June 2022--The Coalition for Operational Research on Neglected Tropical Diseases with support from the United States Agency for International Development (USAID) announces the grant recipients of the 2022 Request for Proposals (RFP): New diagnostics for schistosomiasis monitoring and evaluation.
The goal of this RFP was to produce diagnostic tools that can be used at the point of care, on non-stool samples, to reliably detect active infection and to measure infection prevalence at the community level. The tests funded through this RFP must have addressed the characteristics outlined in the new WHO Schistosomiasis Monitoring and Evaluation Target Product Profile (TPP). TPPs describe the ideal and minimally acceptable characteristics of health products aimed at particular diseases and/or programmatic use cases. The availability of WHO TPPs for schistosomiasis help to ensure that diagnostic test developers and researchers focus their efforts on the development of diagnostic tools that meet the needs of schistosomiasis programs.
“The current lack of an accurate, sensitive and scalable test that is more field-friendly than stool sampling, has held back the full potential of achieving the goal of eliminating or controlling schistosomiasis. We are optimistic that these new studies may create the means to better monitor and evaluate schistosomiasis control and elimination programs under MDA. Additionally, we are very pleased to bring new companies and investigators into NTD diagnostics, to promote the diversity of products,” said Joseph Shott, USAID NTD Division.
Schistosomiasis is a disease caused by parasitic worms in contaminated freshwater bodies. An infection that is left untreated can cause liver, bladder or intestinal disease, infertility and other health problems. Thankfully, there is medication that can treat schistosomiasis, but it is not always available to the people in need and sometimes individuals do not always seek treatment because they are not aware of the disease and its symptoms. Therefore, public health officials use a strategy called mass drug administration (MDA), to distribute treatment to community members where the disease is endemic, regardless of individual infection status.
In order to decide when mass treatment is warranted or whether treatment frequency should change, NTD control programs use population-based surveys to show that disease prevalence in a given area is likely above or below a designated action threshold. The main strategy for schistosomiasis control is based on MDA of praziquantel to primary school age children, and in certain high-risk areas, high-risk adults as well. The working guidance for control programs is that communities with ≥ 10% prevalence among primary school age children should receive annual MDA.
Thirty-one proposals were submitted in response to the RFP. Proposals were reviewed by an independent panel of experts who made funding recommendations based on scientific merit, alignment with the WHO TPP, suitability for use at the point of care, and feasibility of near-term launch for programmatic use. As a result of intensive review, the following projects have been selected for funding:
Molecular Isothermal Diagnostics for Schistosomiasis (MIDS)
Principle investigator: Bonnie L Webster, Natural History Museum London (NHM)
- Dr Steffi Knopp, SwissTPH, Switzerland
- Dr Fatma Kabole, Neglected Diseases Program, Ministry of Health, Zanzibar, Tanzania
- Said M. Ali, Public Health Laboratory, Ivo de Carneri, Pemba, Zanzibar, Tanzania
- Silvia Mesquita, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
Description: The Schistosoma haematobium Recombinase Polymerase Amplification (Sh-RPA) assay is an isothermal molecular diagnostic for urogenital schistosomiasis with high sensitivity and specificity achieved in pilot laboratory and clinical sample testing. With its speed and portability, it is a promising tool for point-of-care diagnosis in endemic settings. The objective of this study is to refine specific aspects of the testing protocol in order to fully optimize the test for use at the point-of-care level. This study is expected to result in an optimized Sh-RPA assay that meets or exceeds the TPP requirements. We hope that this study will also result in learnings that can be used in other contexts to bring molecular diagnostics closer to field use. (See full study details.)
Improving POC-CCA reliability and interpretation in low and high S. mansoni endemicity settings using recombinant Ab-based POC-CCAs and improved quality assurance and control.
Principle investigator: Dr Poppy Lamberton, University of Glasgow, Infectious Diseases, Institute of Biodiversity, Animal Health & Comparative Medicine, Wellcome Centre for Integrative Parasitology, University of Glasgow, United Kingdom
- Elías Kabbas-Piñango, PhD Student in Infectious Diseases, Institute of Biodiversity, Animal Health & Comparative Medicine, Wellcome Centre for Integrative Parasitology, University of Glasgow, United Kingdom
- Adriko Moses, Program Officer, Vector Control Division, Ministry of Health, Uganda
- Arinaitwe Moses, Laboratory and Field Technician, Vector Control Division, Ministry of Health, Uganda
- Dr Joaquín Prada, Senior Lecturer in Veterinary Epidemiology, Faculty of Health & Medical Sciences, University of Surrey, United Kingdom
- Dr Govert van Dam, Senior Researcher, Department of Parasitology, Leiden University Medical Center, The Netherlands
- Dr Lisette van Lieshout, Associate Professor, Department of Parasitology, Leiden University Medical Center, The Netherlands
- Dr René Paulussen, Managing Director, Mondial Diagnostics, The Netherlands
- Theresia Abdoel, Senior Development Specialist, Mondial Diagnostics, The Netherlands
Description: The point-of-care circulating cathodic antigen test (POC-CCA) has been commercially available since 2008 for detecting Schistosoma mansoni infections. However, its utility for programmatic use has suffered due to challenges related to batch-to-batch variation and interpretation of trace readings. To address these issues, the non-profit foundation, MondialDx, in collaboration with Leiden University Medical Center (LUMC), developed an updated version of the POC-CCA test using recombinant antibodies, referred to as the recPOC-CCA. Here we aim to further improve the quality of recPOC-CCA tests across batches (including reducing the number of subjective readouts close to the test’s cutoff), and evaluate the inclusion of one or more (lyophilized) calibrators with recPOC-CCA kits in combination with standardized visual reading. Using latent class analyses, recPOC-CCA results from the lab and Ugandan settings will be compared to data from three days of duplicate Kato-Katz thick smears and the standard POC-CCA test. These will provide guidance to end users on the appropriate cutoff for these recPOC-CCA tests. This study is expected to result in improved reliability of the test, an associated higher specificity and sensitivity of the test and greatly enhanced accuracy and support for monitoring and evaluation of mass drug administration programmes in endemic countries.(See full study details).
“Congratulations to all of the recipients and thank you to everyone who submitted a proposal. The challenge to develop these diagnostics is large but imperative in the fight to beat NTDs,” said Pat Lammie, program director, NTD-SC. “We look forward to working with these principal investigators on their studies and diagnostic developments.”
The U.S. Agency for International Development (USAID) leads international development and humanitarian efforts to save lives, reduce poverty, strengthen democratic governance, and help people progress beyond assistance.
The Coalition for Operational Research on Neglected Tropical Diseases (COR-NTD) includes researchers, program implementers, and their supporters with the shared goal of optimizing the control and elimination of neglected tropical diseases. The COR-NTD secretariat is the Neglected Tropical Diseases Support Center, a program at The Task Force for Global Health in Decatur, GA, USA.
Photo credit: Elías Kabbas-Piñango.