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Bhowmick S, Fritz ML, Smith RL. Host-feeding preferences and temperature shape the dynamics of West Nile virus: A mathematical model to predict the impacts of vector-host interactions and vector management on R 0. Acta Trop 2024; 258:107346. [PMID: 39111645 DOI: 10.1016/j.actatropica.2024.107346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 07/23/2024] [Accepted: 07/30/2024] [Indexed: 08/22/2024]
Abstract
West Nile virus (WNV) is prevalent across the United States, but its transmission patterns and spatio-temporal intensity vary significantly, particularly in the Eastern United States. For instance, Chicago has long been a hotspot for WNV cases due to its high cumulative incidence of infection, with the number of cases varying considerably from year to year. The abilities of host species to maintain and disseminate WNV, along with eco-epidemiological factors that influence vector-host contact rates underlie WNV transmission potential. There is growing evidence that several vectors exhibit strong feeding preferences towards different host communities. In our research study, we construct a process based weather driven ordinary differential equation (ODE) model to understand the impact of one vector species (Culex pipiens), its preferred avian and non-preferred human hosts on the basic reproduction number (R0). In developing this WNV transmission model, we account for the feeding index, which is defined as the relative preference of the vectors for taking blood meals from a competent avian host versus a non-competent mammalian host. We also include continuous introduction of infected agents into the model during the simulations as the introduction of WNV is not a single event phenomenon. We derive an analytic form of R0 to predict the conditions under which there will be an outbreak of WNV and the relationship between the feeding index and the efficacy of adulticide is highly nonlinear. In our mechanistic model, we also demonstrate that adulticide treatments produced significant reductions in the Culex pipiens population. Sensitivity analysis demonstrates that feeding index and rate of introduction of infected agents are two important factors beside the efficacy of adulticide. We validate our model by comparing simulations to surveillance data collected for the Culex pipiens complex in Cook County, Illinois, USA. Our results reveal that the interaction between the feeding index and mosquito abatement strategy is intricate, especially considering the fluctuating temperature conditions. This induces heterogeneous transmission patterns that need to be incorporated when modelling multi-host, multi-vector transmission models.
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Affiliation(s)
- Suman Bhowmick
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
| | - Megan Lindsay Fritz
- Department of Entomology, Institute for Advanced Computer Studies, University of Maryland, USA
| | - Rebecca Lee Smith
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA; Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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2
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Parker N. Exploring the role of temperature and other environmental factors in West Nile virus incidence and prediction in California counties from 2017-2022 using a zero-inflated model. PLoS Negl Trop Dis 2024; 18:e0012051. [PMID: 38913741 PMCID: PMC11226093 DOI: 10.1371/journal.pntd.0012051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 07/05/2024] [Accepted: 06/07/2024] [Indexed: 06/26/2024] Open
Abstract
West Nile virus (WNV) is the most common mosquito-borne disease in the United States, resulting in hundreds of reported cases yearly in California alone. The transmission cycle occurs mostly in birds and mosquitoes, making meteorological conditions, such as temperature, especially important to transmission characteristics. Given that future increases in temperature are all but inevitable due to worldwide climate change, determining associations between temperature and WNV incidence in humans, as well as making predictions on future cases, are important to public health agencies in California. Using surveillance data from the California Department of Public Health (CDPH), meteorological data from the National Oceanic and Atmospheric Administration (NOAA), and vector and host data from VectorSurv, we created GEE autoregressive and zero-inflated regression models to determine the role of temperature and other environmental factors in WNV incidence and predictions. An increase in temperature was found to be associated with an increase in incidence in 11 high-burden Californian counties between 2017-2022 (IRR = 1.06), holding location, time of year, and rainfall constant. A hypothetical increase of two degrees Fahrenheit-predicted for California by 2040-would have resulted in upwards of 20 excess cases per year during our study period. Using 2017-2021 as a training set, meteorological and host/vector data were able to closely predict 2022 incidence, though the models did overestimate the peak number of cases. The zero-inflated model closely predicted the low number of cases in winter months but performed worse than the GEE model during high-transmission periods. These findings suggests that climate change will, and may be already, altering transmission dynamics and incidence of WNV in California, and provides tools to help predict incidence into the future.
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Affiliation(s)
- Noah Parker
- Department of Epidemiology, Berkeley School of Public Health, University of California, Berkeley, Berkeley, California, United States of America
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3
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de Wit MM, Dimas Martins A, Delecroix C, Heesterbeek H, ten Bosch QA. Mechanistic models for West Nile virus transmission: a systematic review of features, aims and parametrization. Proc Biol Sci 2024; 291:20232432. [PMID: 38471554 PMCID: PMC10932716 DOI: 10.1098/rspb.2023.2432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 02/14/2024] [Indexed: 03/14/2024] Open
Abstract
Mathematical models within the Ross-Macdonald framework increasingly play a role in our understanding of vector-borne disease dynamics and as tools for assessing scenarios to respond to emerging threats. These threats are typically characterized by a high degree of heterogeneity, introducing a range of possible complexities in models and challenges to maintain the link with empirical evidence. We systematically identified and analysed a total of 77 published papers presenting compartmental West Nile virus (WNV) models that use parameter values derived from empirical studies. Using a set of 15 criteria, we measured the dissimilarity compared with the Ross-Macdonald framework. We also retrieved the purpose and type of models and traced the empirical sources of their parameters. Our review highlights the increasing refinements in WNV models. Models for prediction included the highest number of refinements. We found uneven distributions of refinements and of evidence for parameter values. We identified several challenges in parametrizing such increasingly complex models. For parameters common to most models, we also synthesize the empirical evidence for their values and ranges. The study highlights the potential to improve the quality of WNV models and their applicability for policy by establishing closer collaboration between mathematical modelling and empirical work.
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Affiliation(s)
- Mariken M. de Wit
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Afonso Dimas Martins
- Department of Population Health Sciences, Faculty of Veterinary Medicine, University of Utrecht, Utrecht, The Netherlands
| | - Clara Delecroix
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, The Netherlands
- Department of Environmental Sciences, Wageningen University and Research, Wageningen, The Netherlands
| | - Hans Heesterbeek
- Department of Population Health Sciences, Faculty of Veterinary Medicine, University of Utrecht, Utrecht, The Netherlands
| | - Quirine A. ten Bosch
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, The Netherlands
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4
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Ward MJ, Sorek‐Hamer M, Henke JA, Little E, Patel A, Shaman J, Vemuri K, DeFelice NB. A Spatially Resolved and Environmentally Informed Forecast Model of West Nile Virus in Coachella Valley, California. GEOHEALTH 2023; 7:e2023GH000855. [PMID: 38077289 PMCID: PMC10702611 DOI: 10.1029/2023gh000855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 10/03/2023] [Accepted: 10/05/2023] [Indexed: 01/11/2024]
Abstract
West Nile virus (WNV) is the most significant arbovirus in the United States in terms of both morbidity and mortality. West Nile exists in a complex transmission cycle between avian hosts and the arthropod vector, Culex spp. mosquitoes. Human spillover events occur when humans are bitten by an infected mosquito and predicting these rates of infection and therefore the risk to humans may be associated with fluctuations in environmental conditions. In this study, we evaluate the hydrological and meteorological drivers associated with mosquito biology and viral development to determine if these associations can be used to forecast seasonal mosquito infection rates with WNV in the Coachella Valley of California. We developed and tested a spatially resolved ensemble forecast model of the WNV mosquito infection rate in the Coachella Valley using 17 years of mosquito surveillance data and North American Land Data Assimilation System-2 environmental data. Our multi-model inference system indicated that the combination of a cooler and dryer winter, followed by a wetter and warmer spring, and a cooler than normal summer was most predictive of the prevalence of West Nile positive mosquitoes in the Coachella Valley. The ability to make accurate early season predictions of West Nile risk has the potential to allow local abatement districts and public health entities to implement early season interventions such as targeted adulticiding and public health messaging before human transmission occurs. Such early and targeted interventions could better mitigate the risk of WNV to humans.
