Resources Repository
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ArticlePublication 2017Likelihood Approach for Calibration of Stochastic Epidemic Models
Stochastic transmission dynamic models are especially useful for studying the early emergence of novel pathogens …
Stochastic transmission dynamic models are especially useful for studying the early emergence of novel pathogens given the importance of chance events when the number of infectious individuals is small. However, methods for parameter estimation and prediction for these types of stochastic models remain limited. This paper describes a calibration and prediction framework for stochastic compartmental transmission models of epidemics. The proposed method applies a linear noise approximation to describe the size of the fluctuations, and…
Dynamic Simulation | Dynamic Transmission | Infectious Diseases | Calibration/Validation | Health Systems | Health/Medicine | Global -
ArticlePublication 2016Identifying Cost-Effective Dynamic Policies to Control Epidemics
This paper describes a mathematical decision model for identifying dynamic health policies for controlling epidemics. …
This paper describes a mathematical decision model for identifying dynamic health policies for controlling epidemics. The dynamic policies aim to select the best current intervention based on accumulating epidemic data and the availability of resources at each decision point. An algorithm is proposed to approximate dynamic policies that optimize the population's net health benefit, a performance measure which accounts for both health and monetary outcomes. The authors further illustrate how dynamic policies can be defined and…
Dynamic Simulation | Dynamic Transmission | Infectious Diseases | Mathematical Models | Cost-Effectiveness Analysis | Health/Medicine -
ArticlePublication 2011Dynamic Policies for Controlling Spread of Emerging Infections
This paper illustrates the design and implementation of a dynamic health policy for the control …
This paper illustrates the design and implementation of a dynamic health policy for the control of a novel strain of influenza, where two types of interventions are assumed to be available during the epidemic: (1) vaccines and antiviral drugs, and (2) transmission reducing measures, such as social distancing or mask use, that may be turned "on" or "off" repeatedly during the course of epidemic. A modeling approach is described for developing dynamic health policies that allow…
Dynamic Simulation | Dynamic Transmission | Infectious Diseases | Mathematical Models | Health Systems | Policy/Regulation | Health/Medicine | Science/Technology | Global -
ArticlePublication 2020Testing for SARS-CoV-2 Antibodies
Antibody testing can determine previous exposure to SARS-CoV-2 virus. Recently, the UK government has made …
Antibody testing can determine previous exposure to SARS-CoV-2 virus. Recently, the UK government has made antibody testing available to anyone wanting it, even if there is no clinical indication. The purpose of this article is to provide guidance for when to consider antibody testing in individuals with and without symptoms suggestive of current or past SARS-CoV-2 infection. Key points made by the authors include: (1) antibody testing is likely to be most useful 2 weeks…
Probability/Bayes | Infectious Diseases | Test Performance | Technology Assessment | Clinical Care | Health/Medicine -
ArticlePublication 2020Bayes' Theorem, COVID-19, and Screening Tests
This article reviews the implications of increased testing for COVID-19 using reverse transcriptase polymerase chain …
This article reviews the implications of increased testing for COVID-19 using reverse transcriptase polymerase chain reaction (rRT-PCR) through the application of Bayes’ Theorem for three hypothetical, stylized case scenarios. The scenarios involve three patients with a low, moderate, and high pre-test probability of COVID-19 infection. The category of low probability would include "asymptomatic individuals in a presumed low prevalence environment" and might vary from 10 to 20%. The category of moderate probability would include "individuals…
Probability/Bayes | Infectious Diseases | Test Performance | Clinical Care | Health/Medicine -
ArticlePublication 2020Interpreting COVID-19 Test Results: A Bayesian Approach
This article considers the following question with respect to interpreting the results of polymerase chain reaction …
This article considers the following question with respect to interpreting the results of polymerase chain reaction (PCR) assays from nasal and pharyngeal swabs for COVID-19 to inform clinical decision making: "While a positive result in an acutely ill patient is straightforward, how should physicians interpret negative tests in patients with suspected COVID-19 infection?" Using an assumption of near-perfect specificity of PCR assays for COVID-19, the authors acknowledge the uncertainty of test sensitivity. They consider two clinical scenarios…
Probability/Bayes | Infectious Diseases | Test Performance | Health/Medicine | Science/Technology | Global -
ArticlePublication 2019Cost-Effectiveness of Latent TB Screening before Immigration to Low-Incidence Countries
Despite prospective migrants to countries where the incidence of TB is low receiving TB screening …
Despite prospective migrants to countries where the incidence of TB is low receiving TB screening for active infections, screening for latent TB infection before immigration is rare. The authors used discrete event simulation to evaluate the cost-effectiveness preimmigration latent TB infection screening for migrants to low-incidence countries. They calculated cost per quality-adjusted life-year gained for migrants from countries with different TB incidences. Their analysis when combined with research on sustainability, acceptability, and program implementation can…
Dynamic Simulation | Infectious Diseases | Mathematical Models | Cost-Effectiveness Analysis | Government/Law | Health/Medicine | Global -
ArticleWeb Portal 2017PLoS Collection: Prevention, Diagnosis and Treatment of Sexually Transmitted Infections
Globally, the World Health Organization (WHO) estimates that more than one million new sexually transmitted …
Globally, the World Health Organization (WHO) estimates that more than one million new sexually transmitted infections (STIs) occur each day, incurring a very substantial burden of morbidity, mortality and additional infections. The pathogens responsible include bacteria, parasites and viruses, and intensive research is needed to address the substantial barriers to diagnosis and treatment of STIs, and the behavioral challenges of prevention. This PLOS collection, published in collaboration with WHO, focuses on global policy and systems…
Dynamic Transmission | Infectious Diseases | Priority Setting/Ethics | Costing Methods | Mathematical Models | Cost-Effectiveness Analysis | Health Systems | Economics/Finance | Health/Medicine | Sub-Saharan Africa | Middle East & North Africa | Latin America & Caribbean | Asia & Pacific -
ArticlePublication 2017Estimating the Fitness Cost and Benefit of Cefixime Resistance in Neisseria Gonorrhoeae
Gonorrhoea is one of the most common bacterial sexually transmitted infections in England, and more …
Gonorrhoea is one of the most common bacterial sexually transmitted infections in England, and more than half of annual infections occur in men who have sex with men (MSM). As the bacterium has developed resistance to each first-line antibiotic in turn, an improved understanding is needed of fitness benefits and costs of antibiotic resistance to inform control policy and planning. The authors developed a stochastic compartmental model representing the natural history and transmission of cefixime-sensitive…
Dynamic Transmission | Infectious Diseases | Decision Analysis | Risk Analysis | Health Systems | Policy/Regulation | Government/Law | Health/Medicine | Science/Technology | Global