Barrett D. Slenning

Global Climate Change and Implications for Disease Emergence

The early consequences of global climate change (GCC) are well documented. However, future impacts on ecosystem health, and on the health of humans, domestic animals, and wildlife, are much less well understood. Evidence of increasing frequency of extreme weather events (the 2003 trans-European heat wave, extended droughts in Australia and South America), of geographic changes in vector-borne disease (bluetongue and hanta viruses emerging in northern Europe, dengue virus expanding in central and northern America), and of altered animal behavioral responses (changes in bird migration patterns and fishery numbers) warrants action. To make valid choices, however, practitioners and decision makers must understand what is known about GCC and what is only theory. There will be a multitude of microbial, vector, and host responses to climate change, for example, and not all organisms will respond similarly or across equal time scales. Unfortunately, for many organisms and ecosystems the scientific community has a relatively poor understanding of current effectors and balances, making it problematic to describe the current situation, let alone to validate future predictions. The need for enhanced basic research and systematic surveillance programs is obvious, but putting such programs into place is daunting. However, the threats are real and fast approaching. What is done in the next few years may be decisive, whether for the good or the ill of all.

Decision analysis: dealing with uncertainty in diagnostic testing.

Decision analysis is a process for systematically analyzing complex choices by considering all pertinent information. In this paper, we discuss how uncertainty associated with diagnostic testing can be included in a decision analysis using pay-off tables and decision trees (decision-flow diagrams). Variables associated with diagnostic test interpretation (such as pre-test and post-test probability of disease; test sensitivity, specificity and predictive values; fixed cut-offs versus continuous measurement scales; test dependence associated with the use of multiple tests) are considered. Several decision criteria and output measures are discussed (including MAXIMIN and MAXIMAX criteria, opportunity costs, expected monetary values, expected utility, sensitivity and risk-profile analysis, and threshold analysis). The application of decision analysis to diagnostic testing for Johnes disease and traumatic reticuloperitonitis of cattle, and for canine heartworm disease are used to illustrate both population- and patient-oriented applications and criteria for ranking the desirability of different outcomes.

Second-order modeling of variability and uncertainty in microbial hazard characterization

This study describes an analytical framework that permits quantitative consideration of variability and uncertainty in microbial hazard characterization. Second-order modeling that used two-dimensional Monte Carlo simulation and stratification into homogeneous population subgroups was applied to integrate uncertainty and variability. Specifically, the bootstrap method was used to simulate sampling error due to the limited sample size in microbial dose-response modeling. A data set from human feeding trials with Campylobacter jejuni was fitted to the log-logistic dose-response model, and results from the analysis of FoodNet surveillance data provided further information on variability and uncertainty in Campylobacter susceptibility due to the effect of age. Results of our analyses indicate that uncertainty associated with dose-response modeling has a dominating influence on the analytical outcome. In contrast, inclusion of the age factor has a limited impact. While the advocacy of more closely modeling variability in hazard characterization is warranted, the characterization of key sources of uncertainties and their consistent propagation throughout a microbial risk assessment actually appear of greater importance.

Estrus detection efficiency and the effects of using prostaglandin-F2α in a commercial dairy herd

Abstract The purpose of this study was to define the biological efficiency of a standard estrus detection regimen, both with and without use of prostaglandin-F2α, under commercial dairy conditions. At regular pre-breeding examinations, cows were allocated randomly to two cohorts: (1) prostaglandin (PT) — cows with palpable corpora lutea were injected with 25 mg dinoprost tromethamine and bred 72 and 96 h later; and (2) heat detection (HD) — cows identified as being “in heat” through twice daily observation with tail chalking were bred ∼ 12 h later. Age, body weight, milk production and reproductive data were collected for all cows, as were milk samples for progesterone analysis. Prostaglandin use significantly affected the sensitivity of the estrus detection test, lowering it by half (0.26 vs. 0.53), plus it increased the proportion of false negatives by 61% (0.34 vs. 0.21) over controls. Consequently, the predictive value of a positive test in the PT cohort was lowered by 14% (0.79 vs. 0.90) compared with control animals. Over both cohorts, the standard estrus detection test displayed a low sensitivity and a high specificity, characteristic of a diagnostic test, but not of a screening test. The findings from this dairy suggest that current recommended estrus detection procedures may be inappropriate for their declared purpose of being screening tests for estrus and that routine prostaglandin use may exacerbate the problem.

