Table 3.
Pooled prevalence of Brucella in buffalo worldwide.
| No. studies | No. tested | No. positive | % (95% CI*) | Heterogeneity | Univariate meta-regression | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| χ2 | P-value | I2 (%) | P-value | Coefficient (95% CI) | ||||||
| Region* | ||||||||||
| Asia | 12 | 26,099 | 503 | 3.9% (1.5–7.2) | 1,105.92 | <0.01 | 99.0% | |||
| North America | 3 | 3,020 | 362 | 17.2% (0–78.5) | 1,017.03 | <0.01 | 99.8% | |||
| South America | 3 | 4,733 | 225 | 5.0% (3.7–6.3) | 4.08 | 0.13 | 51.0% | |||
| Europe | 4 | 1,790 | 622 | 35.1% (4.8–74.6) | 666.23 | <0.01 | 99.5% | 0.0002 | 0.368 (0.176 to 0.560) | |
| Africa | 4 | 1,071 | 115 | 11.3% (3.3–22.9) | 49.66 | <0.01 | 94.0% | |||
| Sampling years | ||||||||||
| After 2010 | 16 | 25,890 | 685 | 4.2% (1.8–7.5) | 1,395.04 | <0.01 | 98.9% | |||
| Before 2010 | 10 | 10,487 | 1,116 | 20.8% (5.6–42.2) | 2,955.04 | 0 | 99.7% | 0.0026 | 0.262 (0.091 to 0.433) | |
| Quality level | ||||||||||
| 4–5 | 10 | 17,782 | 999 | 10.8% (5.5–17.6) | 1,317.67 | <0.01 | 99.3% | 0.7643 | 0.027 (−0.148 to 0.201) | |
| 2–3 | 16 | 18,931 | 828 | 9.1% (2.6–18.7) | 3,202.11 | 0 | 99.5% | |||
| 0–1 | 0 | 0 | 0 | ND | ND | ND | ND | ND | ND | |
| Method* | ||||||||||
| RBPT | 6 | 16,010 | 113 | 6.5% (2.1–13.0) | 409.32 | <0.01 | 98.8% | |||
| SAT | 6 | 9,087 | 497 | 7.3% (0–25.1) | 1,243.59 | <0.01 | 99.6% | |||
| ELISA | 11 | 10,432 | 508 | 13.5% (8.5–19.4) | 544.23 | <0.01 | 98.2% | |||
| CFT | 2 | 794 | 101 | 27.3% (0.7–70.8) | 34.64 | <0.01 | 97.1% | 0.0997 | 0.209 (−0.040 to 0.458) | |
| Reproductive health | ||||||||||
| Reproductive issues | 2 | 1,607 | 101 | 4.8% (3.6–6.0) | 0.30 | 0.58 | 0.0% | |||
| Health | 2 | 2,736 | 108 | 4.8% (2.1–8.7) | 8.60 | <0.01 | 88.4% | 0.5150 | −0.039 (−0.157 to 0.079) | |
| Feeding mode | ||||||||||
| Captive | 13 | 25,833 | 829 | 10.6% (4.9–18.1) | 2,641.95 | 0 | 99.5% | |||
| Stock | 10 | 7,857 | 931 | 11.5% (3.6–23.0) | 1,469.46 | <0.01 | 99.4% | 0.8654 | 0.015 (−0.159 to 0.189) | |
| Farming mode | ||||||||||
| Intensification | 10 | 15,824 | 509 | 8.5% (0.9–22.2) | 2,246.06 | 0.00 | 99.6% | |||
| Artificial | 8 | 12,998 | 526 | 10.7% (6.6–15.7) | 320.63 | <0.01 | 97.8% | 0.5670 | 0.059 (−0.142 to 0.259) | |
| Environment | ||||||||||
| Wetland | 8 | 18,016 | 234 | 5.1% (1.8–10.4) | 678.65 | <0.01 | 99.0% | |||
| Dryland | 6 | 3,796 | 239 | 6.4% (2.0–12.9) | 120.24 | <0.01 | 95.8% | 0.7100 | 0.028 (−0.121 to 0.178) | |
| Sex | ||||||||||
| Male | 2 | 266 | 13 | 4.4% (2.0–7.4) | 0.45 | 0.50 | 0.0% | |||
