TABLE 4.

Percentages of fecal PCR assay and serologic assay results that were positive by fecal shedding level based on an average of three bacterial culture methods

TestNo. positive/total (%), P valuea
All fecal sheddersLight-to-moderate fecal sheddersbHeavy fecal sheddersc
Fecal PCR91/395 (23.0)10/244 (4.1)60/79 (76.0)
Serum ELISA A102/367 (27.8), 0.0429/234 (12.4), 0.00256/77 (72.7), 0.72
Serum ELISA B101/367 (27.5), 0.0631/234 (13.2), 0.00153/77 (68.8), 0.34
Milk ELISA84/327 (25.7), 0.3127/202 (13.4), 0.00244/66 (66.7), 0.059
  • a P value from McNemar's test to detect differences in M. avium subsp. paratuberculosis detection between fecal PCR assay and other assays.

  • b Light-to-moderate fecal shedders defined as 1+ to 2+ (see Materials and Methods).

  • c Heavy fecal shedders defined as 3+ to 4+ (see Materials and Methods).