Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche
Webzine Sanità Pubblica Veterinaria: Numero 44, Novembre 2007 [http://www.spvet.it/] ISSN 1592-1581
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A SEROLOGICAL SURVEY ON MYCOBACTERIUM AVIUM SUBSP. PARATUBERCULOSIS IN WILD RUMINANTS OF THE PESARO-URBINO DISTRICT (ITALY).

Bartolini C., De Curtis M., Costarelli S., Moscati L., Orazietti N., Grassi F., Gavaudan S.

Introduction
Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of a chronic pathology that affects both domestic and wild ruminants manifesting as an inflammatory gastro-enteritis, with epithelial thickening in the lower intestine causing malabsorption of nutrients and leading to wasting and eventual death in affected animal (1) The control and eradication in livestock remain worldwide problem and changes in herd management in interface pastures could limit opportunities for infection transmission to young stocks (2) wherever field circulation of the causative agent is demonstrated. During summer in 2004-2005, there has been an increase of diagnosis of paratuberculosis in domestic ruminants of Pesaro-Urbino district. In the same period we had just few evidences of presence of MAP (hystological referable lesions of ileo-ciecal valves and MAP’s DNA detected by PCR procedures on the target organ) in wild ruminants found dead and sent to the laboratory for necropsy. In order to carry an efficient sanitary control plan for paratuberculosis we estimated the serological prevalence in cervids of the district.

Materials & methods
The target is the entire population of wild ruminants in the Pesaro-Urbino district which was estimated to be of 17.620 ungulates among roe deer (Capreolus capreolus), fallow deer (Dama dama) and deer (Cervus elaphus). The volontary serological sampling of cervids practised by authorised hunters was the only possibility to reach the whole district. Even if performances of serological assay in cervids are acceptable only for pathological cases (3), the relative costs of AGID and ELISA tests allow to make a first diagnostic approach in lack of other epidemiological information. A random sample of 179 ungulates was selected in august - september 2005. 179 serum samples were collected and analysed both by ELISA and AGID tests to detect antibodies against MAP. The AGID test was performed using PPA antigen (Allied Monitor Missouri, USA). The ELISA test is a commercial kit for ruminants, produced by Pourquier Resulting data were analysed using the software Epi-Info 6.4, Microsoft Access 2003 and MapInfo Professional v 8.5.




Results
No sample resulted positive so estimated prevalence is ? 1.65% (L.C. 95%) and the expected maximum number of positive animals in the population is 291.

Conclusions
This preliminary investigation suggests that during summer 2004 -2005 there wasn’t detectable antibodies circulation of MAP in wild ruminants of the Pesaro-Urbino district; however, pasture is the main wildlife/livestock interface in this district and wildlife could have a role as carrier between farms. To better evaluate the presence of MAP in wildlife and in order to define intra-species and inter-species transmission further research are requested. As a low-cost method for the surveillance we suggest the correct post-mortem inspection of carcasses after every sanitary culling in the district.

References
1. J.Frank T. et al.. “Immunoglobulin G1 enzime-Linked Immunosorbent Assay for diagnosis of Johne’s disease in red deer (Cervus elaphus)”; Clinical and Diagnostic Laboratory Immunology. p.1401-1409, 12-2005. 2. Michael.T. Collins et al.. ”Evaluation of five antibody detection tests for diagnosis of bovine paratuberculosis”; Clinical and Diagnostic Laboratory Immunology, p.685-692, 6-2005. 3. Nebbia P., et al.. “Studi sulla presenza della paratubercolosi in cervi del Parco Naturale Gran Bosco di Salbeltrand” J. Mt. Ecol., 7 (Suppl.), 2003.