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Articles 1 - 30 of 67

Full-Text Articles in Veterinary Preventive Medicine, Epidemiology, and Public Health

The Economic Impacts Of Blackbird (Icteridae) Damage To Sunflower In The Usa, Karina Ernst, Julie Elser, George Linz, Hans Kandel, Jason Holderieath, Samantha Degroot, Steven Shwiff, Stephanie Shwiff Oct 2019

The Economic Impacts Of Blackbird (Icteridae) Damage To Sunflower In The Usa, Karina Ernst, Julie Elser, George Linz, Hans Kandel, Jason Holderieath, Samantha Degroot, Steven Shwiff, Stephanie Shwiff

Jason Holderieath

BACKGROUND: Blackbird (Icteridae) damage to ripening sunflower (Helianthus annuus L.) has been a persistent economic issue in the USA for the last five decades. To quantify losses, we surveyed blackbird damage from 2001 to 2013 (excluding 2004) to physiologically mature sunflower in eight states: North Dakota, South Dakota, Texas, Nebraska, Minnesota, Colorado, Kansas, and Vermont.

RESULTS:We pooled data gathered during the most recent 5 years (2009 to 2013) of the survey and found losses averaged $US2.5 million and $US11.3 million for confectionery and oilseed hybrids, respectively. Three states, North Dakota, South Dakota, and Nebraska, had sufficient acreage and bird damage …


Analysis Of Porcine Transcriptional Response To Salmonella Enterica Serovar Choleraesuis Suggests Novel Targets Of Nfkappab Are Activated In The Mesenteric Lymph Node, Yanfang Wang, Olivre P. Couture, Long Qu, Jolita J. Uthe, Shawn M. D. Bearson, Daniel Kuhar, Joan K. Lunney, Dan Nettleton, Jack C. M. Dekkers, Christopher K. Tuggle Jul 2019

Analysis Of Porcine Transcriptional Response To Salmonella Enterica Serovar Choleraesuis Suggests Novel Targets Of Nfkappab Are Activated In The Mesenteric Lymph Node, Yanfang Wang, Olivre P. Couture, Long Qu, Jolita J. Uthe, Shawn M. D. Bearson, Daniel Kuhar, Joan K. Lunney, Dan Nettleton, Jack C. M. Dekkers, Christopher K. Tuggle

Dan Nettleton

Background: Specific knowledge of the molecular pathways controlling host-pathogen interactions can increase our understanding of immune response biology as well as provide targets for drug development and genetic improvement of disease resistance. Toward this end, we have characterized the porcine transcriptional response to Salmonella enterica serovar Choleraesuis (S. Choleraesuis), a Salmonella serovar that predominately colonizes swine, yet can cause serious infections in human patients. Affymetrix technology was used to screen for differentially expressed genes in pig mesenteric lymph nodes (MLN) responding to infection with S. Choleraesuis at acute (8 hours (h), 24 h and 48 h post-inoculation (pi)) and chronic …


Distinct Peripheral Blood Rna Responses To Salmonella In Pigs Differing In Salmonella Shedding Levels: Intersection Of Ifng, Tlr And Mirna Pathways, Ting-Hua Huang, Jolita J. Uthe, Shawn M. D. Bearson, Cumhur Yusuf Demirkale, Dan Nettleton, Susan Knetter, Curtis Christian, Amanda E. Ramer-Tait, Michael J. Wannemeuhler, Christopher K. Tuggle Jul 2019

Distinct Peripheral Blood Rna Responses To Salmonella In Pigs Differing In Salmonella Shedding Levels: Intersection Of Ifng, Tlr And Mirna Pathways, Ting-Hua Huang, Jolita J. Uthe, Shawn M. D. Bearson, Cumhur Yusuf Demirkale, Dan Nettleton, Susan Knetter, Curtis Christian, Amanda E. Ramer-Tait, Michael J. Wannemeuhler, Christopher K. Tuggle

Dan Nettleton

Transcriptomic analysis of the response to bacterial pathogens has been reported for several species, yet few studies have investigated the transcriptional differences in whole blood in subjects that differ in their disease response phenotypes. Salmonella species infect many vertebrate species, and pigs colonized with Salmonella enterica serovar Typhimurium (ST) are usually asymptomatic, making detection of these Salmonella-carrier pigs difficult. The variable fecal shedding of Salmonella is an important cause of foodborne illness and zoonotic disease. To investigate gene pathways and biomarkers associated with the variance in Salmonellashedding following experimental inoculation, we initiated the first analysis of the whole …


