Comparison of multi-parallel qPCR and double-slide Kato-Katz for detection of soil-transmitted helminth infection among children in rural Bangladesh.
PLoS Negl Trop Dis
; 14(4): e0008087, 2020 04.
Article
in En
| MEDLINE
| ID: mdl-32330127
ABSTRACT
There is growing interest in local elimination of soil-transmitted helminth (STH) infection in endemic settings. In such settings, highly sensitive diagnostics are needed to detect STH infection. We compared double-slide Kato-Katz, the most commonly used copromicroscopic detection method, to multi-parallel quantitative polymerase chain reaction (qPCR) in 2,799 stool samples from children aged 2-12 years in a setting in rural Bangladesh with predominantly low STH infection intensity. We estimated the sensitivity and specificity of each diagnostic using Bayesian latent class analysis. Compared to double-slide Kato-Katz, STH prevalence using qPCR was almost 3-fold higher for hookworm species and nearly 2-fold higher for Trichuris trichiura. Ascaris lumbricoides prevalence was lower using qPCR, and 26% of samples classified as A. lumbricoides positive by Kato-Katz were negative by qPCR. Amplicon sequencing of the 18S rDNA from 10 samples confirmed that A. lumbricoides was absent in samples classified as positive by Kato-Katz and negative by qPCR. The sensitivity of Kato-Katz was 49% for A. lumbricoides, 32% for hookworm, and 52% for T. trichiura; the sensitivity of qPCR was 79% for A. lumbricoides, 93% for hookworm, and 90% for T. trichiura. Specificity was ≥ 97% for both tests for all STH except for Kato-Katz for A. lumbricoides (specificity = 68%). There were moderate negative, monotonic correlations between qPCR cycle quantification values and eggs per gram quantified by Kato-Katz. While it is widely assumed that double-slide Kato-Katz has few false positives, our results indicate otherwise and highlight inherent limitations of the Kato-Katz technique. qPCR had higher sensitivity than Kato-Katz in this low intensity infection setting.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Microbiological Techniques
/
Molecular Diagnostic Techniques
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Real-Time Polymerase Chain Reaction
/
Helminthiasis
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Intestinal Diseases, Parasitic
Type of study:
Diagnostic_studies
/
Evaluation_studies
/
Risk_factors_studies
Limits:
Animals
/
Child
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Child, preschool
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Female
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Humans
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Infant
/
Male
Country/Region as subject:
Asia
Language:
En
Journal:
PLoS Negl Trop Dis
Journal subject:
MEDICINA TROPICAL
Year:
2020
Type:
Article
Affiliation country:
United States