Skip to main content
. 1999 Mar;37(3):620–627. doi: 10.1128/jcm.37.3.620-627.1999

TABLE 4.

Microscopic lesion scores from pigs inoculated with either PRRSV, M. hyopneumoniae, or both

Group Score for pneumonia induced by PRRSVa or M. hyopneumoniaeb at the following necropsy date:
Day 3
Day 10
Day 28
PRRSV M. hyopneumoniae PRRSV M. hyopneumoniae PRRSV M. hyopneumoniae
A 1.2 ± 1.1 Bc 0 4.0 ± 0.9 A 1.7 ± 1.0 A 4.8 ± 0.7 A 3.9 ± 0.4 A
B 1.0 ± 0 B 0.3 ± 0.5 3.3 ± 1.5 A 0.8 ± 0.4 B 1.3 ± 0.5 B 1.6 ± 1.1 C
Cd 3.3 ± 0.5 A 0 3.3 ± 0.5 A 1.8 ± 1.0 A 4.3 ± 1.2 A 3.8 ± 0.5 A
D 0 C 0.2 ± 0.4 0 B 0.5 ± 0.6 B,C 0.1 ± 0.4 C 1.0 ± 0 C
E 0.2 ± 0.4 C 0 0 B 0.5 ± 0.6 B,C 0 C 2.5 ± 0.8 B
F 1.5 ± 0.8 B 0.3 ± 0.5 3.7 ± 0.8 A 0 C 1.4 ± 0.5 B 1.1 ± 0.6 C
G 0.2 ± 0.4 C 0 0 B 0.8 ± 0.4 B,C 0 C 0.3 ± 0.5 D
a

PRRSV scores are based on the severity of interstitial pneumonia. 0, no microscopic lesions; 1, mild multifocal pneumonia; 2, mild diffuse pneumonia; 3, moderate multifocal pneumonia; 4, moderate diffuse pneumonia; 5, severe multifocal pneumonia; 6, severe diffuse pneumonia. 

b

M. hyopneumoniae scores are based on the severity of peribronchiolar and perivascular cuffing and lymphoid nodule formation, as follows: 1, mild; 2, moderate; 3, severe; 4, very severe. 0, no microscopic lesions. 

c

Within each column, values followed by different letters (A, B, C, or D) are significantly different from each other (P < 0.001). 

d

Group C received PRRSV on day −10 and M. hyopneumoniae on day 0 and so is not matched with the other groups with respect to the number of days after inoculation with PRRSV.