Table 4.
Preschool (PSAC) and school (SAC) aged pre-treatment prevalence % (95%CI) and relative reductions % (Wald test: Z-statistic, p-value) for Trichuris trichiura infection in 20 counties in Kenya.
| County | Year 1 | Year 3 | Year 5 | Year 6 | Relative Reduction (Year 1–Year 6) RR% (Wald test, p-value) | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| PSAC | SAC | PSAC | SAC | PSAC | SAC | PSAC | SAC | PSAC | SAC | |
| Bomet | 9.1 (5.2–15.8) | 3.7 (1.8–7.2) | 7.1 (3.4–14.8) | 5.7 (2.7–11.7) | 5.0 (1.9–13.1) | 4.4 (2.7–7.2) | 0 | 1.2 (0.3–4.7) | 100 (Z = −8.49, p < 0.001)* | 66.9 (Z = −1.96, p = 0.050) |
| Bungoma | 0 | 0.9 (0.5–1.7) | 0 | 0 | 0 | 0.2 (0.1–0.8) | 0 | 0 | 0 | 100 (Z = −14.21, p < 0.001)* |
| Busia | 7.6 (2.9–19.9) | 12.7 (8.2–19.6) | 9.9 (4.8–20.6) | 14.4 (8.1–25.7) | 10.0 (4.7–21.5) | 10.2 (5.6–18.5) | 28.6 (10.8–75.5) | 21.2 (7.3–61.3) | Increase (274.6%, p = 0.009)** | Increase (66.8%, p = 0.257) |
| Garissa | -ns | -ns | -ns | -ns | -ns | -ns | 0 | 0 | -ns | -ns |
| Homa Bay | 4.3 (2.4–7.7) | 6.0 (4.3–8.4) | 0.9 (0.2–3.6) | 3.1 (2.1–4.7) | 1.7 (0.2–12.3) | 3.0 (1.8–4.8) | 28.6 (12.3–66.2) | 4.6 (2.5–8.2) | Increase (569.8%, p < 0.001)** | 24.6 (Z = −0.98, p = 0.326) |
| Kakamega | 0.6 (0.1–3.8) | 0.7 (0.3–1.7) | 0.6 (0.1–3.8) | 0.7 (0.3–1.8) | 0 | 0.3 (0.1–0.8) | 2.4 (0.2–23.8) | 1.2 (0.8–1.8) | Increase (331.7%, p = 0.310) | Increase (78.6%, p = 0.233) |
| Kericho | 6.2 (2.6–14.7) | 4.5 (2.4–8.6) | 7.3 (1.9–28.5) | 3.8 (2.1–6.7) | 5.5 (1.9–16.0) | 4.8 (2.6–9.0) | 2.7 (0.1–14.2) | 1.2 (0.6–2.3) | 56.5 (Z = −0.82, p = 0.413) | 73.2 (Z = −3.46, p = 0.001)* |
| Kilifi | 0 | 1.8 (0.6–5.0) | 20.0 (1.9–48.0) | 1.8 (0.6–5.1) | 0 | 1.1 (0.2–7.2) | 1.8 (0.3–10.7) | 4.3 (0.9–20.3) | Increase (97.5%, p = 0.001)** | Increase (142.6%, p = 0.362) |
| Kisii | 2.0 (0.5–7.6) | 1.3 (0.7–2.3) | 0 | 1.2 (0.4–3.3) | 1.7 (0.4–7.3) | 0.9 (0.5–1.6) | 4.3 (1.3–14.2) | 1.1 (0.4–2.8) | Increase (195.6%, p = 0.128) | 12.4 (Z = −0.23, p = 0.815) |
| Kisumu | 6.6 (2.6–16.8) | 3.6 (1.9–6.9) | 1.1 (0.2–7.4) | 2.2 (1.4–3.4) | 2.6 (0.6–12.2) | 1.8 (1.1–3.1) | 7.1 (1.2–41.4) | 1.9 (0.7–5.6) | Increase (7.7%, p = 0.928) | 47.0 (Z = −1.06, p = 0.289) |
