I.M.L.)Motivated by the rapid spread of COVID-19 in Mainland China, we use a global metapopulation disease transmission model to project the impact of travel limitations on the national and international spread of the epidemic. The model is calibrated based on internationally reported cases, and shows that at the start of the travel ban from Wuhan on 23 January 2020, most Chinese cities had already received many infected travelers. The travel quarantine of Wuhan delayed the overall epidemic progression by only 3 to 5 days in Mainland China, but has a more marked effect at the international scale, where case importations were reduced by nearly 80% until mid February. Modeling results also indicate that sustained 90% travel restrictions to and from Mainland China only modestly affect the epidemic trajectory unless combined with a 50% or higher reduction of transmission in the community.
We use a data-driven global stochastic epidemic model to analyze the spread of the Zika virus (ZIKV) in the Americas. The model has high spatial and temporal resolution and integrates real-world demographic, human mobility, socioeconomic, temperature, and vector density data. We estimate that the first introduction of ZIKV to Brazil likely occurred between August 2013 and April 2014 (90% credible interval). We provide simulated epidemic profiles of incident ZIKV infections for several countries in the Americas through February 2017. The ZIKV epidemic is characterized by slow growth and high spatial and seasonal heterogeneity, attributable to the dynamics of the mosquito vector and to the characteristics and mobility of the human populations. We project the expected timing and number of pregnancies infected with ZIKV during the first trimester and provide estimates of microcephaly cases assuming different levels of risk as reported in empirical retrospective studies. Our approach represents a modeling effort aimed at understanding the potential magnitude and timing of the ZIKV epidemic and it can be potentially used as a template for the analysis of future mosquito-borne epidemics. Using a data-driven stochastic and spatial epidemic model, we present numerical results providing insight into the first introduction in the region and the epidemic dynamics across the Americas. We use the model to analyze the spatiotemporal spread and magnitude of the epidemic in the Americas through to February 2017, accounting for seasonal environmental factors and detailed population data. We also provide projections of the number of pregnancies infected with ZIKV during the first trimester, along with estimates for the number of microcephaly cases per country using three different levels of risk based on empirical retrospective studies (36, 37). ResultsIntroduction of ZIKV to the Americas. We identify 12 major transportation hubs in areas related to major events held in Brazil,
Background: The 2014 West African Ebola Outbreak is so far the largest and deadliest recorded in history. The affected countries, Sierra Leone, Guinea, Liberia, and Nigeria, have been struggling to contain and to mitigate the outbreak. The ongoing rise in confirmed and suspected cases, 2615 as of 20 August 2014, is considered to increase the risk of international dissemination, especially because the epidemic is now affecting cities with major commercial airports. Method: We use the Global Epidemic and Mobility Model to generate stochastic, individual based simulations of epidemic spread worldwide, yielding, among other measures, the incidence and seeding events at a daily resolution for 3,362 subpopulations in 220 countries. The mobility model integrates daily airline passenger traffic worldwide and the disease model includes the community, hospital, and burial transmission dynamic. We use a multimodel inference approach calibrated on data from 6 July to the date of 9 August 2014. The estimates obtained were used to generate a 3-month ensemble forecast that provides quantitative estimates of the local transmission of Ebola virus disease in West Africa and the probability of international spread if the containment measures are not successful at curtailing the outbreak. Results: We model the short-term growth rate of the disease in the affected West African countries and estimate the basic reproductive number to be in the range 1.5 − 2.0 (interval at the 1/10 relative likelihood). We simulated the international spreading of the outbreak and provide the estimate for the probability of Ebola virus disease case importation in countries across the world. Results indicate that the short-term (3 and 6 weeks) probability of international spread outside the African region is small, but not negligible. The extension of the outbreak is more likely occurring in African countries, increasing the risk of international dissemination on a longer time scale.
Many anti-diabetic drugs with different mechanisms of action are now available for treatment of type 2 diabetes mellitus. Sulfonylureas have been extensively used for treatment of type 2 diabetes for nearly 50 years and, even in our times, are widely used for treatment of this devastating chronic illness. Here, we review some of the available data on sulfonylureas, evaluating their mechanism of action and their effects on glycemic control. We can conclude that sulfonylureas are still the most used anti-diabetic agents: maybe this is due to their lower cost, to the possibility of mono-dosing and to the presence of an association with metformin in the same tablet. However, sulfonylureas, especially the older ones, are linked to a greater prevalence of hypoglycemia, and cardiovascular risk; newer prolonged-release preparations of sulfonylureas are undoubtedly safer, mainly due to reducing hypoglycemia, and for this reason should be preferred.