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Affiliation(s)
- Matthew J. Ward
- Environmental Medicine and Public HealthIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Meytar Sorek‐Hamer
- Universities Space Research Association (USRA) at NASA Ames Research CenterMoffett FieldCAUSA
| | | | - Eliza Little
- Connecticut Department of Public HealthHartfordCTUSA
| | - Aman Patel
- Environmental Medicine and Public HealthIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Jeffery Shaman
- Columbia Climate SchoolNew YorkNYUSA
- Mailman School of Public HealthNew YorkNYUSA
| | - Krishna Vemuri
- Environmental Medicine and Public HealthIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Nicholas B. DeFelice
- Environmental Medicine and Public HealthIcahn School of Medicine at Mount SinaiNew YorkNYUSA
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5
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Holcomb KM, Staples JE, Nett RJ, Beard CB, Petersen LR, Benjamin SG, Green BW, Jones H, Johansson MA. Multi-Model Prediction of West Nile Virus Neuroinvasive Disease With Machine Learning for Identification of Important Regional Climatic Drivers. GEOHEALTH 2023; 7:e2023GH000906. [PMID: 38023388 PMCID: PMC10654557 DOI: 10.1029/2023gh000906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/15/2023] [Accepted: 10/21/2023] [Indexed: 12/01/2023]
Abstract
West Nile virus (WNV) is the leading cause of mosquito-borne illness in the continental United States (CONUS). Spatial heterogeneity in historical incidence, environmental factors, and complex ecology make prediction of spatiotemporal variation in WNV transmission challenging. Machine learning provides promising tools for identification of important variables in such situations. To predict annual WNV neuroinvasive disease (WNND) cases in CONUS (2015-2021), we fitted 10 probabilistic models with variation in complexity from naïve to machine learning algorithm and an ensemble. We made predictions in each of nine climate regions on a hexagonal grid and evaluated each model's predictive accuracy. Using the machine learning models (random forest and neural network), we identified the relative importance and variation in ranking of predictors (historical WNND cases, climate anomalies, human demographics, and land use) across regions. We found that historical WNND cases and population density were among the most important factors while anomalies in temperature and precipitation often had relatively low importance. While the relative performance of each model varied across climatic regions, the magnitude of difference between models was small. All models except the naïve model had non-significant differences in performance relative to the baseline model (negative binomial model fit per hexagon). No model, including the ensemble or more complex machine learning models, outperformed models based on historical case counts on the hexagon or region level; these models are good forecasting benchmarks. Further work is needed to assess if predictive capacity can be improved beyond that of these historical baselines.
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Affiliation(s)
- Karen M. Holcomb
- Global Systems LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
- Now at Division of Vector‐Borne DiseasesCenters for Disease Control and PreventionFort CollinsCOUSA
| | - J. Erin Staples
- Division of Vector‐Borne DiseasesCenters for Disease Control and PreventionFort CollinsCOUSA
| | - Randall J. Nett
- Division of Vector‐Borne DiseasesCenters for Disease Control and PreventionFort CollinsCOUSA
| | - Charles B. Beard
- Division of Vector‐Borne DiseasesCenters for Disease Control and PreventionFort CollinsCOUSA
| | - Lyle R. Petersen
- Division of Vector‐Borne DiseasesCenters for Disease Control and PreventionFort CollinsCOUSA
| | - Stanley G. Benjamin
- Global Systems LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
| | - Benjamin W. Green
- Global Systems LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
| | - Hunter Jones
- Climate Prediction OfficeNational Oceanic and Atmospheric AdministrationSilver SpringMDUSA
| | - Michael A. Johansson
- Division of Vector‐Borne DiseasesCenters for Disease Control and PreventionSan JuanPRUSA
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6
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Holcomb KM, Nguyen C, Komar N, Foy BD, Panella NA, Baskett ML, Barker CM. Predicted reduction in transmission from deployment of ivermectin-treated birdfeeders for local control of West Nile virus. Epidemics 2023; 44:100697. [PMID: 37348378 PMCID: PMC10529638 DOI: 10.1016/j.epidem.2023.100697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/01/2023] [Accepted: 06/12/2023] [Indexed: 06/24/2023] Open
Abstract
Ivermectin (IVM)-treated birds provide the potential for targeted control of Culex mosquitoes to reduce West Nile virus (WNV) transmission. Ingestion of IVM increases mosquito mortality, which could reduce WNV transmission from birds to humans and in enzootic maintenance cycles affecting predominantly bird-feeding mosquitoes and from birds to humans. This strategy might also provide an alternative method for WNV control that is less hampered by insecticide resistance and the logistics of large-scale pesticide applications. Through a combination of field studies and modeling, we assessed the feasibility and impact of deploying IVM-treated birdfeed in residential neighborhoods to reduce WNV transmission. We first tracked 105 birds using radio telemetry and radio frequency identification to monitor their feeder usage and locations of nocturnal roosts in relation to five feeder sites in a neighborhood in Fort Collins, Colorado. Using these results, we then modified a compartmental model of WNV transmission to account for the impact of IVM on mosquito mortality and spatial movement of birds and mosquitoes on the neighborhood level. We found that, while the number of treated lots in a neighborhood strongly influenced the total transmission potential, the arrangement of treated lots in a neighborhood had little effect. Increasing the proportion of treated birds, regardless of the WNV competency status, resulted in a larger reduction in infection dynamics than only treating competent birds. Taken together, model results indicate that deployment of IVM-treated feeders could reduce local transmission throughout the WNV season, including reducing the enzootic transmission prior to the onset of human infections, with high spatial coverage and rates of IVM-induced mortality in mosquitoes. To improve predictions, more work is needed to refine estimates of daily mosquito movement in urban areas and rates of IVM-induced mortality. Our results can guide future field trials of this control strategy.
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Affiliation(s)
- Karen M Holcomb
- Davis Arbovirus Research and Training Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA, United States.
| | - Chilinh Nguyen
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States; Arboviral Diseases Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO, United States
| | - Nicholas Komar
- Arboviral Diseases Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO, United States
| | - Brian D Foy
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States
| | - Nicholas A Panella
- Arboviral Diseases Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO, United States
| | - Marissa L Baskett
- Department of Environmental Science and Policy, University of California, Davis, CA, United States
| | - Christopher M Barker
- Davis Arbovirus Research and Training Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA, United States.