Unique Genome-Wide Transcriptome Profiles Of Chicken Macrophages Exposed To Salmonella-Derived Endotoxin, Ceren Ciraci, Christopher K. Tuggle, Michael J. Wannemeuhler, Dan Nettleton, Susan J. Lamont Jul 2019

Unique Genome-Wide Transcriptome Profiles Of Chicken Macrophages Exposed To Salmonella-Derived Endotoxin, Ceren Ciraci, Christopher K. Tuggle, Michael J. Wannemeuhler, Dan Nettleton, Susan J. Lamont

Dan Nettleton

Background: Macrophages play essential roles in both innate and adaptive immune responses. Bacteria require endotoxin, a complex lipopolysaccharide, for outer membrane permeability and the host interprets endotoxin as a signal to initiate an innate immune response. The focus of this study is kinetic and global transcriptional analysis of the chicken macrophage response to in vitro stimulation with endotoxin from Salmonella typhimurium-798.

Results: The 38535-probeset Affymetrix GeneChip Chicken Genome array was used to profile transcriptional response to endotoxin 1, 2, 4, and 8 hours post stimulation (hps). Using a maximum FDR (False Discovery Rate) of 0.05 to declare genes as differentially …


Arca Controls Metabolism, Chemotaxis, And Motility Contributing To The Pathogenicity Of Avian Pathogenic Escherichia Coli, Fengwei Jiang, Chunxia An, Yinli Bao, Xuefeng Zhao, Robert L. Jernigan, Andrew Lithio, Dan Nettleton, Ling Li, Eve S. Wurtele, Lisa K. Nolan, Chengping Lu, Ganwu Li Jun 2019

Arca Controls Metabolism, Chemotaxis, And Motility Contributing To The Pathogenicity Of Avian Pathogenic Escherichia Coli, Fengwei Jiang, Chunxia An, Yinli Bao, Xuefeng Zhao, Robert L. Jernigan, Andrew Lithio, Dan Nettleton, Ling Li, Eve S. Wurtele, Lisa K. Nolan, Chengping Lu, Ganwu Li

Dan Nettleton

Avian pathogenic Escherichia coli (APEC) strains cause one of the three most significant infectious diseases in the poultry industry and are also potential food-borne pathogens threating human health. In this study, we showed that ArcA (aerobic respiratory control), a global regulator important for E. coli's adaptation from anaerobic to aerobic conditions and control of that bacterium's enzymatic defenses against reactive oxygen species (ROS), is involved in the virulence of APEC. Deletion of arcA significantly attenuates the virulence of APEC in the duck model. Transcriptome sequencing (RNA-Seq) analyses comparing the APEC wild type and the arcA mutant indicate that ArcA regulates …


Resolving Animal Distress And Pain: Principles And Examples Of Good Practice In Various Fields Of Research, Alicia Karas, Matthew C. Leach, Karl A. Andrutis, Kathleen Conlee, John P. Gluck, Andrew N. Rowan, Martin L. Stephens Jul 2016

Resolving Animal Distress And Pain: Principles And Examples Of Good Practice In Various Fields Of Research, Alicia Karas, Matthew C. Leach, Karl A. Andrutis, Kathleen Conlee, John P. Gluck, Andrew N. Rowan, Martin L. Stephens

Martin Stephens, PhD

Pain and distress are central topics in legislation, regulations, and standards regarding the use of animals in research. However, in practice, pain has received greatly increased attention in recent years, while attention to distress has lagged far behind, especially for distress that is not induced by pain. A contributing factor is that there is less information readily available on distress, including practical information on its recognition, assessment and alleviation.

