FREEBILY

Fast and reliable easy-to-use-diagnostics for eliminating Bilharzia in young children and mothers

01.03.2018 bis 28.02.2022

Schistosoma antigen detection tests have a large potential for schistosomiasis control programmes due to their much higher sensitivity compared to parasitological methods and preferred use of urine over stool samples. Highly accurate diagnostics are of paramount importance especially in low transmission areas (after years of advanced control programmes). Pregnant women and young children could especially benefit from affordable and easy-to-use antigen tests as inclusion of this particularly vulnerable groups in mass drug administration (MDA) campaigns with praziquantel (PZQ) will always require higher justification hurdles, especially in middle to low endemic regions with a higher proportion of individuals who are not-infected and thus unnecessarily exposed to PZQ.

Since 2008, a point-of-care diagnostic test (POC-CCA) detecting Schistosoma derived circulating cathodic antigen (CCA) in urine is commercially available. This diagnostic test is particularly useful for diagnosing intestinal schistosomiasis with weaker test performance (sensitivity) for urinary schistosomiasis. In contrast, the laboratory-based, up-converting phosphor based lateral flow (UCP-LF) test detecting circulating anodic antigen (CAA) of all Schistosoma species in urine is exceptionally sensitive and specific, and quantifies CAA levels reflecting active, ongoing infections of less than a single Schistosoma worm.

The FREEBILY project will thoroughly evaluate the accuracy of CAA and CCA tests to diagnose Schistosoma infections in women and young children. It has several secondary objectives: 1) To integrate POC-CCA Test-Based-Schistosomiasis-Treatment (TBST) into routine mother child primary health care programmes in Madagascar in order to demonstrate its usefulness for controlling schistosomiasis in pregnant women and young children and assess the diagnostic performance of the POC-CCA test; 2) To thoroughly evaluate the accuracy of the UCP-LF-CAA test in a cross-sectional, multicentre, prospective clinical study in pregnant women for detection of S. Haematobium infections and to validate CAA as an endpoint measure to determine PZQ efficacy in an intervention trial in pregnant women in Gabon; 3) To develop a CAA/CCA duplex test for diagnosis of schistosomiasis for application in various infection areas (potentially capable to differentiate between different schistosome species). 4) To assess cost-effectiveness of TBST using POC-CCA as primary health care diagnostic with PZQ treatment on child development in comparison with traditional primary health care approach.

The FREEBILY sub-studies will be implemented in areas of high and low S. mansoni and S. haematobium endemicity in Madagascar and in Gabon, however the generated research findings from the implementation of TBST and the UCP-LF-CAA test in test-and-treat programs are generalizable to other schistosomiaisis affected countries.