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7
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Liu L. The dynamics of early-stage transmission of COVID-19: A novel quantification of the role of global temperature. GONDWANA RESEARCH : INTERNATIONAL GEOSCIENCE JOURNAL 2023; 114:55-68. [PMID: 35035256 PMCID: PMC8747780 DOI: 10.1016/j.gr.2021.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 12/16/2021] [Accepted: 12/19/2021] [Indexed: 05/11/2023]
Abstract
The global outbreak of COVID-19 has emerged as one of the most devastating and challenging threats to humanity. As many frontline workers are fighting against this disease, researchers are struggling to obtain a better understanding of the pathways and challenges of this pandemic. This paper evaluates the concept that the transmission of COVID-19 is intrinsically linked to temperature. Some complex nonlinear functional forms, such as the cubic function, are introduced to the empirical models to understand the interaction between temperature and the "growth" in the number of infected cases. An accurate quantitative interaction between temperature and the confirmed COVID-19 cases is obtained as log(Y) = -0.000146(temp_H)3 + 0.007410(temp_H)2 -0.063332 temp_H + 7.793842, where Y is the periodic growth in confirmed COVID-19 cases, and temp_H is the maximum daily temperature. This equation alone may be the first confirmed way to measure the quantitative interaction between temperature and human transmission of COVID-19. In addition, four important regions are identified in terms of maximum daily temperature (in Celsius) to understand the dynamics in the transmission of COVID-19 related to temperature. First, the transmission decreases within the range of -50 °C to 5.02 °C. Second, the transmission accelerates in the range of 5.02 °C to 16.92 °C. Essentially, this is the temperature range for an outbreak. Third, the transmission increases more slowly in the range of 16.92 °C to 28.82 °C. Within this range, the number of infections continues to grow, but at a slower pace. Finally, the transmission decreases in the range of 28.82 °C to 50 °C. Thus, according to this hypothesis, the threshold of 16.92 °C is the most critical, as the point at which the infection rate is the greatest. This result sheds light on the mechanism in the cyclicity of the ongoing COVID-19 pandemic worldwide. The implications of these results on policy issues are also discussed concerning a possible cyclical fluctuation pattern between the Northern and Southern Hemispheres.
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Affiliation(s)
- Lu Liu
- School of Economics, Southwestern University of Finance and Economics, China
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8
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Keyel AC, Kilpatrick AM. Better null models for assessing predictive accuracy of disease models. PLoS One 2023; 18:e0285215. [PMID: 37146010 PMCID: PMC10162537 DOI: 10.1371/journal.pone.0285215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 04/17/2023] [Indexed: 05/07/2023] Open
Abstract
Null models provide a critical baseline for the evaluation of predictive disease models. Many studies consider only the grand mean null model (i.e. R2) when evaluating the predictive ability of a model, which is insufficient to convey the predictive power of a model. We evaluated ten null models for human cases of West Nile virus (WNV), a zoonotic mosquito-borne disease introduced to the United States in 1999. The Negative Binomial, Historical (i.e. using previous cases to predict future cases) and Always Absent null models were the strongest overall, and the majority of null models significantly outperformed the grand mean. The length of the training timeseries increased the performance of most null models in US counties where WNV cases were frequent, but improvements were similar for most null models, so relative scores remained unchanged. We argue that a combination of null models is needed to evaluate the forecasting performance of predictive models for infectious diseases and the grand mean is the lowest bar.
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Affiliation(s)
- Alexander C Keyel
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, United States of America
- Department of Atmospheric and Environmental Sciences, University at Albany, SUNY, Albany, NY, United States of America
| | - A Marm Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United States of America
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9
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Ward MJ, Sorek-Hamer M, Vemuri KK, DeFelice NB. Statistical Tools for West Nile Virus Disease Analysis. Methods Mol Biol 2023; 2585:171-191. [PMID: 36331774 DOI: 10.1007/978-1-0716-2760-0_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
West Nile virus (WNV) is the most widespread arbovirus in the world and endemic to much of the United States. Its range continues to expand as land use patterns change, creating more habitable environments for the mosquito vector. Though WNV is endemic, the year-to-year risk is highly variable, thus making it difficult to understand the risk for human spillover events. Abatement districts monitor for infected mosquitoes to help understand these potential risks and to help guide our understanding of the risk posed by these observed infected mosquitoes. Creating optimal monitoring networks will provide more informed decision-making tools for abatement districts and policy makers. Investment in these monitoring networks that capture robust observations on mosquito infection rates will allow for environmentally informed inference systems to help guide decision-making and WNV risk. In turn, enhanced decision-making tools allow for faster response times of more targeted and economical surveillance and mosquito population reduction efforts and the overall reduction of WNV transmission. Here we discuss the data streams, their processing, and specifically three ways to calculate WNV infection rates in mosquitoes.
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Affiliation(s)
- Matthew J Ward
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Meytar Sorek-Hamer
- Environmental Analytics Group (USRA), NASA Ames Research Center, Moffett Field, CA, USA
| | - Krishna Karthik Vemuri
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Nicholas B DeFelice
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Global Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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10
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Fehér OE, Fehérvári P, Tolnai CH, Forgách P, Malik P, Jerzsele Á, Wagenhoffer Z, Szenci O, Korbacska-Kutasi O. Epidemiology and Clinical Manifestation of West Nile Virus Infections of Equines in Hungary, 2007-2020. Viruses 2022; 14:v14112551. [PMID: 36423160 PMCID: PMC9694158 DOI: 10.3390/v14112551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/06/2022] [Accepted: 11/15/2022] [Indexed: 11/19/2022] Open
Abstract
West Nile virus (WNV) is an emerging pathogen in Hungary, causing severe outbreaks in equines and humans since 2007. The aim of our study was to provide a comprehensive report on the clinical signs of West Nile neuroinvasive disease (WNND) in horses in Hungary. Clinical details of 124 confirmed equine WNND cases were collected between 2007 and 2019. Data about the seasonal and geographical presentation, demographic data, clinical signs, treatment protocols, and disease progression were evaluated. Starting from an initial case originating from the area of possible virus introduction by migratory birds, the whole country became endemic with WNV over the subsequent 12 years. The transmission season did not expand significantly during the data collection period, but vaccination protocols should be always reviewed according to the recent observations. There was not any considerable relationship between the occurrence of WNND and age, breed, or gender. Ataxia was by far the most common neurologic sign related to the disease, but weakness, behavioral changes, and muscle fasciculation appeared frequently. Apart from recumbency combined with inappetence, no other clinical sign or treatment regime correlated with survival. The survival rate showed a moderate increase throughout the years, possibly due to the increased awareness of practitioners.
