Department of Agriculture, Food and the MarineTeagascDeposited by bulk impor

Bradley, Jim

Costello, Eamon

Fogarty, Ursula

Higgins, Isabella M.

Kelleher, Pat F.

O'Boyle, Ian

Power, Eugene P.

Quigley, Frances

Redahan, E.

O\u27Boyle, Ian

Irish Universities

Review of badger (meles meles) research licences in 2002

Research Repository UCD

Title Review of badger (meles meles) research licences in 2002Authors(s) O'Boyle, Ian, Costello, Eamon, Power, Eugene P., Kelleher, Pat F., Bradley, Jim, Redahan, E., Quigley, Frances, Fogarty, Ursula, Higgins, Isabella M.Publication date 2003-12Publication information O’Boyle, Ian, Eamon Costello, Eugene P. Power, Pat F. Kelleher, Jim Bradley, E. Redahan, Frances Quigley, Ursula Fogarty, and Isabella M. Higgins. Review of Badger (Meles Meles) Research Licences in 2002. Edited by John D. Collins and Robert F. Hammond. University College Dublin. Centre for Veterinary Epidemiology and Risk Analysis, December, 2003.Series Selected Papers, 2002-2003Publisher University College Dublin. Centre for Veterinary Epidemiology and Risk AnalysisItem record/more informationhttp://hdl.handle.net/10197/8888Downloaded 2023-11-01T04:02:15ZThe UCD community has made this article openly available. Please share how this accessbenefits you. Your story matters! (@ucd_oa)© Some rights reserved. For more informationReview of Badger (Me/es me/es) Research Licences in 2002 I. O'Boyle, E. Costello1, E.P. Power1, P.F. Kelleher1, J. Bradley1, E. Redahan1, F. Quigley1, U. Fogarty2 and I. Higgins Introduction The National Bovine Tuberculosis Eradication Scheme includes a research programme involving diagnostic, epidemiological and wildlife investigation projects. As part of this research programme badgers (Me/es meles) are caught under licence and examined for evidence of tuberculosis. Data relating to licences used and badgers removed are described in this review. Materials and Methods A Veterinary Inspector, in the course of the epidemiological investigation of a tuberculosis breakdown in a herd, may make an application for a licence if wildlife involvement is suspected. Licences to remove and examine badgers are issued by the National Parks and Wildlife Service of the Department of the Environment and Local Government. Each licence is valid for one year from the date of issue and is operated by or under the direct supervision of staff of the Department of Agriculture and Food. These local research licences are operated within a two-kilometre radius of the index farm, to assist in the epidemiological investigation of the breakdown. Other research licences, such as those granted for the Four Area Badger Study and the East Offaly Project, cover a larger area and are operated with the aim of quantifying the contribution of badgers to the spread of tuberculosis in cattle. All badgers removed under licence undergo gross post-mortem examination at the Regional Veterinary Laboratories of the Department of Agriculture and Food or under contract at the laboratory of the Irish Equine Centre. In addition, a number of road casualties are submitted each year, which are also examined for evidence of tuberculosis. A proportion of badgers also had tissues submitted for further pathological tests. For example, where visible lesions of tuberculosis were found in a badger carcass this was taken as significant, and histopathological examination and culture were used as confirmatory tests in most cases. However, this was not done in all cases. Data relating to both confirmed and unconfirmed cases are presented. These extra tests were also carried out on a proportion of gross lesion negative badgers. 1 Department of Agriculture and Food 2 Irish Equine Centre ERADITEAGASC 13 Veterinary Epidemiology & Tuberculosis Investigation Unit, UCO Results Origin of cases This review presents results from 5,945 badgers submitted under local licences and the East Offaly Project. It also includes data from 450 badgers submitted as casualties. Badgers were also submitted as part of the Four Area Badger Study. A summary of the origin of all cases is given in Table 1. Detailed analysis of data from badgers removed in the Four Area Badger Study is reported separately (Griffin et al., 2003). A small number of badgers were submitted but were not examined for various reasons, such as carcass decomposition. Table 1. Origin of cases. 