David C. Hall

Prof. Dr. David C. Hall

orcid

Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2021 in Journal of Dairy Science
Verified
Journal Article
Open access
PRPhilip Rasmussen
Philip Rasmussen
HBHerman W. Barkema
Herman W. Barkema
SMSteve Mason
Steve Mason
EBEugene Beaulieu
Eugene Beaulieu
DHDavid C. Hall
David C. Hall
Johne's disease (JD), or paratuberculosis, is an infectious inflammatory disorder of the intestines primarily associated with domestic and wild ruminants including dairy cattle. The disease, caused by an infection with Mycobacterium avium subspecies paratuberculosis (MAP) bacteria, burdens both animals and producers through reduced milk production, premature culling, and reduced salvage values among MAP-infected animals. The economic losses associated with these burdens have been measured before, but not across a comprehensive selection of major dairy-producing regions within a single methodological framework. This study uses a Markov chain Monte Carlo approach to estimate the annual losses per cow within MAP-infected herds and the total regional losses due to JD by simulating the spread and economic impact of the disease with region-specific economic variables. It was estimated that approximately 1% of gross milk revenue, equivalent to US$33 per cow, is lost annually in MAP-infected dairy herds, with those losses primarily driven by reduced production and being higher in regions characterized by above-average farm-gate milk prices and production per cow. An estimated US$198 million is lost due to JD in dairy cattle in the United States annually, US$75 million in Germany, US$56 million in France, US$54 million in New Zealand, and between US$17 million and US$28 million in Canada, one of the smallest dairy-producing regions modeled.

1 April 2019 in PLOS Neglected Tropical Diseases
Verified
Journal Article
Open access
PDF file
SRSangay Rinchen
Sangay Rinchen
TTTenzin Tenzin
Tenzin Tenzin
DHDavid C. Hall
David C. Hall
FMFrank Van Der Meer
Frank Van Der Meer
BSBasant Sharma
Basant Sharma
SCSusan Cork
Susan Cork
Rabies remains a disease of significant zoonotic and economic concern in rabies endemic areas of Bhutan. Rabies outbreaks in livestock threaten the livelihoods of subsistent farming communities and pose a potential public health threat. As a part of identifying approaches to prevent rabies in cattle, a Knowledge, Attitude, and Practice (KAP) survey was conducted among cattle owners in selected rural areas of the southern rabies high-risk zone and low-risk zone in eastern Bhutan. Between March and April 2017, 562 cattle owners (281 in the east and 281 in the south) were interviewed using a questionnaire. Eighty-eight percent of the participants had heard of rabies but only 39% of the participants who had heard of rabies had adequate knowledge about rabies. Multivariable logistic regression analysis showed that residing in the south [OR = 9.25 (95% CI: 6.01–14.53)] and having seen a rabies case [OR = 2.46 (95% CI: 1.6–3.82)] were significantly associated with having adequate knowledge about rabies. Based on our scoring criteria, 65% of the total participants who had heard of rabies had a favorable attitude towards rabies control and prevention programs. The participants residing in the east were two times more likely to have a favourable attitude than their counterparts in the south [OR = 2.08 (95% CI: 1.43–3.05)]. More than 70% of the participants reported engaging in farm activities such as examining the oral cavity of sick cattle and assisting cattle during parturition. Only 25% of the participants reported using personal protective equipment while undertaking these activities. Despite a high level of rabies awareness, we observed that there is a lack of comprehensive knowledge about rabies regarding susceptible hosts, transmission routes, the health outcome of rabies infection in humans, and appropriate health-seeking behaviours. This study highlights the need to strengthen rabies education programs in rural communities to address the knowledge gaps that have been identified. The impacts of rabies outbreaks in cattle and other livestock are multifold. At the local level, economic losses resulting from the direct loss of cattle and the animal’s future productivity is a significant threat to the livelihoods of subsistent farming communities. Besides, rabies in livestock poses a potential public health threat associated with human exposures that result during handling sick animals and dressing carcasses of animals that had died of rabies. Furthermore, the Government incurs costs for responding to outbreaks and providing post-exposure prophylaxis (PEP) to potentially exposed individuals. We conducted a KAP questionnaire surveys among cattle owners in two selected study areas of Bhutan to understand the level of rabies awareness among the cattle owners, their attitude towards rabies prevention and control and to identify existing on-farm practices that can result in potential exposure to rabies in animals and humans. We observed that there was a lack of comprehensive knowledge about rabies especially regarding the post exposure care and outcome of rabies infection in humans and animals. Given that most participants lacked knowledge about clinical signs of rabies in cattle their engagement in practices such as examining oral cavity, assisting cattle during parturition and dressing wounds without wearing minimal protective equipment, was concerning. Our study identifies the need to extend rabies education into the rural communities of Bhutan. Furthermore, our findings reiterate the importance of rabies education as a crucial component of the global initiative to eliminate dog-mediated rabies in humans and animals.

