Asunto(s)
Betacoronavirus , Control de Enfermedades Transmisibles , Infecciones por Coronavirus , Transmisión de Enfermedad Infecciosa , Salud Global/estadística & datos numéricos , Pandemias , Neumonía Viral , Betacoronavirus/aislamiento & purificación , Betacoronavirus/patogenicidad , COVID-19 , Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/organización & administración , Control de Enfermedades Transmisibles/normas , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/transmisión , Transmisión de Enfermedad Infecciosa/prevención & control , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Humanos , Internacionalidad , Mortalidad , Pandemias/prevención & control , Neumonía Viral/epidemiología , Neumonía Viral/prevención & control , Neumonía Viral/transmisión , Mejoramiento de la Calidad , SARS-CoV-2RESUMEN
It is of critical importance to estimate changing disease-transmission rates and their dependence on population mobility. A common approach to this problem involves fitting daily transmission rates using a susceptible-exposed-infected-recovered-(SEIR) model (regularizing to avoid overfitting) and then computing the relationship between the estimated transmission rate and mobility. Unfortunately, there are often several very different transmission-rate trajectories that can fit the reported cases well, meaning that the choice of regularization determines the final solution (and thus the mobility-transmission rate relationship) selected by the SEIR model. Moreover, the classical approaches to regularization-penalizing the derivative of the transmission rate trajectory-do not correspond to realistic properties of pandemic spread. Consequently, models fitted using derivative-based regularization are often biased toward underestimating the current transmission rate and future deaths. In this work, we propose mobility-driven regularization of the SEIR transmission rate trajectory. This method rectifies the artificial regularization problem, produces more accurate and unbiased forecasts of future deaths, and estimates a highly interpretable relationship between mobility and the transmission rate. For this analysis, mobility data related to the coronavirus disease 2019 pandemic was collected by Safegraph (San Francisco, California) from major US cities between March and August 2020.
Asunto(s)
COVID-19/transmisión , Susceptibilidad a Enfermedades/epidemiología , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Modelos Estadísticos , Dinámica Poblacional/estadística & datos numéricos , Predicción , Humanos , SARS-CoV-2 , Estados UnidosAsunto(s)
Número Básico de Reproducción/estadística & datos numéricos , Infecciones por Coronavirus , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Monitoreo Epidemiológico , Pandemias , Neumonía Viral , Betacoronavirus/aislamiento & purificación , Sesgo , COVID-19 , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/transmisión , Transmisión de Enfermedad Infecciosa/prevención & control , Mediciones Epidemiológicas , Salud Global , Humanos , Pandemias/prevención & control , Pandemias/estadística & datos numéricos , Neumonía Viral/epidemiología , Neumonía Viral/prevención & control , Neumonía Viral/transmisión , SARS-CoV-2 , Suiza/epidemiologíaRESUMEN
Following the rapid dissemination of COVID-19 cases in Switzerland, large-scale non-pharmaceutical interventions (NPIs) were implemented by the cantons and the federal government between 28 February and 20 March 2020. Estimates of the impact of these interventions on SARS-CoV-2 transmission are critical for decision making in this and future outbreaks. We here aim to assess the impact of these NPIs on disease transmission by estimating changes in the basic reproduction number (R0) at national and cantonal levels in relation to the timing of these NPIs. We estimated the time-varying R0 nationally and in eleven cantons by fitting a stochastic transmission model explicitly simulating within-hospital dynamics. We used individual-level data from more than 1000 hospitalised patients in Switzerland and public daily reports of hospitalisations and deaths. We estimated the national R0 to be 2.8 (95% confidence interval 2.1–3.8) at the beginning of the epidemic. Starting from around 7 March, we found a strong reduction in time-varying R0 with a 86% median decrease (95% quantile range [QR] 79–90%) to a value of 0.40 (95% QR 0.3–0.58) in the period of 29 March to 5 April. At the cantonal level, R0 decreased over the course of the epidemic between 53% and 92%. Reductions in time-varying R0 were synchronous with changes in mobility patterns as estimated through smartphone activity, which started before the official implementation of NPIs. We inferred that most of the reduction of transmission is attributable to behavioural changes as opposed to natural immunity, the latter accounting for only about 4% of the total reduction in effective transmission. As Switzerland considers relaxing some of the restrictions of social mixing, current estimates of time-varying R0 well below one are promising. However, as of 24 April 2020, at least 96% (95% QR 95.7–96.4%) of the Swiss population remains susceptible to SARS-CoV-2. These results warrant a cautious relaxation of social distance practices and close monitoring of changes in both the basic and effective reproduction numbers.
