Craniometric variation in the Eurasian badger, Meles meles

A multivariate examination of cranial variation within and between European populations of Meles meles (L.) revealed that populations from Ireland, Great Britain, Norway, and the Slovak Republic could be differentiated both by cranial form and by the degree of sexual dimorphism exhibited. Irish material was characterized by low sexual dimorphism, particularly when compared to Slovak specimens. Badgers from the British Isles had larger skulls than other samples and were more similar to each other than they were to badgers from mainland Europe. Size played a greater role in differentiating samples of female badgers than it did in males. Significant variation occurred within the British Isles, with individual samples being highly differentiable. There was, however, little relationship between morphological similarity and geographic proximity. We contend that macrogeographical (between-country) variation in the species is primarily determined by historical factors and adaptation to current conditions, while microgeographic (within-country) variation is a result of selectively neutral processes.     

Morphological and meristic differences among spawning aggregations of north-east Atlantic herring, Clupea harengus L.

Univariate and multivariate analyses were performed on seven anatomical characters of Atlantic herring, Clupea harengus , sampled from seven discrete spawning grounds to the west of the British Isles and from spawning sites in the Baltic and Thames Estuary. Analysis of mean similarities, Mahalanobis D², percentage overlap and projections from prinicipal co-ordinate analysis demonstrated that a high degree of anatomical similarity exists among the herring spawning communities to the west of the British Isles. Although local aggregations had distinct centres of abundance they appeared to have large overlapping distributions. However, the Celtic Sea sample was found to be distinctly different from adjacent and neighbouring stocks. The samples of coastal herring from the Thames Estuary and the Baltic Sea showed little overlap with other samples.     

MORBILLIVIRUS INFECTION IN MANATEES

The first evidence of exposure of free-ranging Florida manatees ( Trichechus manatees latirostris ) to a morbillivirus is reported. Blood samples were collected from 148 Florida manatees between 1977 and 1994. The sample included manatees that were under rehabilitation (n = 97), free-ranging (n = 40) and fresh necropsy specimens (n = 11). Serum from six animals (4%) neutralized porpoise and dolphin morbilliviruses to a higher titer than any other member of the Morbillivirus genus. Antibodies were not detected in sera from 12 free-ranging Antillean manatees ( T. manatus manatus ) from Guyana sampled in 1992 or from 12 hand-reared Amazonian manatees ( T. inunguis ) sampled in 1984. Immunoprecipitation studies using radio-labelled canine distemper virus protein and serum from Florida manatees showed precipitation of the nucleo-capsid (N) protein. The combination of low antibody titers and absence of clinical disease suggest that the Florida manatee is a dead-end host. Sporadic infection may occur following contact with another species in which infection is enzootic. Morbillivirus could, either by fatal infection or more insidious effects on the immune system or reproduction, pose a problem to this already threatened species.     

Absence of antibodies against canine distemper virus in free-ranging populations of the Eurasian badger in Great Britain

Canine distemper virus (CDV) is a serious disease of wild carnivores throughout the world. In Europe, infection has been detected in several carnivores including the Eurasian badger (Meles meles). In the present study 182 badger blood samples were collected from an intensively studied population of wild badgers in southwestern England (January-July, 1997), and a further 286 from throughout southern Britain (June 1996-November 1998). A neutralizing peroxidase-linked antibody test was used for the detection of antibodies against CDV. All the samples were negative for CDV antibodies, suggesting that in contrast to mainland Europe, the disease may be either absent or maintained at low levels in British badgers.     

Antibodies to Toxoplasma gondii in Eurasian badgers

Antibodies to Toxoplasma gondii were detected in samples collected from 90 live-trapped adult Eurasian badgers (Meles meles) sampled at three sites (two agricultural and one woodland) in southern England. Serum was tested using a qualitative latex agglutination test procedure and 63 of 90 (70%) badgers tested positive for T. gondii antibodies. Antibody prevalence varied between the sites; 67% and 77% of badgers from agricultural sites and 39% from a nonagricultural site tested positive.     

