Beschrijving

Human African Trypanosomiasis (HAT) or sleeping sickness is a parasitic disease that causes immense suffering in Subsaharan-Africa. After a major epidemic during the 1990s, HAT is now again on the decrease in most affected areas. The disease was recently targeted by the World Health Organization (WHO) for elimination by 2020 and interruption of transmission by 2030. Until HAT transmission has been eliminated, there will be a need for active case finding and surveillance; the need for surveillance will continue even when there will be no more HAT cases in the community. The current approach to case finding and surveillance is based on mobile teams conducting exhaustive population screening. This approach is very costly and becomes less effective when HAT prevalence is low because people do not participate any longer (1). There is therefore an urgent need to develop a more affordable and sustainable mechanism for active case finding and surveillance, adapted to the environment of rural Sub-Saharan Africa. In addition there are populations currently not covered by the screening efforts because they live in locations that are not readily accessible for the mobile teams.

Apart from the introduction of the CATT screening test at the end of the 1980s not much has changed in HAT control since colonial times but some recent technological developments could open up new perspectives (2). Two new rapid tests have been developed that are easily applicable in the field and can be stored at ambient temperature (3,4). A new molecular test based on loop mediated isothermal amplification (LAMP), has been developed and is currently in the process of being evaluated(5). LAMP has been automated to such a degree that it can be used at the level of a district hospital. Outside the health field there have been other innovations that have not yet been used in HAT control. These include GPS technology and availability of mobile devices for communication and data registration.

In this project we will develop and evaluate an alternative approach to active case finding and surveillance in HAT that incorporates these recent technological developments. Rather than to send out a full-fledged mobile screening team as is currently done, we will send out a single health worker equipped with a PDA, rapid tests, and some cryotubes for blood sampling. The health worker will go from house to house and use his PDA to register all inhabitants and record the geographic coordinates of each house. For all those present during the survey he will conduct a rapid test. For those testing positive a small volume of blood will be collected on the spot in a cryo tube with stabilization buffer and stored at ambient temperature.  Once every 2-4 weeks these samples will be delivered to a laboratory at district or provincial level and tested by LAMP. If positive, the subject will be invited for a full diagnostic workup and treated according to national guidelines. The district health management team will continuously analyze the information on new cases detected and decide on a village by village basis whether additional screening is required.

 

The goal of this project is to develop, evaluate, and position for scale-up this alternative mechanism for active HAT case finding and surveillance in the DRC. For research purposes we will- in addition to the samples required for the algorithm described above-  (i) collect samples from a control group of RDT-negative subjects and (ii) conduct Immune Trypanolysis on all samples. The latter test is a highly sensitive antibody detection test that has been adopted by WHO as a reference test for HAT surveillance (6,7). All results will be entered in a database, incorporating data downloaded from the PDA of the health worker, and used at district level to decide on further follow-up required at the level of the individual and at the level of the village. Cost-effectiveness will be assessed in comparison to the classic mobile team approach. All activities will be planned and carried out in close collaboration between ITM and the national HAT control program of the DRC (PNLTHA) with whom ITM has a longstanding cooperation.

 

In the first phase, described in this proposal, we will identify the optimal population screening methodology and develop the tools necessary for implementation by district and provincial level health authorities. This phase is expected to last 2 years. There will be a 6-months set-up phase during which equipment is purchased and set-up, and optimal screening procedures are identified for further evaluation. In the meantime a research protocol will be developed and submitted for ethics approval. At the end of the set-up phase there will be a stakeholders meeting during which a first go-no-go decision needs to be taken. Assuming that the proposed strategy will be endorsed, the next 9-12 months will be devoted to implementing the new screening strategy in pilot areas and collecting data. At the end of this period a mobile team will conduct a classic HAT screening in the same villages. The final 6-9 months of the first phase of project will be for data analysis and, conditional on a positive evaluation of the strategy, to design an implementation plan for scaling up. Scaling up will be the subject of a second phase for which a new proposal will be developed. In this second phase the methodology will be implemented on large scale and fine-tuned if required. In that phase we will also develop mathematical models to assess the effectiveness of the strategy in monitoring HAT prevalence at village level and its potential impact on HAT transmission.

AcroniemScreening HAT
StatusVoltooid
Effectieve start/einddatum20/09/1331/12/15

Financiering

  • BILL & MELINDA GATES FOUDATION: 706.819,00 €

ID: 1094688