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Geology topics

T.J. Roffe

Publications and source records attributed to T.J. Roffe.

9 recordsLinked to original sources
USGS2005

Wildlife health and disease investigations

Wildlife population management requires knowledge of factors that affect population sustainability. Mortality is one of the most important of those factors. Without a clear understanding of the causes of mortality, decisions by managers of whether or how to intercede may be inappropriate. Wildlife biologists are usually the first to discover, assess, and respond to wildlife mortality. Biologists who make accurate, complete and timely field investigations, and proper collection and shipment of samples to a diagnostic facility are essential for an accurate diagnosis. In combination with wildlife disease specialists, biologists can identify causes of wildlife mortality, detect long-term patterns in factors that affect the survival of populations, and take appropriate corrective action to minimize the impact of some mortality factors on wildlife populations.

Book chapter↗
USGS2004

Efficacy of single calfhood vaccination of elk with Brucella abortus strain 19

Brucellosis has been eradicated from cattle in the states of Wyoming, Montana, and Idaho, USA. However, free-ranging elk (Cervus elaphus) that use feedgrounds in the Greater Yellowstone Area (GYA) and bison (Bison bison) in Yellowstone and Grand Teton national parks still have high seroprevalence to the disease and have caused loss of brucellosis-free status in Wyoming. Management tools to control or eliminate the disease are limited; however, wildlife vaccination is among the methods currently used by wildlife managers in Wyoming. We conducted a controlled challenge study of single calfhood vaccination. Elk calves, caught in January and February of 1999 and 2000 and acclimated to captivity for 3 weeks, were randomly assigned to control or vaccinate groups. The vaccinate groups received Brucetta abortus vaccine strain 19 (S19) by hand-delivered intramuscular injection. Calves were raised to adulthood and bred at either 2.5 or 3.5 years of age for 2000 and 1999 captures, respectively. Eighty-nine (44 controls, 45 vaccinates) pregnant elk entered the challenge portion of the study. We challenged elk at mid-gestation with pathogenic B. abortus strain 2308 by intraconjunctival instillation. Abortion occurred in significantly more (P = 0.002) controls (42; 93%) than vaccinates (32; 71%), and vaccine protected 25% of the vaccinate group. We used Brucella culture of fetus/calf tissues to determine the efficacy of vaccination for preventing infection, and we found that the number of infected fetuses/calves did not differ between controls and vaccinates (P = 0.14). Based on these data, single calfhood vaccination with S19 has low efficacy, will likely have only little to moderate effect on Brucella prevalence in elk, and is unlikely to eradicate the disease in wildlife of the GYA.

Journal of Wildlife Management↗
USGS2001

Pathology of brucellosis in bison from Yellowstone National Park

Between February 1995 and June 1999, specimens from seven aborted bison ( Bison bison ) fetuses or stillborn calves and their placentas, two additional placentas, three dead neonates, one 2-wk-old calf, and 35 juvenile and adult female bison from Yellowstone National Park (USA) were submitted for bacteriologic and histopathologic examination. One adult animal with a retained placenta had recently aborted. Serum samples from the 35 juvenile and adult bison were tested for Brucella spp. antibodies. Twenty-six bison, including the cow with the retained placenta, were seropositive, one was suspect, and eight were seronegative. Brucella abortus biovar 1 was isolated from three aborted fetuses and associated placentas, an additional placenta, the 2-wk-old calf, and 11 of the seropositive female bison including the animal that had recently aborted. Brucella abortus biovar 2 was isolated from one additional seropositive adult female bison. Brucella abortus was recovered from numerous tissue sites from the aborted fetuses, placentas and 2-wk-old calf. In the juvenile and adult bison, the organism was more frequently isolated from supramammary (83%), retropharyngeal (67%), and iliac (58%) lymph nodes than from other tissues cultured. Cultures from the seronegative and suspect bison were negative for B. abortus . Lesions in the B. abortus -infected, aborted placentas and fetuses consisted of necropurulent placentitis and mild bronchointerstitial pneumonia. The infected 2-wk-old calf had bronchointerstitial pneumonia, focal splenic infarction, and purulent nephritis. The recently-aborting bison cow had purulent endometritis and necropurulent placentitis. Immunohistochemical staining of tissues from the culture-positive aborted fetuses, placentas, 2-wk-old calf, and recently-aborting cow disclosed large numbers of B. abortus in placental trophoblasts and exudate, and fetal and calf lung. A similar study with the same tissue collection and culture protocol was done using six seropositive cattle from a B. abortus -infected herd in July and August, 1997. Results of the bison and cattle studies were similar.

