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
| Test | No. positive/total (%), P valuea
|
||
|---|---|---|---|
| All fecal shedders | Light-to-moderate fecal sheddersb | Heavy fecal sheddersc | |
| Fecal PCR | 91/395 (23.0) | 10/244 (4.1) | 60/79 (76.0) |
| Serum ELISA A | 102/367 (27.8), 0.04 | 29/234 (12.4), 0.002 | 56/77 (72.7), 0.72 |
| Serum ELISA B | 101/367 (27.5), 0.06 | 31/234 (13.2), 0.001 | 53/77 (68.8), 0.34 |
| Milk ELISA | 84/327 (25.7), 0.31 | 27/202 (13.4), 0.002 | 44/66 (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).