A5030642208- COVID-19 epidemiological studies
- HIV/AIDS Research and Interventions
- Adolescent Sexual and Reproductive Health
- SARS-CoV-2 and COVID-19 Research
- HIV, Drug Use, Sexual Risk
- COVID-19 Digital Contact Tracing
- demographic modeling and climate adaptation
- Cervical Cancer and HPV Research
- Data-Driven Disease Surveillance
- Vaccine Coverage and Hesitancy
- COVID-19 Pandemic Impacts
- Influenza Virus Research Studies
- Infection Control and Ventilation
- Viral Infections and Outbreaks Research
- Reproductive tract infections research
- Hepatitis B Virus Studies
- HIV Research and Treatment
- COVID-19 Clinical Research Studies
- HIV/AIDS Impact and Responses
- Simulation Techniques and Applications
- Statistical Methods and Bayesian Inference
- Gaussian Processes and Bayesian Inference
- Genital Health and Disease
- Family Dynamics and Relationships
- Assisted Reproductive Technology and Twin Pregnancy
United States Military Academy
2023-2025
Gates Foundation
2020-2024
Institute for Disease Modeling
2015-2024
Los Angeles Medical Center
2024
University of Southern California
2024
State Street (United States)
2024
Burnet Institute
2023
QIMR Berghofer Medical Research Institute
2023
London School of Hygiene & Tropical Medicine
2021
University College London
2021
The COVID-19 pandemic has created an urgent need for models that can project epidemic trends, explore intervention scenarios, and estimate resource needs. Here we describe the methodology of Covasim (COVID-19 Agent-based Simulator), open-source model developed to help address these questions. includes country-specific demographic information on age structure population size; realistic transmission networks in different social layers, including households, schools, workplaces, long-term care...
Background Many mathematical models have investigated the impact of expanding access to antiretroviral therapy (ART) on new HIV infections. Comparing results and conclusions across is challenging because addressed slightly different questions reported outcome metrics. This study compares predictions several simulating same ART intervention programmes determine extent which agree about epidemiological expanded ART. Methods Findings Twelve independent evaluated a set standardised scenarios in...
As lockdown measures to slow the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection begin ease in UK, it is important assess impact any changes policy, including school reopening and broader relaxation physical distancing measures. We aimed use an individual-based model predict two possible strategies for schools all students UK from September, 2020, combination with different assumptions about scale-up testing.In this modelling study, we used Covasim, a...
New WHO guidelines recommend ART initiation for HIV-positive persons with CD4 cell counts ≤500 cells/µL, a higher threshold than was previously recommended. Country decision makers must consider whether to further expand eligibility accordingly.We used multiple independent mathematical models in four settings-South Africa, Zambia, India, and Vietnam-to evaluate the potential health impact, costs, cost-effectiveness of different adult criteria under scenarios current expanded treatment...
Abstract The COVID-19 pandemic has created an urgent need for models that can project epidemic trends, explore intervention scenarios, and estimate resource needs. Here we describe the methodology of Covasim (COVID-19 Agent-based Simulator), open-source model developed to help address these questions. includes country-specific demographic information on age structure population size; realistic transmission networks in different social layers, including households, schools, workplaces,...
Abstract Initial COVID-19 containment in the United States focused on limiting mobility, including school and workplace closures. However, these interventions have had enormous societal economic costs. Here, we demonstrate feasibility of an alternative control strategy, test-trace-quarantine: routine testing primarily symptomatic individuals, tracing their known contacts, placing contacts quarantine. We perform this analysis using Covasim, open-source agent-based model, which has been...
Individual-based models provide modularity and structural flexibility necessary for modeling of infectious diseases at the within-host population levels, but are challenging to implement. Levels complexity can exceed capacity timescales students trainees in most academic institutions. Here we describe process advantages a multi-disease framework approach developed with formal software support. The epidemiological software, EMOD, has undergone decade development. It is structured so that...
In the last 20 years, China ramped up a DOTS (directly observed treatment, short-course)-based tuberculosis (TB) control program with 80% population coverage, achieving 2015 Millennium Development Goal of 50% reduction in TB prevalence and mortality. Recently, World Health Organization developed End Strategy, an overall goal 90% incidence 95% deaths from 2015–2035. As burden shifts to older individuals China's ages, it is unclear if maintaining current strategy will be sufficient for reach...
Objectives To assess the risks associated with relaxing coronavirus disease 2019 (COVID-19)-related physical distancing restrictions and lockdown policies during a period of low viral transmission. Design Network-based transmission in households, schools, workplaces, variety community spaces activities were simulated an agent-based model, Covasim. Setting The model was calibrated for baseline scenario reflecting epidemiological policy environment Victoria March–May 2020, Intervention Policy...
To quantify the contribution of specific sexual partner age groups to risk HIV acquisition in men and women a hyperendemic region South Africa.We conducted population-based cohort study among (15-49 years age) (15-55 between 2004 2015 KwaZulu-Natal, Africa.Generalized additive models were used estimate smoothed incidence rates across partnership pairings women. Cox proportional hazards regression was relative by group.A total 882 seroconversions observed 15 935 person-years for women, rate =...
Policymakers must make management decisions despite incomplete knowledge and conflicting model projections. Little guidance exists for the rapid, representative, unbiased collection of policy-relevant scientific input from independent modeling teams. Integrating approaches decision analysis, expert judgment, aggregation, we convened multiple teams to evaluate COVID-19 reopening strategies a mid-sized United States county early in pandemic. Projections seventeen distinct models were...
