scholarly journals Surveillance and movements of Virginia opossum (Didelphis virginiana) in the bovine tuberculosis region of Michigan

2013 ◽  
Vol 141 (7) ◽  
pp. 1498-1508 ◽  
Author(s):  
W. D. WALTER ◽  
J. W. FISCHER ◽  
C. W. ANDERSON ◽  
D. R. MARKS ◽  
T. DELIBERTO ◽  
...  

SUMMARYWildlife reservoir hosts of bovine tuberculosis (bTB) include Eurasian badgers (Meles meles) and brushtail possum (Trichosurus vulpecula) in the UK and New Zealand, respectively. Similar species warrant further investigation in the northern lower peninsula of Michigan, USA due to the continued presence of bTB on cattle farms. Most research in Michigan, USA has focused on interactions between white-tailed deer (Odocoileus virginianus) and cattle (Bos taurus) for the transmission of the infectious agent of bTB, Mycobacterium bovis, due to high deer densities and feeding practices. However, limited data are available on medium-sized mammals such as Virginia opossum (Didelphis virginiana; hereafter referred to as opossum) and their movements and home range in Michigan near cattle farms. We conducted surveillance of medium-sized mammals on previously depopulated cattle farms for presence of M. bovis infections and equipped opossum with Global Positioning System (GPS) technology to assess potential differences in home range between farms inside and outside the bTB core area that has had cattle test positive for M. bovis. On farms inside the bTB core area, prevalence in opossum was comparable [6%, 95% confidence interval (CI) 2·0–11·0] to prevalence in raccoon (Procyon lotor; 4%, 95% CI 1·0–9·0, P = 0·439) whereas only a single opossum tested positive for M. bovis on farms outside the bTB core area. The prevalence in opossum occupying farms that had cattle test positive for M. bovis was higher (6·4%) than for opossum occupying farms that never had cattle test positive for M. bovis (0·9%, P = 0·01). Mean size of home range for 50% and 95% estimates were similar by sex (P = 0·791) both inside or outside the bTB core area (P = 0·218). Although surveillance efforts and home range were not assessed on the same farms, opossum use of farms near structures was apparent as was selection for farms over surrounding forested habitats. The use of farms, stored feed, and structures by opossum, their ability to serve as vectors of M. bovis, and their propensity to ingest contaminated sources of M. bovis requires additional research in Michigan, USA.

2013 ◽  
Vol 141 (7) ◽  
pp. 1407-1416 ◽  
Author(s):  
I. J. YOCKNEY ◽  
G. NUGENT ◽  
M. C. LATHAM ◽  
M. PERRY ◽  
M. L. CROSS ◽  
...  

SUMMARYSentinel species are increasingly used by disease managers to detect and monitor the prevalence of zoonotic diseases in wildlife populations. Characterizing home-range movements of sentinel hosts is thus important for developing improved disease surveillance methods, especially in systems where multiple host species co-exist. We studied ranging activity of major hosts of bovine tuberculosis (TB) in an upland habitat of New Zealand: we compared home-range coverage by ferrets (Mustela furo), wild deer (Cervus elaphus), feral pigs (Sus scrofa), brushtail possums (Trichosurus vulpecula) and free-ranging farmed cattle (Bos taurus). We also report in detail the proportional utilization of a seasonal (4-monthly) range area for the latter four species. Possums covered the smallest home range (<30 ha), ferrets covered ∼100 ha, pigs ∼4 km2, deer and cattle both >30 km2. For any given weekly period, cattle, deer and pigs were shown to utilize 37–45% of their estimated 4-month range, while possums utilized 62% during any weekly period and 85% during any monthly period of their estimated 4-month range. We suggest that present means for estimating TB detection kernels, based on long-term range size estimates for possums and sentinel species, probably overstate the true local surveillance coverage per individual.


2019 ◽  
Vol 31 (2) ◽  
pp. 330-339 ◽  
Author(s):  
Katie K Y Wat ◽  
Anushika P H M Herath ◽  
Adrian I Rus ◽  
Peter B Banks ◽  
Clare Mcarthur

Abstract Personality traits shape individual perceptions of risks and rewards, and so, should affect how animals value and use their environment. Evidence is emerging that personality affects foraging, space use, and exploitation of novel environments such as urban habitat. But the influence of personality is also hypothesized to be sex-dependent when primary motivation for space use differs between sexes, as often occurs in polygynous species. We tested the influence of personality traits, interacting with sex, on space use by the polygynous common brushtail possum, Trichosurus vulpecula, in an urban-woodland boundary in Sydney, Australia. We quantified personality traits, including exploration, using behavioral assays in an artificial arena. We also GPS-tracked free-ranging individuals, and measured range size, core area: home range, and proportional urban range. We found that personality traits affected space use either as a main effect or, as predicted, an interaction with sex. More exploratory animals, regardless of sex, had higher core area: home range ratios and proportionally larger ranges within urban habitat. However, less exploratory females yet more exploratory males had larger ranges. Our findings provide new insight into movement ecology by demonstrating, for the first time, the sex-dependent influence of personality. The demonstrated influence of personality on urban use by possums also suggests a personality filter for wildlife, as populations transition into urban areas. Finally, as individuals at the interface between urban and natural habitat are also a conduit between the two, a corollary of our findings is that there may be personality-mediated spread of disease across this boundary.


