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Mortality from cerebrospinal parelaphostrongylosis caused by the meningeal worm (Parelaphostrongylus tenuis) has been hypothesized to limit elk (Cervus elaphus nelsoni) populations in areas where elk are conspecific with white-tailed deer (Odocoileus virginianus). Elk were reintroduced into Michigan (USA) in the early 1900s and subsequently greatly increased population size and distribution despite sympatric high-density (>or=12/km2) white-tailed deer populations. We monitored 100 radio-collared elk of all age and sex classes from 1981-94, during which time we documented 76 mortalities. Meningeal worm was a minor mortality factor for elk in Michigan and accounted for only 3% of mortalities, fewer than legal harvest (58%), illegal kills (22%), other diseases (7%), and malnutrition (4%). Across years, annual cause-specific mortality rates due to cerebrospinal parelaphostrongylosis were 0.033 (SE=0.006), 0.029 (SE=0.005), 0.000 (SE=0.000), and 0.000 (SE=0.000) for calves, 1-yr-old, 2-yr-old, and >or=3-yr-old, respectively. The overall population-level mortality rate due to cerebrospinal parelaphostrongylosis was 0.009 (SE=0.001). Thus, meningeal worm had little impact on elk in Michigan during our study despite greater than normal precipitation (favoring gastropods) and record (>or=14 km2) deer densities. Further, elk in Michigan have shown sustained population rates-of-increase of >or=18%/yr and among the highest levels of juvenile production and survival recorded for elk in North America, indicating that elk can persist in areas with meningeal worm at high levels of population productivity. It is likely that local ecologic characteristics among elk, white-tailed deer, and gastropods, and degree of exposure, age of elk, individual and population experience with meningeal worm, overall population vigor, and moisture determine the effects of meningeal worm on elk populations.

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. Key words bovine tuberculosis, Mycobacterium bovis, occupational safety, wildlife disease surveillanceFollowing internal discussions, we determined From the Field • O'Brien et al. 993