Table 3 The infection rates of TBPs in yaks and Tibetan sheep by prefecture and altitude of the sampling sites

Yak

Prefecture

 Guoluo

0

13 (6.2)

0

0

5 (2.4)

6 (2.9)

 Yushu

0

14 (6.5)

0

0

15 (7.0)

8 (3.7)

Statistical analysis

 χ²

0.02

4.56

0.23

 df

1

1

1

 P-value

0.8987

0.0328

0.6293

Altitude (m)

 3000–4000

0

13 (5.8)

0

0

5 (2.2)

12 (5.4)

 4000–5000

0

14 (6.9)

0

0

15 (7.4)

2 (1.0)

Statistical analysis

 χ²

0.19

5.77

6.02

 df

1

1

1

 P-value

0.6628

0.0163

0.0141

Tibetan sheep

Prefecture

 Guoluo

132 (72.1)

92 (50.3)

154 (84.2)

29 (15.8)

0

120 (65.6)

 Yushu

30 (23.8)

1 (0.8)

19 (15.1)

31 (24.6)

0

8 (6.3)

Statistical analysis

 χ²

23.77

52.14

46.81

2.44

50.75

 df

1

1

1

1

1

 P-value

< 0.0001

< 0.0001

< 0.0001

0.1185

< 0.0001

Altitude (m)

 3000–4000

92 (50.3)

46 (25.1)

107 (58.5)

55 (30.1)

0

80 (43.7)

 4000–5000

70 (55.6)

47 (37.3)

66 (52.4)

5 (4.0)

0

48 (38.1)

Statistical analysis

 χ²

0.26

2.78

0.32

23.10

0.41

 df

1

1

1

1

1

 P-value

0.6108

0.0956

0.5721

< 0.0001

0.5242