Application of a multiplex quantitative PCR to assess prevalence and intensity Of intestinal parasite infections in a controlled clinical trial

Llewellyn, Stacey, Inpankaew, Tawin, Nery, Susana Vaz, Gray, Darren J., Verweij, Jaco J., Clements, Archie C. A., Gomes, Santina J., Traub, Rebecca and McCarthy, James S. (2016) Application of a multiplex quantitative PCR to assess prevalence and intensity Of intestinal parasite infections in a controlled clinical trial. PLoS Neglected Tropical Diseases, 10 1: 1-19. doi:10.1371/journal.pntd.0004380


Author Llewellyn, Stacey
Inpankaew, Tawin
Nery, Susana Vaz
Gray, Darren J.
Verweij, Jaco J.
Clements, Archie C. A.
Gomes, Santina J.
Traub, Rebecca
McCarthy, James S.
Title Application of a multiplex quantitative PCR to assess prevalence and intensity Of intestinal parasite infections in a controlled clinical trial
Journal name PLoS Neglected Tropical Diseases   Check publisher's open access policy
ISSN 1935-2735
Publication date 2016-01-28
Sub-type Article (original research)
DOI 10.1371/journal.pntd.0004380
Open Access Status DOI
Volume 10
Issue 1
Start page 1
End page 19
Total pages 19
Place of publication San Francisco, CA United States
Publisher Public Library of Science
Collection year 2017
Language eng
Formatted abstract
Background

Accurate quantitative assessment of infection with soil transmitted helminths and protozoa is key to the interpretation of epidemiologic studies of these parasites, as well as for monitoring large scale treatment efficacy and effectiveness studies. As morbidity and transmission of helminth infections are directly related to both the prevalence and intensity of infection, there is particular need for improved techniques for assessment of infection intensity for both purposes. The current study aimed to evaluate two multiplex PCR assays to determine prevalence and intensity of intestinal parasite infections, and compare them to standard microscopy.

Methodology/Principal Findings

Faecal samples were collected from a total of 680 people, originating from rural communities in Timor-Leste (467 samples) and Cambodia (213 samples). DNA was extracted from stool samples and subject to two multiplex real-time PCR reactions the first targeting: Necator americanus, Ancylostoma spp., Ascaris spp., and Trichuris trichiura; and the second Entamoeba histolytica, Cryptosporidium spp., Giardia. duodenalis, and Strongyloides stercoralis. Samples were also subject to sodium nitrate flotation for identification and quantification of STH eggs, and zinc sulphate centrifugal flotation for detection of protozoan parasites. Higher parasite prevalence was detected by multiplex PCR (hookworms 2.9 times higher, Ascaris 1.2, Giardia 1.6, along with superior polyparasitism detection with this effect magnified as the number of parasites present increased (one: 40.2% vs. 38.1%, two: 30.9% vs. 12.9%, three: 7.6% vs. 0.4%, four: 0.4% vs. 0%). Although, all STH positive samples were low intensity infections by microscopy as defined by WHO guidelines the DNA-load detected by multiplex PCR suggested higher intensity infections.

Conclusions/Significance

Multiplex PCR, in addition to superior sensitivity, enabled more accurate determination of infection intensity for Ascaris, hookworms and Giardia compared to microscopy, especially in samples exhibiting polyparasitism. The superior performance of multiplex PCR to detect polyparasitism and more accurately determine infection intensity suggests that it is a more appropriate technique for use in epidemiologic studies and for monitoring large-scale intervention trials.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
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