[1] CTR DIS CONTROL, CTR INFECT DIS, DIV PARASIT DIS, ATLANTA, GA 30338 USA
[2] WISCONSIN DIV HLTH, BUR COMMUNITY HLTH & PREVENT, MADISON, WI USA
[3] DULUTH CLIN, DEPT INFECT DIS, DULUTH, MN USA
[4] RES ANIM RESOURCES CTR, MADISON, WI USA
[5] UNIV WISCONSIN, SCH VET MED, MADISON, WI 53706 USA
[6] UNIV WISCONSIN, SCH MED, DEPT PREVENT MED, MADISON, WI 53706 USA
[7] UNIV WISCONSIN, SCH MED, DEPT PEDIAT, MADISON, WI 53706 USA
[8] WISCONSIN DEPT NAT RESOURCES, MADISON, WI USA
[9] MINNESOTA STATE DEPT HLTH, MINNEAPOLIS, MN USA