Table 3.

Herd size, number of E. coli O157:H7-positive samples, and the number and source of samples tested

FarmHerd sizeaNo. of samples positive/no. of samples tested for E. coli O157:H7Sample no./herd size ratio
Cohort groupbContact cattlecOther cattledBirdseAnimalsfFeedWaterMisc.gTotal
C1130/4410/330/690/281/370/70/230/31/6415.67
H2420/6330/00/710/00/20/100/330/00/7493.10
R36542/6556/552/171/710/220/226/1310/657/9792.68
X17063/6666/534/440/01/203/3218/1190/295/9365.51
  • a Total number of cattle and calves present at the start of the study.

  • b The 15 calves monitored weekly from date of birth through at least 7 months of age.

  • c Cattle that had direct or indirect (i.e., shared water) contact with cohort animals.

  • d Cattle that were on the same farm but did not have direct or indirect contact with cohort animals.

  • e Cloacal swabs from pigeons, sparrows, and starlings.

  • f Other animals included deer, dogs, flies, mice, opossums, raccoons, rats, and wild turkeys.

  • g Miscellaneous samples included bedding, milk, and cattle saliva.