| Female | 3 | 4,183 | 214 | 10.1% (3.4–19.7) | 27.63 | <0.01 | 92.8% | 0.4600 | 0.080 (−0.132 to 0.292) | |
| Age of buffalo* | ||||||||||
| Lactating buffalo | 3 | 2,378 | 447 | 26.9% (1.8–66.5) | 742.12 | <0.01 | 99.7% | 0.2619 | 0.247 (−0.185 to 0.680) | |
| Juvenile buffalo | 2 | 3,934 | 181 | 3.4% (2.8–4.1) | 0.37 | 0.54 | 0.0% | |||
| Adult buffalo | 2 | 477 | 37 | 10.8% (1.1–28.0) | 14.73 | <0.01 | 93.2% | |||
| Income level | ||||||||||
| High | 6 | 2,224 | 907 | 32.8% (7.5–65.2) | 1,000.03 | <0.01 | 99.5% | <0.0001 | 0.386 (0.244 to 0.528) | |
| Middle | 11 | 30,300 | 647 | 5.0% (2.3–8.6) | 1,225.49 | <0.01 | 99.2% | |||
| Low | 9 | 4,189 | 273 | 5.3% (3.2–7.9) | 76.94 | <0.01 | 89.6% | |||
| Country | ||||||||||
| China | 3 | 12,831 | 2 | 0.5% (0–1.2) | 9.67 | <0.01 | 79.3% | |||
| Pakistan | 5 | 2,340 | 218 | 4.6% (2.5–7.2) | 22.64 | <0.01 | 82.3% | |||
| Trinidad | 2 | 434 | 285 | 27.8% (0–99.9) | 178.75 | <0.01 | 99.4% | |||
| Brazil | 3 | 4,733 | 225 | 5.0% (3.7–6.3) | 4.08 | 0.13 | 51.0% | |||
| India | 3 | 10,088 | 326 | 10.4% (3.9–19.3) | 202.04 | <0.01 | 99.0% | |||
| Italy | 4 | 1,790 | 622 | 35.1% (3.8–74.6) | 666.23 | <0.01 | 99.5% | |||
| Costa Rica | 1 | 2,586 | 77 | 3.0% (3.7–7.6) | 0.00 | ND* | ND | |||
| Egypt | 2 | 903 | 80 | 4.5% (0–18.5) | 27.90 | <0.01 | 96.4% | |||
| Zimbabwe | 1 | 106 | 18 | 17.0% (10.4–24.8) | 0.00 | ND | ND | |||
| Sri Lanka | 1 | 840 | 35 | 4.2% (2.9–5.6) | 0.00 | ND | ND | |||
| Africa | 1 | 62 | 17 | 27.4% (17.0–39.3) | 0.00 | ND | ND | |||
| Sample | ||||||||||
| Serum | 25 | 36,599 | 1,827 | 10.3% (5.9–15.8) | 4,942.66 | 0.00 | 99.5% | 0.1798 | 0.284 (−0.131 to 0.699) | |
| Milk | 1 | 114 | 0 | 0% (0–1.5) | 0.00 | ND* | ND* | |||
| Wild* | ||||||||||
| No | 2 | 206 | 7 | 2.1% (0–12.9) | 9.83 | <0.01 | 89.8% | |||
| Yes | 2 | 426 | 40 | 11.1% (3.1–22.9) | 8.27 | <0.01 | 87.9% | 0.1583 | 0.185 (−0.072 to 0.443) | |
| Total | 26 | 36,713 | 1,827 | 9.7% (5.5–14.9) | 4,948.43 | 0.00 | 99.5% | |||
CI*: Confidence interval.
Region*: Asia: China, Pakistan, India, and Sri Lanka; North America: Trinidad and Costa Rica; South America: Brazil; Europe: Italy; Africa: Egypt, Zimbabwe, and South Africa.
Method*: CFT, Complement fixation test; ELISA, Enzyme-linked immunosorbent assay; RBPT, Rose Bengal plate test; SAT, Serum agglutination test.
Age of buffalo*: Lactating buffalo: >1 year; Juvenile buffalo: 1–3 years; Adult buffalo: >3 years.
Others*: Aborted fetuses and vaginal swabs.
ND*: no data.
Wild*: Contact with wild animals.