Management of an outbreak of brucellosis due to B. melitensis in dairy cattle in Spain

Brucella melitensis is a major human and animal pathogen, with a wide host range that includes all domestic ruminant species, although small ruminants are its preferred hosts. Outbreaks in cattle due to B. melitensis have become a worldwide emerging problem particularly difficult to control due to the lack of knowledge on the epidemiology in this host species and of an effective vaccine. However, combination of molecular tools and strict biosecurity measures can help to solve these difficulties and eventually eradicate the disease from infected herds. In the present report, management of an outbreak in Spain involving four farms, more than 2000 cattle and several human cases is described. Application of Multiple Locus VNTR Analysis (MLVA) allowed identifying the most likely source of infection. Stamping out and test-and-slaughter strategies were applied, proving their usefulness to control the outbreak depending on infection level, and without the need of other alternative measures.