Bovine tuberculosis in “Eurasian” badgers (Meles meles) in France

In France, several surveillance programmes have been carried out to monitor the presence of bovine tuberculosis (bTB) in badgers in regions where cattle or wildlife show high bTB prevalence (Seine-Maritime, Côte d’Or, Dordogne/Charente). Diagnostic methods include post-mortem examination, polymerase chain reaction (PCR) and/or microbiological culture. The frequency of visible lesions was significantly higher in Dordogne/Charente (14/283, 4.9 %) than in Côte d’Or (19/1146, 1.7 %) and Seine-Maritime (2/160, 1.25 %) (Fisher’s exact test, p?<?0.001). Lesions were mainly located in cephalic and thoracic lymph nodes with one badger showing generalised tuberculosis. Near infected cattle farms or pastures, Mycobacterium bovis was detected using the culture method in roughly 1 % (1/103) of the badgers sampled in Seine-Maritime and in 5.6 % (49/878) of the badgers sampled in Côte d’Or. In Dordogne/Charente, the prevalence determined by PCR was 13.3 % (29/218). M. bovis was not found in badgers trapped in areas where there are no infected cattle. Spoligotyping and multiple locus variable number tandem repeat analysis showed that all M. bovis strains isolated from badgers were of the same genotype as those isolated from cattle in the vicinity, demonstrating an epidemiological link between both species. These are the first cases of bTB in badgers reported in France. Further surveys and research are needed to investigate the role badgers play in the epidemiology of bTB.     

Importance of the wild boar in the epidemiology of wild trichinellosis in Piedmont and Liguria

Muscle samples from 1,508 wild boars (Sus scrofa) harvested in Piedmont and Liguria between 1987 and 1990 were examined for larvae of Trichinella sp. by trichinelloscopy and peptic digestion. No wild boar was infected, though trichinellosis was present in foxes (Vulpes vulpes) from the same areas (14 positives out of 608) with the highest prevalence in the mountain range (25.0%). Infection was also not found in 40 stone martens, 5 badgers and 3 stoats. Five vulpine isolates were identified as belonging to T3 zymodeme. These results show that free-ranging wild boars, although being a source of trichinellosis infection for man in Italy (9.2% of the 584 cases diagnosed since 1961), have no significance in maintaining the sylvatic cycle of this parasite in the study area. The data agree with the low infectivity of Italian strains of fox origin for swine seen in the experimental infections carried out so far.     

Vertically transmitted HIV infection in the British Isles.

OBJECTIVE--To describe the epidemiology of vertically acquired HIV infection in the British Isles, the level of underreporting, the vertical transmission rate, and clinical spectrum of paediatric AIDS. DESIGN--Confidential, linked registers based on reporting from obstetricians and paediatricians; anonymous unlinked neonatal HIV serosurveys. SETTING--British Isles. SUBJECTS--Children born to mothers with HIV infection. MAIN OUTCOME MEASURES--Trends in HIV infection and vertical transmission rate. RESULTS--In Scotland and the Irish Republic, where most maternal HIV infection is related to drug misuse, the annual number of reports of children born to infected mothers has fallen since 1989. In England and Wales nearly half of maternal infections have been acquired overseas, and the number of children born to these women, and to women who became infected in Britain, is increasing. In south east England the proportion of live births to women whose infection was identified before delivery was only 17% (50/287), compared with 68% (26/38) in Scotland. The vertical transmission rate was 13.7% (23/168), and 23% of infected children developed AIDS in the first year of life. 41% (38/92) of children born to infected mothers who were ascertained after delivery were breast fed, compared with 5% (12/236) of those ascertained before delivery. CONCLUSIONS--The incidence of vertically transmitted HIV infection is increasing in England and Wales. More extensive antenatal testing would enable infected women to be counselled against breast feeding, which could prevent a substantial proportion of vertical transmission in some areas, and would increase opportunities for early diagnosis and treatment of infected children.     