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Affiliation(s)
- Orsolya Eszter Fehér
- Institute for Animal Breeding, Nutrition and Laboratory Animal Science, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
- Correspondence:
| | - Péter Fehérvári
- Department of Biomathematics and Informatics, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
- Centre for Translational Medicine, Semmelweis University, 1085 Budapest, Hungary
| | - Csenge Hanna Tolnai
- University Equine Clinic, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Wien, Austria
| | - Petra Forgách
- Department of Microbiology and Infectious Diseases, University of Veterinary Medicine, Hungária Krt. 23-25, 1143 Budapest, Hungary
| | - Péter Malik
- National Food Chain Safety Office, Veterinary Diagnostic Directorate, Tábornok u. 2., 1143 Budapest, Hungary
| | - Ákos Jerzsele
- Department of Pharmacology and Toxicology, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
- National Laboratory of Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, University of Veterinary Medicine Budapest, István utca 2, 1078 Budapest, Hungary
| | - Zsombor Wagenhoffer
- Institute for Animal Breeding, Nutrition and Laboratory Animal Science, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
| | - Otto Szenci
- Department of Obstetrics and Food Animal Medicine Clinic, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
| | - Orsolya Korbacska-Kutasi
- Institute for Animal Breeding, Nutrition and Laboratory Animal Science, University of Veterinary Medicine, István utca 2, 1078 Budapest, Hungary
- University Equine Clinic, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Wien, Austria
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11
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Marini G, Pugliese A, Wint W, Alexander NS, Rizzoli A, Rosà R. Modelling the West Nile virus force of infection in the European human population. One Health 2022; 15:100462. [DOI: 10.1016/j.onehlt.2022.100462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/17/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
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12
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Wimberly MC, Davis JK, Hildreth MB, Clayton JL. Integrated Forecasts Based on Public Health Surveillance and Meteorological Data Predict West Nile Virus in a High-Risk Region of North America. ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:87006. [PMID: 35972761 PMCID: PMC9380861 DOI: 10.1289/ehp10287] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 07/29/2022] [Accepted: 08/01/2022] [Indexed: 06/09/2023]
Abstract
BACKGROUND West Nile virus (WNV), a global arbovirus, is the most prevalent mosquito-transmitted infection in the United States. Forecasts of WNV risk during the upcoming transmission season could provide the basis for targeted mosquito control and disease prevention efforts. We developed the Arbovirus Mapping and Prediction (ArboMAP) WNV forecasting system and used it in South Dakota from 2016 to 2019. This study reports a post hoc forecast validation and model comparison. OBJECTIVES Our objective was to validate historical predictions of WNV cases with independent data that were not used for model calibration. We tested the hypothesis that predictive models based on mosquito surveillance data combined with meteorological variables were more accurate than models based on mosquito or meteorological data alone. METHODS The ArboMAP system incorporated models that predicted the weekly probability of observing one or more human WNV cases in each county. We compared alternative models with different predictors including a) a baseline model based only on historical WNV cases, b) mosquito models based on seasonal patterns of infection rates, c) environmental models based on lagged meteorological variables, including temperature and vapor pressure deficit, d) combined models with mosquito infection rates and lagged meteorological variables, and e) ensembles of two or more combined models. During the WNV season, models were calibrated using data from previous years and weekly predictions were made using data from the current year. Forecasts were compared with observed cases to calculate the area under the receiver operating characteristic curve (AUC) and other metrics of spatial and temporal prediction error. RESULTS Mosquito and environmental models outperformed the baseline model that included county-level averages and seasonal trends of WNV cases. Combined models were more accurate than models based only on meteorological or mosquito infection variables. The most accurate model was a simple ensemble mean of the two best combined models. Forecast accuracy increased rapidly from early June through early July and was stable thereafter, with a maximum AUC of 0.85. The model predictions captured the seasonal pattern of WNV as well as year-to-year variation in case numbers and the geographic pattern of cases. DISCUSSION The predictions reached maximum accuracy early enough in the WNV season to allow public health responses before the peak of human cases in August. This early warning is necessary because other indicators of WNV risk, including early reports of human cases and mosquito abundance, are poor predictors of case numbers later in the season. https://doi.org/10.1289/EHP10287.
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Affiliation(s)
- Michael C. Wimberly
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, Oklahoma, USA
| | - Justin K. Davis
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, Oklahoma, USA
| | - Michael B. Hildreth
- Department of Biology and Microbiology, South Dakota State University, Brookings, South Dakota, USA
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A climate-dependent spatial epidemiological model for the transmission risk of West Nile virus at local scale. One Health 2021; 13:100330. [PMID: 34632040 PMCID: PMC8493582 DOI: 10.1016/j.onehlt.2021.100330] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 11/22/2022] Open
Abstract
In this study, initial elements of a modelling framework aimed to become a spatial forecasting model for the transmission risk of West Nile virus (WNV) are presented. The model describes the dynamics of a WNV epidemic in population health states of mosquitoes, birds and humans and was applied to the case of Greece for the period 2010–2019. Calibration was performed with the available epidemiological data from the Hellenic Centre for Disease Control and Prevention and the environmental data from the European Union's earth observation program, Copernicus. Numerical results of the model for each municipality were evaluated against observations. Specifically, the occurrence of WNV, the number of infected humans and the week of incidence predicted from the model were compared to the corresponding numbers from observations. The results suggest that dynamic downscaling of a climate-dependent epidemiological model is feasible down-to roughly 80km2. This below nomenclature of territorial units for statistics (NUTS) 3 level represents the municipalities being the lowest level of administrative units, able to cope with WNV and take actions. The average detection probability in hindcast mode was 72%, improving strongly as the number of infected humans increased. Using the developed model, we were also able to show the fundamental importance of the May temperatures in shaping the WNV dynamics. The modeling framework couples epidemiological and environmental dynamical variables with surveillance data producing risk maps downscaled at a local level. The approach can be expanded to provide targeted early warning probabilistic forecasts that can be used to inform public health policy decision making. Downscaling of a climate-dependent epidemiological model feasible to roughly 80 km2. The model demonstrates competence in reproducing WNV event occurrence spatially at the municipality scale. The average detection probability is 72%, improving with increasing human infections. The hardest to model WNV events occurred at municipalities and years with only one human infection annually. Temperatures in May are found most critical in shaping the WNV dynamics.
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14
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Keyel AC, Gorris ME, Rochlin I, Uelmen JA, Chaves LF, Hamer GL, Moise IK, Shocket M, Kilpatrick AM, DeFelice NB, Davis JK, Little E, Irwin P, Tyre AJ, Helm Smith K, Fredregill CL, Elison Timm O, Holcomb KM, Wimberly MC, Ward MJ, Barker CM, Rhodes CG, Smith RL. A proposed framework for the development and qualitative evaluation of West Nile virus models and their application to local public health decision-making. PLoS Negl Trop Dis 2021; 15:e0009653. [PMID: 34499656 PMCID: PMC8428767 DOI: 10.1371/journal.pntd.0009653] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
West Nile virus (WNV) is a globally distributed mosquito-borne virus of great public health concern. The number of WNV human cases and mosquito infection patterns vary in space and time. Many statistical models have been developed to understand and predict WNV geographic and temporal dynamics. However, these modeling efforts have been disjointed with little model comparison and inconsistent validation. In this paper, we describe a framework to unify and standardize WNV modeling efforts nationwide. WNV risk, detection, or warning models for this review were solicited from active research groups working in different regions of the United States. A total of 13 models were selected and described. The spatial and temporal scales of each model were compared to guide the timing and the locations for mosquito and virus surveillance, to support mosquito vector control decisions, and to assist in conducting public health outreach campaigns at multiple scales of decision-making. Our overarching goal is to bridge the existing gap between model development, which is usually conducted as an academic exercise, and practical model applications, which occur at state, tribal, local, or territorial public health and mosquito control agency levels. The proposed model assessment and comparison framework helps clarify the value of individual models for decision-making and identifies the appropriate temporal and spatial scope of each model. This qualitative evaluation clearly identifies gaps in linking models to applied decisions and sets the stage for a quantitative comparison of models. Specifically, whereas many coarse-grained models (county resolution or greater) have been developed, the greatest need is for fine-grained, short-term planning models (m-km, days-weeks) that remain scarce. We further recommend quantifying the value of information for each decision to identify decisions that would benefit most from model input.
