Rapid clearance of schistosomal circulating cathodic antigen (CCA) after treatment shown by urine strip tests - importance for monitoring treatment efficacy and re-infection

Publikation: Bidrag til tidsskriftKonferenceabstrakt i tidsskriftForskningfagfællebedømt

Schistosomiasis elimination has reached agendas in many public health sectors; however, reaching this goal remains a substantial challenge. In order to assess the progress of interventions and monitor treatment efficacy, accurate, feasible and affordable diagnostic tools are an absolute requirement. Detection of Schistosoma mansoni by circulating cathodic antigen (CCA) in urine is an attractive option as this measure describes active worm infection noninvasively. In order to interpret treatment efficacy and re-infections, knowledge about clearance of this antigen is necessary. This study aims to investigate whether systemic antigen clearance is reflected in decreasing CCA levels in urine afteronly 24 h in response to both a single and two treatments with praziquantel.The study was designed as a series of cross-sectional sample collections from 426 individuals nested in a two-arm randomised single blinded longitudinal clinical trial cohort matched by gender and age (ClinicalTrials.gov Identifier: NCT00215267). One arm was baseline treatment only, whereas the other arm received a second treatment at 2 weeks. Samples from baseline (urine+stool), baseline+24 h (urine), 2 weeks (urine), 2 weeks+24 h (urine), 9 weeks (urine+stool) and 2 years (urine+stool) were analysed. CCA levels in urine were determined by carbon-conjugated monoclonal antibody lateral flow strip assay and S. mansoni and soil-transmitted helminths eggs per gram (EPG) by Kato-Katz (six slides). Significant correlations between CCA levels and S. mansoniEPG at baseline, 9 weeks and 2 years regardless of treatment arm were observed. Both tests showed significantly lower levels at 9 weeks in the two treatments group compared to those only receiving one treatment. Furthermore, presence of hookworm was found not to be a confounder for CCA specificity. At baseline mean CCA scores were significantly reduced 24 h after treatment (P < 0.001). Again, at 2 weeks CCA scores were significantly lowered (P < 0.001) 24 h after the second treatment in contrast to the one treatment arm (P = 0.568). In conclusion, CCA clearance in response to treatment is measurable in urine already after 24 h. This is imperative when monitoring treatment efficacy as well as assessing re-infection proportions, because this antigen detecting assay provides information on the presence of actively feeding stages of S. mansoni, which conventional faecal microscopy methods do not accurately reflect.Disclosure This study was funded by the Commission of theEuropean Community0s Science and Technology forDevelopment Programme [INCO-DEV Contract No: 517733 (MUSTSchistUKEMA)]. The funders had no role in study design, data collection and analysis.
TidsskriftTropical Medicine & International Health
Udgave nummerSupplement 1
Sider (fra-til)52
Antal sider1
StatusUdgivet - sep. 2015
Begivenhed9th European Congress on Tropical Medicine and International Health: Driving the Best Science to Meet Global Health Challenges - Basel, Schweiz
Varighed: 6 sep. 201510 sep. 2015


Konference9th European Congress on Tropical Medicine and International Health

ID: 144007443