Publications by authors named "Espana G"
Article Synopsis
- COVID-19 is still a major public health issue in the U.S., with projected hospitalizations and deaths over the next two years varying based on assumptions about immune escape and vaccine recommendations.
- Researchers used modeling to create six different scenarios combining levels of immune escape (20% and 50% per year) and CDC vaccination recommendations for different age groups.
- In the worst-case scenario (high immune escape and no vaccination), COVID-19 could lead to over 2.1 million hospitalizations and around 209,000 deaths, while targeted vaccinations for seniors could significantly reduce these numbers.
Over the past several years, the emergence of novel SARS-CoV-2 variants has led to multiple waves of increased COVID-19 incidence. When the Omicron variant emerged, there was considerable concern about its potential impact in the winter of 2021-2022 due to its increased fitness. However, there was also considerable uncertainty regarding its likely impact due to questions about its relative transmissibility, severity, and degree of immune escape.
View Article and Find Full Text PDFOur ability to forecast epidemics far into the future is constrained by the many complexities of disease systems. Realistic longer-term projections may, however, be possible under well-defined scenarios that specify the future state of critical epidemic drivers. Since December 2020, the U.
View Article and Find Full Text PDFArticle Synopsis
- COVID-19 is expected to continue causing significant hospitalizations and deaths in the U.S. from April 2023 to April 2025, with projections varying based on assumptions about immune escape and vaccination recommendations.
- The study analyzes six scenarios based on different levels of immune escape (20% and 50% per year) and three vaccination strategies (no recommendation, vaccination for ages 65+, or vaccination for all eligible groups).
- In the worst-case scenario, without vaccination and with high immune escape, projections estimate up to 2.1 million hospitalizations and 209,000 deaths, indicating a public health crisis that could surpass pre-pandemic influenza and pneumonia mortality rates.
Article Synopsis
- New technology is needed to help control mosquito-borne diseases like dengue, and big tests (called CRTs) help figure out how well these technologies work.
- A recent test showed that releasing special infected mosquitoes can reduce the spread of dengue, but there are factors (like people and mosquito movements) that might affect results.
- The study found that if these factors are not considered, the benefits might be underestimated, meaning these mosquitoes could be even more effective than previously thought.
Our ability to forecast epidemics more than a few weeks into the future is constrained by the complexity of disease systems, our limited ability to measure the current state of an epidemic, and uncertainties in how human action will affect transmission. Realistic longer-term projections (spanning more than a few weeks) may, however, be possible under defined scenarios that specify the future state of critical epidemic drivers, with the additional benefit that such scenarios can be used to anticipate the comparative effect of control measures. Since December 2020, the U.
View Article and Find Full Text PDFOptimization of control measures for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in high-risk institutional settings (e.g., prisons, nursing homes, or military bases) depends on how transmission dynamics in the broader community influence outbreak risk locally.
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- Aedes aegypti mosquitoes are known carriers of several serious viruses, and controlling their population is crucial for managing diseases like dengue and Zika.
- Researchers have developed complex models to understand how interventions affect mosquito populations, but these models can sometimes struggle to match real-world data due to their assumptions.
- The authors propose a new approach that combines the realism of mechanistic models with the flexibility of statistical models, using data from Iquitos, Peru, to effectively analyze mosquito dynamics and evaluate the impact of insecticide spraying.
Article Synopsis
- Policymakers face challenges in making decisions with limited information and conflicting predictions from different models, especially during crises like the COVID-19 pandemic.
- A study brought together multiple modeling teams to assess reopening strategies in a mid-sized U.S. county, revealing consistent rankings for interventions despite variations in projection magnitudes.
- The findings indicated that reopening workplaces could lead to a significant increase in infections, while restrictions could greatly reduce cumulative infections, highlighting the trade-offs between public health and economic activity with no optimal reopening strategy identified.
The COVID-19 pandemic has affected millions of people around the world. In Colombia, 1.65 million cases and 43,495 deaths were reported in 2020.
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- The COVID-19 Scenario Modeling Hub brought together nine teams to analyze the effects of vaccinating children aged 5-11 against SARS-CoV-2 on COVID-19 outcomes in the U.S. from September 2021 to March 2022.
- The study compared outcomes under scenarios with and without vaccination and the potential emergence of more transmissible variants, providing insights on case counts, hospitalizations, and deaths.
- Findings indicated that vaccinating children could significantly reduce COVID-19 cases, hospitalizations, and deaths, offering both direct benefits for kids and indirect benefits for the broader population, even in scenarios with more transmissible variants.
Like other congregate living settings, military basic training has been subject to outbreaks of COVID-19. We sought to identify improved strategies for preventing outbreaks in this setting using an agent-based model of a hypothetical cohort of trainees on a U.S.
View Article and Find Full Text PDFShort-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.
