Journal Article

Diagnostic performance of a single and duplicate Kato-Katz, Mini-FLOTAC, FECPAKG2 and qPCR for the detection and quantification of soil-transmitted helminths in three endemic countries

Dana, Daniel, Matoso, Leonardo F., Ame, Shaali, Maya, Catalina, Pinto, Simone A., Thomas, Eurion, Corrêa-Oliveira, Rodrigo, Cools, Piet, Vlaminck, Johnny, Verweij, Jaco J., Vercruysse, Jozef, Maurelli, Maria P., Rinaldi, Laura, Keiser, Jennifer, Montresor, Antonio, Sayasone, Somphou, Mekonnen, Zeleke, Mirams, Greg, José Antonio, Barrios Perez, Albonico, Marco, Ayana, Mio, Cringoli, Giuseppe, Levecke, Bruno

2019

Overview

Because the success of deworming programs targeting soil-transmitted helminths (STHs) is evaluated through the periodically assessment of prevalence and infection intensities, the use of the correct diagnostic method is of utmost importance. The STH community has recently published for each phase of a deworming program the minimal criteria that a potential diagnostic method needs to meet, the so-called target product profiles (TPPs). We compared the diagnostic performance of a single Kato-Katz (reference method) with that of other microscopy-based methods (duplicate Kato-Katz, Mini-FLOTAC and FECPAKG2) and one DNA-based method (qPCR) for the detection and quantification of STH infections in three drug efficacy trials in Ethiopia, Lao PDR, and Tanzania. Furthermore, we evaluated a selection of minimal diagnostic criteria of the TPPs. All diagnostic methods showed a clinical sensitivity of ≥90% for all STH infections of moderate-to-heavy intensities. For infections of very low intensity, only qPCR resulted in a sensitivity that was superior to a single Kato-Katz for all STHs. Compared to the reference method, both Mini-FLOTAC and FECPAKG2 resulted in significantly lower fecal egg counts for some STHs, leading to a substantial underestimation of the infection intensity. For qPCR, there was a positive significant correlation between the egg counts of a single Kato-Katz and the DNA concentration. Our results indicate that the diagnostic performance of a single Kato-Katz is underestimated by the community and that diagnostic specific thresholds to classify intensity of infection are warranted for Mini-FLOTAC, FECPAKG2 and qPCR. When we strictly apply the TPPs, Kato-Katz is the only microscopy-based method that meets the minimal diagnostic criteria for application in the planning, monitoring and evaluation phase of an STH program. qPCR is the only method that could be considered in the phase that aims to seek confirmation for cessation of program. ClinicalTrials.gov NCT03465488.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adolescent / Animals / Biology and Life Sciences / Brazil / Child / Clinical trials / Communities / Criteria / Deoxyribonucleic acid / Detection / Diagnostic software / Diagnostic systems / Diagnostic Tests, Routine - instrumentation / Diagnostic Tests, Routine - methods / DNA / Drug efficacy / Eggs / Ethiopia - epidemiology / Feces - parasitology / Female / Funding / Helminthiasis - diagnosis / Helminthiasis - epidemiology / Helminthiasis - parasitology / Helminthiasis - transmission / Helminths - genetics / Helminths - isolation & purification / Humans / Immunology / Infections / Laboratories / Laos - epidemiology / Male / Medicine and Health Sciences / Methods / Microscopy / Molecular Diagnostic Techniques - instrumentation / Molecular Diagnostic Techniques - methods / Parasite Egg Count - methods / Parasitology / Prevalence / Profiles / Public health / Real-Time Polymerase Chain Reaction - methods / Reproduction (copying) / Research and analysis methods / Sensitivity / Sensitivity and Specificity / Software / Soil / Soil - parasitology / Soils / Supervision / Tanzania - epidemiology / Tropical diseases / Veterinary medicine / Virology / World Health Organization