Asunto(s)
Betacoronavirus/aislamiento & purificación , Control de Enfermedades Transmisibles , Infecciones por Coronavirus , Transmisión de Enfermedad Infecciosa , Pandemias/estadística & datos numéricos , Neumonía Viral , COVID-19 , Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/organización & administración , Control de Enfermedades Transmisibles/estadística & datos numéricos , Enfermedades Transmisibles Emergentes/prevención & control , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/transmisión , Transmisión de Enfermedad Infecciosa/prevención & control , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Hospitalización/estadística & datos numéricos , Humanos , Modelos Estadísticos , Mortalidad , Pandemias/prevención & control , Neumonía Viral/epidemiología , Neumonía Viral/prevención & control , Neumonía Viral/transmisión , SARS-CoV-2 , Agrupamiento Espacio-Temporal , Procesos EstocásticosAsunto(s)
Betacoronavirus , Infecciones por Coronavirus/transmisión , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Modelos Estadísticos , Pandemias , Neumonía Viral/transmisión , COVID-19 , Infecciones por Coronavirus/epidemiología , Humanos , Neumonía Viral/epidemiología , SARS-CoV-2Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/transmisión , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Neumonía Viral/transmisión , Síndrome Respiratorio Agudo Grave/transmisión , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo , COVID-19 , Humanos , Pandemias , SARS-CoV-2Asunto(s)
Prueba de COVID-19/métodos , COVID-19/transmisión , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Grupo de Atención al Paciente , COVID-19/epidemiología , COVID-19/prevención & control , Transmisión de Enfermedad Infecciosa/prevención & control , Humanos , Comunicación Interdisciplinaria , Estados Unidos/epidemiologíaAsunto(s)
Prueba de COVID-19/métodos , COVID-19/epidemiología , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Unidades de Diagnóstico Rápido/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , COVID-19/diagnóstico , COVID-19/transmisión , Niño , Preescolar , Delaware , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Adulto JovenAsunto(s)
COVID-19 , Control de Enfermedades Transmisibles , COVID-19/epidemiología , COVID-19/prevención & control , Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/organización & administración , Trazado de Contacto/métodos , Transmisión de Enfermedad Infecciosa/prevención & control , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Humanos , Irán/epidemiología , Evaluación de Necesidades , Distanciamiento Físico , Prevalencia , SARS-CoV-2/aislamiento & purificaciónAsunto(s)
COVID-19 , Control de Enfermedades Transmisibles , Transmisión de Enfermedad Infecciosa , Composición Familiar , SARS-CoV-2/aislamiento & purificación , Adulto , COVID-19/epidemiología , COVID-19/prevención & control , COVID-19/transmisión , Prueba de Ácido Nucleico para COVID-19/estadística & datos numéricos , Control de Enfermedades Transmisibles/métodos , Control de Enfermedades Transmisibles/organización & administración , Punto Alto de Contagio de Enfermedades , Transmisión de Enfermedad Infecciosa/prevención & control , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Registros Electrónicos de Salud/estadística & datos numéricos , Femenino , Humanos , Masculino , Massachusetts/epidemiología , Persona de Mediana Edad , Medición de Riesgo/métodos , Factores de RiesgoRESUMEN
