Development of a combined field-based diagnostic test for human African trypanosomiasis and malaria

Human African trypanosomiasis (HAT) has been the scourge of rural Africa for centuries. The disease is caused by two species of Trypanosoma brucei parasites (T.b. gambiense in West Africa and T.b. rhodesiense in East Africa) and is transmitted by tsetse flies. It continues to pose a significant threat, particularly in resource-poor settings far from laboratory facilities. Recently, Malawi has experienced a significant HAT outbreak. Challenge Diagnosis of T.b. gambiense relies on serological tests and microscopy. A T.b. rhodesiense serological test has not been developed, and diagnosis is based on microscopy alone following the observation of clinical symptoms. Current diagnostic methods for both subspecies lack sensitivity, require trained personnel, and their ability to detect asymptomatic infections is very limited. Furthermore, in the early stages of disease, HAT resembles malaria (caused by Plasmodium spp) leading to frequent misdiagnosis. The World Health Organization (WHO) has recognised that current diagnostics are hindering their progress towards the target of zero HAT transmission by 2030, and so have published target product profiles (TPP) for T.b. gambiense and T.b. rhodesiense diagnostic tests, highlighting required factors such as: low cost; being operational in remote locations in rural Africa with limited staff training and no requirement for cold chain, instrumentation or precise liquid handling. Previously, the researcher have developed a point-of-care technology for the detection of malaria. The diagnostic is housed in an autonomous chamber, containing all reagents for DNA extraction and amplification. The method was subsequently adapted to detect other molecular targets in large volumes of water. Here, in a unique sentinel approach, the team will build on these advances to develop a low-cost test that primarily diagnoses malaria (always co-endemic with HAT and with higher prevalence) together with infections from T.b. gambiense, T.b. rhodesiensespecies. This strategy not only addresses WHO’s specifications on HAT but also allows the introduction of HAT testing in high-risk areas, through malaria diagnosis, decreasing barriers to implementation and commercialisation, as well as tackling the issue of malaria misdiagnosis. Subsequently we will validate our diagnostic in HAT-affected communities in Malawi, providing critical data on the diagnostic’s performance in real-world conditions. Patient and public engagement activities involving stakeholders and policymakers in HAT-affected regions will ensure that the diagnostic aligns with regional needs and minimises risk to future translational activities. The resulting analytical, field, and engagement data will be used to generate a detailed business case for the technology, which will pave the way to future product development activities. The diagnostic proposed here is in direct response to WHO’s recent call for HAT diagnostics: it is in alignment with their TPPs, and additionally addresses the issue of malaria misdiagnosis (at minimal additional cost). It offers an accurate, affordable, easy-to-use, field-applicable diagnostic with no cold chain, electrical power, or precise liquid handling requirements and is therefore readily applicable to HAT-affected regions in rural Africa. It will also be able to analyse large volumes of blood to detect low numbers of parasites in blood, increasing sensitivity. The project will provide a pathway towards sustainable upscaling so that this rapid point-of-care diagnostic will be used for the detection of cases and asymptomatic carriers providing a rapid pathway to treatment, and the interruption of disease transmission. This diagnostic will also transform disease surveillance methods, providing essential data for evaluating disease control strategies.

Project details

Diagnostics
Social Science
Surveillance

Jul 2024 — Jan 2026

$331,278

United Kingdom