Summary Background The 2014 Ebola epidemic in West Africa defines an unprecedented health threat. We developed a model of Ebola transmission that integrates detailed geographical and demographic data from Liberia to overcome the limitations of non-spatial approaches in projecting the disease dynamics and assessing non-pharmaceutical control interventions. Methods We use a spatial agent-based model calibrated using a Markov chain Monte Carlo approach. The model is used to estimate Ebola transmission parameters and investigate the effectiveness of interventions such as availability of Ebola Treatment Units, safe burials procedures and household protection kits. Findings Through August 16, 2014, we estimate that 38·3% (95%CI 17·4-76·4) of infections were acquired in hospitals, 30·7% (95%CI 14·1-46·4) in households, and 8·9% (95%CI 3·3-11·8) while participating in funerals. The movement and mixing of Ebola and non-Ebola patients in hospitals at the early stage of the epidemic is found to be a sufficient driver of the observed pattern of spatial spread. The subsequent decrease of incidence at country and county level is ascribable to the increasing availability of Ebola treatment units – which in turn contributed to drastically decrease hospital transmission – safe burials, and distribution of household protection kits. Interpretation The model allows evaluating intervention options and disentangling their role in the decrease of incidence observed since September 7, 2014. High-quality data - e.g. to estimate household secondary attack rate, contact patterns within hospitals, and effects of ongoing interventions - are needed to reduce uncertainty in model estimates.
Motivated by the rapid spread of a novel coronavirus (2019-nCoV) in Mainland China, we use a global metapopulation disease transmission model to project the impact of both domestic and international travel limitations on the national and international spread of the epidemic. The model is calibrated on the evidence of internationally imported cases before the implementation of the travel quarantine of Wuhan. By assuming a generation time of 7.5 days, the reproduction number is estimated to be 2.4 [90% CI 2.2-2.6]. The median estimate for number of cases before the travel ban implementation on January 23, 2020 is 58, 956 [90% CI 40,471] in Wuhan and 3,491 [90% CI 1,924 -7,360] in other locations in Mainland China. The model shows that as of January 23, most Chinese cities had already received a considerable number of infected cases, and the travel quarantine delays the overall epidemic progression by only 3 to 5 days. The travel quarantine has a more marked effect at the international scale, where we estimate the number of case importations to be reduced by 80% until the end of February. Modeling results also indicate that sustained 90% travel restrictions to and from Mainland China only modestly affect the epidemic trajectory unless combined with a 50% or higher reduction of transmission in the community.
Aims Our aim was to describe the electrocardiographic features of critical COVID-19 patients. Methods and results We carried out a multicentric, cross-sectional, retrospective analysis of 431 consecutive COVID-19 patients hospitalized between 10 March and 14 April 2020 who died or were treated with invasive mechanical ventilation. This project is registered on ClinicalTrials.gov (identifier: NCT04367129). Standard ECG was recorded at hospital admission. ECG was abnormal in 93% of the patients. Atrial fibrillation/flutter was detected in 22% of the patients. ECG signs suggesting acute right ventricular pressure overload (RVPO) were detected in 30% of the patients. In particular, 43 (10%) patients had the S1Q3T3 pattern, 38 (9%) had incomplete right bundle branch block (RBBB), and 49 (11%) had complete RBBB. ECG signs of acute RVPO were not statistically different between patients with (n = 104) or without (n=327) invasive mechanical ventilation during ECG recording (36% vs. 28%, P = 0.10). Non-specific repolarization abnormalities and low QRS voltage in peripheral leads were present in 176 (41%) and 23 (5%), respectively. In four patients showing ST-segment elevation, acute myocardial infarction was confirmed with coronary angiography. No ST-T abnormalities suggestive of acute myocarditis were detected. In the subgroup of 110 patients where high-sensitivity troponin I was available, ECG features were not statistically different when stratified for above or below the 5 times upper reference limit value. Conclusions The ECG is abnormal in almost all critically ill COVID-19 patients and shows a large spectrum of abnormalities, with signs of acute RVPO in 30% of the patients. Rapid and simple identification of these cases with ECG at hospital admission can facilitate classification of the patients and provide pathophysiological insights.
Agrobacterium tumefaciens transfers transferred DNA (T-DNA), a single-stranded segment of its tumorinducing (Ti) plasmid, to the plant cell nucleus. The Tiplasmid-encoded virulence E2 (VirE2) protein expressed in the bacterium has single-stranded DNA (ssDNA)-binding properties and has been reported to act in the plant cell. This protein is thought to exert its influence on transfer efficiency by coating and accompanying the single-stranded T-DNA (ss-T-DNA) to the plant cell genome. Here, we analyze different putative roles of the VirE2 protein in the plant cell. In the absence of VirE2 protein, mainly truncated versions of the T-DNA are integrated. We infer that VirE2 protects the ss-T-DNA against nucleolytic attack during the transfer process and that it is interacting with the ss-T-DNA on its way to the plaht cell nucleus. Furthermore, the VirE2 protein was found not to be involved in directing the ss-T-DNA to the plant cell nucleus in a manner dependent on a nuclear localization signal, a function which is carried by the NLS of VirD2. In addition, the efficiency of T-DNA integration into the plant genome was found to be VirE2 independent. We conclude that the VirE2 protein ofA. tumefaciens is required to preserve the integrity of the T-DNA but does not contribute to the efficiency of the integration step per se.
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