BACKGROUND: Health care workers (HCWs) are particularly exposed to COVID-19 and therefore it is important to study preventive measures in this population. AIM: To investigate socio-demographic factors and professional practice associated with the risk of COVID-19 among HCWs in health establishments in Normandy, France. METHODS: A cross-sectional and 3 case-control studies using bootstrap methods were conducted in order to explore the possible risk factors that lead to SARS-CoV2 transmission within HCWs. Case-control studies focused on risk factors associated with (a) care of COVID-19 patients, (b) care of non COVID-19 patients and (c) contacts between colleagues. PARTICIPANTS: 2,058 respondents, respectively 1,363 (66.2%) and 695 (33.8%) in medical and medico-social establishments, including HCW with and without contact with patients. RESULTS: 301 participants (14.6%) reported having been infected by SARS-CoV2. When caring for COVID-19 patients, HCWs who declared wearing respirators, either for all patient care (ORa 0.39; 95% CI: 0.29-0.51) or only when exposed to aerosol-generating procedures (ORa 0.56; 95% CI: 0.43-0.70), had a lower risk of infection compared with HCWs who declared wearing mainly surgical masks. During care of non COVID-19 patients, wearing mainly a respirator was associated with a higher risk of infection (ORa 1.84; 95% CI: 1.06-3.37). An increased risk was also found for HCWs who changed uniform in workplace changing rooms (ORa 1.93; 95% CI: 1.63-2.29). CONCLUSION: Correct use of PPE adapted to the situation and risk level is essential in protecting HCWs against infection.
Asunto(s)
COVID-19/prevención & control , Control de Enfermedades Transmisibles/instrumentación , Transmisión de Enfermedad Infecciosa/prevención & control , Personal de Salud/clasificación , Exposición Profesional/prevención & control , Adulto , COVID-19/epidemiología , Estudios de Casos y Controles , Estudios Transversales , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Femenino , Francia , Humanos , Masculino , Persona de Mediana Edad , Exposición Profesional/estadística & datos numéricos , Equipo de Protección Personal , Práctica Profesional , Conducta de Reducción del RiesgoRESUMEN
Computational fluid dynamics (CFD) modelling and 3D simulations of the air flow and dispersion of droplets or drops in semi-confined ventilated spaces have found topical applications with the unfortunate development of the Covid-19 pandemic. As an illustration of this scenario, we have considered the specific situation of a railroad coach containing a seated passenger infected with the SARS-CoV-2 virus (and not wearing a face mask) who, by breathing and coughing, releases droplets and drops that contain the virus and that present aerodynamic diameters between 1 and 1000 µm. The air flow is generated by the ventilation in the rail coach. While essentially 3D, the flow is directed from the bottom to the top of the carriage and comprises large to small eddies visualised by means of streamlines. The space and time distribution of the droplets and drops is computed using both an Eulerian model and a Lagrangian model. The results of the two modelling approaches are fully consistent and clearly illustrate the different behaviours of the drops, which fall down close to the infected passenger, and the droplets, which are carried along with the air flow and invade a large portion of the rail coach. This outcome is physically sound and demonstrates the relevance of CFD for simulating the transport and dispersion of droplets and drops with any diameter in enclosed ventilated spaces. As coughing produces drops and breathing produces droplets, both modes of transmission of the SARS-CoV-2 virus in human secretions have been accounted for in our 3D numerical study. Beyond the specific, practical application of the rail coach, this study offers a much broader scope by demonstrating the feasibility and usefulness of 3D numerical simulations based on CFD. As a matter of fact, the same computational approach that has been implemented in our study can be applied to a huge variety of ventilated indoor environments such as restaurants, performance halls, classrooms and open-plan offices in order to evaluate if their occupation could be critical with respect to the transmission of the SARS-CoV-2 virus or to other airborne respiratory infectious agents, thereby enabling relevant recommendations to be made.
