Table 2 Summary statistics of the number of tested weeks and SVA status in processing fluids over time for 10 sow farms undergoing an outbreak

Total follow-up time in weeks

16

21.2

22

22

30

22.5

4.5

No. of followed weeks before outbreak detection

0

2

2.5

3

6

2.7

1.8

No. of followed weeks after outbreak detection

16

17.2

18.5

19

26

19.1

3.1

Last positive week after outbreak detection

1

9.5

11.5

14.7

21

11.8

5.2

Number of negative weeks between positive weeks

1

1.2

2

3

10

2.9

3

Number of negative weeks after the last positive week

2

4.2

6

8.5

18

7.3

5.2