View Article and Find Full Text PDFBackground: SARS-CoV-2 vaccination of persons aged 12 years and older has reduced disease burden in the United States. The COVID-19 Scenario Modeling Hub convened multiple modeling teams in September 2021 to project the impact of expanding vaccine administration to children 5-11 years old on anticipated COVID-19 burden and resilience against variant strains.
Methods: Nine modeling teams contributed state- and national-level projections for weekly counts of cases, hospitalizations, and deaths in the United States for the period September 12, 2021 to March 12, 2022.
Article Synopsis
- Plasmodium vivax relapses due to re-activating hypnozoites hinder disease control, but radical cure therapy shows varying efficacy (65-94%) in clinical trials depending on the trial site.* -
- Simulated analyses reveal that differences in conditions like transmission intensity and relapse rate can cause efficacy estimates to vary significantly (12-78%), complicating treatment comparisons.* -
- To improve the reliability of efficacy estimates, future trials should focus on low-transmission settings, implement vector control, and utilize parasite genotyping to manage biases from re-infections.*
Article Synopsis
- Probabilistic forecasts are crucial for understanding how newly emerged pathogens, like Zika, spread, but uncertainties about these pathogens complicate model selection.
- A study evaluated 16 different forecasting models during the 2015-2016 Zika epidemic in Colombia, each with unique assumptions regarding human mobility and virus introduction.
- Results indicated that model effectiveness varied over time, with some individual models doing better early on, but overall, ensemble models that considered multiple assumptions provided more reliable forecasts.
In the United States, schools closed in March 2020 due to COVID-19 and began reopening in August 2020, despite continuing transmission of SARS-CoV-2. In states where in-person instruction resumed at that time, two major unknowns were the capacity at which schools would operate, which depended on the proportion of families opting for remote instruction, and adherence to face-mask requirements in schools, which depended on cooperation from students and enforcement by schools. To determine the impact of these conditions on the statewide burden of COVID-19 in Indiana, we used an agent-based model calibrated to and validated against multiple data types.
View Article and Find Full Text PDFBackground: The COVID-19 pandemic has induced unprecedented reductions in human mobility and social contacts throughout the world. Because dengue virus (DENV) transmission is strongly driven by human mobility, behavioral changes associated with the pandemic have been hypothesized to impact dengue incidence. By discouraging human contact, COVID-19 control measures have also disrupted dengue vector control interventions, the most effective of which require entry into homes.
View Article and Find Full Text PDFAn effective and widely used vaccine could reduce the burden of dengue virus (DENV) around the world. DENV is endemic in Puerto Rico, where the dengue vaccine CYD-TDV is currently under consideration as a control measure. CYD-TDV has demonstrated efficacy in clinical trials in vaccinees who had prior dengue virus infection.
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- After a decline in Zika and dengue cases in Brazil between 2017-2018, dengue resurged dramatically in 2019 with approximately 2.1 million reported cases.
- The study analyzes epidemiological, climatological, and genomic data to understand the dynamics of dengue in Brazil, highlighting low transmission rates despite suitable conditions in 2017-2018.
- Researchers found that the local dengue virus lineages responsible for outbreaks in 2018-2019 had been circulating quietly for several years, suggesting that dengue could remain at low levels before causing significant outbreaks when conditions improve.
During the 2015-2017 Zika epidemic, dengue and chikungunya-two other viral diseases with the same vector as Zika-were also in circulation. Clinical presentation of these diseases can vary from person to person in terms of symptoms and severity, making it difficult to differentially diagnose them. Under these circumstances, it is possible that numerous cases of Zika could have been misdiagnosed as dengue or chikungunya, or vice versa.
View Article and Find Full Text PDFObjective: To characterize the dynamics of the coronavirus disease 2019 (COVID-19) epidemic, for modeling purposes.
Methods: Data from Colombian official case information were collated for a period of 5 months. Dynamical parameters of the disease spread were then estimated from the data.
Policymakers make decisions about COVID-19 management in the face of considerable uncertainty. We convened multiple modeling teams to evaluate reopening strategies for a mid-sized county in the United States, in a novel process designed to fully express scientific uncertainty while reducing linguistic uncertainty and cognitive biases. For the scenarios considered, the consensus from 17 distinct models was that a second outbreak will occur within 6 months of reopening, unless schools and non-essential workplaces remain closed.
View Article and Find Full Text PDFOptimal Control of the COVID-19 Pandemic with Non-pharmaceutical Interventions.
Bull Math Biol
September 2020
Article Synopsis
- The COVID-19 pandemic has led to social distancing measures worldwide, and there is a push to relax these restrictions due to economic impacts.
- An optimal control analysis of SARS-CoV-2 transmission was conducted, focusing on strategies from May 2020 to December 2021, and informed by data from the USA.
- The study found that maintaining stringent controls longer initially leads to fewer deaths and better control options later, whereas quickly relaxing measures increases the risk of overwhelming hospitals and complications in managing the pandemic.