Asunto(s)
COVID-19/transmisión , Vías Férreas , SARS-CoV-2/metabolismo , COVID-19/virología , Simulación por Computador , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Humanos , Imagenología TridimensionalAsunto(s)
COVID-19/complicaciones , Cánula/normas , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Terapia por Inhalación de Oxígeno/normas , COVID-19/fisiopatología , Cánula/estadística & datos numéricos , Humanos , Ventilación no Invasiva/efectos adversos , Ventilación no Invasiva/métodos , Oxígeno/uso terapéutico , Terapia por Inhalación de Oxígeno/efectos adversos , Terapia por Inhalación de Oxígeno/estadística & datos numéricos , Pandemias/estadística & datos numéricosRESUMEN
The transmission of COVID-19 is dependent on social mixing, the basic rate of which varies with sociodemographic, cultural, and geographic factors. Alterations in social mixing and subsequent changes in transmission dynamics eventually affect hospital admissions. We employ these observations to model and predict regional hospital admissions in Sweden during the COVID-19 pandemic. We use an SEIR-model for each region in Sweden in which the social mixing is assumed to depend on mobility data from public transport utilisation and locations for mobile phone usage. The results show that the model could capture the timing of the first and beginning of the second wave of the pandemic 3 weeks in advance without any additional assumptions about seasonality. Further, we show that for two major regions of Sweden, models with public transport data outperform models using mobile phone usage. We conclude that a model based on routinely collected mobility data makes it possible to predict future hospital admissions for COVID-19 3 weeks in advance.
Asunto(s)
Algoritmos , COVID-19/transmisión , Teléfono Celular/estadística & datos numéricos , Hospitalización/estadística & datos numéricos , Modelos Teóricos , Admisión del Paciente/estadística & datos numéricos , COVID-19/epidemiología , COVID-19/virología , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Predicción/métodos , Geografía , Hospitalización/tendencias , Humanos , Pandemias/prevención & control , Admisión del Paciente/tendencias , Estudios Retrospectivos , SARS-CoV-2/fisiología , Suecia/epidemiología , Viaje/estadística & datos numéricosRESUMEN
The COVID-19 pandemic has been particularly threatening to patients with end-stage kidney disease (ESKD) on intermittent hemodialysis and their care providers. Hemodialysis patients who receive life-sustaining medical therapy in healthcare settings, face unique challenges as they need to be at a dialysis unit three or more times a week, where they are confined to specific settings and tended to by dialysis nurses and staff with physical interaction and in close proximity. Despite the importance and critical situation of the dialysis units, modelling studies of the SARS-CoV-2 spread in these settings are very limited. In this paper, we have used a combination of discrete event and agent-based simulation models, to study the operations of a typical large dialysis unit and generate contact matrices to examine outbreak scenarios. We present the details of the contact matrix generation process and demonstrate how the simulation calculates a micro-scale contact matrix comprising the number and duration of contacts at a micro-scale time step. We have used the contacts matrix in an agent-based model to predict disease transmission under different scenarios. The results show that micro-simulation can be used to estimate contact matrices, which can be used effectively for disease modelling in dialysis and similar settings.
Asunto(s)
COVID-19/transmisión , Trazado de Contacto/estadística & datos numéricos , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Unidades de Hemodiálisis en Hospital/estadística & datos numéricos , Simulación por Computador , Humanos , Modelos EstadísticosRESUMEN
The coronavirus disease 2019 (COVID-19) pandemic became an important public health problem affecting all age groups. The aim of this study was to evaluate clinical and laboratory findings of newborns born to mothers with COVID-19. Thirty pregnant women with COVID-19 were admitted to Turgut Ozal University Hospital for delivery. Fourteen pregnant women had at least one symptom associated with COVID-19. Positive polymerase chain reaction (PCR) results were seen in only 3 (9.7%) of 31 newborns. A statistically significant difference was observed between PCR-positive and PCR-negative newborns in terms of any adverse pregnancy outcomes. Neonatal lymphocyte count and partial arterial oxygen pressure were significantly lower in the PCR-positive group. Results were also compared according to the interval from the maternal diagnosis time to delivery. Hemoglobin and hematocrit levels in newborns born to mothers diagnosed more than 7 days before delivery were significantly lower. Neonates born to mothers with COVID-19 had mild clinical symptoms and favorable outcomes.