Table 1. Summary of descriptive and analytic statistics for Brucella spp. seropositivity in small ruminants from selected smallholder farming areas of Zimbabwe (2020).
| Variable | Level | Distribution d | Association testingd | Univariable logistic regressiond | ||||
|---|---|---|---|---|---|---|---|---|
| N | Prevalence (%) | CI (95%) | Fisher’s exact | OR | CI (95%) | p value | ||
| Seropositivity | Overall | 398 | 36 (9.1) [9.2] | 6.4–12.3 | - | - | - | - |
| Location*a | 1: Chivio | 138 | 0 | 0–2.6 | p<0.000 | (empty) | ||
| 2: Zvimbao | 162 | 0 | 0–2.3 | (empty) | ||||
| 3: Makoni | 64 | 10 (15.6) | 7.8–26.9 | Ref | - | - | ||
| 4: Abattoir | 34 | 26 (76.5) | 58.8–89.3 | 17.6 | 6.2–49.7 | 0.000 | ||
| Species | 1: Caprine | 335 | 33 (9.9) | 6.9–13.6 | p = 0.239 | |||
| 2: Ovine | 63 | 3 (4.8) | 1.0–13.3 | |||||
| Age*a | 1: 1<x≤2 yearsc | 69 | 0 | - | p<0.000 | |||
| 2: 2<x≤3 yearsc | 59 | 5 (8.5) | 2.8–18.7 | Ref | - | - | ||
| 3: 3<x≤4 years | 93 | 9 (9.7) | 4.5–17.6 | 2.6 | 0.9–8.1 | 0.092 | ||
| 4: 4<x≤5 years | 120 | 9 (7.5) | 3.5–13.8 | 2.0 | 0.7–6.1 | 0.228 | ||
| 5: x>5 years | 57 | 13 (22.8) | 12.7–35.8 | 7.3 | 2.5–21.6 | 0.000 | ||
| Parity*a | 0: 0o | 1 | 0 | - | p = 0.010 | (empty) | ||
| 1: 1–2 | 212 | 11 (5.2) | 2.6–9.1 | Ref | - | - | ||
| 2: 3–4c | 144 | 21 (14.6) | 9.3–21.4 | 2.9 | 1.4–6.0 | 0.005 | ||
| 3: ≥5c | 28 | 4 (14.3) | 4.0–32.7 | |||||
| Sex | 1: Female | 385 | 36 (9.4) | 6.6–12.7 | p = 0.618 | |||
| 2: Male | 13 | 0 | - | |||||
| Abortion history*a | 0: No | 281 | 18 (6.4) | 3.8–9.9 | p = 0.002 | Ref | - | - |
| 1: Yes | 104 | 18 (17.3) | 10.6–26.0 | 3.1 | 1.5–6.1 | 0.002 | ||
N, number of animals; P, probability value; CI, Confidence Interval
*These variables had Fisher’s Exact p < 0.05 and were used in the univariable logistic regression analysis
a These variables showed a significant independent association (p<0.05) in the univariable logistic regression analysis and were used in the multivariable logistic regression model
d Dependent variable: small ruminant seropositivity for Brucella sp. (negative = 0, positive = 1)
c These groups were combined to form a single group within that particular level; o/empty: These groups were omitted from the regression analyses because they did not have any positives; [%] test adjusted prevalence.