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Affiliation(s)
- Alexander C. Keyel
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
- Department of Atmospheric and Environmental Sciences, University at Albany, Albany, New York, United States of America
| | - Morgan E. Gorris
- Information Systems and Modeling & Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Ilia Rochlin
- Center for Vector Biology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Johnny A. Uelmen
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Luis F. Chaves
- Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud (INCIENSA), Tres Rios, Cartago, Costa Rica
| | - Gabriel L. Hamer
- Department of Entomology, Texas A&M University, College Station, Texas, United States of America
| | - Imelda K. Moise
- Department of Geography & Regional Studies, University of Miami, Coral Gables, Florida, United States of America
| | - Marta Shocket
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, United States of America
| | - A. Marm Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, California, United States of America
| | - Nicholas B. DeFelice
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Institute for Exposomic Research, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York, United States of America
| | - Justin K. Davis
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, Oklahoma, United States of America
| | - Eliza Little
- Connecticut Agricultural Experimental Station, New Haven, Connecticut, United States of America
| | - Patrick Irwin
- Northwest Mosquito Abatement District, Wheeling, Illinois, United States of America
- Department of Entomology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Andrew J. Tyre
- School of Natural Resources, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Kelly Helm Smith
- National Drought Mitigation Center, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Chris L. Fredregill
- Mosquito and Vector Control Division, Harris County Public Health, Houston, Texas, United States of America
| | - Oliver Elison Timm
- Department of Atmospheric and Environmental Sciences, University at Albany, Albany, New York, United States of America
| | - Karen M. Holcomb
- Department of Pathology, Microbiology, and Immunology, University of California Davis, California, United States of America
| | - Michael C. Wimberly
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, Oklahoma, United States of America
| | - Matthew J. Ward
- Environmental Analytics Group, Universities Space Research Association, NASA Ames Research Center, Moffett Field, California, United States of America
- Department of Tropical Medicine, Tulane University School of Public Health & Tropical Medicine, New Orleans, Louisiana, United States of America
| | - Christopher M. Barker
- Department of Pathology, Microbiology, and Immunology, University of California Davis, California, United States of America
| | - Charlotte G. Rhodes
- Department of Entomology, Texas A&M University, College Station, Texas, United States of America
| | - Rebecca L. Smith
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
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Damos PT, Dorrestijn J, Thomidis T, Tuells J, Caballero P. A Temperature Conditioned Markov Chain Model for Predicting the Dynamics of Mosquito Vectors of Disease. INSECTS 2021; 12:insects12080725. [PMID: 34442291 PMCID: PMC8396828 DOI: 10.3390/insects12080725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 11/16/2022]
Abstract
Understanding and predicting mosquito population dynamics is crucial for gaining insight into the abundance of arthropod disease vectors and for the design of effective vector control strategies. In this work, a climate-conditioned Markov chain (CMC) model was developed and applied for the first time to predict the dynamics of vectors of important medical diseases. Temporal changes in mosquito population profiles were generated to simulate the probabilities of a high population impact. The simulated transition probabilities of the mosquito populations achieved from the trained model are very near to the observed data transitions that have been used to parameterize and validate the model. Thus, the CMC model satisfactorily describes the temporal evolution of the mosquito population process. In general, our numerical results, when temperature is considered as the driver of change, indicate that it is more likely for the population system to move into a state of high population level when the former is a state of a lower population level than the opposite. Field data on frequencies of successive mosquito population levels, which were not used for the data inferred MC modeling, were assembled to obtain an empirical intensity transition matrix and the frequencies observed. Our findings match to a certain degree the empirical results in which the probabilities follow analogous patterns while no significant differences were observed between the transition matrices of the CMC model and the validation data (ChiSq = 14.58013, df = 24, p = 0.9324451). The proposed modeling approach is a valuable eco-epidemiological study. Moreover, compared to traditional Markov chains, the benefit of the current CMC model is that it takes into account the stochastic conditional properties of ecological-related climate variables. The current modeling approach could save costs and time in establishing vector eradication programs and mosquito surveillance programs.
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Affiliation(s)
- Petros T. Damos
- Department of Community Nursing, Preventive Medicine, Public Health and History of Science, Faculty of Health Science, University of Alicante, Carretera San Vicente s/n, 03690 San Vicente del Raispeig, ALC, Spain; (J.T.); (P.C.)
- Pharmacy Department, University General Infectious Disease Hospital of Thessaloniki AHEPA, Aristotle University of Thessaloniki, 54136 Thessaloniki, Greece
- Department of Nutritional Sciences and Dietetics, International Hellenic University of Thessaloniki, 57400 Thessaloniki, Greece;
- Correspondence: or
| | - Jesse Dorrestijn
- Faculty of Civil Engineering and Geoscience, Delft University of Technology, 2628 CN Delft, The Netherlands;
| | - Thomas Thomidis
- Department of Nutritional Sciences and Dietetics, International Hellenic University of Thessaloniki, 57400 Thessaloniki, Greece;
| | - José Tuells
- Department of Community Nursing, Preventive Medicine, Public Health and History of Science, Faculty of Health Science, University of Alicante, Carretera San Vicente s/n, 03690 San Vicente del Raispeig, ALC, Spain; (J.T.); (P.C.)
| | - Pablo Caballero
- Department of Community Nursing, Preventive Medicine, Public Health and History of Science, Faculty of Health Science, University of Alicante, Carretera San Vicente s/n, 03690 San Vicente del Raispeig, ALC, Spain; (J.T.); (P.C.)
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Senay E, Gore K, Sherman J, Patel S, Ziska L, Lucchini R, DeFelice N, Just A, Nabeel I, Thanik E, Sheffield P, Rizzo A, Wright R. Coming Together for Climate and Health: Proceedings of the Second Annual Clinical Climate Change Meeting, January 24, 2020. J Occup Environ Med 2021; 63:e308-e313. [PMID: 33710106 PMCID: PMC8842823 DOI: 10.1097/jom.0000000000002186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Climate change is imposing increasingly severe impacts on public health. Addressing these impacts requires heightened awareness of climate-driven health conditions and appropriate clinical practices to manage these conditions. Within this context, the 2nd Annual Clinical Climate Change Conference, held January 24, 2020 at the New York Academy of Medicine, brought together more than 150 allied health practitioners from across the United States for a one-day conference showcasing the state of the science on the climate and health. Eight platform presentations—including a keynote address from Karenna Gore of the Center for Earth Ethics at Union Theological Seminary—covered a range of environmentally induced, climate-related disease areas as well as topics related to environmental justice. Additionally, key workshops engaged participants in the clinical management of climate-related health conditions. Communicating the existing evidence base for climate change-driven impacts on human health is crucial for preparing practitioners to identify and address these impacts. Further partnership between researchers and practitioners to extend and disseminate this evidence base will yield important advancements toward protecting patients and improving health outcomes in an era of climate crisis.