A Y chromosome census of the British Isles

The degree of population replacement in the British Isles associated with cultural changes has been extensively debated. Recent work has demonstrated that comparisons of genetic variation in the British Isles and on the European Continent can illuminate specific demographic processes in the history of the British Isles. For example, Wilson et al. used the similarity of Basque and Celtic Y chromosomes to argue for genetic continuity from the Upper Palaeolithic to the present in the paternal history of these populations (see also ). Differences in the Y chromosome composition of these groups also suggested genetic signatures of Norwegian influence in the Orkney Islands north of the Scottish mainland, an important center of Viking activities between 800 and 1300 A.D. More recently, Weale et al. argued for substantial Anglo-Saxon male migration into central England based on the analysis of eight British sample sets collected on an east-west transect across England and Wales. To provide a more complete assessment of the paternal genetic history of the British Isles, we have compared the Y chromosome composition of multiple geographically distant British sample sets with collections from Norway (two sites), Denmark, and Germany and with collections from central Ireland, representing, respectively, the putative invading and the indigenous populations. By analyzing 1772 Y chromosomes from 25 predominantly small urban locations, we found that different parts of the British Isles have sharply different paternal histories; the degree of population replacement and genetic continuity shows systematic variation across the sampled areas.     

Bovine tuberculosis (Mycobacterium bovis) in British farmland wildlife: the importance to agriculture

Bovine tuberculosis (bTB) is an important disease of cattle and an emerging infectious disease of humans. Cow- and badger-based control strategies have failed to eradicate bTB from the British cattle herd, and the incidence is rising by about 18%per year. The annual cost to taxpayers in Britain is currently 74 million UK pounds. Research has focused on the badger as a potential bTB reservoir, with little attention being paid to other mammals common on farmland. We have conducted a systematic survey of wild mammals (n=4393 individuals) present on dairy farms to explore the role of species other than badgers in the epidemiology of bTB. Cultures were prepared from 10397 samples (primarily faeces, urine and tracheal aspirates). One of the 1307 bank voles (Clethrionomys glareolus) live-sampled, and three of the 43 badgers (Meles meles), yielded positive isolates of Mycobacterium bovis. This is the first time the bacterium has been isolated from the bank vole. The strain type was the same as that found in cattle and badgers on the same farm. However, our work indicates that the mean prevalence of infectious individuals among common farmland wildlife is extremely low (the upper 95% confidence interval is < or =2.0 for all of the abundant species). Mathematical models illustrate that it is highly unlikely the disease could be maintained at such low levels. Our results suggest that these animals are relatively unimportant as reservoirs of bTB, having insufficient within-species (or within-group) transmission to sustain the infection, though occasional spill-overs from cattle or badgers may occur.     

Isolation by distance and gene flow in the Eurasian badger (Meles meles) at both a local and broad scale

Eurasian badgers, Meles meles, have been shown to possess limited genetic population structure within Europe; however, field studies have detected high levels of philopatry, which are expected to increase population structure. Population structure will be a consequence of both contemporary dispersal and historical processes, each of which is expected to be evident at a different scale. Therefore, to gain a greater understanding of gene flow in the badger, we examined microsatellite diversity both among and within badger populations, focusing on populations from the British Isles and western Europe. We found that while populations differed in their allelic diversity, the British Isles displayed a similar degree of diversity to the rest of western Europe. The lower genetic diversity occurring in Ireland, Norway and Scotland was more likely to have resulted from founder effects rather than contemporary population density. While there was significant population structure (F ST = 0.19), divergence among populations was generally well explained by geographic distance (P < 0.0001) across the entire range studied of more than 3000 km. Transient effects from the Pleistocene appear to have been replaced by a strong pattern of genetic isolation by distance across western Europe, suggestive of colonization from a single refugium. Analysis of individuals within British populations through Mantel tests and spatial autocorrelation demonstrated that there was significant local population structure across 3-30 km, confirming that dispersal is indeed restricted. The isolation by distance observed among badger populations across western Europe is likely to be a consequence of this restricted local dispersal.     

Insulin dependent diabetes in children under 5: incidence and ascertainment validation for 1992.

