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Active screening (AS) Mobile teams travelling to at-risk villages to test to any person willing to participate.
Disability-adjusted life years (DALYs) Estimates how much disease affects (‘burdens’) the life of the population. It is a metric used by the international community and the World Health Organization (WHO) to assess the global burden of disease, combining (a) mortality: years lost because of premature death due to disease; and (b) morbidity: years of life lived adversely affected by disease.
Deterministic model A type of mathematical model used for projections that simulates expected average (mean) dynamics.
Diagnostic algorithm In the context of diagnosing gHAT cases, the algorithm is the combination of tests that are used to diagnose an infected person, from initial detection (e.g. initial blood test) to confirmation of a case (identifying the parasite under a microscope). There are a number of steps involved and different diagnostics have different characteristics and give a higher or lower chance of accurately finding real cases. This is done to avoid treating people who are not infected.
Endemic Cases of sleeping sickness have been consistently and recent reported. A village is considered endemic if there have been cases reported in the last 3 years.
Ensemble model

All the considered models together with the contribution of each individual model being based on the relative probability of that model being the best.

Elimination of Transmission (EOT) Reduction to zero cases of sleeping sickness in a defined geographical area, with minimal risk of reintroduction, as a result of deliberate efforts. A target defined and set by the World Health Organization (WHO).
Elimination as a Public Health Problem (EPHP) Fewer than 1 case/10,000 inhabitants/year (averaged over a 5-year period) of sleeping sickness reported in each health district of a country, in conjunction with adequate control and surveillance. A target defined and set by the World Health Organization (WHO).
Fitting The process of matching a mathematical model to real case data (cases of sleeping sickness reported in a country) so that the model parameters better reflect what is happening on the ground and modelling results take into account local variation and varying needs and experiences in different geographical areas of a country.
Health zones Administrative geographic regions for health care delivery. In the Democratic Republic of Congo each health zone is a specific geographical area comprising about 150,000 inhabitants and 200 communities, 20 satellite centres and a referral hospital, which are themselves composed of a lower set of subdivisions called health areas.
Mathematical modelling A method of simulating real-life situations with mathematical equations to forecast what might happen in the future, e.g. how a disease might spread.
Mass Drug Administration (MDA) The administration of drugs to whole populations.
Passive surveillance (PS) Individuals self-presenting to fixed health facilities due to gHAT symptoms and being tested with gHAT diagnostics (usually rapid diagnostic tests). This compliments active screening with mobile teams going out to at-risk villages to test any person willing to participate.
Reactive screening (RS) Active screening that restarts after a case is detected from passive surveillance or active screening identifying cases amongst people from another village.
RDT, Rapid Diagnostic Test A quick, easy and inexpensive medical diagnostic test designed for use at the point-of-care, and particularly good for resource poor settings.
Stage 1 treatment  Treatment of infected patient in the first stage of the disease, which is when the trypanosomes multiply in subcutaneous tissues, blood and lymph.
Stage 2 treatment Treatment of infected patient in the second stage of the disease, which is when the parasites cross the blood-brain barrier to infect the central nervous system.
Stochastic model A type of mathematical model used for projections that can simulate small random effects/chance events and produce whole numbers (e.g. of expected human cases, as opposed to a non-integer number that a deterministic model will produce when working with small numbers). Stochastic models are therefore often considered the preferred model when working with very low infection prevalences or small population sizes.
Tsetse A type of bloodsucking fly, of which, several species can transmit infections such as sleeping sickness.
Willingness to pay (WTP) In the context of the HAT MEPP project, different WTP thresholds are the different budget options associated with different interventions strategies and will depend on what the country and/or donor are willing to pay to avert DALYs (i.e. save lives or stop disability). WTP thresholds can be compared across diseases.