TABLE 2.
Clinical signs of pigs postchallenge with the highly virulent strain PC21A
| Inoculum group | Piglet dataa |
Sow data |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| No. of surviving pigsb | Challenge age (days [dpi]) | Diarrhea rate (%)c,d | Mortality rate (%)d | Onset of diarrhea (dpc) | Mean cumulative FC score of each pige | Highest fecal PEDV RNA shedding titer (log10 GE/ml)f | Duration of diarrhea (days) | Duration of diarrhea (days) | Highest fecal PEDV RNA shedding titer (log10 GE/ml)f | |
| TC-PC177 | 8 | 23 (19) | 88 (7/8) A | 0 (0/8) | 1.43 ± 0.53 | 6.00 ± 2.69 A | 8.81 ± 1.65 A | 1.88 ± 1.13 B | 2 | 8.00 |
| PC21A | 4 | 24 (20) | 0 (0/4) B | 0 (0/4) | ND | 0.00 ± 0.00 B | 6.83 ± 0.37 B | ND | ND | 6.61 |
| Mock | 5 | 24 (20) | 100 (5/5) A | 0 (0/5) | 1.80 ± 0.45 | 6.80 ± 1.03 A | 10.23 ± 0.66 A | 3.80 ± 0.84 A | 1 | 10.95 |
Different uppercase letters indicate a mean significant difference between groups (P < 0.05). ND, not detected.
Two PC177-infected piglets, two mock-infected piglets, and one surviving PC21A-infected piglet were euthanized at the acute phase for histopathological examination.
Fecal consistency (FC) was scored as follows: 0, solid, 1, pasty, 2, semiliquid; and 3, liquid. An FC score of ≥2 was considered diarrhea.
Values in parentheses are the number of positive results/number of animals tested.
Mean value = (sum of FC scores for each piglet)/N, where N is the number of surviving piglets in the period. Scores were calculated for piglets at 1, 2 4, and 6 days postchallenge (dpc).
The detection limit of PEDV real-time RT-PCR corresponds to 4.8 log10 GE/ml.