Participants who were not linked to the population-based cohort study were excluded from the baseline analysis presented in our previous analyses (Tanser et al., 2018) and those not treated for …
Panel (A) shows the distribution of egg counts/10 mL among children observed at follow-up round 1 and 2, and panel (B) shows the distribution of community piped water coverage among all study …
Blue represents light re-infections (<50 eggs per 10 ml urine) and Red represents heavy re-infections (≥50 eggs per 10 ml urine). Panels A and B show the prevalence of Schistosoma haematobium for …
The margin plot was constructed from the final parsimonious multivariable negative binomial regression model for the pooled dataset (n = 378, incidence rate ratio = 0.96, p=0.004). Piped water …
The map shows the geographical distribution of mean egg counts/10 mL estimated using the Gaussian kernel of 3 km radius for the pooled re-infection cohort datasets (n = 378). Superimposed on the map …
Follow-up round 1 (N = 253) | Follow-up round 2 (N = 125) | |||||
---|---|---|---|---|---|---|
Total | Infected n(%) | (95% CI) | Total | Infected n(%) | (95% CI) | |
Overall | 253 | 61 (24.1) | (19.0–29.9) | 125 | 24 (19.2) | (12.7–27.2) |
Gender | ||||||
Female | 86 | 16 (18.6) | (11.0–28.4) | 33 | 5 (15.2) | (5.1–31.9) |
Male | 167 | 45 (27.0) | (20.4–34.3) | 92 | 19 (20.7 | (12.9–30.4) |
Age group | ||||||
≤10 | 41 | 13 (31.7) | (18.1–48.1) | 28 | 7 (25.0) | (10.7–44.9) |
11 | 71 | 15 (21.1) | (12.3–32.4) | 34 | 5 (14.7) | (5.0–31.1) |
12 | 74 | 18 (24.3) | (15.1–35.7) | 29 | 6 (20.7) | (8.0–39.7) |
≥13 | 67 | 15 (22.4) | (13.1–34.2) | 34 | 6 (17.6) | (6.8–34.5) |
Community piped water coverage (%) | ||||||
<70 | 58 | 17 (29.3) | (18.1–42.7) | 31 | 5 (16.1) | (5.5–33.7) |
70 - < 90 | 66 | 13 (19.7) | (10.9–31.3) | 28 | 8 (28.6) | (13.2–48.7) |
≥90 | 129 | 31 (24.0) | (16.9–32.3) | 66 | 11 (16.6) | (8.6–27.9) |
Altitude class (meters) | ||||||
<50 | 17 | 5 (29.4) | (10.3–56.0) | 14 | 6 (42.9) | (17.7–71.1) |
50–100 | 140 | 31 (22.1) | (15.6–29.9) | 62 | 11 (17.7) | (9.2–29.5) |
100–150 | 84 | 21 (25.0) | (16.2–35.6) | 42 | 5 (11.9) | (4.0–25.6) |
150–200 | 7 | 2 (28.6) | (3.7–71.0) | 3 | 0 (0) | (0–70.8) |
≥200 | 5 | 2 (40.0) | (5.3–85.3) | 4 | 2 (50.0) | (6.8–93.2) |
Distance water body class | ||||||
<1 km | 92 | 20 (21.7) | (13.8–31.6) | 46 | 11 (23.9) | (12.6–38.8) |
1–2 km | 98 | 25 (25.5) | (17.2–35.3) | 42 | 8 (19.1) | (8.6–34.1) |
2–3 km | 46 | 13 (28.3) | (16.0–43.5) | 26 | 5 (19.2) | (6.6–39.4) |
>3 km | 17 | 3 (17.7) | (3.8–43.4) | 11 | 0 (0) | (0–28.5) |
School grade | ||||||
Grade 5 | 144 | 37 (25.7) | (18.8–33.6) | 74 | 13 (17.6) | (9.7–28.2) |
Grade 6 | 109 | 24 (22.0) | (14.6–31.0) | 51 | 11 (21.6) | (11.3–35.3) |
Toilet | ||||||
No Toilet | 47 | 13 (27.7) | (15.6–42.6) | 23 | 1 (4.3) | (0.1–21.9) |
Toilet | 206 | 48 (23.3) | (17.7–29.7) | 102 | 23 (22.6) | (14.9–31.9) |
Land cover classification | ||||||
Closed shrubland | 145 | 35 (24.1) | (17.4–31.9) | 65 | 12 (18.5) | (9.9–30.0) |
Open shrubland | 59 | 14 (23.7) | (13.6–36.6) | 34 | 6 (17.7) | (6.8–34.5) |
Sparse shrubland | 41 | 11 (26.8) | (14.2–42.9) | 19 | 6 (31.6) | (12.6–56.6) |
Thickett | 8 | 1 (12.50) | (0.3–52.7) | 7 | 0 (0) | (0–41.0) |
Baseline intensity of infection | ||||||
Light infection | 105 | 35 (33.3) | (24.4–43.2) | 50 | 12 (24.0) | (13.1–38.2) |
Heavy infection | 148 | 26 (17.6) | (11.8–24.7) | 75 | 12 (16.0) | (8.6–26.3) |
