Non-invasive surveillance of Plasmodium infection by real-time PCR analysis of ethanol preserved faeces from Ugandan school children with intestinal schistosomiasis

AlShehri, Hajri, Power, Joanne, Archer, John, Cousins, Alice, Atuhaire, Aaron, Adriko, Moses, Arinaitwe, Moses, Alanazi, Abduallah D, LaCourse, James ORCID: https://orcid.org/0000-0001-9261-7136, Kabatereine, Narcis B and Stothard, Russell ORCID: https://orcid.org/0000-0002-9370-3420 (2019) 'Non-invasive surveillance of Plasmodium infection by real-time PCR analysis of ethanol preserved faeces from Ugandan school children with intestinal schistosomiasis'. Malaria Journal, Vol 18, Issue 109.

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Abstract

Background
As part of ongoing co-surveillance of intestinal schistosomiasis and malaria in Ugandan school children, a non-invasive detection method for amplification of Plasmodium DNA using real-time (rt)PCR analysis of ethanol preserved faeces (EPF) was assessed. For diagnostic tabulations, results were compared to rtPCR analysis of dried blood spots (DBS) and field-based point-of-care (POC) rapid diagnostic tests (RDTs).
Methods
A total 247 school children from 5 primary schools along the shoreline of Lake Albert were examined with matched EPF and DBS obtained. Mean prevalence and prevalence by school was calculated by detection of Plasmodium DNA by rtPCR using a 18S rDNA Taqman® probe. Diagnostic sensitivity, specificity, positive and negative predictive values were tabulated and compared against RDTs.
Results
By rtPCR of EPF and DBS, 158 (63.9%; 95% CI: 57.8–69.7) and 198 (80.1 %, 95% CI: 74.7–84.6) children were positive for Plasmodium spp. By RDT, 138 (55.8%; 95% CI: 49.6– 61.9) and 45 (18.2%; 95% CI: 13.9–23.5) children were positive for Plasmodium falciparum with non-P. falciparum infections, respectively. Using RDT results as a convenient field-based reference, the sensitivity of rtPCR of EPF and DBS was 73.1% (95% CI: 65.2–79.8) and 94.2% (95% CI: 88.9–97.0) while specificity was 47.7% (95% CI: 38.5–57.0) and 37.6% (95% CI: 29.0–46.9), respectively. With one exception, school prevalence estimated by analysis of EPF was higher than that by RDT. Positive and negative predictive values were compared and dicussed.
Conclusions
In this high transmission setting, EPF sampling by rtPCR has satisfactory diagnostic performance in estimation of mean prevalence and prevalence by school upon direct comparison with POC-RDTs. Although analysis of EPF was judged inferior to that of DBS, it permits an alternative non-invasive sampling regime that could be implemented alongside general monitoring and surveillance for other faecal parasites. EPF analysis may also have future value in passive surveillance of low transmission settings.
Keywords Plasmodium; Schistosoma mansoni, real-time PCR; surveillance; RDT; faecal sampling.

Item Type:	Article
Subjects:	QS Anatomy > QS 4 General works. Classify here works on regional anatomy QX Parasitology > Protozoa > QX 135 Plasmodia WA Public Health > WA 30 Socioeconomic factors in public health (General) WC Communicable Diseases > Tropical and Parasitic Diseases > WC 810 Schistosomiasis
Faculty: Department:	Biological Sciences > Department of Tropical Disease Biology
Digital Object Identifer (DOI):	https://doi.org/10.1186/s12936-019-2748-4
Depositing User:	Stacy Murtagh
Date Deposited:	05 Apr 2019 09:33
Last Modified:	02 Dec 2019 12:53
URI:	https://archive.lstmed.ac.uk/id/eprint/10520

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