Brucella suis infection associated with feral swine hunting - three states, 2007-2008.

Historically, brucellosis from Brucella suis infection occurred among workers in swine slaughterhouses. In 1972, the U.S. Department of Agriculture National Brucellosis Eradication Program was expanded to cover swine herds. Subsequent elimination of brucellosis in commercial swine resulted in a decrease in B. suis-associated illness in humans. Currently, swine-associated brucellosis in humans in the United States is predominantly associated with exposure to infected feral swine (i.e., wild boar or wild hogs). In May and July 2008, CDC was contacted by the state health departments in South Carolina and Pennsylvania regarding two cases of brucellosis possibly linked to feral swine hunts. Both state health departments contacted the state health department in Florida, where the hunts took place. The subsequent investigation, conducted jointly by the three state health departments and CDC, determined that the two patients had confirmed brucellosis from B. suis infection and the brother of one patient had probable brucellosis. All three exposures were associated with feral swine hunting, and at least two patients did not have symptoms until 4-6 months after exposure. The findings from this investigation suggest that clinicians treating patients with unexplained febrile illness should consider brucellosis in the differential diagnosis and obtain a thorough history of travel (e.g., to enzootic areas), food consumption, occupation, and recreational activities, including feral swine hunting. Cross-agency collaboration by state health departments and agriculture agencies is needed on brucellosis investigations to reduce the risk for illness through contact with infected animals.