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Affiliation(s)
- Emily Senay
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Karenna Gore
- Center for Earth Ethics, Union Theological Seminary, New York, NY
| | - Jodi Sherman
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT
- Department of Epidemiology in Environmental Health Sciences, Yale School of Public Health, New Haven, CT
| | - Surili Patel
- The Center for Public Health Policy, Washington, D.C
| | - Lewis Ziska
- Department of Environmental Health Sciences, Columbia University Irving Medical Center, New York, NY
| | - Roberto Lucchini
- Department of Occupational and Environmental Medicine, School of Public Health, Florida International University, Miami, FL
| | - Nicholas DeFelice
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Allan Just
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Ismail Nabeel
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Erin Thanik
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Perry Sheffield
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY
| | | | - Robert Wright
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY
- Mount Sinai Institute for Exposomic Research, Icahn School of Medicine at Mount Sinai, New York, NY
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17
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Keyes KM, Kandula S, Olfson M, Gould MS, Martínez-Alés G, Rutherford C, Shaman J. Suicide and the agent-host-environment triad: leveraging surveillance sources to inform prevention. Psychol Med 2021; 51:529-537. [PMID: 33663629 PMCID: PMC8020492 DOI: 10.1017/s003329172000536x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/14/2020] [Accepted: 01/06/2021] [Indexed: 12/11/2022]
Abstract
Suicide in the US has increased in the last decade, across virtually every age and demographic group. Parallel increases have occurred in non-fatal self-harm as well. Research on suicide across the world has consistently demonstrated that suicide shares many properties with a communicable disease, including person-to-person transmission and point-source outbreaks. This essay illustrates the communicable nature of suicide through analogy to basic infectious disease principles, including evidence for transmission and vulnerability through the agent-host-environment triad. We describe how mathematical modeling, a suite of epidemiological methods, which the COVID-19 pandemic has brought into renewed focus, can and should be applied to suicide in order to understand the dynamics of transmission and to forecast emerging risk areas. We describe how new and innovative sources of data, including social media and search engine data, can be used to augment traditional suicide surveillance, as well as the opportunities and challenges for modeling suicide as a communicable disease process in an effort to guide clinical and public health suicide prevention efforts.
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Affiliation(s)
| | - Sasikiran Kandula
- Department of Environmental Health Sciences, Columbia University, New York, NY, USA
| | - Mark Olfson
- Department of Epidemiology, Columbia University, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Madelyn S. Gould
- Department of Epidemiology, Columbia University, New York, NY, USA
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Gonzalo Martínez-Alés
- Department of Epidemiology, Columbia University, New York, NY, USA
- Universidad Autónoma de Madrid School of Medicine, Madrid, Spain
| | | | - Jeffrey Shaman
- Department of Environmental Health Sciences, Columbia University, New York, NY, USA
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18
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Bertram FM, Thompson PN, Venter M. Epidemiology and Clinical Presentation of West Nile Virus Infection in Horses in South Africa, 2016-2017. Pathogens 2020; 10:pathogens10010020. [PMID: 33396935 PMCID: PMC7823741 DOI: 10.3390/pathogens10010020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/24/2020] [Accepted: 12/26/2020] [Indexed: 01/30/2023] Open
Abstract
Although West Nile virus (WNV) is endemic to South Africa (RSA), it has only become recognized as a significant cause of neurological disease in humans and horses locally in the past 2 decades, as it emerged globally. This article describes the epidemiological and clinical presentation of WNV in horses across RSA during 2016–2017. In total, 54 WNV-positive cases were identified by passive surveillance in horses with febrile and/or neurological signs at the Centre for Viral Zoonoses, University of Pretoria. They were followed up and compared to 120 randomly selected WNV-negative controls with the same case definition and during the same time period. Of the WNV-positive cases, 52% had fever, 92% displayed neurological signs, and 39% experienced mortality. Cases occurred mostly in WNV-unvaccinated horses <5 years old, during late summer and autumn after heavy rain, in the temperate to warm eastern parts of RSA. WNV-positive cases that had only neurological signs without fever were more likely to die. In the multivariable analysis, the odds of WNV infection were associated with season (late summer), higher altitude, more highly purebred animals, younger age, and failure to vaccinate against WNV. Vaccination is currently the most effective prophylactic measure to reduce WNV morbidity and mortality in horses.
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Affiliation(s)
- Freude-Marié Bertram
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa; (F.-M.B.); (P.N.T.)
| | - Peter N. Thompson
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa; (F.-M.B.); (P.N.T.)
| | - Marietjie Venter
- Centre for Viral Zoonoses, Department of Medical Virology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa
- Correspondence: ; Tel.: +27-12-319-2638
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Dellicour S, Lequime S, Vrancken B, Gill MS, Bastide P, Gangavarapu K, Matteson NL, Tan Y, du Plessis L, Fisher AA, Nelson MI, Gilbert M, Suchard MA, Andersen KG, Grubaugh ND, Pybus OG, Lemey P. Epidemiological hypothesis testing using a phylogeographic and phylodynamic framework. Nat Commun 2020; 11:5620. [PMID: 33159066 PMCID: PMC7648063 DOI: 10.1038/s41467-020-19122-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 09/30/2020] [Indexed: 01/05/2023] Open
Abstract
Computational analyses of pathogen genomes are increasingly used to unravel the dispersal history and transmission dynamics of epidemics. Here, we show how to go beyond historical reconstructions and use spatially-explicit phylogeographic and phylodynamic approaches to formally test epidemiological hypotheses. We illustrate our approach by focusing on the West Nile virus (WNV) spread in North America that has substantially impacted public, veterinary, and wildlife health. We apply an analytical workflow to a comprehensive WNV genome collection to test the impact of environmental factors on the dispersal of viral lineages and on viral population genetic diversity through time. We find that WNV lineages tend to disperse faster in areas with higher temperatures and we identify temporal variation in temperature as a main predictor of viral genetic diversity through time. By contrasting inference with simulation, we find no evidence for viral lineages to preferentially circulate within the same migratory bird flyway, suggesting a substantial role for non-migratory birds or mosquito dispersal along the longitudinal gradient.
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Affiliation(s)
- Simon Dellicour
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, CP160/12, 50 Avenue FD Roosevelt, 1050, Bruxelles, Belgium.
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Herestraat 49, 3000, Leuven, Belgium.
| | - Sebastian Lequime
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Bram Vrancken
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Mandev S Gill
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Paul Bastide
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Karthik Gangavarapu
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Nathaniel L Matteson
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Yi Tan
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Infectious Diseases Group, J. Craig Venter Institute, Rockville, MD, USA
| | | | - Alexander A Fisher
- Department of Biomathematics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Martha I Nelson
- Fogarty International Center, National Institutes of Health, Bethesda, MD, 20894, USA
| | - Marius Gilbert
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, CP160/12, 50 Avenue FD Roosevelt, 1050, Bruxelles, Belgium
| | - Marc A Suchard
- Department of Biomathematics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Department of Biostatistics, Fielding School of Public Health, University of California, Los Angeles, CA, USA
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Kristian G Andersen
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
- Scripps Research Translational Institute, La Jolla, CA, 92037, USA
| | - Nathan D Grubaugh
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, 06510, USA
| | | | - Philippe Lemey
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
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20
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West Nile Virus: An Update on Pathobiology, Epidemiology, Diagnostics, Control and "One Health" Implications. Pathogens 2020; 9:pathogens9070589. [PMID: 32707644 PMCID: PMC7400489 DOI: 10.3390/pathogens9070589] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 07/16/2020] [Accepted: 07/16/2020] [Indexed: 02/06/2023] Open
Abstract
West Nile virus (WNV) is an important zoonotic flavivirus responsible for mild fever to severe, lethal neuroinvasive disease in humans, horses, birds, and other wildlife species. Since its discovery, WNV has caused multiple human and animal disease outbreaks in all continents, except Antarctica. Infections are associated with economic losses, mainly due to the cost of treatment of infected patients, control programmes, and loss of animals and animal products. The pathogenesis of WNV has been extensively investigated in natural hosts as well as in several animal models, including rodents, lagomorphs, birds, and reptiles. However, most of the proposed pathogenesis hypotheses remain contentious, and much remains to be elucidated. At the same time, the unavailability of specific antiviral treatment or effective and safe vaccines contribute to the perpetuation of the disease and regular occurrence of outbreaks in both endemic and non-endemic areas. Moreover, globalisation and climate change are also important drivers of the emergence and re-emergence of the virus and disease. Here, we give an update of the pathobiology, epidemiology, diagnostics, control, and “One Health” implications of WNV infection and disease.
