Authors

G J van DamC J de DoodD KornelisL van LieshoutP L Corstjens ¹ LUMC - Dept of Molecular Cell Biology, Netherlands;  ² LUMC - Dept. of Parasitology, Netherlands

Discussion

The  renewed interest in mapping, intensified control and elimination of schistosomiasis has put the need for highly accurate diagnostic assays high on the agenda. Based on the well-studied schistosome antigen detection (CCA and CAA) ELISA’s, a visual, field-friendly point-of-care urine test for CCA and a quantitative, ultra-sensitive reader-assisted assay for CAA have been developed.
The CCA test is commercially available and may replace the Kato-Katz for prevalence mapping of community-level S. mansoni infections using a single drop of urine and also allows quick evaluation (within days) of treatment efficacy.
The recently developed test for CAA is applicable to serum or urine of all schistosome species at sub-pg levels, which allows finding single worm infections. The assay has been transformed into a robust, dry-reagent test, used in several low-resource settings in Africa. In combination with optimized sampling schedules the CAA could rapidly identify foci of low prevalence/intensity of all human schistosome infections. Recent studies using the 2 ml urine format show that in near-elimination settings in China, Africa and Brazil, prevalence of active schistosome infections by egg microscopy may be underestimated up to 10-fold. The CAA strip assay therefore presents itself as a highly accurate diagnostic tool, with a clear value for application in control and elimination settings.