Table 5.
Characteristics of different aquatic habitat types found with late instars of An. funestus and An. arabiensis in the rainy and dry season
| Season | Habitat characteristics | All water bodies n (%) | No. habitats with late instars of An. funestus (%) | No. habitats with late instars of An. arabiensis (%) | An. funestus | An. arabiensis | ||
|---|---|---|---|---|---|---|---|---|
| Odds ratio (95%CI) | p-value | Odds ratio (95%CI) | p-value | |||||
| Rainy season | Water movement | |||||||
| Stagnant | 807 (42%) | 102 (32.4%) | 170 (79.1%) | 1 | 1 | |||
| Flowing | 1113 (58%) | 213 (67.6%) | 45 (20.9%) | 1.1(0.8–1.4) | 0.70 | 0.2 (0.1–0.2) | < 0.01 | |
| Presence of emergent or floating vegetations | ||||||||
| Absent | 1182 (61.6%) | 166 (52.7%) | 110 (51.2%) | 1 | 1 | |||
| Present | 738 (38.4%) | 149 (47.3%) | 105 (48.8%) | 1.4 (1.1–1.8) | 0.01 | 1.3 (1.0–1.8) | 0.06 | |
| Water clarity | ||||||||
| Opaque | 379 (19.7%) | 30 (9.5%) | 49 (22.8%) | 1 | 1 | |||
| Clear | 1541 (80.3%) | 285 (90.5%) | 166 (77.2%) | 2.4 (1.6–3.7) | < 0.01 | 1.8 (1.2–2.6) | < 0.01 | |
| Presence of green algae | ||||||||
| Absent | 1738 (90.5%) | 251 (79.7%) | 188 (87.4%) | 1 | 1 | |||
| Present | 182 (9.5%) | 64 (20.3%) | 27 (12.6%) | 2.8 (2.0–4) | < 0.01 | 1.5 (0.9–2.4) | 0.09 | |
| Habitat shading | ||||||||
| None | 1217 (63.4%) | 202 (64.1%) | 176 (81.9%) | 1 | 1 | |||
| Shaded | 703 (36.6%) | 113 (35.9%) | 39 (18.1%) | 0.9 (0.7–1.2) | 0.69 | 0.4 (0.3–0.6) | < 0.01 | |
| Distance to nearest household | ||||||||
| Greater than 100 m | 874 (45.5%) | 157 (49.8%) | 68 (31.6%) | 1 | 1 | |||
| Less than 100 m | 1046 (54.5%) | 158 (50.2%) | 147 (68.4%) | 0.9 (0.7–1.1) | 0.28 | 1.3 (0.9–1.7) | 0.17 | |
| Habitat size | ||||||||
| Less than 100m2 | 307 (16%) | 24 (7.6%) | 67 (31.2%) | 0.9 (0.7–1.1) | 0.28 | 1 | ||
| Greater than 100m2 | 1613 (84%) | 291 (92.4%) | 148 (68.8%) | 2.1 (1.3–3.4) | < 0.01 | NI | - | |
| Dry season | Water movement | |||||||
| Stagnant | 758 (49.6%) | 85 (36.6%) | 65 (43.9%) | NI | - | 1 | ||
| Flowing | 769 (50.4%) | 147 (63.4%) | 83 (56.1%) | NI | - | 1.0 (0.7–1.5) | 0.97 | |
| Presence of emergent or floating vegetations | ||||||||
| Absent | 1150 (75.3%) | 102 (44%) | 84 (56.8%) | 1 | 1 | |||
| Present | 377 (24.7%) | 130 (56%) | 64 (43.2%) | 3.3 (2.4–4.5) | < 0.01 | 2.0 (1.4–3.0) | < 0.01 | |
| Water clarity | ||||||||
| Opaque | 573 (37.5%) | 51 (22%) | 66 (44.6%) | 1 | 1 | |||
| Clear | 954 (62.5%) | 181 (78%) | 82 (55.4%) | 2.3 (1.6–3.2) | < 0.01 | 0.7 (0.5–1.0) | 0.03 | |
| Presence of green algae | ||||||||
| Absent | 1381 (90.4%) | 187 (80.6%) | 119 (80.4%) | 1 | 1 | |||
| Present | 146 (9.6%) | 45 (19.4%) | 29 (19.6%) | 1.9 (1.2–2.9) | < 0.01 | 2.0 (1.3–3.3) | < 0.01 | |
| Habitat shading | ||||||||
| None | 1014 (66.4%) | 103 (44.4%) | 90 (60.8%) | 1 | 1 | |||
| Shaded | 513 (33.6%) | 129 (55.6%) | 58 (39.2%) | 2.3 (1.7–3.1) | < 0.01 | 1.1 (0.8–1.6) | 0.56 | |
| Distance to nearest household | ||||||||
| Greater than 100 m | 685 (44.9%) | 91 (39.2%) | 64 (43.2%) | 1 | 1 | |||
| Less than 100 m | 842 (55.1%) | 141 (60.8%) | 84 (56.8%) | 1.5 (1.1–2.1) | < 0.01 | 1.2 (0.8–1.7) | 0.32 | |
| Habitat size | ||||||||
| Less than 100m2 | 281 (18.4%) | 5 (2.2%) | 10 (6.8%) | 1 | 1 | |||
| Greater than 100m2 | 1246 (81.6%) | 227 (97.8%) | 138 (93.2%) | 8.8 (3.5–21.9) | < 0.01 | 2.6 (1.3–5.2) | < 0.01 | |
NI Variable not included in the final model