Wyoming↗
USGS1999

Biosafety of parenteral Brucella abortus RB51 vaccine in bison calves

Vaccination is considered among the primary management tools for reducing brucellosis prevalence in Greater Yellowstone Area (GYA) ungulates. Before their use, however, vaccine safety and efficacy must be demonstrated. Twenty-seven female bison (Bison bison) calves (approx 5 months old) were vaccinated with Brucella abortus Strain RB51 (1.5 × 1010 colony forming units [CFU], subcutaneously) as part of routine management. We assessed the persistence, pathology, shedding, and transmission associated with RB51 by serial necropsy, bacteriology, histopathology, and serology of 20 of these 27 vaccinated calves, and RB51 serology of 10 nonvaccinated, commingling adult females. With the exception of 1 calf, RB51 dot-blot titers at necropsy were <1:80. Strain RB51 was cultured from lymph nodes in 4 of 4 calves at 14 weeks postvaccination (PV), 4 of 4 calves at 18 weeks PV, 1 of 4 calves at 22 weeks PV, 3 of 4 at 26 weeks PV, and 0 of 4 calves at 30 weeks PV. No gross lesions were observed. Mild histologic changes occurred only in a few draining lymph nodes early in sampling. Adverse clinical effects were not observed in vaccinates. Swabs from nasopharynx, conjunctiva, rectum, and vagina were uniformly culture negative for RB51. Strain RB51 dot-blot assays of bison cows were negative at a 1:20 dilution at 26 weeks PV. Our results suggest that RB51 persists longer in bison calves than in domestic cattle and is systemically distributed within lymphatic tissues. However, bison apparently clear the RB51 vaccine strain without shedding, transmission, or significant adverse reactions.

Journal of Wildlife Management↗
USGS1999

Brucellosis in Yellowstone National Park bison: Quantitative serology and infection

We collected complete sets of tissues, fluids, and swabs (approx 30) from 37 Yellowstone National Park (YNP) female bison (Bison bison) killed as a result of management actions by the Montana Department of Livestock and YNP personnel. Our goal was to establish the relation between blood tests demonstrating an animal has antibody to Brucella and the potential of that animal to be infected during the second trimester of pregnancy, the time when most management actions are taken. Twenty-eight of the 37 bison were seropositive adults (27) or a seropositive calf (1). We cultured samples using macerated whole tissues plated onto 4 Brucella-selective media and incubated with added CO2 for 1 week. Specimens from 2 adult seropositive females were contaminated, thus eliminating them from our data. Twelve of the remaining 26 seropositive adult and calf female bison (46%) were culture positive for Brucella abortus from 1 or more tissues. Culture positive adult females had high serologic titers. All 11 adults measured <0.115 on the Particle Concentration Fluorescence Immunoassay (PCFIA), and 9 (82%) were <0.085. Complement fixation (CF) titers were >3+ at 1:40 for 10 of 11 (91%) animals. All culture positive female adults had either a PCFIA ???0.080 or a CF reaction ???4+ at 1:80. However 5 (36%) bison with high titers were culture negative for B. abortus. Our findings on the relation between Brucella serology and culture are similar to those reported from studies of chronically infected cattle herds.

Journal of Wildlife Management↗
USGS1993

Perinatal mortality in caribou from the Porcupine herd, Alaska

During the 1989 caribou ( Rangifer tarandus ) calving season on the Arctic National Wildlife Refuge, Alaska (USA), 61 calf carcasses were examined for cause of death and associated pathology. Dead calves were located by low-level aerial searches with two fixed-wing aircraft and a helicopter over high density calving areas between the Hulahula and Aichilik rivers. Primary diagnoses included emaciation (39%), malnutrition (8%), stillbirth (21%), trauma (16%), other primary causes (7%), and undetermined causes (8%). Twenty calves had contributory renal tubular degeneration. The findings indicate that factors contributing to nutritional deprivation in calves were the major cause of neonatal mortality; however, factors affecting stillbirth, abortion, or the urogenital system may have major effects on neonatal caribou and warrant further investigation.

Alaska↗
USGS1992

Brucellosis: a political disease

With the challenges confronting North America's elk herds today, a bacteria that causes a nonfatal disease in a few elk herds seems an unlikely addition to the list. Fragmentation of habitat, dwindling bull-cow ratios, grazing competition from livestock on public rangelands, or the crowding of favorite hunting spots all seem like far more urgent matters to elk junkies. But a twist of fate an a national campaign to eradicate this seemingly innocuous bacterium have put brucellosis on the front burner.

Bugle↗
USGS1992

Tuberculosis: Will it infect wild elk?

Tuberculosis! Just the name conjures up images of a devastating, chronic, debilitating disease. And so it is in both humans and animals. Tuberculosis (TB) is not known to be present to any significant degree in the free-ranging elk herds of North America. But increasing reports of TB in deer species-including elk-on game ranches prompt grave concern.

Bugle↗