Melinda K. Cosgrove

EVALUATION OF BLOOD ASSAYS FOR DETECTION OF MYCOBACTERIUM BOVIS IN WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) IN MICHIGAN

Surveillance and control activities related to bovine tuberculosis (TB) in free-ranging, Michigan white-tailed deer (Odocoileus virginianus) have been underway for over a decade, with significant progress. However, foci of higher TB prevalence on private lands and limited agency ability to eliminate them using broad control strategies have led to development and trial of new control strategies, such as live trapping, testing, and culling or release. Such strategies require a prompt, accurate live animal test, which has thus far been lacking. We report here the ability of seven candidate blood assays to determine the TB infection status of Michigan deer. Our aims were twofold: to characterize the accuracy of the tests using field-collected samples and to evaluate the feasibility of the tests for use in a test-and-cull strategy. Samples were collected from 760 deer obtained via five different surveys conducted between 2004 and 2007. Blood samples were subjected to one or more of the candidate blood assays and evaluated against the results of mycobacterial culture of the cranial lymph nodes. Sensitivities of the tests ranged from 46% to 68%, whereas specificities and negative predictive values were all >92%. Positive predictive values were highly variable. An exploratory analysis of associations among several host and sampling-related factors and the agreement between blood assay and culture results suggested these assays were minimally affected. This study demonstrated the capabilities and limitations of several available blood tests for Mycobacterium bovis on specimens obtained through a variety of field surveillance methods. Although these blood assays cannot replace mass culling, information on their performance may prove useful as wildlife disease managers develop innovative methods of detecting infected animals where mass culling is publicly unacceptable and cannot be used as a control strategy.

Sarcoptic Mange in Raccoons in Michigan

Sarcoptic mange is a cause of pruritic skin disease in domestic dogs and a wide range of wildlife species. We describe sarcoptic mange in free-ranging raccoons (Procyon lotor). Three adult raccoons from upper Wayne County, Michigan (USA), were captured, killed, and submitted for diagnostic evaluation. The animals were intensely pruritic, and two had advanced alopecic and crusting lesions over their dorsum and hind limbs. Skin scrapings and skin biopsies revealed crusting and hyperkeratotic dermatitis with high numbers of Sarcoptes scabiei adults, larvae, nymphs, and eggs. These raccoons were not otherwise debilitated, with minimal internal parasites, good body condition, and no evidence of infectious bacterial or viral diseases. Because sarcoptic mange is highly contagious and affects many species, including humans, transiently, it is important that wildlife biologists and rehabilitators include sarcoptic mange in their differential list for raccoons exhibiting pruritus and alopecia.

Live-trapping and bovine tuberculosis testing of free-ranging white-tailed deer for targeted removal

Abstract Context. Significant efforts have been made in Michigan, USA, to reduce the prevalence of bovine tuberculosis (TB) in free-ranging white-tailed deer (Odocoileus virginianus) over the past 15 years. Since 2002, however, prevalence has changed little, prompting the need for new control strategies. Aims.. In January–March of 2007 and 2008, a trap–test–cull project was conducted on an 11 000-ha property in the north-eastern Lower Peninsula of Michigan. The objectives were to assess the feasibility of live-trapping and testing white-tailed deer for TB as a means for targeted removal and estimate the cost of this effort. Methods.. Live-trapped deer were ear-tagged and a blood sample was drawn for use with the CervidTB STAT-PAK (commonly called Rapid Test) for TB diagnosis in the field. Deer testing negative were released, whereas deer testing positive were euthanised to confirm blood-test results via bacterial culture. Key results.. In all, 762 (741 with known sex and age) individual deer were captured and tested for TB. Adults comprised 59% (437 of 741) of the captures. Eight (1.8%) adults were positive on the blood test; six of eight (1.4% of adults) were confirmed TB positive via bacterial culture. Estimated TB prevalence in the present study was 2.5% (adjusted for Rapid Test sensitivity of 56%), being lower than what would be expected on the basis of routine hunter-harvest surveillance for this site which has yielded prevalence rates from 3.4% to 4.8%. Results demonstrated the ability to trap and test a substantial number of deer given high deer densities (16–20 deer per km2), availability of traps and abundant workers. The 2-year project cost a total of ∼US

Comparison of techniques for sex determination of American martens

228 000, or US

Sarcoptic Mange and Pelodera Dermatitis in an American Black bear (Ursus americanus)

38 000 per culture-positive animal. Conclusions.. Because of the cost and effort involved, a project such as the present one applied to Michigan’s larger TB-management area (148 018 ha) is not feasible. Implications.. If the efficiency and effectiveness of a trap–test–cull project could be improved by vaccinating test-negative animals, should a vaccine be approved for use in free-ranging white-tailed deer, a trap–test–cull project applied on a scale similar to the present study may prove beneficial by possibly reducing disease transmission, in addition to removing TB-positive animals.