| Kitui | -ns | -ns | -ns | -ns | -ns | -ns | 0 | 0 | -ns | -ns |
| Kwale | 6.1 (1.8–21.0) | 6.3 (4.0–9.8) | 1.9 (0.3–12.1) | 3.3 (1.1–10.1) | 3.2 (1.3–7.9) | 1.6 (0.7–4.0) | 12.1 (7.0–21.1) | 3.4 (1.2–9.8) | Increase (98.0%, p = 0.264) | 45.8 (Z = −1.14, p = 0.252) |
| Makueni | -ns | -ns | -ns | -ns | -ns | -ns | 0 | 0 | -ns | -ns |
| Migori | 1.6 (0.2–12.5) | 0.6 (0.1–2.5) | 0 | 0.1 (0–0.9) | 0 | 0.3 (0–1.9) | 0 | 0.6 (0.2–2.5) | 100 (Z = −3.93, p < 0.001)* | Increase (16.3%, p = 0.887) |
| Mombasa | 14.6 (3.7–58.6) | 17.9 (9.7–33.3) | 10.5 (7.7–14.3) | 1.8 (0.5–6.9) | 0 | 1.8 (0.2–17.7) | 3.0 (0.5–17.6) | 0.9 (0.3–2.8) | 79.3 (Z = −1.53, p = 0.127) | 95.1 (Z = −5.08, p < 0.001)* |
| Narok | 31.3 (19.9–49.2) | 29.9 (20.8–43.1) | 29.3 (19.3–44.5) | 26.5 (17.3–40.6) | 26.5 (14.4–48.7) | 29.1 (21.2–40.0) | 23.0 (12.9–40.7) | 13.6 (7.0–26.4) | 26.7 (Z = −1.26, p = 0.208) | 54.6 (Z = −2.73, p = 0.006)* |
| Nyamira | 3.0 (0.4–21.6) | 3.1 (0.6–16.6) | 0 | 0.5 (0.3–1.0) | 0 | 0.4 (0.1–1.9) | 0 | 0.9 (0.2–3.8) | 100 (Z = −3.48, p = 0.001)* | 70.8 (Z = −0.99, p = 0.323) |
| T. Taveta | 0 | 2.1 (0.7–5.9) | 0 | 0 | 2.9 (0.3–33.4) | 0 | 0 | 0 | 0 | 100 (Z = −7.31, p < 0.001)* |
| Vihiga | 8.2 (2.4–28.7) | 10.2 (5.3–19.7) | 3.1 (0.5–19.9) | 7.6 (4.0–14.5) | 7.5 (3.8–14.8) | 6.5 (2.6–16.5) | 3.2 (0.5–22.9) | 8.1 (3.8–17.3) | 60.8 (Z = −1.82, p = 0.068) | 21.2 (Z = −0.87, p = 0.386) |
| Wajir | -ns | -ns | -ns | -ns | -ns | -ns | 0 | 0 | -ns | -ns |
| Overall | 5.9 (4.3–8.1) | 6.3 (5.0–8.0) | 4.2 (2.6–6.7) | 5.1 (3.8–6.9) | 4.5 (3.0–6.8) | 4.6 (3.4–6.2) | 4.8 (2.5–9.0) | 3.5 (2.2–5.7) | 19.2 (Z = −0.80, p = 0.426) | 44.3 (Z = −2.82, p = 0.005)* |
-nsIndicates counties which had not had routine parasitological monitoring, hence, surveys were not conducted in these counties during Year 1, Year 3, and Year 5 assessments.
*
Indicates statistically significant relative reductions since Year 1 (noting that this could be a reflection of sampling technique, and noting also that oftentimes reductions have not been sustained).
**
Indicates statistically significant increase in prevalence since Year 1.