Table 2. Association between household characteristics and the human biting rate at three sites in Uganda.
| Characteristic | Walukuba | Kihihi | Nagongera | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| HBR a (Total collection nights) | IRR (95% CI) b | p | HBR (Total collection nights) | IRR (95% CI) b | p | HBR (Total collection nights) | IRR (95% CI) b | p | ||
| Wealth index, stratified by study site | 1st tertile | 1.97 (692) | 1 | - | 7.92 (830) | 1 | - | 49.24 (787) | 1 | - |
| 2nd tertile | 0.75 (777) | 0.30 (0.18–0.52) | <0.001 | 2.58 (795) | 0.33 (0.20–0.56) | <0.001 | 40.57 (785) | 0.79 (0.58–1.07) | 0.13 | |
| 3rd tertile | 0.58 (715) | 0.25 (0.14–0.43) | <0.001 | 2.78 (627) | 0.38 (0.22–0.66) | 0.001 | 40.02 (757) | 0.76 (0.56–1.04) | 0.09 | |
| Main floor material | Earth, sand, dung or stones | 1.76 (1010) | 1 | - | 5.32 (1778) | 1 | - | 46.93 (1966) | 1 | - |
| Wood, bricks or cement | 0.49 (1174) | 0.25 (0.16–0.40) | <0.001 | 1.93 (474) | 0.38 (0.22–0.65) | 0.001 | 23.74 (363) | 0.49 (0.35–0.68) | <0.001 | |
| Main roof material | Thatched | 1.17 (48) | 1 | - | 8.95 (307) | 1 | - | 54.38 (872) | 1 | - |
| Tiles or metal | 1.08 (2136) | 1.07 (0.18–6.36) | 0.94 | 3.92 (1945) | 0.43 (0.22–0.86) | 0.02 | 36.70 (1457) | 0.65 (0.50–0.83) | 0.001 | |
| Main wall material | Mud | 1.65 (698) | 1 | - | 5.52 (1636) | 1 | - | 49.42 (1800) | 1 | - |
| Cement, wood or metal | 0.81 (1486) | 0.63 (0.37–1.06) | 0.08 | 2.18 (616) | 0.40 (0.24–0.66) | <0.001 | 22.54 (529) | 0.45 (0.34–0.58) | <0.001 | |
| Eaves | Open | 1.73 (616) | 1 | - | 7.63 (579) | 1 | - | 53.86 (1109) | 1 | - |
| Closed | 0.83 (1568) | 0.39 (0.23–0.67) | 0.001 | 3.56 (1673) | 0.45 (0.27–0.77) | 0.004 | 33.74 (1220) | 0.60 (0.48–0.77) | <0.001 | |
| Airbricks | None | 1.39 (1456) | 1 | - | 7.50 (608) | 1 | - | 48.48 (1615) | 1 | - |
| Unscreened | 0.56 (321) | 0.34 (0.17–0.68) | 0.002 | 3.58 (1621) | 0.48 (0.29–0.80) | 0.005 | 33.44 (667) | 0.68 (0.52–0.89) | 0.004 | |
| Screened | 0.39 (407) | 0.26 (0.14–0.49) | <0.001 | 0.43 (23) | 0.06 (0.01–0.65) | 0.02 | 6.21 (47) | 0.13 (0.05–0.30) | <0.001 | |
| House type c | Traditional | 1.68 (1010) | 1 | - | 5.46 (1659) | 1 | - | 49.42 (1800) | 1 | - |
| Modern d | 0.57 (1174) | 0.49 (0.28–0.85) | 0.01 | 2.21 (593) | 0.54 (0.30–0.98) | 0.04 | 22.54 (529) | 0.45 (0.34–0.61) | <0.001 | |
aHBR: Human biting rate, adult female anopheles collected per house per night (total adult female anophelines caught / total nights of collection).
bIRR: Incidence rate ratio; CI: Confidence interval.
cIRR adjusted for household wealth.
dCement, wood or metal wall; tiled or metal roof and closed eaves.