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21
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Ciota AT, Keyel AC. The Role of Temperature in Transmission of Zoonotic Arboviruses. Viruses 2019; 11:E1013. [PMID: 31683823 PMCID: PMC6893470 DOI: 10.3390/v11111013] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 12/31/2022] Open
Abstract
We reviewed the literature on the role of temperature in transmission of zoonotic arboviruses. Vector competence is affected by both direct and indirect effects of temperature, and generally increases with increasing temperature, but results may vary by vector species, population, and viral strain. Temperature additionally has a significant influence on life history traits of vectors at both immature and adult life stages, and for important behaviors such as blood-feeding and mating. Similar to vector competence, temperature effects on life history traits can vary by species and population. Vector, host, and viral distributions are all affected by temperature, and are generally expected to change with increased temperatures predicted under climate change. Arboviruses are generally expected to shift poleward and to higher elevations under climate change, yet significant variability on fine geographic scales is likely. Temperature effects are generally unimodal, with increases in abundance up to an optimum, and then decreases at high temperatures. Improved vector distribution information could facilitate future distribution modeling. A wide variety of approaches have been used to model viral distributions, although most research has focused on the West Nile virus. Direct temperature effects are frequently observed, as are indirect effects, such as through droughts, where temperature interacts with rainfall. Thermal biology approaches hold much promise for syntheses across viruses, vectors, and hosts, yet future studies must consider the specificity of interactions and the dynamic nature of evolving biological systems.
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Affiliation(s)
- Alexander T Ciota
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA.
- Department of Biomedical Sciences, State University of New York at Albany School of Public Health, Rensselaer, NY 12144, USA.
| | - Alexander C Keyel
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA.
- Department of Atmospheric and Environmental Sciences, University at Albany, Albany, NY 12222, USA.
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Barker CM. Models and Surveillance Systems to Detect and Predict West Nile Virus Outbreaks. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:1508-1515. [PMID: 31549727 DOI: 10.1093/jme/tjz150] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Indexed: 06/10/2023]
Abstract
Over the past 20 yr, many models have been developed to predict risk for West Nile virus (WNV; Flaviviridae: Flavivirus) disease in the human population. These models have aided our understanding of the meteorological and land-use variables that drive spatial and temporal patterns of human disease risk. During the same period, electronic data systems have been adopted by surveillance programs across much of the United States, including a growing interest in integrated data services that preserve the autonomy and attribution of credit to originating agencies but facilitate data sharing, analysis, and visualization at local, state, and national scales. At present, nearly all predictive models have been limited to the scientific literature, with few having been implemented for use by public-health and vector-control decision makers. The current article considers the development of models for spatial patterns, early warning, and early detection of WNV over the last 20 yr and considers some possible paths toward increasing the utility of these models for guiding interventions.
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Affiliation(s)
- Christopher M Barker
- Department of Pathology, Microbiology, & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA
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23
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Keyel AC, Elison Timm O, Backenson PB, Prussing C, Quinones S, McDonough KA, Vuille M, Conn JE, Armstrong PM, Andreadis TG, Kramer LD. Seasonal temperatures and hydrological conditions improve the prediction of West Nile virus infection rates in Culex mosquitoes and human case counts in New York and Connecticut. PLoS One 2019; 14:e0217854. [PMID: 31158250 PMCID: PMC6546252 DOI: 10.1371/journal.pone.0217854] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 05/19/2019] [Indexed: 01/05/2023] Open
Abstract
West Nile virus (WNV; Flaviviridae: Flavivirus) is a widely distributed arthropod-borne virus that has negatively affected human health and animal populations. WNV infection rates of mosquitoes and human cases have been shown to be correlated with climate. However, previous studies have been conducted at a variety of spatial and temporal scales, and the scale-dependence of these relationships has been understudied. We tested the hypothesis that climate variables are important to understand these relationships at all spatial scales. We analyzed the influence of climate on WNV infection rate of mosquitoes and number of human cases in New York and Connecticut using Random Forests, a machine learning technique. During model development, 66 climate-related variables based on temperature, precipitation and soil moisture were tested for predictive skill. We also included 20-21 non-climatic variables to account for known environmental effects (e.g., land cover and human population), surveillance related information (e.g., relative mosquito abundance), and to assess the potential explanatory power of other relevant factors (e.g., presence of wastewater treatment plants). Random forest models were used to identify the most important climate variables for explaining spatial-temporal variation in mosquito infection rates (abbreviated as MLE). The results of the cross-validation support our hypothesis that climate variables improve the predictive skill for MLE at county- and trap-scales and for human cases at the county-scale. Of the climate-related variables selected, mean minimum temperature from July-September was selected in all analyses, and soil moisture was selected for the mosquito county-scale analysis. Models demonstrated predictive skill, but still over- and under-estimated WNV MLE and numbers of human cases. Models at fine spatial scales had lower absolute errors but had greater errors relative to the mean infection rates.
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Affiliation(s)
- Alexander C. Keyel
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY, United States of America
- Department of Atmospheric and Environmental Sciences, University at Albany, SUNY, Albany, NY, United States of America
| | - Oliver Elison Timm
- Department of Atmospheric and Environmental Sciences, University at Albany, SUNY, Albany, NY, United States of America
| | - P. Bryon Backenson
- Bureau of Communicable Disease Control, New York State Department of Health, Albany, NY, United States of America
| | - Catharine Prussing
- Department of Biomedical Sciences, University at Albany, SUNY, Albany, NY, United States of America
| | - Sarah Quinones
- Department of Atmospheric and Environmental Sciences, University at Albany, SUNY, Albany, NY, United States of America
| | - Kathleen A. McDonough
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY, United States of America
- Department of Biomedical Sciences, University at Albany, SUNY, Albany, NY, United States of America
| | - Mathias Vuille
- Department of Atmospheric and Environmental Sciences, University at Albany, SUNY, Albany, NY, United States of America
| | - Jan E. Conn
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY, United States of America
| | - Philip M. Armstrong
- Center for Vector Biology & Zoonotic Diseases, Department of Environmental Sciences, The Connecticut Agricultural Experimental Station, New Haven, CT, United States of America
| | - Theodore G. Andreadis
- Center for Vector Biology & Zoonotic Diseases, Department of Environmental Sciences, The Connecticut Agricultural Experimental Station, New Haven, CT, United States of America
| | - Laura D. Kramer
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY, United States of America
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Kioutsioukis I, Stilianakis NI. Assessment of West nile virus transmission risk from a weather-dependent epidemiological model and a global sensitivity analysis framework. Acta Trop 2019; 193:129-141. [PMID: 30844376 DOI: 10.1016/j.actatropica.2019.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 02/07/2019] [Accepted: 03/03/2019] [Indexed: 01/08/2023]
Abstract
West Nile virus (WNV) transmission risk is strongly related to weather conditions due to the sensitivity of the mosquitoes to climatic factors. We assess the WNV transmission risk of humans to seasonal weather conditions and the relative effects of parameters affecting the transmission dynamics. The assessment involves a known epidemiological model we extend to account for temperature and precipitation and a global uncertainty and sensitivity analysis framework. We focus on three relevant quantities, the basic reproduction number (R0), the minimum infection rate (MIR), and the number of infected individuals. The highest-priority weather-related WNV transmission risks can be attributed to the birth and death rate of mosquitoes, the biting rate of mosquitoes to birds, and the probability of transmission from birds to mosquitoes. Global sensitivity analysis indicates that these parameters make up a big part of the explained variance in R0 and MIR. The analysis allows for a dynamic assessment over time capturing the period parameters are more relevant than others. Global uncertainty and sensitivity analysis of WNV transmission risk to humans enable insights into the relative importance of individual parameters of the transmission cycle of the virus facilitating the understanding of the dynamics and the implementation of tailored control strategies.
