Table 1. Characteristics of the study population and environmental conditions at their place of residence.
| Variable Unit | Kyela A | Kyela B | Kyela overall | Other sites | |
|---|---|---|---|---|---|
| Number of observations | N | 295 | 617 | 912 | 5,322 |
| Age (years) | Median | 15.1 | 16.8 | 16.2 | 16.8 |
| (IQR) | (8.7–31.8) | (9.0–35.1) | (8.9–33.8) | (8.9–35.7) | |
| Sex male | % | 50.2 | 48.5 | 49.0 | 46.6 |
| T. trichiura infection prevalence | % | 2.7 | 38.1 | 26.6 | 0.1 |
| Infection intensitya): | |||||
| No infection (0 EPG) | % | 97.3 | 61.9 | 73.4 | 99.9 |
| Light infection (1–999 EPG) | % | 2.7 | 36.6 | 25.7 | 0.1 |
| Moderate infection (1000–9999 EPG) | % | 0.0 | 1.5 | 1.0 | 0.0 |
| Heavy infection (≥10000 EPG) | % | 0.0 | 0.0 | 0.0 | 0.0 |
| Co-infection with A. lumbricoides and/or hookwormb) | n (%) | 7 (87.5) | 186 (79.2) | 193 (79.4) | 1 (16.7) |
| SES score | Median | 0.08 | -0.73 | -0.60 | -0.01 |
| (IQR) | (-0.76–0.38) | (-1.21 –-0.21) | (-1.10–0.10) | (-0.52–0.61) | |
| Latrine coverage in surroundings (%) | Median | 99.3 | 92.1 | 96.4 | 100.0 |
| (IQR) | (98.2–100.0) | (76.6–97.3) | (83.8–99.1) | (98.8–100.0) | |
| Worm treatment last year | |||||
| Treated | % | 4.1 | 4.1 | 4.1 | 6.9 |
| Untreated | % | 64.8 | 60.6 | 62.0 | 88.9 |
| No information | % | 31.2 | 35.3 | 34.0 | 4.2 |
| Latrine type | |||||
| None | % | 2.0 | 11.8 | 8.7 | 1.5 |
| Simple pit latrine | % | 94.2 | 88.2 | 90.1 | 92.1 |
| Ventilated pit latrine | % | 2.0 | 0.0 | 0.7 | 4.2 |
| Water flush toilet | % | 1.7 | 0.0 | 0.6 | 2.2 |
| Population density (persons/km2) | Median | 1,117 | 423 | 441 | 404 |
| (IQR) | (285–2,326) | (340–520) | (319–644) | (207–2,348) | |
| Household density (households/ km2) | Median | 316 | 110 | 111 | 99 |
| (IQR) | (70–662) | (87–142) | (80–171) | (48–593) | |
| EVI | Median | 0.33 | 0.39 | 0.37 | 0.28 |
| (IQR) | (0.32–0.34) | (0.37–0.41) | (0.34–0.40) | (0.25–0.31) | |
| LST Day (°C) | Median | 33.6 | 31.0 | 32.1 | 33.4 |
| (IQR) | (33.2–33.9) | (29.9–32.1) | (30.2–33.2) | (30.7–34.2) | |
| LST Night (°C) | Median | 21.0 | 21.1 | 21.1 | 13.7 |
| (IQR) | (20.7–21.1) | (21.0–21.2) | (20.9–21.2) | (11.7–15.4) | |
| Elevation (m) | Median | 519 | 483 | 485 | 1584 |
| (IQR) | (506–522) | (481–486) | (482–506) | (1,446–1,768) | |
| Slope (°) | Median | 1.04 | 0.68 | 0.70 | 2.7 |
| (IQR) | (0.71–1.98) | (0.61–0.75) | (0.62–0.83) | (1.8–4.6) | |
| Rainfall (mm) | Median | 2,311 | 1,958 | 1,984 | 1,244 |
| (IQR) | (2,209–2,334) | (1,908–1,984) | (1,940–2,209) | (1,115–1,479) | |
Environmental variables are averaged for a buffer area of 1 km radius around each household. N = number of observations, n = number of A. lumbricoides and/or hookworm infected among T. trichiura infected in site, EPG = egg per gram of feces, SES = socio-economic status, EVI = enhanced vegetation index, LST = land surface temperature.
a) According to Montresor, 1998 [27].
b) Coinfection was only calculated for participants who had T. trichiura infection.