This chapter attempts to help fill that void by reversing the usual pattern and giving greater attention to distress than to pain. In addition, we also bypass the pain versus distress …


Exclusion Of The Unfolded Protein Response In Light-Induced Retinal Degeneration In The Canine T4r Rho Model Of Autosomal Dominant Retinitis Pigmentosa, Stefania Marsilli, Sem Genini, Raghavi Sudharsan, Jeremy Gingrich, Gustavo D. Aguirre, William Beltran Feb 2016

Exclusion Of The Unfolded Protein Response In Light-Induced Retinal Degeneration In The Canine T4r Rho Model Of Autosomal Dominant Retinitis Pigmentosa, Stefania Marsilli, Sem Genini, Raghavi Sudharsan, Jeremy Gingrich, Gustavo D. Aguirre, William Beltran

Gustavo D. Aguirre, VMD, PhD

Purpose To examine the occurrence of endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) following acute light damage in the naturally-occurring canine model of RHO-adRP (T4R RHOdog). Methods The left eyes of T4R RHOdogs were briefly light-exposed and retinas collected 3, 6 and 24 hours later. The contra-lateral eyes were shielded and used as controls. To evaluate the time course of cell death, histology and TUNEL assays were performed. Electron microscopy was used to examine ultrastructural alterations in photoreceptors at 15 min, 1 hour, and 6 hours after light exposure. Gene expression of markers of ER stress and …


Three Rs Approaches In The Production And Quality Control Of Fish Vaccines, Paul J. Midtlyng, Coenraad F.M. Hendriksen, Elisabeth Balks, Lukas Bruckner, Lawrence Elsken, Øystein Evensen, Kjetil Fyrand, Allison Guy, Marlies Halder, Penny Hawkins, Gunn Kisen, Anne Berit Romstad, Kira Salonius, Patrick Smith, Lynne U. Sneddon Aug 2015

Three Rs Approaches In The Production And Quality Control Of Fish Vaccines, Paul J. Midtlyng, Coenraad F.M. Hendriksen, Elisabeth Balks, Lukas Bruckner, Lawrence Elsken, Øystein Evensen, Kjetil Fyrand, Allison Guy, Marlies Halder, Penny Hawkins, Gunn Kisen, Anne Berit Romstad, Kira Salonius, Patrick Smith, Lynne U. Sneddon

Lynne Sneddon, PhD

The workshop on Three Rs Approaches in the Production and Quality Control of Fish Vaccines aimed a) to identify animal tests currently stipulated for the production and quality control of fish vaccines and to highlight animal welfare concerns associated with these tests; b) to identify viable options to replace, reduce, and refine animal use for fish vaccine testing; and c) to discuss the way forward and set out how the Three Rs may be implemented without jeopardizing the quality of the vaccines. The workshop participants -- experts from academia, regulatory authorities, a scientific animal welfare organization, and the fish vaccine …


Free-Roaming Dogs In Developing Countries: The Benefits Of Capture, Neuter, And Return Programs, Jennifer Jackman, Andrew N. Rowan Jul 2015

Free-Roaming Dogs In Developing Countries: The Benefits Of Capture, Neuter, And Return Programs, Jennifer Jackman, Andrew N. Rowan

Jennifer Jackman, Ph.D.

This chapter provides an overview of animal welfare and public health problems associated with free-roaming dog populations and strategies to resolve these problems. Placing CNR programs in the context of earlier dog and rabies control methods, the chapter explores CNR’s potential to overcome some of the shortcomings of earlier approaches and to improve animal welfare, reduce dog population growth, and prevent the spread of rabies and other canine-transmitted diseases. Constraints and current debates on current implementation of CNR programs are also examined.


Resolving Animal Distress And Pain: Principles And Examples Of Good Practice In Various Fields Of Research, Alicia Karas, Matthew C. Leach, Karl A. Andrutis, Kathleen Conlee, John P. Gluck, Andrew N. Rowan, Martin L. Stephens Mar 2015

Resolving Animal Distress And Pain: Principles And Examples Of Good Practice In Various Fields Of Research, Alicia Karas, Matthew C. Leach, Karl A. Andrutis, Kathleen Conlee, John P. Gluck, Andrew N. Rowan, Martin L. Stephens

Andrew N. Rowan, DPhil

Pain and distress are central topics in legislation, regulations, and standards regarding the use of animals in research. However, in practice, pain has received greatly increased attention in recent years, while attention to distress has lagged far behind, especially for distress that is not induced by pain. A contributing factor is that there is less information readily available on distress, including practical information on its recognition, assessment and alleviation.

