[1] USDA ARS, Beltsville Agr Res Ctr, Inst Livestock & Poultry Sci, Parasite Biol & Epidemiol Lab, Beltsville, MD 20705 USA
[2] Univ Illinois, Coll Vet Med, Dept Vet Pathobiol, Urbana, IL 61801 USA
[3] Inst Puericulture, Lab Toxoplasmose, F-75014 Paris, France
[4] Univ Nebraska, Great Plains Vet Educ Ctr, Dept Vet & Biomed Sci, Inst Agr & Nat Resources, Clay Ctr, NE 68933 USA
[5] Forest Preserve District Cook Country, Elgin, IL 60120 USA
[6] Illinois Nat Hist Survey, Champaign, IL 61820 USA