Table 1.
Soil-transmitted helminth prevalence and intensity at study time points, as measured by qPCR and SNF
| Prevalence by qPCR (95% CI) | Prevalence by SNF (95% CI) | P value* | Mean cycle threshold value (range) | Mean eggs per gram (range) | |
|---|---|---|---|---|---|
| Baseline (N = 462) | |||||
| Ascaris spp. | 40.0% (35.7–44.6) | 30.3% (26.2–34.7) | 0.002 | 18.3 (9.1–31.0) | 568.2 (4.0–5,244.0) |
| Hookworm | 14.7% (11.8–18.3) | 12.6% (9.8–15.9) | 0.300 | – | 26.6 (2.0–180.0) |
| Necator americanus | 13.9% (11.0–17.3) | – | 25.1 (24.1–26.0) | – | |
| Ancylostoma spp. | 0.9% (0.3–2.3) | – | 22.4 (20.5–24.4) | – | |
| Trichuris spp. | 2.2% (1.2–4.0) | 2.8% (1.6–4.8) | 0.547 | 31.7 (25.7–35.0) | 21.6 (4.4–54.6) |
| Coinfections | 6.1% (4.2–8.7)† | 5.8% (4.0–8.4)‡ | 0.851 | – | – |
| Follow-up (N = 403) | |||||
| Ascaris spp. | 17.9% (14.4–21.9) | 11.4% (8.7–14.9) | 0.010 | 22.6 (11.2–31.0) | 350.8 (2.9–3,373.0) |
| Hookworm | 8.7% (6.3–11.9) | 8.2% (5.9–11.3) | 0.800 | – | 21.2 (2.2–128.6) |
| N. americanus | 8.7% (6.3–11.9) | – | 25.4 (18.6–31.8) | – | |
| Anyclostoma spp. | 0 | – | – | – | |
| Trichuris spp. | 1.7% (0.8–3.6) | 3.2% (1.9–5.5) | 0.174 | 29.7 (21.2–34.1) | 11.1 (2.5–36.7) |
| Coinfections | 2.2% (1.2–4.3)§ | 3.2% (1.9–5.5)¶ | 0.387 | – | – |
CI = confidence interval; qPCR = quantitative polymerase chain reaction; SNF = sodium nitrate flotation.
P values comparing prevalence obtained using SNF and qPCR.
Of 28 coinfections on qPCR at baseline: 21 Ascaris spp. + N. americanus; six Ascaris spp. + Trichuris spp; one Ascaris spp. + Ancylostoma spp.
Of 27 coinfections on SNF at baseline: 19 Ascaris lumbricoides + hookworm, five A. lumbricoides + Trichuris trichiura; two hookworm + T. trichiura; one triple infection.
Of 9 coinfections on qPCR at follow-up: eight Ascaris spp. + N. americanus; one Ascaris spp. + Trichuris spp.
Of 13 coinfections on SNF at follow-up: nine A. lumbricoides + hookworm; three A. lumbricoides + T. trichiura; one triple infection.