Sample size (N) | 253 | 125 |
Model 1 presents results from the univariable negative binomial model and Model 2 presents results from the final parsimonious multivariable negative binomial model. Homestead level piped water …
Model 1: univariable (n = 378) | Model 2: multivariable (n = 378) | |||||
---|---|---|---|---|---|---|
Covariates | IRR | 95% | P-value | IRR | 95% | P-value |
Female | 0.17 | 0.06–0.54 | 0.003 | 0.14 | 0.06–0.32 | <0.001 |
Community piped water coverage (continuous effect) | 0.96 | 0.93–0.98 | 0.002 | 0.96 | 0.93–0.98 | 0.004 |
Age at baseline (years) | 0.68 | 0.50–0.93 | 0.017 | 0.78 | 0.59–1.04 | 0.094 |
Altitude class (ref < 50) | ||||||
50–100 | 3.65 | 0.91–14.5 | 0.067 | 1.20 | 0.31–4.56 | 0.793 |
100–150 | 0.72 | 0.21–2.54 | 0.612 | 0.41 | 0.1–1.74 | 0.226 |
≥150 | 0.11 | 0.02–0.62 | 0.012 | 0.05 | 0.01–0.32 | 0.001 |
Land cover class (ref. Sparse shrubland) | ||||||
Closed shrubland | 1.96 | 0.51–7.57 | 0.327 | 0.86 | 0.34–2.21 | 0.754 |
Open shrubland/grassland | 1.77 | 0.33–9.49 | 0.508 | 1.41 | 0.48–4.16 | 0.533 |
Thickett | 0.01 | 0.00–0.06 | <0.001 | 0.02 | 0.00–0.20 | 0.001 |
Toilet in household (ref. no toilet) | 2.71 | 0.70–10.4 | 0.148 | 0.77 | 0.24–2.46 | 0.662 |
Grade (ref. Grade 5) | 0.24 | 0.08–0.75 | 0.014 | 1.35 | 0.52–3.48 | 0.540 |
Visit (ref. Follow up 1) | 1.01 | 0.21–4.92 | 0.989 | 0.74 | 0.31–1.76 | 0.494 |
Distance to water body class (ref. < 1 km) | ||||||
1–2 km | 0.11 | 0.03–0.34 | <0.001 | |||
2–3 km | 0.18 | 0.04–0.85 | 0.031 | |||
>3 km | 0.08 | 0.01–0.54 | 0.010 | |||
Household wealth index (ref. 1st quintile) | ||||||
2 | 3.75 | 0.49–28.7 | 0.203 | |||
3 | 0.38 | 0.08–1.83 | 0.233 | |||
4 | 3.22 | 0.63–16.3 | 0.159 | |||
5 | 1.71 | 0.03–1.70 | 0.432 | |||
Square root of slope | 0.77 | 0.45–1.32 | 0.340 | |||
Baseline intensity of infection (ref. Light infection) | 2.59 | 0.81–8.30 | 0.110 | |||
Alpha (overdispersion parameter) | 22.6 | 17.9–28.3 | <0.001 |
Prevalence of re-infection, intensity of re-infection and re-infection rate (per 100-person year of follow-up) among individuals treated at baseline for S. haematobium infection.
Predictors of Schistosoma haematobium re-infection using data from follow up round 1 only.
Model 1 presents results from a univariable negative binomial model and Model 2 presents results from a multivariable negative binomial model (N = 253).
Predictors of Schistosoma haematobium re-infection using data from follow up round 2 only.
Model 1 presents results from a univariable negative binomial and Model 2 presents results from a multivariable negative binomial model (N = 125).
Characteristics of participants who dropped out of the study at follow-up round 1.
Piped water coverage (exposure variable) was similar between participants who dropped out of the study and those that were enrolled and examined. Significantly higher dropouts were only observed among participants residing further from water bodies. Piped water coverage was derived from the Gaussian kernel density estimation of radius three kilometers.
Characteristics of participants who dropped out of the study at follow-up round 2.
Piped water coverage (exposure variable) was similar between participants who dropped out of the study and those that were enrolled and examined. Significantly higher dropouts were only observed among girls. Piped water coverage was derived from the Gaussian kernel density estimation of radius three kilometers.