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Affiliation(s)
| | - Nikolaos I Stilianakis
- Joint Research Centre (JRC), European Commission, Ispra, VA, Italy; Department of Biometry and Epidemiology, University of Erlangen-Nuremberg, Erlangen, Germany
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25
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Effects of climate change on vector-borne diseases: an updated focus on West Nile virus in humans. Emerg Top Life Sci 2019; 3:143-152. [DOI: 10.1042/etls20180124] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 03/31/2019] [Accepted: 04/05/2019] [Indexed: 11/17/2022]
Abstract
Abstract
One of the main impacts of climate change on health is the influence on vector-borne diseases (VBDs). During the last few years, yearly outbreaks of the West Nile virus (WNV) have occurred in many locations, providing evidence of ongoing transmission. Currently, it is the most widely distributed arbovirus in the world. Increases in ambient temperature have impacts on WNV transmission. Indeed, clear associations were found between warm conditions and WNV outbreaks in various areas. The impact of changes in rainfall patterns on the incidence of the disease is influenced by the amount of precipitation (increased rainfall, floods or droughts), depending on the local conditions and the differences in the ecology and sensitivity of the species of mosquito. Predictions indicate that for WNV, increased warming will result in latitudinal and altitudinal expansions of regions climatically suitable for transmission, particularly along the current edges of its transmission areas. Extension of the transmission season is also predicted. As models show that the current climate change trends are expected to continue, it is important to reinforce WNV control efforts and increase the resilience of population health. For a better preparedness, any assessment of future transmission of WNV should consider the impacts of the changing climate.
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DeFelice NB, Birger R, DeFelice N, Gagner A, Campbell SR, Romano C, Santoriello M, Henke J, Wittie J, Cole B, Kaiser C, Shaman J. Modeling and Surveillance of Reporting Delays of Mosquitoes and Humans Infected With West Nile Virus and Associations With Accuracy of West Nile Virus Forecasts. JAMA Netw Open 2019; 2:e193175. [PMID: 31026036 PMCID: PMC6487631 DOI: 10.1001/jamanetworkopen.2019.3175] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
IMPORTANCE West Nile virus (WNV) is the leading cause of domestically acquired arboviral disease. OBJECTIVE To develop real-time WNV forecasts of infected mosquitoes and human cases. DESIGN, SETTING, AND PARTICIPANTS Real-time forecasts of WNV in 4 geographically dispersed locations in the United States were generated using a WNV model-inference forecasting system previously validated with retrospective data. Analysis was performed to evaluate how observational reporting delays of mosquito WNV assay results and human medical records were associated with real-time forecast accuracy. EXPOSURES Mosquitoes positive for WNV and human cases. MAIN OUTCOMES AND MEASURES Delays in reporting mosquito WNV assay results and human medical records and the association of these delays with real-time WNV forecast accuracy. RESULTS Substantial delays in data reporting exist for both infected mosquitoes and human WNV cases. For human cases, confirmed data (n = 37) lagged behind the onset of illness by a mean (SD) of 5.5 (2.3) weeks (range, 2-14 weeks). These human case reporting lags reduced mean forecast accuracy for the total number of human cases over the season in 110 simulated outbreaks for 2 forecasting systems by 26% and 14%, from 2 weeks before to 3 weeks after the predicted peak of infected mosquitoes. This period is the time span during which 47% of human cases are reported. Of 7064 mosquito pools, 500 (7%) tested positive; the reporting lag for these data associated with viral testing at a state laboratory was a mean (SD) of 6.6 (2.6) days (range, 4-11 days). This reporting lag was associated with decreased mean forecast accuracy for the 3 mosquito infection indicators, timing, magnitude, and season, by approximately 5% for both forecasting systems. CONCLUSIONS AND RELEVANCE Delays in reporting human WNV disease and infected mosquito information are associated with difficulties in outbreak surveillance and decreased real-time forecast accuracy. Infected mosquito lags were short enough that skillful forecasts could still be generated for mosquito infection indicators, but the human WNV case lags were too great to support accurate forecasting in real time. Forecasting WNV is potentially an important evidence-based decision support tool for public health officials and mosquito abatement districts; however, to operationalize real-time forecasting, more resources are needed to reduce human case reporting lags between illness onset and case confirmation.
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Affiliation(s)
- Nicholas B. DeFelice
- Department of Environmental Medicine & Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Ruthie Birger
- Earth Institute, Columbia University, New York, New York
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York
| | - Nathaniel DeFelice
- Division of Infectious Diseases, University of California, Davis School of Medicine, Sacramento
- Division of Pulmonary/Critical Care Medicine, University of California, Davis School of Medicine, Sacramento
| | - Alexandra Gagner
- Communicable Disease Program, Chicago Department of Public Health, Chicago, Illinois
| | - Scott R. Campbell
- Arthropod-Borne Disease Laboratory, Suffolk County, Department of Health Services, Yaphank, New York
| | - Christopher Romano
- Arthropod-Borne Disease Laboratory, Suffolk County, Department of Health Services, Yaphank, New York
| | - Michael Santoriello
- Arthropod-Borne Disease Laboratory, Suffolk County, Department of Health Services, Yaphank, New York
| | - Jennifer Henke
- Coachella Valley Mosquito and Vector Control District, Indio, California
| | - Jeremy Wittie
- Coachella Valley Mosquito and Vector Control District, Indio, California
| | - Barbara Cole
- Disease Control Branch, Riverside County, Department of Public Health, Riverside, California
| | - Cameron Kaiser
- Disease Control Branch, Riverside County, Department of Public Health, Riverside, California
| | - Jeffrey Shaman
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York
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27
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Pei S, Cane MA, Shaman J. Predictability in process-based ensemble forecast of influenza. PLoS Comput Biol 2019; 15:e1006783. [PMID: 30817754 PMCID: PMC6394909 DOI: 10.1371/journal.pcbi.1006783] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 01/12/2019] [Indexed: 11/18/2022] Open
Abstract
Process-based models have been used to simulate and forecast a number of nonlinear dynamical systems, including influenza and other infectious diseases. In this work, we evaluate the effects of model initial condition error and stochastic fluctuation on forecast accuracy in a compartmental model of influenza transmission. These two types of errors are found to have qualitatively similar growth patterns during model integration, indicating that dynamic error growth, regardless of source, is a dominant component of forecast inaccuracy. We therefore examine the nonlinear growth of model initial error and compute the fastest growing directions using singular vector analysis. Using this information, we generate perturbations in an ensemble forecast system of influenza to obtain more optimal ensemble spread. In retrospective forecasts of historical outbreaks for 95 US cities from 2003 to 2014, this approach improves short-term forecast of incidence over the next one to four weeks.
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Affiliation(s)
- Sen Pei
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States of America
| | - Mark A. Cane
- Lamont-Doherty Earth Observatory, Columbia University, New York, NY, United States of America
| | - Jeffrey Shaman
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States of America
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