2002 Offaly Licence 168 Road Casualty 4 Total 172 Local Licence 5327 446 5773 Total excl. Four Total Four Area Area 188 5683 0 450 (5945) 188 6133 A total of 638 local licences were used in 2002. The average number of badgers removed per licence was 8.3 and the range was one to 66. Every county, except Dublin, submitted badger carcasses under local licences in 2002. Sex Ratio Of the 5,906 cases where sex was recorded (Table 2), the sex ratio was almost even. However, significantly more males had confirmed tuberculosis (P<0.001). The sex was not recorded in two confirmed cases. There was no significant difference in sexes between those removed under licence and those submitted as casualties. Table 2. Sex ratio of cases. Weight Sex Female Male Total All Badgers (%) 3025 (51.2) 2881 (48.8) 5906 Tb confirmed badgers (%) 328 (44.3) 413 (55.7) 741 Weight was recorded in 4,776 cases and average weights are shown in Table 3. The range was 1.4 kg. to 16.5 kg. for males and 2.2 kg. to 16.4 kg. for females. ERAD/TEAGASC Table 3. Weight distribution (average, in kg.) Year 2002. Sex Males Females All cases 9.6 8.9 9.3 14 Veterinary Epidemiology & Tuberculosis Investigation Unit, UCO No significant weight difference was found between badgers positive and negative for tuberculosis, or between those removed under licence and those submitted as casualties. Disease Profile All badgers underwent gross post-mortem examination. In addition, further laboratory tests were carried out on a number of badgers. Results of the gross post-mortem examination of badgers are presented in Table 4. Some 6.2% of cases were found to be positive for tuberculosis and a further 25.2% were inconclusive. Table 4. Results of gross post-mortem examination, 2002. Result Local Licence (%) Casualty(%) Total(%) Positive 325 (5.9) 41 (9.1) 366 (6.2) Inconclusive 1373 (25.0) 126 (28.0) 1499 (25.2) Negative 3797 (69.1) 283 (62.9) 4080 (68.6) Total 5495 450 5945 The additional laboratory tests consisted of histpathological examination and culture of selected lymph nodes or other tissues. The application of these tests was not uniform due to different resources at different laboratories. Thus, there is a geographical bias towards particular cases. There is also a disease bias, as the "inconclusive" cases received a disproportionate number of additional tests compared with those cases that were deemed to be negative for tuberculosis on gross post-mortem examination. The numbers of cases in each category, based upon the gross p ost-mortem result, that underwent additional tests, together with the results of the latter tests, are shown in Table 5. ERAD /TEAGASC Table 5. Numbers and results of additional laboratory diagnostic tests, 2002. Result of gross Results of No. of Badgers examination additional diagnostic tests Positive Positive 190 Positive Inconclusive 8 Positive Negative 70 Positive Not done 98 sub-total 366 Inconclusive Positive 360 Inconclusive Inconclusive 5 Inconclusive Negative 1091 Inconclusive Not done 43 sub-total 1499 Negative Positive 193 Negative Inconclusive 8 Negative Negative 820 Negative Not done 3059 sub-total 4080 Totals 5945 I 5 Veterinary Epidemiology & Tuberculosis Investigation Unit, UCO Of the 366 gross lesion positive cases, 268 (73.2%) had additional tests; 190 (70.9%) of these were confirmed. Of 1,499 gross lesion inconclusive cases, 1,456 (97.l % ) had additional tests and 360 (24.7%) of these were confirmed as positive for tuberculosis. Of 4,080 gross lesion negative cases, 1,021 (25%) had additional tests and 193 (18.9%) of these were also confirmed. Overall, tuberculosis was confirmed in 743 (12.5%) badgers. A comparison of rates of confirmed infection over the past five years is given in Table 6. * Table 6. Rates of confirmed tuberculosis in badgers, 1998-2002 . Year No. examined No. confirmed % confirmed (gross post- positive (by addit- positive mortem1 ional tests 1 1998 1,997 258 12.9 1999 3,457 458 13.2 2000 4,757 580 12.2 2001 3,542 463 13.1 2002 5,945 743 12.5 *limited sampling in 2000 -2001 In addition 52 (11.6%) of the 450 road casualty cases were confirmed with tuberculosis. Lesion Location - confirmed tuberculosis The locations of lesions in 377 badgers in which a single location was recorded are presented in Table 7. In a further 352 cases, lesions were recorded in more than one location; their distribution is shown in Table 8. No location was recorded for 14 cases that were initially found to be gross lesion negative. · Table 7. Location oflesions in 377 confirmed cases showing a single lesion, 2002. Lesion location Axillary lymph node 5 Bronchial/Mediastinal lymph nodes 69 Hepatic lymph node 13 Kidney 17 Inguinal lymph node 2 Liver 4 Lung 47 Mesenteric lymph node 4 Pharyngeal, parotid or submandibular lymph node 118 Popliteal lymph node 57 Prescapular lymph node 32 Skin 9 Total 377 ERADITEAGASC 16 Veterinary Epidemiology & Tuberculosis Investigation Unit, UCO Table 8. Distribution of lesions in 352 cases showing multiple lesions, 2002. Lesion location Axillary lymph node Bronchial/Mediastinal lymph