Fig 1.
Observed soil-transmitted helminth prevalence by Double-Slide Kato-Katz and qPCR.
Prevalence was estimated from stool samples collected from children aged 2–12 years in rural Bangladesh (N = 2,799).
Fig 2.
Venn diagram of co-infections detected by Double-Slide Kato-Katz and qPCR.
Soil-transmitted helminth ova or DNA were detected in stool samples collected from children aged 2–12 years in rural Bangladesh using Kato-Katz or multi-parallel qPCR (N = 2,799).
Table 1.
Observed soil-transmitted helminth prevalence, Double-Slide Kato-Katz eggs per gram, and qPCR Cq values (N = 2,799).
Table 2.
Classification of qPCR and Double-Slide Kato-Katz for each type of STH (N = 2,799).
Table 3.
Estimated sensitivity, and specificity of each diagnostic method using Bayesian latent class models.
Fig 3.
Relationship between Cq values measured by qPCR and eggs per gram estimated using Double-Slide Kato-Katz.
Soil-transmitted helminth ova or DNA were detected by Kato-Katz and qPCR in stool samples collected from children aged 2–12 years in rural Bangladesh (N = 2,799). The black solid line is the LOESS smoother for values that were classified as positive using both tests. Gray points indicate results that were negative by qPCR but positive by Kato-Katz; they are gray because Kato-Katz cannot differentiate between hookworm species. The Kendall’s tau comparing eggs per gram and Cq values was -0.442 for A. lumbricoides, -0.346 for N. americanus, -0.266 for A. ceylanicum, and -0.248 for T. trichiura (for each, the p-value was < 0.001).
Fig 4.
Distribution of A. lumbricoides Cq values within infection intensity categories using Double-Slide Kato-Katz.
Light intensity infections were defined as < 5,000 epg for A. lumbricoides, < 1,000 epg for T. trichiura, and < 2,000 epg for hookworm; moderate intensity infections were defined as 5,000 ≤ epg < 50,000 for A. lumbricoides, 1,000 ≤ epg < 10,000 for T. trichiura, and 2,000 ≤ epg < 4,000 for hookworm; heavy intensity infections were defined as ≥ 50,000 epg for A. lumbricoides, ≥ 10,000 epg for T. trichiura, and ≥ 4,000 epg for hookworm per the World Health Organization definition.