OBJECTIVE--To establish the incidence of insulin dependent diabetes diagnosed in children under 5 years of age in the British Isles during 1992, comparing the national and regional results with those of our 1988 national study, and estimating the 1992 study''s level of case ascertainment. DESIGN--Active monthly reporting of cases by consultant paediatricians through the framework of the British Paediatric Surveillance Unit, with additional reports from specialist diabetes nurses and regional health authorities. SUBJECTS--All children diagnosed under the age of 5 years with primary insulin dependent diabetes from 1 January to 31 December 1992 (inclusive) and resident in the British Isles at diagnosis. RESULTS--387 children (208 boys and 179 girls) were confirmed to have insulin dependent diabetes, giving a national incidence of 9.3/100,000/year. This is similar to the 9.9/100,000/year found in 1988. Three sample capture-recapture analysis, which could only be applied across the 12 (out of 18) regions supplying regional information to the study, suggested ascertainment rates of 78% for the British Paediatric Surveillance Unit, 67% for specialist nurses, 69% for regional health authorities, and 99% for the aggregated registry. CONCLUSIONS--The national incidence of diabetes in the under 5s in the British Isles did not differ between 1988 and 1992. Nearly complete (99%) ascertainment of cases was possible only for regions for which three data sources were available. Capture-recapture analysis highlighted both the need for more than one data source and for each data source to be complete for the whole study area.     

Tuberculosis in Tanzanian wildlife

Bovine tuberculosis, caused by Mycobacterium bovis, is a pathogen of growing concern in free-ranging wildlife in Africa, but little is known about the disease in Tanzanian wildlife. Here, we report the infection status of Mycobacterium bovis in a range of wildlife species sampled from protected areas in northern Tanzania. M. bovis was isolated from 11.1% (2/18) migratory wildebeest (Connochaetes taurinus) and 11.1% (1/9) topi (Damaliscus lunatus) sampled systematically in 2000 during a meat cropping program in the Serengeti ecosystem, and from one wildebeest and one lesser kudu (Tragelaphus imberbis) killed by sport hunters adjacent to Tarangire National Park. A tuberculosis antibody enzyme immunoassay (EIA) was used to screen serum samples collected from 184 Serengeti lions (Panthera leo) and 19 lions from Ngorongoro Crater sampled between 1985 and 2000. Samples from 212 ungulates collected throughout the protected area network between 1998 and 2001 also were tested by EIA. Serological assays detected antibodies to M. bovis in 4% of Serengeti lions; one positive lion was sampled in 1984. Antibodies were detected in one of 17 (6%) buffalo (Syncerus caffer) in Tarangire and one of 41 (2%) wildebeest in the Serengeti. This study confirms for the first time the presence of bovine tuberculosis in wildlife of northern Tanzania, but further investigation is required to assess the impact on wildlife populations and the role of different wildlife species in maintenance and transmission.     

Reliable microsatellite genotyping of the Eurasian badger (Meles meles) using faecal DNA

The potential link between badgers and bovine tuberculosis has made it vital to develop accurate techniques to census badgers. Here we investigate the potential of using genetic profiles obtained from faecal DNA as a basis for population size estimation. After trialling several methods we obtained a high amplification success rate (89%) by storing faeces in 70% ethanol and using the guanidine thiocyanate/silica method for extraction. Using 70% ethanol as a storage agent had the advantage of it being an antiseptic. In order to obtain reliable genotypes with fewer amplification reactions than the standard multiple-tubes approach, we devised a comparative approach in which genetic profiles were compared and replication directed at similar, but not identical, genotypes. This modified method achieved a reduction in polymerase chain reactions comparable with the maximum-likelihood model when just using reliability criteria, and was slightly better when using reliability criteria with the additional proviso that alleles must be observed twice to be considered reliable. Our comparative approach would be best suited for studies that include multiple faeces from each individual. We utilized our approach in a well-studied population of badgers from which individuals had been sampled and reliable genotypes obtained. In a study of 53 faeces sampled from three social groups over 10 days, we found that direct enumeration could not be used to estimate population size, but that the application of mark-recapture models has the potential to provide more accurate results.     

Diagnostic Accuracy and Optimal Use of Three Tests for Tuberculosis in Live Badgers

Background

Accurate diagnosis of tuberculosis (TB) due to infection with Mycobacterium bovis is notoriously difficult in live animals, yet important if we are to understand the epidemiology of TB and devise effective strategies to limit its spread. Currently available tests for diagnosing TB in live Eurasian badgers (Meles meles) remain unvalidated against a reliable gold standard. The aim of the present study was to evaluate the diagnostic accuracy and optimal use of three tests for TB in badgers in the absence of a gold standard.