This chapter attempts to help fill that void by reversing the usual pattern and giving greater attention to distress than to pain. In addition, we also bypass the pain versus distress …


Effects Of Forage Quality, Mdgs, And Monensin On Performance, Methane Concentration, And Ruminal Fermentation Of Growing Cattle, Anna C. Pesta, Andrea K. Watson, Samodha Fernando, Galen E. Erickson Mar 2015

Effects Of Forage Quality, Mdgs, And Monensin On Performance, Methane Concentration, And Ruminal Fermentation Of Growing Cattle, Anna C. Pesta, Andrea K. Watson, Samodha Fernando, Galen E. Erickson

Samodha C. Fernando

A growing study was conducted to evaluate a novel method for measuring methane concentration by feedlot cattle, and to determine the effects of forage quality, inclusion of modified distillers grains plus solubles (MDGS), and presence or absence of monensin on performance, methane concentration, and rumen fermentation characteristics. Performance was improved by use of high-quality forage and MDGS, while response to monensin was variable across basal diet type. Response of methane concentration and volatile fatty acid (VFA) profile due to diet was variable and subject to multiple interactions, reflecting the complexity of the microbial processes involved within the rumen.


Differences In Fecal Bacterial Community Composition Between Beef Steers Which Are High-Shedders And Low-Shedders Of Shiga Toxin-Producing Escherichia Coli (Stec), Nirosh D. Aluthge, Yoshitha A. Wanniarachchi, Brandon L. Nuttelman, Cody J. Schneider, Terry J. Klopfenstein, Galen E. Erickson, Samodha C. Fernando Mar 2015

Differences In Fecal Bacterial Community Composition Between Beef Steers Which Are High-Shedders And Low-Shedders Of Shiga Toxin-Producing Escherichia Coli (Stec), Nirosh D. Aluthge, Yoshitha A. Wanniarachchi, Brandon L. Nuttelman, Cody J. Schneider, Terry J. Klopfenstein, Galen E. Erickson, Samodha C. Fernando

Samodha C. Fernando

The community composition of the fecal microbiota was compared between beef steers which were high-shedders and low-shedders of Shiga toxin-producing Escherichia coli. Based on Shannon and Chao 1 diversity indices, the high-shedders had a more diverse fecal bacterial community than the low-shedding steers. Members of the genus Prevotella were observed as being more abundant in the low-shedders compared to the high-shedders, while Succinivibrio were more abundant in the high-shedders. Isolation of specific bacteria which are significantly more abundant in low-shedders may pave the way to developing direct-fed microbials which are effective in reducing STEC shedding among high-shedding beef steers.


Crypto Prevention, Brian K. Whitlock Feb 2015

Crypto Prevention, Brian K. Whitlock

Brian K Whitlock, PhD, DVM, DACT

No abstract provided.


Infection And Immunity In The Pacific White Shrimp, Litopenaeus Vannamei, John Dustin Loy Oct 2014

Infection And Immunity In The Pacific White Shrimp, Litopenaeus Vannamei, John Dustin Loy

John Loy

Infectious diseases are significant impediments to the growth and sustainability of commercial shrimp aquaculture. Endemic diseases such as that caused by the obligate intracellular parasite the Necrotizing Hepatopancreatitis Bacterium (NHPB), cause significant losses to shrimp producers thoughout the Americas. New and emerging viral diseases, such as that caused by Infectious myonecrosis virus (IMNV), have caused tremendous economic losses in farmed Pacific white shrimp (Litopenaeus vannamei), since it emerged in Brazil and subsequently spread across the globe to Indonesia. No methods exist to propagate and model these infections in vitro), as no cell culture lines are available for shrimp. Therefore, we …


Acceptance Of Simulated Oral Rabies Vaccine Baits By Urban Raccoons, John Hadidian, Suzanne R. Jenkins, David H. Johnston, Peter J. Savarie, Victor F. Nettles, David M. Manski, George M. Baer Aug 2014

Acceptance Of Simulated Oral Rabies Vaccine Baits By Urban Raccoons, John Hadidian, Suzanne R. Jenkins, David H. Johnston, Peter J. Savarie, Victor F. Nettles, David M. Manski, George M. Baer