Preparedness and Disaster Response Training for Veterinary Students: Literature Review and Description of the North Carolina State University Credentialed Veterinary Responder Program

The nations veterinary colleges lack the curricula necessary to meet veterinary demands for animal/public health and emergency preparedness. To this end, the authors report a literature review summarizing training programs within human/veterinary medicine. In addition, the authors describe new competency-based Veterinary Credential Responder training at North Carolina State University College of Veterinary Medicine (NCSU CVM). From an evaluation of 257 PubMed-derived articles relating to veterinary/medical disaster training, 14 fulfilled all inclusion requirements (nine were veterinary oriented; five came from human medical programs). Few offered ideas on the core competencies required to produce disaster-planning and response professionals. The lack of published literature in this area points to a need for more formal discussion and research on core competencies. Non-veterinary articles emphasized learning objectives, commonly listing an incident command system, the National Incident Management System, teamwork, communications, and critical event management/problem solving. These learning objectives were accomplished either through short-course formats or via their integration into a larger curriculum. Formal disaster training in veterinary medicine mostly occurs within existing public health courses. Much of the literature focuses on changing academia to meet current and future needs in public/animal health disaster-preparedness and careers. The NCSU CVM program, in collaboration with North Carolina Department of Agriculture and Consumer Service, Emergency Programs and University of North Carolina at Chapel Hill School of Public Health, operates as a stand-alone third-year two-week core-curriculum training program that combines lecture, online, experiential, and group exercises to meet entry-level federal credentialing requirements. The authors report here its content, outcomes, and future development plans.

Perceptions of veterinarians regarding privatization of veterinary services delivery in Ghana and Jamaica

There are on-going reforms in the delivery of veterinary services in many developing countries, with privatization of certain veterinary activities as one of the approaches. In Jamaica, with the support of veterinarians, clinical aspects of veterinary services were privatized in 1992. In contrast, Ghanaian veterinarians are generally wary of the governments on-going privatization process. The objective of this study was to find out if perceptions of the veterinarians from these two countries on certain issues of privatization were sufficiently different to explain the willingness or reluctance to go into private practice. The response proportions for predominantly self-administered questionnaires were 83% (121/145) and 92% (35/38) for Ghana and Jamaica, respectively. There was a very good (92%) agreement in the perceptions of veterinarians in Ghana and Jamaica on a battery of 24 responses pertaining to privatization of veterinary services. Generally, the perceptions of the veterinarians in Ghana and Jamaica were similar even though the predominant delivery systems for animal health services were different. Therefore, reasons other than those examined in this study may explain the differences in willingness to go into private practice. The need to account for these other reasons is discussed.

Financial analysis of a clinical trial comparing simple estrus detection with estrus detection after prostaglandin-based appointment breeding in a commercial dairy herd in California, USA☆

Abstract An economic analysis of the outcomes from a clinical trial on dairy cow reproduction was performed. The trial compared two prospective cohorts from a California dairy herd of 670 cows: (1) a cohort of 56 cows initially treated with prostaglandin-F2α and appointment inseminated at 72 and 96 h post-treatment, followed in 7 days by estrus detection based breeding (PT); (2) a cohort of 53 cows that was managed strictly for estrus detection based breeding (HD). There were no significant differences between the cohorts for days in milk at conception, services per conception, or time to events. The economic analysis consisted of three parts: (1) a partial budget analysis of the two breeding strategies; (2) a deterministic decision analysis of the two practices; (3) a stochastic evaluation of the strategies. Both the deterministic and stochastic analyses used time value of money calculattions PT insemination cost the farm approximately

STOCHASTIC AND DETERMINISTIC MODELS FOR AGRICULTURAL PRODUCTION NETWORKS

32 compared with an HD cost of approximately

Effects of sample storage and delayed secondary enrichment on detection of Salmonella spp in swine feces.

17. However, the costs of getting the average animal pregnant were approximately respectively. Expected monetary values were

Comparison of storage methods for reverse-transcriptase PCR amplification of rotavirus RNA from gorilla (Gorilla g. gorilla) fecal samples.

588 and