Methodology/Principal Findings

A Bayesian approach was used to evaluate the diagnostic accuracy and optimal use of mycobacterial culture, gamma-interferon assay and a commercially available serological test using multiple samples collected from 305 live wild badgers. Although no single test was judged to be sufficiently sensitive and specific to be used as a sole diagnostic method, selective combined use of the three tests allowed guidelines to be formulated that allow a diagnosis to be made for individual animals with an estimated overall accuracy of 93% (range: 75% to 97%). Employing this approach in the study population of badgers resulted in approximately 13 out of 14 animals having their true infection status correctly classified from samples collected on a single capture.

Conclusions/Significance

This method of interpretation represents a marked improvement on the current procedure for diagnosing M. bovis infection in live badgers. The results should be of use to inform future test and intervention strategies with the aim of reducing the incidence of TB in free-living wild badger populations.     

Serosurvey of viral infections in free-ranging Namibian cheetahs (Acinonyx jubatus)

Cheetahs (Acinonyx jubatus) in captivity have unusually high morbidity and mortality from infectious diseases, a trait that could be an outcome of population homogeneity or the immunomodulating effects of chronic stress. Free-ranging Namibian cheetahs share ancestry with captive cheetahs, but their susceptibility to infectious diseases has not been investigated. The largest remaining population of free-ranging cheetahs resides on Namibian farmlands, where they share habitat with domestic dogs and cats known to carry viruses that affect cheetah health. To assess the extent to which free-ranging cheetahs are exposed to feline and canine viruses, sera from 81 free-ranging cheetahs sampled between 1992 and 1998 were evaluated for antibodies against canine distemper virus (CDV), feline coronavirus (feline infectious peritonitis virus; FCoV/ FIPV), feline herpesvirus 1 (FHV1), feline panleukopenia virus (FPV), feline immunodeficiency virus (FIV), and feline calicivirus (FCV) and for feline leukemia virus (FeLV) antigens. Antibodies against CDV, FCoV/FIPV, FHV1, FPV, and FCV were detected in 24, 29, 12, 48, and 65% of the free-ranging population, respectively, although no evidence of viral disease was present in any animal at the time of sample collection. Neither FIV antibodies nor FeLV antigens were present in any free-ranging cheetah tested. Temporal variation in FCoV/FIPV seroprevalence during the study period suggested that this virus is not endemic in the free-ranging population. Antibodies against CDV were detected in cheetahs of all ages sampled between 1995 and 1998, suggesting the occurrence of an epidemic in Namibia during the time when CDV swept through other parts of sub-Saharan Africa. This evidence in free-ranging Namibian cheetahs of exposure to viruses that cause severe disease in captive cheetahs should direct future guidelines for translocations, including quarantine of seropositive cheetahs and preventing contact between cheetahs and domestic pets.     

Feasibility and utility of microsatellite markers in archaeological cattle remains from a Viking Age settlement in Dublin

Nineteen cattle bones from the Viking 10th and early 11th century levels in Dublin were assessed for presence of reliable genotypes from three autosomal markers. Due to the good preservational condition of the samples, it was possible to amplify and type at least two out of three of the microsatellite markers (CSRM60, HEL1 and ILSTS001) in 11 specimens. Full three-loci genotypes were obtained from a subset of seven of these samples. A comparative analysis was performed using data from the same three markers in 11 extant British, Irish and Nordic cattle breeds. Although the medieval remains displayed lower levels of diversity than the modern European breeds, the results fit within the ranges obtained from the extant populations. The results indicate a probable origin for the ancient Irish cattle as the remains group significantly more closely with breeds from the British Isles than with those from Scandinavia. The data collected indicate that microsatellites may be useful for the further study of ancient cattle.     

Direction of Association between Bite Wounds and Mycobacterium bovis Infection in Badgers: Implications for Transmission

Background

Badgers are involved in the transmission to cattle of bovine tuberculosis (TB), a serious problem for the UK farming industry. Cross-sectional studies have shown an association between bite wounds and TB infection in badgers which may have implications for M. bovis transmission and control, although the sequence of these two events is unclear. Transmission during aggressive encounters could potentially reduce the effectiveness of policies which increase the average range of a badger and thus its opportunities for interaction with other social groups.

