Elimination of bovine tuberculosis has been heterogeneous in Spain
Despite control campaigns carried out since 1956, Bovine tuberculosis eradication has not yet been achieved and prevalence has remained between 1.6% and 1.8%. Researchers from the CReSA and UAB studied the success of these campaigns in Spain and concluded that the elimination pattern was not homogeneous throughout Spain and the ratio of elimination was different among zones.
Relative risk of being positive in 2008
Bovine tuberculosis (BTB) is a chronic disease of animals caused by Mycobacterium bovis. Due to its zoonotic nature and the high economic impact in livestock production and in animal health policies, the eradication of BTB has been a major objective of farming communities and public health authorities over decades.
In Spain, between 1956 and 1964, the first legal initiative was established, with the culling of positive animals. Nevertheless, this measure did not succeed due to the high cost imposed onto the farmers. In 1965, thanks to government economical support the BTB control campaign began to be successful. This campaign was focused on dairy cattle and data obtained revealed an animal prevalence of around 20%. In 1986, when Spain became a member of the European Economic Community (EEC), national programs were reinforced and efforts were focused on increasing the testing coverage, including beef cattle. However, it was not until 1993, when the EU was established, that the BTB national eradication program included all dairy and beef cattle. Despite these advances, BTB eradication has not yet been achieved and prevalence has remained between 1.6% and 1.8%.
The main objective of this study was to explore the spatial distribution of BTB risk in Spain in order to summarize the spatial risk heterogeneity, but not to identify factors associated with the spatial distribution of the disease. For the period 2006–2009, annual data by on the total number of herds, type of herd, BTB positive herds and new positive herds were provided, at county level, by the Spanish Ministry of Environment and Rural and Marine Affairs (MARM). Data at farm-level were obtained due to the implementation of the Spanish national BTB eradication program, annually approved by the European Commission for its financial support
The risk of persistence and elimination were lower in counties located in the north and north-east of Spain, the Balearic and the Canary Islands than in the rest of the country. With regard to the risk of persistence of BTB positive herds, counties located in the central, western and south-western part of the country had a higher risk in the three studied periods. In these areas the risk of persistence of positive BTB herds was more than 3 times higher than in the rest of the country. The likelihood of elimination of BTB positive herds was very variable, remaining high in some counties in central Spain.
This work has been recently published in:
Allepuz A, Casal J, Napp S, Saez M, Alba A, Vilar M, Domingo M, González MA, Duran-Ferrer M, Vicente J, Alvarez J, Muñoz M, Saez JL. Analysis of the spatial variation of Bovine tuberculosis disease risk in Spain (2006-2009). Prev Vet Med. 2011 Jun 1;100(1):44-52.
To contact with the author of this paper:
Alberto Allepuz Palau
Download the full paper: ScienceDirect