| Environmental factor | B | S.E | Wals | Odd Ratio (95% CI) | P-value |
| Date |
|
| 10.07 |
| 0.07 |
| May | 0.73 | 0.42 | 3.04 | 2.065 (0.91 - 4.66) | 0.08 |
| Jun | −0.45 | 0.37 | 1.48 | 0.635 (0.31 - 1.32) | 0.22 |
| Jul | 0.21 | 0.40 | 0.27 | 1.228 (0.57 - 2.66) | 0.60 |
| Aug | 0.37 | 0.40 | 0.85 | 1.447 (0.66 - 3.18) | 0.36 |
| Sept | 0.05 | 0.39 | 0.02 | 1.053 (0.49 - 2.26) | 0.90 |
| Oct | - | - | - | 1.00 | - |
| Land use type |
|
| 37.53 |
| 0.00 |
| Woodland | −1.82 | 0.30 | 37.35 | 0.16 (0.09 - 0.29) | 0.00 |
| Grassland | −1.36 | 0.34 | 15.82 | 0.26 (0.13 - 0.50) | 0.00 |
| Residential area | - | - | - | 1.00 | - |
| Soil type |
|
| 53.77 |
| 0.00 |
| Neritic yellow laterite | 0.84 | 0.82 | 1.04 | 2.32 (0.46 - 11.62) | 0.31 |
| Granite yellow laterite | 2.61 | 0.80 | 10.54 | 13.62 (2.82 - 65.91) | 0.00 |
| Granite yellow red soil | 2.87 | 0.80 | 12.90 | 17.57 (3.68 - 83.95) | 0.00 |
| Sand shale yellow red soil | 4.91 | 1.28 | 14.70 | 135.00 (11.00 - 1657.37) | 0.00 |
| Paddy soil | - | - | - | 1.00 | - |
| Distance to highway | −0.00 | 0.00 | 9.10 | 1.00 (1.00 - 1.00) | 0.00 |
| Distance to river | −0.02 | 0.00 | 25.91 | 0.98 (0.98 - 0.99) | 0.00 |
| Distance to household | 0.01 | 0.00 | 7.91 | 1.01 (1.00 - 1.01) | 0.01 |
| Elevation | 0.00 | 0.00 | 0.78 | 1.00 (1.00 - 1.01) | 0.38 |
| Temperature | −0.40 | 0.10 | 14.90 | 0.67 (0.55 - 0.82) | 0.00 |
| Air pressure | −0.18 | 0.04 | 26.11 | 0.84 (0.78 - 0.90) | 0.00 |
| Relative humidity | −0.09 | 0.02 | 15.50 | 0.91 (0.87 - 0.95) | 0.00 |