John Hadidian, PhD

In summer 1986, a study was conducted to evaluate raccoon (Procyon lotor) acceptance of oral baits that could be used for rabies vaccination, One thousand wax-coated sponge bait cubes were filled with 5 mg of a seromarker (iophenoxic acid), placed in polyethylene bags, and hand-distributed in an 80 ha area within an urban National Park in Washington, D.C. (USA), After 3 wk, target and nontarget animals were trapped and blood samples collected to evaluate bait uptake. Thirty-three of 52 (63%) raccoons had elevated blood iodine levels indicating they had eaten at least one bait, 13 (25%) were negative, and six …


The Human/Animal Interface: Emergence And Resurgence Of Zoonotic Infectious Diseases, Michael Greger May 2014

The Human/Animal Interface: Emergence And Resurgence Of Zoonotic Infectious Diseases, Michael Greger

Michael Greger, MD, FACLM

Emerging infectious diseases, most of which are considered zoonotic in origin, continue to exact a significant toll on society. The origins of major human infectious diseases are reviewed and the factors underlying disease emergence explored. Anthropogenic changes, largely in land use and agriculture, are implicated in the apparent increased frequency of emergence and reemergence of zoonoses in recent decades. Special emphasis is placed on the pathogen with likely the greatest zoonotic potential, influenzavirus A.


Amyloid Fibrils: Potential Food Safety Implications, Michael Greger May 2014

Amyloid Fibrils: Potential Food Safety Implications, Michael Greger

Michael Greger, MD, FACLM

The demonstration of oral Amyloid-A (AA) fibril transmissibility has raised food safety questions about the consumption of amyloidotic viscera. In a presumed prion-like mechanism, amyloid fibrils have been shown to trigger and accelerate the development of AA amyloidosis in rodent models. The finding of amyloid fibrils in edible avian and mammalian food animal tissues, combined with the inability of cooking temperatures to eliminate their amyloidogenic potential, has led to concerns that products such as pâté de foie gras may activate a reactive systemic amyloidosis in susceptible consumers. Given the ability of amyloid fibrils to cross-seed the formation of chemically heterologous …


Their Bugs Are Worse Than Their Bite: Emerging Infectious Disease And The Human-Animal Interface, Michael Greger May 2014

Their Bugs Are Worse Than Their Bite: Emerging Infectious Disease And The Human-Animal Interface, Michael Greger

Michael Greger, MD, FACLM

In the twenty-five years since that announcement, what we now know as AIDS has killed 20 million people (National AIDS Trust 2005). Where did the AIDS virus— and other emerging diseases, such as severe acute respiratory syndrome (SARS), Ebola, mad cow— come from?


Introduction Infectious Disease Modeling, Cristina Lanzas Jul 2013

Introduction Infectious Disease Modeling, Cristina Lanzas

Cristina Lanzas

No abstract provided.


Investigating Effects Of Between- And Within- Host Variability On Escherichia Coli O157 Shedding Pattern And Transmission, Shi Chen, Mike Sanderson, Cristina Lanzas Jan 2013

Investigating Effects Of Between- And Within- Host Variability On Escherichia Coli O157 Shedding Pattern And Transmission, Shi Chen, Mike Sanderson, Cristina Lanzas

Cristina Lanzas

Healthy cattle and their environment are the reservoir for the human pathogen Escherichia coli O157. In E. coli O157 epidemiology, supershedders have been loosely defined as cattle that shed high concentrations of E. coli O157 (≥104 colony-forming cells (CFU)/g of feces) at a single (or multiple) cross-section in time. Due to the variability in the pathogen shedding level among animals (between-host variability), as well as fluctuations in the level shed by a single animal (within-host variability), it is difficult to interpret fecal bacteria distributions, as well as to parse the relative contribution of between- and within-host variability to the observed …


Socioeconomic Determinants Of Geographic Disparities In Campylobacteriosis Risk: A Comparison Of Global And Local Modeling Approaches, Jennifer Weisent, Barton Rohrbach, John Dunn, Agricola Odoi Oct 2012

Socioeconomic Determinants Of Geographic Disparities In Campylobacteriosis Risk: A Comparison Of Global And Local Modeling Approaches, Jennifer Weisent, Barton Rohrbach, John Dunn, Agricola Odoi

