Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) infects domestic cattle, sheep, goats, deer, camelids and wild ruminants leading to chronic enteritis known as paratuberculosis (Johne’s disease). The infection is chronic, progressive and unresponsive to treatment. Most infected animals do not develop clinical disease but may excrete the bacteria. Clinically sick animals suffer emaciation and in some species diarrhoea, followed by eventual death. During the course of the disease, excretion of M. paratuberculosis in faeces and milk occurs, and the organism spreads through the blood and lymph vessels of infected animals to multiple internal organs. The infection disseminates to both the female and male reproductive organs. Though M. paratuberculosis is not classified as a human pathogen, current opinions on the possible role of this mycobacteria in public health is discussed. This article attempts to review the ways and circumstances by which M. paratuberculosis is transmitted within an animal population and the importance of the disease on animal production. Published reports concerning the transmission and epidemiology of the disease are reviewed herein, and preventive and control measures are summarised.

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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 ca�le 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 ca�le and other domestic animals as well as in wild animals held in captivity or living in the wild. This favourable 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 1983-2001. 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

The study was undertaken in Croatia, Czech Republic, Hungary, Poland, Slovakia and Slovenia laying between Baltic and Adriatic seas on 610 402 km². Mycobacterium bovis infection was diagnosed in 70 animals belonging to 17 species other than cattle. The set of wild animals comprised 12 European bison (Bison bonasus), one red deer (Cervus elaphus), five wild boars (Sus scrofa), and one European wild goat (Capra aegagrus) bred in a game park. Further positive animals included two farmed red deer (Cervus elaphus) and one bactrian camel (Camelus ferus) owned by a circus. The infection was also demonstrated in 18 domestic animals belonging to 3 species living on farms where bovine tuberculosis was diagnosed in cattle. This set included 12 domestic pigs (Sus scrofa f. domestica), two domestic sheep (Ovis ammon f. aries), and four dogs (Canis lupus f. familiaris). The set of animals bred in zoological gardens consisted of 30 animals belonging to 9 species as follows: three bison (Bison bison), four tapirs (Tapirus terrestris), one cassowary (Casuarius casuarius – isolate identified by the biological assay in guinea pigs only), eight sitatungas (Tragelaphus spekei), three elands (Taurotragus oryx), one gnu (Connochaetes taurinus), eight reticulated giraffes (Giraffa cameloparadlis reticulata), one puma (Puma concolor), and one Vietnamese pot-bellied pig (Sus bucculentus). Although, considering the population sizes, absolute numbers of the infected individuals are rather low, wild animals or such animals bred in captivity should be regarded as possible reservoirs of the causative agent of bovine tuberculosis. Tests for bovine tuberculosis are therefore necessary before transportation of all wild animals. Any lesion arousing suspicion of tuberculosis found on necropsy of wild animals must be laboratory examined for the presence of mycobacteria.

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