unknown. In this study, we show that Ca2+/calmodulin-dependent protein kinase II (CaMKII)-dependent activity control of parvalbumin (PV)-expressing cortical neurons is involved in homeostatic regulation of sleep in male mice. Prolonged wakefulness enhances cortical PV-neuron activity. Chemogenetic suppression or activation of cortical PV neurons inhibits or induces rebound sleep, implying that rebound sleep is dependent on increased activity of cortical PV neurons. Furthermore, we discovered that CaMKII kinase activity boosts the activity of cortical PV neurons, and that kinase activity is important for homeostatic sleep rebound. Here, we propose that CaMKII-dependent PV-neuron activity represents negative feedback inhibition of cortical neural excitability, which serves as the distributive cortical circuits for sleep homeostatic regulation. The role of cortical PV neurons in the regulation of sleep architecture and homeostatic sleep rebound is not fully understood. Here, the authors show that CaMKII-mediated control of cortical parvalbumin-neuron activity regulates the homeostatic sleep rebound in mice. [ABSTRACT FROM AUTHOR]

Background: Coronavirus disease 2019 (COVID-19) continues to be a major global health burden. This study aims to estimate the all-cause excess mortality occurring in the COVID-19 outbreak in Japan, 2020, by sex and age group.Methods: Daily time series of mortality for the period January 2015-December 2020 in all 47 prefectures of Japan were obtained from the Ministry of Health, Labour and Welfare, Japan. A two-stage interrupted time-series design was used to calculate excess mortality. In the first stage, we estimated excess mortality by prefecture using quasi-Poisson regression models in combination with distributed lag non-linear models, adjusting for seasonal and long-term variations, weather conditions and influenza activity. In the second stage, we used a random-effects multivariate meta-analysis to synthesize prefecture-specific estimates at the nationwide level.Results: In 2020, we estimated an all-cause excess mortality of -20 982 deaths [95% empirical confidence intervals (eCI): -38 367 to -5472] in Japan, which corresponded to a percentage excess of -1.7% (95% eCI: -3.1 to -0.5) relative to the expected value. Reduced deaths were observed for both sexes and in all age groups except those aged <60 and 70-79 years.Conclusions: All-cause mortality during the COVID-19 outbreak in Japan in 2020 was decreased compared with a historical baseline. Further evaluation of cause-specific excess mortality is warranted. [ABSTRACT FROM AUTHOR]