Agricola Odoi

Background: Socioeconomic factors play a complex role in determining the risk of campylobacteriosis. Understanding the spatial interplay between these factors and disease risk can guide disease control programs. Historically, Poisson and negative binomial models have been used to investigate determinants of geographic disparities in risk. Spatial regression models, which allow modeling of spatial effects, have been used to improve these modeling efforts. Geographically weighted regression (GWR) takes this a step further by estimating local regression coefficients, thereby allowing estimations of associations that vary in space. These recent approaches increase our understanding of how geography influences the associations between determinants and …


Does Place Of Residence Affect Risk Of Suicide? A Spatial Epidemiologic Investigation In Kentucky From 1999 To 2008, Daniel M. Saman, Sabrina Walsh, Anna Borowko, Agricola Odoi Feb 2012

Does Place Of Residence Affect Risk Of Suicide? A Spatial Epidemiologic Investigation In Kentucky From 1999 To 2008, Daniel M. Saman, Sabrina Walsh, Anna Borowko, Agricola Odoi

Agricola Odoi

Background: Approximately 32,000 people take their own lives every year in the United States. In Kentucky, suicide mortality rates have been steadily increasing since 1999. Few studies in the United States have assessed spatial clustering of suicides. The purpose of this study was to identify high-risk clusters of suicide at the county level in Kentucky and assess the characteristics of those suicide cases within the clusters. Methods: A spatial epidemiological study was undertaken using suicide data for the period January 1, 1999 to December 31, 2008, obtained from the Kentucky Office of Vital Statistics. Descriptive analyses using Pearson's chi-square test …


A Spatial Cluster Analysis Of Tractor Overturns In Kentucky From 1960 To 2002, Daniel M. Saman, Henry P. Cole, Agricola Odoi, Melvin L. Myers, Daniel I. Carey, Susan C. Westneat Jan 2012

A Spatial Cluster Analysis Of Tractor Overturns In Kentucky From 1960 To 2002, Daniel M. Saman, Henry P. Cole, Agricola Odoi, Melvin L. Myers, Daniel I. Carey, Susan C. Westneat

Agricola Odoi

Background: Agricultural tractor overturns without rollover protective structures are the leading cause of farm fatalities in the United States. To our knowledge, no studies have incorporated the spatial scan statistic in identifying high-risk areas for tractor overturns. The aim of this study was to determine whether tractor overturns cluster in certain parts of Kentucky and identify factors associated with tractor overturns. Methods: A spatial statistical analysis using Kulldorff’s spatial scan statistic was performed to identify county clusters at greatest risk for tractor overturns. A regression analysis was then performed to identify factors associated with tractor overturns. Results: The spatial analysis …


In Vitro Investigation Of A Terbinafine Impregnated Subcutaneous Implant For Veterinary Use, Marcy J. Souza, Tim Cairns, Jason Yarbrough, Sherry Cox Jan 2012

In Vitro Investigation Of A Terbinafine Impregnated Subcutaneous Implant For Veterinary Use, Marcy J. Souza, Tim Cairns, Jason Yarbrough, Sherry Cox

Marcy J Souza

No abstract provided.


Neighborhood Disparities In Stroke And Myocardial Infarction Mortality: A Gis And Spatial Scan Statistics Approach, Agricola Odoi Aug 2011

Neighborhood Disparities In Stroke And Myocardial Infarction Mortality: A Gis And Spatial Scan Statistics Approach, Agricola Odoi

Agricola Odoi

Background: Stroke and myocardial infarction (MI) are serious public health burdens in the US. These burdens vary by geographic location with the highest mortality risks reported in the southeastern US. While these disparities have been investigated at state and county levels, little is known regarding disparities in risk at lower levels of geography, such as neighborhoods. Therefore, the objective of this study was to investigate spatial patterns of stroke and MI mortality risks in the East Tennessee Appalachian Region so as to identify neighborhoods with the highest risks. Methods: Stroke and MI mortality data for the period 1999-2007, obtained free …


Mathematical Modeling Of The Transmission And Control Of Foodborne Pathogens And Antimicrobial Resistance At Preharvest, Cristina Lanzas, Zhao Lu, Yrjo T. Grohn Jan 2011

Mathematical Modeling Of The Transmission And Control Of Foodborne Pathogens And Antimicrobial Resistance At Preharvest, Cristina Lanzas, Zhao Lu, Yrjo T. Grohn

