scholarly journals Estimating epidemiological parameters using diagnostic testing data from low pathogenicity avian influenza infected turkey houses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Peter J. Bonney ◽  
Sasidhar Malladi ◽  
Amos Ssematimba ◽  
Erica Spackman ◽  
Mia Kim Torchetti ◽  
...  

AbstractLimiting spread of low pathogenicity avian influenza (LPAI) during an outbreak is critical to reduce the negative impact on poultry producers and local economies. Mathematical models of disease transmission can support outbreak control efforts by estimating relevant epidemiological parameters. In this article, diagnostic testing data from each house on a premises infected during a LPAI H5N2 outbreak in the state of Minnesota in the United States in 2018 was used to estimate the time of virus introduction and adequate contact rate, which determines the rate of disease spread. A well-defined most likely time of virus introduction, and upper and lower 95% credibility intervals were estimated for each house. The length of the 95% credibility intervals ranged from 11 to 22 with a mean of 17 days. In some houses the contact rate estimates were also well-defined; however, the estimated upper 95% credibility interval bound for the contact rate was occasionally dependent on the upper bound of the prior distribution. The estimated modes ranged from 0.5 to 6.0 with a mean of 2.8 contacts per day. These estimates can be improved with early detection, increased testing of monitored premises, and combining the results of multiple barns that possess similar production systems.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Divine Ekwem ◽  
Thomas A. Morrison ◽  
Richard Reeve ◽  
Jessica Enright ◽  
Joram Buza ◽  
...  

AbstractIn Africa, livestock are important to local and national economies, but their productivity is constrained by infectious diseases. Comprehensive information on livestock movements and contacts is required to devise appropriate disease control strategies; yet, understanding contact risk in systems where herds mix extensively, and where different pathogens can be transmitted at different spatial and temporal scales, remains a major challenge. We deployed Global Positioning System collars on cattle in 52 herds in a traditional agropastoral system in western Serengeti, Tanzania, to understand fine-scale movements and between-herd contacts, and to identify locations of greatest interaction between herds. We examined contact across spatiotemporal scales relevant to different disease transmission scenarios. Daily cattle movements increased with herd size and rainfall. Generally, contact between herds was greatest away from households, during periods with low rainfall and in locations close to dipping points. We demonstrate how movements and contacts affect the risk of disease spread. For example, transmission risk is relatively sensitive to the survival time of different pathogens in the environment, and less sensitive to transmission distance, at least over the range of the spatiotemporal definitions of contacts that we explored. We identify times and locations of greatest disease transmission potential and that could be targeted through tailored control strategies.


2021 ◽  
Author(s):  
Divine Ekwem ◽  
Thomas A. Morrison ◽  
Richard Reeve ◽  
Jessica Enright ◽  
Joram Buza ◽  
...  

Abstract In Africa, livestock are important to local and national economies, but their productivity is constrained by infectious diseases. Comprehensive information on livestock movements and contacts is required to devise appropriate disease control strategies; yet, understanding contact risk in systems where herds mix extensively, and where different pathogens can be transmitted at different spatial and temporal scales, remains a major challenge. We deployed Global Positioning System collars on cattle in 52 herds in a traditional agropastoral system in western Serengeti, Tanzania, to understand fine-scale movements and between-herd contacts, and to identify locations of greatest interaction between herds. We examined contact across spatiotemporal scales relevant to different disease transmission scenarios. Daily cattle movements increased with herd size and rainfall. Generally, contact was greatest away from households, during periods with low rainfall and in locations close to dipping points. We demonstrate how movements and contacts affect the risk of disease spread. For example, contact rate was relatively sensitive to the survival time of different pathogens in the environment, and less sensitive to transmission distance, at least over the range of values that we explored. We identify times and locations of greatest disease transmission potential and that could be targeted through tailored control strategies.


