Table 2.
Meta-analysis of studies reporting the prevalence of PI animals.
| No. prevalence inputs | Sample size (No. animals) | Weighted mean estimate | Confidence Interval (95%) | I2 (%) | |
|---|---|---|---|---|---|
| Overall | 121 | 4,904,119 | 0.77 | (0.59–0.97) | 99.73 |
| Subgroup a | |||||
| UN Region | |||||
| Europe | 59 | 4,698,632 | 0.76 | (0.50–1.08) | 99.89 |
| North America | 32 | 106,647 | 0.50 | (0.29–0.75) | 94.02 |
| East Asia | 11 | 58,188 | 1.07 | (0.36–2.08) | 98.06 |
| West Asia | 6 | 2,309 | 2.61 | (1.36–4.23) | 72.52 |
| Australia | 13 | 38,343 | 0.46 | (0.22–0.76) | 38.71 |
| Period | |||||
| 1980–1991 | 6 | 4,361 | 1.85 | (0.65–3.59) | 86.50 |
| 1992–2001 | 25 | 92,689 | 0.90 | (0.53–1.36) | 96.64 |
| 2002–2016 | 59 | 4,765,501 | 0.36 | (0.23–0.51) | 99.72 |
| Not specified | 31 | 41,568 | 1.58 | (1.03–2.23) | 94.59 |
| Production system | |||||
| Beef | 28 | 201,743 | 0.35 | (0.20–0.54) | 95.88 |
| Dairy | 51 | 85,786 | 1.13 | (0.82–1.49) | 91.86 |
| Mixed | 19 | 2,660,173 | 1.10 | (0.64–1.67) | 99.87 |
| Not specified | 23 | 1,956,417 | 0.51 | (0.13–1.08) | 99.93 |
| Age group | |||||
| ≤6 months | 23 | 2,282,771 | 0.70 | (0.27–1.29) | 99.93 |
| >6 months | 13 | 144,800 | 0.93 | (0.28–1.88) | 99.29 |
| Mixed | 32 | 1,624,080 | 0.71 | (0.41–1.08) | 98.54 |
| Not specified | 53 | 852,468 | 0.82 | (0.57–1.10) | 98.67 |
| Vaccination | |||||
| Yes | 19 | 139,423 | 0.24 | (0.15–0.36) | 87.46 |
| No | 34 | 2,547,568 | 0.54 | (0.28–0.86) | 99.76 |
| Not specified | 68 | 2,217,128 | 1.08 | (0.79–1.41) | 99.70 |
| Clinical signs | |||||
| Yes | 15 | 44,514 | 2.22 | (1.26–3.43) | 97.66 |
| No | 5 | 25,597 | 1.45 | (0.51–2.81) | 97.65 |
| Not specified | 101 | 4,834,008 | 0.55 | (0.41–0.72) | 99.67 |
| Programme | |||||
| Yes | 34 | 4,707,613 | 0.47 | (0.25–0.74) | 99.90 |
| No | 3 | 2,284 | 0.59 | (0.00–1.77) | 76.20 |
| Not specified | 84 | 194,222 | 0.94 | (0.69–1.22) | 96.08 |
| Diagnostic method b | |||||
| Direct detection method | 6 | 18,165 | 0.97 | (0.28–2.00) | 96.69 |
| RT-PCR | 12 | 184,472 | 0.32 | (0.02–0.83) | 99.24 |
| AG ELISA | 49 | 1,279,649 | 0.75 | (0.50–1.04) | 99.47 |
| Cell culture-based system | 21 | 40,848 | 1.42 | (0.75–2.28) | 96.59 |
| Mixed | 33 | 3,380,985 | 0.57 | (0.33–0.86) | 99.82 |
aAll p-values except for Australia (p = 0.01) were ≤0.01 and were calculated using the Cochran’s Q-test.
bThe description of the diagnostic methods is provided in Table 1.