nodes Hepatic lymph node Kidney Inguinal Liver Lung Mesenteric lymph nodes Pharyngeal, parotid or submandibular lymph node Popliteal lymph node Prescapular lymph node Skin Spleen Other location * 20 197 50 36 2 34 134 38 194 89 123 16 7 4 * "Other locations" were omentum, pleura, pericardium and mammary gland In 216 cases there were two locations, in 76 cases three locations, in 35 cases four locations and in 14 cases five locations. Six cases had lesions recorded in six locations; two cases had lesions in seven locations and three in eight locations. Licences with con.firmed cases Overall in 2002, of the 638 licences issued, 303 (47.5%) yielded tuberculous badgers. Again it should be stated that many badgers that had gross evidence of tuberc_ulosis had not been subjected to any further confirmatory tests; these cases are not reflected in the data presented in Table 9. Table 9. Badgers removed per licence and "confirmed Tb" licences, 2002. No. of badgers No. of No. of "confirmed % of "confirmed removed licences Tb" licences Tb" licences 1 - 5 304 93 30.6 6-10 165 82 49.7 11 - 15 84 58 69.0 16-20 39 27 69.2 > 20 46 43 93.5 Total 638 303 47.5 As the number of badgers removed under a licence increased, the greater the likelihood of finding one with tuberculosis. Density of setts in areas will vary depending on habitat type (Smal, 1995) and this is reflected in the number of badgers removed under individual licences. Interference at setts by blocking, digging etc. continues to be reported. This also results in lower numbers being captured at these setts. In other situations, the number of positive cases may have been reduced because of the prior death of affected badgers. ERADITEAGASC 17 Veterinary Epidemiology & Tuberculosis Investigation Unit, UCO Discussion These data demonstrate that the badger population examined here had a minimum rate of infection of 12.5% in 2002 (Table 6). This is remarkably similar to the rate of infection in badgers disclosed in previous years. The population studied was biased towards infected groups, as the initial selection was in areas of cattle herd breakdowns. Nevertheless, the presence of tuberculosis in 11.6% of the 450 road casualties examined, i.e. a more representative sample, and the fact that positive badgers were found in every county (except Dublin) in 2002, supports the view that tuberculosis is endemic in the Irish badger population. The respiratory route appears to be an important route of infection. Of the positive cases, 47% had lesions in the lungs or pulmonary lymph nodes. Fagan (1993) reported respiratory disease in 13 (46%) of 28 badgers with gross evidence of tuberculosis. The fact that significantly more males than females were found to be tuberculous is attributed to the extra contact and fighting which occurs in the breeding season. Similar findings were reported in badgers in 1997 (O'Boyle, 1997), 1999 (O'Boyle 1999) and 2000/2001 (O'Boyle 2001) but not in 1998 (O'Boyle 1998). Acknowledgments We wish to thank the laboratory staff involved in the post-mortem examinations -W.J. Byrne, J. Moriarty, P. Breslin, M. Parada-Gomez, C. Sanchez-Miguel, Dr. T. Henaghan, P. Jones, D. Toolan, A. Johnson, D. Kelly, M. Casey, C. O'Muireagain, J. Quinlan and J. Fagan. We also wish to thank Ms. Tracy Clegg for undertaking the statistical analyses. References Fagan, J. (1993). Tuberculosis in Badgers in Ireland: Pathology. In The Badger, pp. 117-122. Hayden, T.J. (ed.) 1993 Dublin: Royal Irish Academy. Griffin, J.M., Clegg, T.A. , Quigley, F., Hammond, R.F., McGrath, G. , Sleeman, D.P., Costello, E. , and O'Boyle, I. (2003). The Four-Area Badger Study: A Progress Report, 1997-2002. Tuberculosis Investigation Unit, University College Dublin, Selected Papers 2002-2003, 1-12 O'Boyle, I. (1997). Review of Badger (Meles me/es) Research Licences in 1996. Tuberculosis Investigation Unit, University College Dublin, Selected Papers 1997, 37-40. O'Boyle, I. ( 1998). Review of Badger (Me/es me/es) Research Licences in 1997. Tuberculosis Investigation Unit, University College Dublin, Selected Papers 1997, 10-14. O'Boyle, I. (1999). Review of Badger (Me/es me/es) Research Licences in 1998. Tuberculosis Investigation Unit, University College Dublin, Selected Papers 1999, 15-21. O'Boyle, I. (2002). Review of Badger (Me/es me/es) Research Licences in 2000 and 2001. Tuberculosis Investigation Unit, University College Dublin, Selected Papers 2000-2001, 15-21. Smal, C. (1995). In The Badger and Habitat Survey of Ireland. Stationery Office, Dublin. ERADITEAGASC I 8 Veterinary Epidemiology & Tuberculosis Investigation Unit, UCO 

Review of badger (meles meles) research licences in 2002

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