Brucella include arthritis or epididymo-orchitis, spondylitis, neurobrucellosis, liver abscess formation, and endocarditis, the latter potentially fatal. Human brucellosis is usually not transmitted from human to human; people become infected by contact with fluids from infected animals (sheep, cattle, or pigs) or derived food products, such as unpasteurized milk and cheese. Brucellosis is also considered an occupational disease because of a higher incidence in people working with animals (slaughterhouse cases). People may also be infected by inhalation of contaminated dust or aerosols, and as such, the CDC has labeled "Brucella" species as highly weaponizable. Human and animal brucellosis share the persistence of
Swine brucellosis Swine also develop orchitis (swelling of the testicles), lameness (movement disability), hind limb paralysis, or spondylitis (inflammation in joints). Because "B. suis" is facultative and intracellular, and is able to adapt to environmental conditions in macrophages, treatment failure and relapse rates are high. The only effective way to control and eradicate zoonosis is by vaccination of all susceptible hosts and elimination of infected animals. The "Brucella abortus" (rough LPS "Brucella") vaccine, developed for bovine brucellosis and licensed by the USDA Animal Plant Health Inspection Service, has shown protection for some swine and is also effective against "B. suis" infection, but