Cristina Lanzas

Foodborne diseases are a significant health care and economical burden. Most foodborne pathogens are enteric pathogens harbored in the gastrointestinal tract of farm animals. Understanding the transmission of foodborne pathogens and dissemination of antimicrobial resistance at the farm level is necessary to design effective control strategies at preharvest. Mathematical models improve our understanding of pathogen dynamics by providing a theoretical framework in which factors affecting transmission and the control of the pathogens can be explicitly considered. In this review, we aim to present the principles underlying the mathematical modeling of foodborne pathogens and antimicrobial resistance at the farm level to …


Model Or Meal? Farm Animal Populations As Models For Infectious Diseases Of Humans, Cristina Lanzas, P Ayscue, R Ivanek, Y T. Grohn Feb 2010

Model Or Meal? Farm Animal Populations As Models For Infectious Diseases Of Humans, Cristina Lanzas, P Ayscue, R Ivanek, Y T. Grohn

Cristina Lanzas

In recent decades, theory addressing the processes that underlie the dynamics of infectious diseases has progressed considerably. Unfortunately, the availability of empirical data to evaluate these theories has not grown at the same pace. Although laboratory animals have been widely used as models at the organism level, they have been less appropriate for addressing issues at the population level. However, farm animal populations can provide empirical models to study infectious diseases at the population level.


Assessing Risk In Focal Arboviral Infections: Are We Missing The Big Or Little Picture?, A D. Haddow, Agricola Odoi, C J. Jones Sep 2009

Assessing Risk In Focal Arboviral Infections: Are We Missing The Big Or Little Picture?, A D. Haddow, Agricola Odoi, C J. Jones

Agricola Odoi

BACKGROUND: Focal arboviral infections affecting a subset of the overall population present an often overlooked set of challenges in the assessment and reporting of risk and the detection of spatial patterns. Our objective was to assess the variation in risk when using different at-risk populations and geographic scales for the calculation of incidence risk and the detection of geographic hot-spots of infection. We explored these variations using a pediatric arbovirus, La Crosse virus (LACV), as our model. METHODS AND FINDINGS: Descriptive and cluster analyses were performed on probable and confirmed cases of LACV infections reported to the Tennessee Department of …


Development Of A Mechanistic Model To Represent The Dynamics Of Particle Flow Out Of The Rumen And To Predict Rate Of Passage Of Forage Particles In Dairy Cattle., S Seo, Cristina Lanzas, L O. Tedeschi, A Pell, D G. Fox Aug 2009

Development Of A Mechanistic Model To Represent The Dynamics Of Particle Flow Out Of The Rumen And To Predict Rate Of Passage Of Forage Particles In Dairy Cattle., S Seo, Cristina Lanzas, L O. Tedeschi, A Pell, D G. Fox

Cristina Lanzas

A mechanistic and dynamic model was developed to represent physiological aspects of particle dynamics in the reticulo-rumen (RR) and to predict rate of passage out of the RR (Kp) of forage particles quantitatively. The model consists of 2 conceptual pools with 3 spatial compartments of particles; the compartment the particle enters is based on functional specific gravity (FSG). The model assumes 2 major pressure gradient-driven flows of particles out of the RR through the reticulo-omasal orifice between 2 consecutive primary reticular contractions. One is associated with the second phase of primary reticular contraction and involves propulsion of particles in the …


Modeling On-Farm Escherichia Coli O157:H7 Population Dynamics, P Ayscue, Cristina Lanzas, R Ivanek, Y T. Grohn May 2009

Modeling On-Farm Escherichia Coli O157:H7 Population Dynamics, P Ayscue, Cristina Lanzas, R Ivanek, Y T. Grohn

Cristina Lanzas

Escherichia coli O157:H7 is a potentially fatal foodborne pathogen with a putative reservoir for human infection in feedlot cattle. In order to more effectively identify targets for intervention strategies, we aimed to (1) assess the role of various feedlot habitats in E. coli O157:H7 propagation and (2) provide a framework for examining the relative contributions of animals and the surrounding environment to observed pathogen dynamics. To meet these goals we developed a mathematical model based on an ecological metapopulation framework to track bacterial population dynamics inside and outside the host. We used E. coli O157:H7 microbiological and epidemiological literature to …