Authors: Daniels MJ, Hutchings MR, Allcroft DJ, McKendrick J, Greig A.

Institution: Animal Nutrition and Health Department, Scottish Agricultural College, Edinburgh.

Summary: The reported incidence of Johne's disease has been increasing in the east of Scotland since 1993. A postal questionnaire survey was sent to 127 farms to identify potential risk factors for Johne's disease in relation to wildlife and farm management practices, and 86 returns were obtained.

Of 22 farms which had been assumed to be free of the disease, on the basis of information held by local veterinary centres, seven (32 per cent) reported cases of Johne's disease in the 1990s, indicating that the disease is under-reported. Logistic regression analyses showed that eight of 63 potentially explanatory variables were significant at the 5 per cent level in affecting the likelihood of farms reporting Johne's disease. Of these, large numbers of livestock and rabbits, and access of wildlife to feed stores were the clearest and most consistent risk factors associated with the disease.

The application of manure to grazing pasture, the type of water supply for the cattle and the numbers of crows were also related to the presence of Johne's disease but the nature of these relationships was less clear. Only 38 per cent of the farms reported taking any control measures to combat Johne's disease, but three of the control measures were relevant to risk factors identified as significant by the survey, namely maintaining a clean water supply, controlling rabbits and not spreading manure on to grazing pasture.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11871666&query_hl=12&itool=pubmed_docsum

Authors: Bakker D, Willemsen PT, van Zijderveld FG.

Institution: Department of Bacteriology, Institute for Animal Science and Health, Lelystad. d.bakker@id.wag-ur.nl

Summary: This article attempts to review briefly current opinions on Johne's disease, or paratuberculosis, in ruminants caused by Mycobacterium avium subsp. paratuberculosis. Paratuberculosis has been known to be prevalent in domestic livestock, such as cattle, goats, and sheep, for more than a century. Despite this knowledge only minor efforts have been made to control the disease and, with the attention being focussed on the eradication of other diseases, the problem of paratuberculosis has been neglected in most countries in the past decades.

However, recent epidemiological surveys performed in Europe showed a high prevalence of paratuberculosis in cattle and sheep, indicating that the situation has become quite alarming. In addition, the possible role of M. avium subsp. paratuberculosis in the aetiology of Crohn's disease in humans is still debated, as discussed in this article.

Therefore, there is suddenly a renewed interest in paratuberculosis, and the disease is recognized as a significant problem. As a consequence, there is a need for reliable diagnostic tools for large-scale use to allow the introduction of programmes to control and eventually eradicate the disease. The current status and the possibilities for such programmes are discussed.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11087130&query_hl=26&itool=pubmed_docsum