2015 ◽  
Vol 112 (9) ◽  
pp. 2723-2728 ◽  
Author(s):  
Wan Yang ◽  
Marc Lipsitch ◽  
Jeffrey Shaman

The inference of key infectious disease epidemiological parameters is critical for characterizing disease spread and devising prevention and containment measures. The recent emergence of surveillance records mined from big data such as health-related online queries and social media, as well as model inference methods, permits the development of new methodologies for more comprehensive estimation of these parameters. We use such data in conjunction with Bayesian inference methods to study the transmission dynamics of influenza. We simultaneously estimate key epidemiological parameters, including population susceptibility, the basic reproductive number, attack rate, and infectious period, for 115 cities during the 2003–2004 through 2012–2013 seasons, including the 2009 pandemic. These estimates discriminate key differences in the epidemiological characteristics of these outbreaks across 10 y, as well as spatial variations of influenza transmission dynamics among subpopulations in the United States. In addition, the inference methods appear to compensate for observational biases and underreporting inherent in the surveillance data.


2021 ◽  
Author(s):  
Sasidhar Malladi ◽  
Amos Ssematimba ◽  
Peter J. Bonney ◽  
Kaitlyn M. St. Charles ◽  
Timothy Boyer ◽  
...  

Abstract Background: African swine fever (ASF) is a highly contagious and devastating pig disease that has caused extensive global economic losses. Understanding ASF virus (ASFV) transmission dynamics within a herd is necessary in order to prepare for and respond to an outbreak in the United States. Although the transmission parameters for the highly virulent ASF strains have been estimated in several articles, there are relatively few studies focused on moderately virulent strains. Using an approximate Bayesian computation algorithm in conjunction with Monte Carlo simulation, we have estimated the adequate contact rate for moderately virulent ASFV strains and determined the statistical distributions for the durations of mild and severe clinical signs using individual, pig-level data. A discrete individual based disease transmission model was then used to estimate the time to detect ASF infection based on increased mild clinical signs, severe clinical signs, or daily mortality. Results: Our results indicate that it may take two weeks or longer to detect ASF in a finisher swine herd via mild clinical signs or increased mortality beyond levels expected in routine production. A key factor contributing to the extended time to detect ASF in a herd is the fairly long latently infected period for an individual pig (mean 4.5, 95% P.I., 2.4 - 7.2 days). Conclusion: These transmission model parameter estimates and estimated time to detection via clinical signs provide valuable information that can be used not only to support emergency preparedness but also to inform other simulation models of evaluating regional disease spread.


2009 ◽  
Vol 133 (12) ◽  
pp. 1975-1980
Author(s):  
Hilary Somerset ◽  
J. Peter Witt ◽  
Bette K. Kleinschmidt-DeMasters

Abstract Hepatocellular carcinoma (HCC) is relatively uncommon in the United States, although hepatitis C, one of the known risk factors for disease, is currently showing burgeoning growth in the country. Hence, it is possible that the incidence of HCC also will increase. Clinicians and pathologists in the United States are relatively unfamiliar with the patterns of metastatic spread for HCC. We report 2 US-native patients with cirrhosis and HCC who developed epidural space metastasis, a pattern of disease spread seen infrequently, even in endemic areas. Diagnostic testing was delayed in both patients because of the lowered suspicion for metastasis and the fact that neither patient had recognized metastatic spread to more common sites, such as lung or lymph nodes. New-onset neck or back pain—especially with symptoms of paresthesia, radiculopathy, or cord compression—in the setting of HCC warrants prompt investigation for metastases to the spine and epidural space.


Author(s):  
Amy Hasselkus

The need for improved communication about health-related topics is evident in statistics about the health literacy of adults living in the United States. The negative impact of poor health communication is huge, resulting in poor health outcomes, health disparities, and high health care costs. The importance of good health communication is relevant to all patient populations, including those from culturally and linguistically diverse backgrounds. Efforts are underway at all levels, from individual professionals to the federal government, to improve the information patients receive so that they can make appropriate health care decisions. This article describes these efforts and discusses how speech-language pathologists and audiologists may be impacted.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 548a-548 ◽  
Author(s):  
D.M. Glenn ◽  
G. Puterka ◽  
T. Baugher ◽  
T. Unruh ◽  
S. Drake

Hydrophobic particle film technology (HPF) is a developing pest control system for tree fruit production systems. Studies were established in Chile, and Washington, Pennsylvania, and West Virginia in the United States, to evaluate the effect of HPF technology on tree fruit yield and quality. Studies in Chile, Washington, and West Virginia demonstrated increased photosynthetic rate at the leaf level. Yield was increased in peaches (Chile) and apples (West Virginia), and fruit size was increased in apples (Washington and Pennsylvania). Increased red color in apple was demonstrated at all sites with reduced russetting and `Stayman' cracking in Pennsylvania. HPF technology appears to be an effective tool in reducing water and heat stress in tree fruit resulting in increased fruit quality.