Author(s):  
Tabassom Sedighi ◽  
Liz Varga

Controlling bovine tuberculosis (bTB) disease in cattle farms in England is seen as a challenge for farmers, animal health, environment and policy-makers. The difficulty in diagnosis and controlling bTB comes from a variety of factors: the lack of an accurate diagnostic test which is higher in specificity than the currently available skin test; isolation periods for purchased cattle; and the density of active badgers, especially in high-risk areas. In this paper, to enable the complex evaluation of bTB disease, a dynamic Bayesian network (DBN) is designed with the help of domain experts and available historical data. A significant advantage of this approach is that it represents bTB as a dynamic process that evolves periodically, capturing the actual experience of testing and infection over time. Moreover, the model demonstrates the influence of particular risk factors upon the risk of bTB breakdown in cattle farms.


2012 ◽  
Vol 48 (No. 3) ◽  
pp. 51-65 ◽  
Author(s):  
M. Machackova ◽  
L. Matlová ◽  
J. Lamka ◽  
J. Smolík ◽  
IMelicharek ◽  
...  

Infected animals in the wild, which can act as a reservoir and/or vector for the origin of bovine tuberculosis, are a great problem for national programmes seeking to free herds of cattle from the infection. The circulation of Mycobacterium bovis in the wild animal population might cause a slow-down in the progress of control programmes through the reinfection of herds of livestock. The Eurasian badger (Meles meles) and red deer (Cervus elaphus) living in the wild in Great Britain and Ireland, brushtail possum (Trichosurus vulpecula), ferrets (Mustela putorius f. furo) in New Zealand and wild buffalo (Bubalus arnee) in Australia are among already known reservoirs and vectors of bovine tuberculosis. In 7 countries of Central Europe (Bosnia and Herzegovina, Croatia, Czech Republic, Hungary, Poland, Slovakia and Slovenia) bovine tuberculosis in ca􀄴le was controlled as part of national control programmes more than 20 years ago. In the last decade M. bovis has been diagnosed extremely sporadically in cattle and other domestic animals as well as in wild animals held in captivity or living in the wild. This favour&shy;able situation could be threatened by the mycobacteria spreading via the wild boar (Sus scrofa) which is susceptible to mycobacterial infection and very abundant in Central Europe. According to available literary data, mycobacteria were detected in 361 wild boar originating from countries other than those of Central Europe, such as Australia, Bulgaria, Germany, the Hawaiian island of Molokai, Italy and Spain. M. tuberculosis complex (33.9%) and M. bovis complex (39.8%) isolates were most frequently detected in the faeces and/or parenchymatous organs of wild boar. Of other mycobacterial species, M. intracellulare (3.8%), M. avium subsp. avium (3.8%), M. terrae (2.4%), M. fortuitum (2.2%), M. scrofulaceum (2.2%), M. gordonae (0.8%), M. simiae (0.5%), M. szulgai (0.5%), M. xenopi (0.5%), M. smegmatis (0.2%), M. vaccae (0.2%), fast-growing, further unspecified species (0.2%) and unidentified mycobacteria (8.8%) were isolated. Following the analysis of literary data and our own results, it was found that, in the area covered by the above-mentioned 7 countries of Central Europe, a total of 431 wild boar were examined for mycobacterial infections in the years 1983&ndash;2001. Tuberculous lesions in parenchymatous organs were found in 43 (10.0%) animals. M. bovis was identified in 22 (5.1%) animals, M. a. avium in 2 (0.4%), M. a. paratuberculosis in 1 (0.2%) animal and atypical mycobacteria in 27 (6.3%) animals. The wild boar may therefore represent, under certain unfavourable epizootio&shy;logical conditions, a vector of some mycobacterial infections in not only animals, but also humans.


2019 ◽  
Vol 6 (2) ◽  
pp. 180719 ◽  
Author(s):  
Helen R. Fielding ◽  
Trevelyan J. McKinley ◽  
Matthew J. Silk ◽  
Richard J. Delahay ◽  
Robbie A. McDonald

Network analyses can assist in predicting the course of epidemics. Time-directed paths or ‘contact chains' provide a measure of host-connectedness across specified timeframes, and so represent potential pathways for spread of infections with different epidemiological characteristics. We analysed networks and contact chains of cattle farms in Great Britain using Cattle Tracing System data from 2001 to 2015. We focused on the potential for between-farm transmission of bovine tuberculosis, a chronic infection with potential for hidden spread through the network. Networks were characterized by scale-free type properties, where individual farms were found to be influential ‘hubs' in the network. We found a markedly bimodal distribution of farms with either small or very large ingoing and outgoing contact chains (ICCs and OCCs). As a result of their cattle purchases within 12-month periods, 47% of British farms were connected by ICCs to more than 1000 other farms and 16% were connected to more than 10 000 other farms. As a result of their cattle sales within 12-month periods, 66% of farms had OCCs that reached more than 1000 other farms and 15% reached more than 10 000 other farms. Over 19 000 farms had both ICCs and OCCs reaching more than 10 000 farms for two or more years. While farms with more contacts in their ICCs or OCCs might play an important role in disease spread, farms with extensive ICCs and OCCs might be particularly important by being at higher risk of both acquiring and disseminating infections.


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