Sex-Age Selectivity and Correlates of Capture for Winter-Trapped White-Tailed Deer

ABSTRACT Accurate determination of sex in harvested species is critical for understanding demography and developing population models for management. We used genetic-based sex identification to assess accuracy of external carcass and pelt examination at registration and maximum canine root area (MRA) to determine sex of American martens (Martes americana) trapped in the Upper Peninsula of Michigan, 2000–2004. Overall percent similarity between MRA and genetic-based sex determination was 98.4% (n = 188). In contrast, only 84.6% (n = 421) of martens were similarly classified using external examination. For external examination, percent similarity to genetic-based sex determination for juveniles (<1-yr old) and adults (≥1-yr old; Wald &khgr;21 = 2.168, P = 0.141), as well as for males and females (Wald &khgr;21 = 0.005, P = 0.946), was similar. We recommend MRA as a suitable technique for sex determination of martens; thus, marten sex and age (using cementum annuli counts) can be obtained from one lower canine tooth. We do not recommend use of external examination at registration to identify sex of martens without implementing additional quality assurance measures.

Serum 25-hydroxyvitamin D Concentrations in Captive and Free-ranging, White-tailed Deer (Odocoileus virginianus)

Abstract An adult female free-ranging American black bear (Ursus americanus) was presented in poor body condition, with advanced skin disease. Skin changes included hair loss, lichenification, crusting, and focal erosions. Skin scrapings and histopathology identified two distinct parasitic conditions that were contributing to this animals dermatitis. Large numbers of larvae, nymphs, and adults of Sarcoptes scabiei were present in the superficial epidermis, and nematodes consistent with Pelodera strongyloides were abundant within the hair follicles. This appears to be the first reported case of Pelodera dermatitis in a bear species, adding a new differential agent to the list for dermatitis in bears. The sarcoptic mange and poor body condition of this bear may have been contributing factors to the development of the opportunistic Pelodera infestation.

An occupational safety program for wildlife professionals involved with bovine tuberculosis surveillance

Abstract Despite the common use of Clover traps to capture white-tailed deer (Odocoileus virginianus), little published information exists quantifying trap success, trap selectivity (sex-age selection), or weather correlates of trap success. We quantified these relationships using white-tailed deer data from 3 study sites in the Lower Peninsula of Michigan, USA, during winters 2001–2007. We captured 610 deer in 8,569 trap-nights; pooled capture success was 0.07 deer/trap-night, although site-year success varied from 0.021 to 0.086. We compared sex-age classes (fawn [pooled by sex], ad M, ad F) captured with sex-age classes estimated to be available on each study site during each capture season. We used generalized linear mixed modeling to construct 19 a priori models to describe probability of capture success as a function of weather covariates (daily min. temp [° C], daily snowfall [cm], daily snow depth [cm]), Julian day, site, and year. General selection patterns included fawns captured more than expected and adult males captured less than expected; adult females were generally neutrally selected. The quasi-Akaikes Information Criterion best model within our set was described by the global model without Julian day and contained all 3 weather covariates and site-year effects. Our model provided some evidence that as daily snow depth increased, probability of capture increased; the positive effect of daily snowfall on capture probability was dependent on decreasing daily minimum temperature. Our results may be used to increase efficacy of deer capture programs by researchers and managers through informed decision-making about when to allocate effort (e.g., if extreme winter weather conditions are predicted) and when to consider alternative methods (e.g., if capture of ad M is an objective).

Performance of Diagnostic Tests for Bovine Tuberculosis in North American Furbearers and Implications for Surveillance

Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were determined for free-ranging and captive white-tailed deer (WTD). Effects of gender, season, and age on 25(OH)D concentrations were determined as well as comparisons to concentrations in serum from captive reindeer and elk. Seasonal variations in 25(OH)D concentrations were detected for both captive and free-ranging WTD with greatest concentrations detected in August/September (approximately 25 ng/mL) and lowest concentrations in February (approximately 5 - 10 ng/mL). Free-ranging WTD < 1 year of age had lower 25(OH)D concentrations (approximately 6 ng/mL) than did free-ranging WTD > 1 year of age (approximately12 ng/mL). For captive WTD fawns, 25(OH)D concentrations increased from 1 to 9 days of age (exceeding 100 ng/mL) and then steadily declined to approximately 10 ng/mL by 3 months of age. In general, differences in 25(OH)D concentrations based on gender were not detected. 25(OH)D concentrations in captive WTD did not differ from that of captive reindeer; yet, 25(OH)D concentrations were lower in WTD than in captive elk. Additional research is necessary to determine if low serum 25(OH)D concentrations during the winter or pre-weaning period are associated with increased rates of infectious and metabolic disease.

Forecasting eradication of bovine tuberculosis in Michigan white-tailed deer

Abstract The discovery of bovine tuberculosis (caused by Mycobacterium bovis) in white-tailed deer (Odocoileus virginianus) and other free-ranging Michigan wildlife has made ongoing surveillance for the disease a reality for wildlife professionals. The wide susceptibility of mammals, including humans, to M. bovis led us to be concerned with the potential risks of acquiring tuberculosis that Michigan Department of Natural Resources staff face in their occupational activities. Consequently, we developed a bovine tuberculosis occupational safety program for our staff and volunteer cooperators taking part in disease surveillance. Close similarities between bovine and human tuberculosis allowed occupational safety principles used in human health care to be used as a guide. We produced an occupational safety training document to educate personnel about bovine tuberculosis in humans, evaluate the risk posed by job duties, and make recommendations on risk mitigation. Following implementation, the National Institute for Occupational Safety and Health conducted field evaluations of the occupational safety program that validated its protectiveness for workers. As wildlife disease surveillance becomes a greater responsibility for management agencies across the United States, we believe the lessons learned in development of the Michigan program can be widely adapted to other areas and potentially to other diseases, and can raise awareness of occupational exposure to zoonotic diseases.