1 December 2003 in Applied Economic Perspectives and Policy
Verified
Journal Article
Closed access
PDF file
DHDavid C. Hall
David C. Hall
TKThomas O. Knight
Thomas O. Knight
KCKeith H. Coble
Keith H. Coble
ABAlan E. Baquet
Alan E. Baquet
GPGeorge F. Patrick
George F. Patrick

1 June 2009 in Journal of Veterinary Medical Education
Verified
Journal Article
Closed access
KHKent Hecker
Kent Hecker
TDTyrone Donnon
Tyrone Donnon
CFCarmen Fuentealba
Carmen Fuentealba
DHDavid C. Hall
David C. Hall
OIOscar Illanes
Oscar Illanes
CMChristoph Muelling
Christoph Muelling
This study describes the development, implementation, and psychometric assessment of the multiple mini-interview (MMI) for the inaugural class of veterinary medicine applicants at the University of Calgary Faculty of Veterinary Medicine (UCVM). The MMI is a series of approximately five to 12 10-minute interviews that consist of situational events. Applicants are given a scenario and asked to work through an issue or behavioral-type questions that are meant to assess one attribute (e.g., empathy) at a time. This structure allows for multiple assessments of the applicants by trained interviewers on the same questions. MMI scenario development was based on a review of the noncognitive attributes currently assessed by the 31 veterinary schools across Canada and the United States and the goals and objectives of UCVM. The noncognitive attributes of applicants (N = 110) were assessed at five stations, by two interviewers within each station, on three items using a standardized rating form on an anchored 1–5 scale. The method was determined to be reliable (G-coefficient = 0.88) and demonstrated evidence of validity. The MMI score did not correlate with grade-point average (r = 0.12, p = 0.22). While neither the applicants nor interviewers had participated in an MMI format before, both groups reported the process to be acceptable in a post-interview questionnaire. This analysis provides preliminary evidence of the reliability, validity, and acceptability of the MMI in assessing the noncognitive attributes of applicants for veterinary medical school admissions.

10 May 2019 in Systematic Reviews
Verified
Journal Article
Open access
PDF file
AMAbraham Munene
Abraham Munene
DHDavid C. Hall
David C. Hall
An estimated four million and 43 million people in Canada and the USA use private water supplies. Private water supplies are vulnerable to waterborne disease outbreaks. Private water supplies in Canada and the USA are often unregulated and private water management is often a choice left to the owner. Perceptions of water quality become important in influencing the adoption of private water stewardship practices, therefore safeguarding public health. We conducted a systematic literature review to understand factors that shape perceptions of water quality among private water users. We searched six computer databases (Web of science, Medline, Scopus, EBSCO, PubMed and Agricola). The search was limited to primary peer-reviewed publications, grey literature and excluded conference proceedings, review articles, and non-peer review articles. We restricted the search to papers published in English and to articles which published data on surveys of private water users within Canada and the USA. The search was also restricted to publications from 1986 to 2017. The literature search generated 36,478 records. Two hundred and four full text were reviewed. Fifty-two articles were included in the final review. Several factors were found to influence perceptions of water quality including organoleptic preferences, chemical and microbiological contaminants, perceived risks, water well infrastructure, past experience with water quality, external information, demographics, in addition to the values, attitudes, and beliefs held by well owners. Understanding the factors that shape perceptions of water quality among private water users is an important step in developing private water management policies to increase compliance towards water testing and treatment in Canada and the USA. As many jurisdictions in Canada and the USA do not have mandatory private water testing or treatment guidelines, delineating these factors is an important step in informing future research and guiding policy on the public health of private water systems.

1 January 2004 in Journal of Agricultural and Environmental Ethics
Verified
Journal Article
Closed access
PDF file
DHDavid C. Hall
David C. Hall
SESimeon Ehui
Simeon Ehui
CDChristopher Delgado
Christopher Delgado