Mathematical models are widely used to simulate the effects of interventions control HIV and project future epidemiological trends resource needs. We aimed validate past model projections against data from a large household survey done in South Africa 2012.We compared ten prevalence, incidence, antiretroviral therapy (ART) coverage for with estimates national 2012. Model 2012 were made before publication survey. adult (age 15-49 years) prevalence 2012, change between 2008 ART by sex age...
Abstract 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 United States, novel process designed fully express scientific uncertainty while reducing linguistic and cognitive biases. For scenarios considered, consensus from 17 distinct models was that second outbreak will occur within 6 months reopening, unless schools non-essential workplaces remain closed....
Vietnam has emerged as one of the world's leading success stories in responding to COVID-19. After a prolonged period little no transmission, there was an outbreak unknown source July, 2020, Da Nang region, but quickly suppressed. We aimed use epidemiological, behavioural, demographic, and policy data from COVID-19 calibrate agent-based model transmission for Vietnam, estimate risk future outbreaks associated with reopening international borders country.
Marked reductions in the incidence of measles and rubella have been observed since widespread use vaccines. Although no global goal for eradication has established, all six WHO regions set elimination targets. However, a gap remains between current control levels targets, as shown by large outbreaks 2017 2019. We aimed to model potential globally inform report 73rd World Health Assembly on feasibility eradication.In this study, we modelled probability 2020 2100 under different vaccination...
Efficient planning and evaluation of human immunodeficiency virus (HIV) prevention programmes requires an understanding what sustains the epidemic, including mechanism by which HIV transmission keeps pace with ageing infected population. Recently, more detailed population models have been developed represent epidemic sufficient detail to characterize dynamics ongoing transmission. Here, we describe structure parameters such a model, called EMOD-HIV v. 0.7. We analyse chains that allow...
The English SARS-CoV-2 epidemic has been affected by the emergence of new viral variants such as B.1.177, Alpha and Delta, changing restrictions. We used statistical models agent-based model Covasim, in June 2021, to estimate B.1.177 be 20% more transmissible than wild type, 50-80% Delta 65-90% Alpha. Using these estimates Covasim (calibrated 1 September 2020 20 2021), we found that due high transmissibility resurgence infections driven variant would not prevented, but strongly reduced...
In 2020, the WHO launched its first global strategy to accelerate elimination of cervical cancer, outlining an ambitious set targets for countries achieve over next decade. At same time, new tools, technologies, and strategies are in pipeline that may improve screening performance, expand reach prophylactic vaccines, prevent acquisition, persistence progression oncogenic HPV. Detailed mechanistic modelling can help identify combinations current future combat cancer. Open-source tools needed...
Acinetobacter baumannii is a Gram-negative pathogen responsible for pneumonia and wound, bloodstream, urinary tract infections, particularly patients in intensive care units. Using phenotypic screening we have identified novel class of small molecule inhibitors that potent highly selective antibacterial activity against baumannii. Resistance selection the molecular target as MsbA, an essential ABC transporter functions by flipping lipid A across inner membrane most gram-negative bacteria....
Abstract Background School closures around the world contributed to reducing transmission of COVID-19. In face significant uncertainty epidemic impact in-person schooling, policymakers, parents, and teachers are weighing risks benefits returning education. this context, we examined different school reopening scenarios on within outside schools share days that would need be spent learning at a distance. Methods We used an agent-based mathematical model COVID-19 interventions quantify disease...
Abstract Initial COVID-19 containment in the United States focused on limiting mobility, including school and workplace closures. However, these interventions have had enormous societal economic costs. Here we demonstrate feasibility of an alternative control strategy, test-trace-quarantine: routine testing primarily symptomatic individuals, tracing their known contacts, placing contacts quarantine. We performed this analysis using Covasim, open-source agent-based model, which was calibrated...
Abstract The functional relationship between neutralizing antibodies (NAbs) and protection against SARS-CoV-2 infection disease remains unclear. We jointly estimated progression following natural vaccination from meta-study data. find that NAbs are strongly correlated with prevention of any history will stimulate immune memory to moderate progression. also provides stronger than for the same level NAbs, noting itself, unlike vaccination, carries risk morbidity mortality, our most potent...
In settings with zero community transmission, any new SARS-CoV-2 outbreaks are likely to be the result of random incursions. The level restrictions in place at time incursion is considerably affect possible outbreak trajectories, but probability that a large eventuates not known.We used an agent-based model investigate relationship between ongoing and behavioural factors, causing resulting growth rate. We applied our state Victoria, Australia, which has reached transmission as November...
Objective: EMOD-HIV v0.8 has been used to estimate the potential impact of expanding treatment guidelines allow earlier initiation antiretroviral therapy (ART) in sub-Saharan Africa with current or improved coverage. In generating these results, a model must additionally make assumptions about rates dropout and re-initiation into ART programs before after program change, which little is known. The objective this work rigorously analyze modeling sensitivity results respect relevant mechanisms...
Typhoid fever is endemic in many developing countries. In the early 20th century, newly industrializing countries including United States successfully controlled typhoid as water treatment (chlorination/sand filtration) and improved sanitation became widespread. Enigmatically, remained through 1980s Santiago, Chile, despite potable municipal widespread household sanitation. Data were collected across multiple stages of endemicity control offering a unique resource for gaining insight into...