Methods

Data were obtained on badgers captured during a long term study at Woodchester Park, UK (1998–2006). Many badgers had multiple observations. At each observation, the badger was assigned a “state” depending on presence of bite wounds and/or TB infection. Hence each badger had a “transition” from the previous state to the current state. We calculated the numbers of each type of transition and the time spent in each state. Transition rates were calculated for each transition category, dividing the number of such transitions by the total time at risk. We compared the rate of bite wound acquisition in infected badgers with that for uninfected badgers and the rate of positive M.bovis test results in bitten badgers with that in unbitten badgers.

Results

The rate of bite wound acquisition in infected badgers (0.291 per year) was 2.09 (95% CI: 1.41, 3.08) times that in uninfected badgers (0.139 per year). The rate of positive M.bovis test results in bitten badgers (0.097 per year) was 2.45 (95% CI: 1.29, 4.65) times that in unbitten badgers (0.040 per year).

Conclusions

We found strong evidence of both potential sequences of events consistent with transmission via bite wounds and distinctive behaviour in infected badgers. The complex relationship between behaviour and infection must be considered when planning TB control strategies.     

Epizootiology and pathologic findings associated with a newly described adenovirus in the red squirrel, Sciurus vulgaris

An infectious disease caused by Squirrelpox virus has contributed to the decline of red squirrels, Sciurus vulgaris, in the British Isles. Because of the heightened disease surveillance activity in red squirrels, adenovirus infection with associated mortality has been detected. Adenoviral disease is described in other rodent species usually associated with stressors. Here we 1) describe the pathologic findings in red squirrels found dead with adenoviral infection and gastrointestinal disease, and 2) investigate the epizootiology of the disease through pathologic investigation, scanning surveillance, and virologic studies. Ten red squirrels involved in conservation studies were diagnosed with adenoviral infection by electron microscopy or PCR. All squirrels exhibited diarrhea and small intestinal inflammation or hemorrhage was evident in seven cases. Lesions indicative of splenic lymphocytolysis were observed in one squirrel and leukocytic hepatitis in another. No adenovirus was detected in grey squirrels, Sciurus carolinensis, inhabiting the same forest area, but previous serologic studies showed that grey squirrels cannot be discounted as a reservoir of the virus. Scanning surveillance showed that 12% of 493 red squirrels had diarrheal disease and two of 13 free-living red squirrels with diarrheal disease had adenovirus infection. Adenoviral disease in declining free-living wild red squirrel populations in the British Isles occurs at a detectable frequency and its impact on the conservation of this species deserves further attention.     

Optimising and Evaluating the Characteristics of a Multiple Antigen ELISA for Detection of Mycobacterium bovis Infection in a Badger Vaccine Field Trial

A long-term research programme has been underway in Ireland to evaluate the usefulness of badger vaccination as part of the national bTB (bovine tuberculosis) control strategy. This culminated in a field trial which commenced in county Kilkenny in 2009 to determine the effects of badger vaccination on Mycobacterium bovis transmission in badgers under field conditions. In the present study, we sought to optimise the characteristics of a multiplex chemiluminescent assay for detection of M. bovis infection in live badgers. Our goal was to maximise specificity, and therefore statistical power, during evaluation of the badger vaccine trial data. In addition, we also aimed to explore the effects of vaccination on test characteristics. For the test optimisation, we ran a stepwise logistic regression with analytical weights on the converted Relative Light Units (RLU) obtained from testing blood samples from 215 badgers captured as part of culling operations by the national Department of Agriculture, Food and the Marine (DAFM). The optimised test was applied to two other datasets obtained from two captive badger studies (Study 1 and Study 2), and the sensitivity and specificity of the test was attained separately for vaccinated and non-vaccinated badgers. During optimisation, test sensitivity was maximised (30.77%), while retaining specificity at 99.99%. When the optimised test was then applied to the captive badger studies data, we observed that test characteristics did not vary greatly between vaccinated and non-vaccinated badgers. However, a different time lag between infection and a positive test result was observed in vaccinated and non-vaccinated badgers. We propose that the optimized multiplex immunoassay be used to analyse the vaccine trial data. In relation to the difference in the time lag observed for vaccinated and non-vaccinated badgers, we also present a strategy to enable the test to be used during trial evaluation.