Author(s):  
Hannah L. Walker

Springing from decades of abuse by law enforcement and an excessive criminal justice system, members of over-policed communities lead the current movement for civil rights in the United States. Activated by injustice, individuals protested police brutality in Ferguson, campaigned to end stop-and-frisk in New York City, and advocated for restorative justice in Washington, D.C. Yet, scholars focused on the negative impact of punitive policy on material resources, and trust in government did not predict these pockets of resistance, arguing instead that marginalizing and demeaning policy teaches individuals to acquiesce and withdraw. Mobilized by Injustice excavates conditions under which, despite otherwise negative outcomes, negative criminal justice experiences catalyze political action. This book argues that when understood as resulting from a system that targets people based on race, class, or other group identifiers, contact can politically mobilize. Negative experiences with democratic institutions predicated on equality under the law, when connected to a larger, group-based struggle, can provoke action from anger. Evidence from several surveys and in-depth interviews reveals that mobilization as result of negative criminal justice experiences is broad, crosses racial boundaries, and extends to the loved ones of custodial citizens. When over half of Blacks and Latinos and a plurality of Whites know someone with personal contact, the mobilizing effect of a sense of injustice promises to have important consequences for American politics.


Author(s):  
Geoffrey Jones

This chapter examines the scaling and diffusion of green entrepreneurship between 1980 and the present. It explores how entrepreneurs and business leaders promoted the idea that business and sustainability were compatible. It then examines the rapid growth of organic foods, natural beauty, ecological architecture, and eco-tourism. Green firms sometimes grew to a large scale, such as the retailer Whole Foods Market in the United States. The chapter explores how greater mainstreaming of these businesses resulted in a new set of challenges arising from scaling. Organic food was now transported across large distances causing a negative impact on carbon emissions. More eco-tourism resulted in more air travel and bigger airports. In other industries scaling had a more positive impact. Towns were major polluters, so more ecological buildings had a positive impact.


Neurosurgery ◽  
2019 ◽  
Vol 86 (1) ◽  
pp. 132-138
Author(s):  
Christopher D Shank ◽  
Nicholas J Erickson ◽  
David W Miller ◽  
Brittany F Lindsey ◽  
Beverly C Walters

Abstract BACKGROUND Neurosciences intensive care units (NICUs) provide institutional centers for specialized care. Despite a demonstrable reduction in morbidity and mortality, NICUs may experience significant capacity strain with resulting supraoptimal utilization and diseconomies of scale. We present an implementation study in the recognition and management of capacity strain within a large NICU in the United States. Excessive resource demand in an NICU creates significant operational issues. OBJECTIVE To evaluate the efficacy of a Reserved Bed Pilot Program (RBPP), implemented to maximize economies of scale, to reduce transfer declines due to lack of capacity, and to increase transfer volume for the neurosciences service-line. METHODS Key performance indicators (KPIs) were created to evaluate RBPP efficacy with respect to primary (strategic) objectives. Operational KPIs were established to evaluate changes in operational throughput for the neurosciences and other service-lines. For each KPI, pilot-period data were compared to the previous fiscal year. RESULTS RBPP implementation resulted in a significant increase in accepted transfer volume to the neurosciences service-line (P = .02). Transfer declines due to capacity decreased significantly (P = .01). Unit utilization significantly improved across service-line units relative to theoretical optima (P < .03). Care regionalization was achieved through a significant reduction in “off-service” patient placement (P = .01). Negative externalities were minimized, with no significant negative impact in the operational KPIs of other evaluated service-lines (P = .11). CONCLUSION Capacity strain is a significant issue for hospital units. Reducing capacity strain can increase unit efficiency, improve resource utilization, and augment service-line throughput. RBPP implementation resulted in a significant improvement in service-line operations, regional access to care, and resource efficiency, with minimal externalities at the institutional level.


Sign in / Sign up

Export Citation Format

Share Document