references
HUMAN AFRICAN TRYPANOSOMIASIS / SLEEPING SICKNESS
R&D MODEL & PORTFOLIO
13.1 million people
were estimated to live in areas at moderate
to very high risk in 2012 (more than one case per 10,000 population)
T. b. gambiense
Disease is caused by two subspecies of Trypanosoma brucei (T. b.) gambiense (g-HAT; 98% of reported sleeping sickness cases) and T. b. rhodesiense (r-HAT), and occurs in two stages: the early stage has non-specific symptoms and is often un- or misdiagnosed, and the late stage, where the parasite crosses the blood-brain barrier, causing serious neurological disorders including sleep cycle disruptions, paralysis, and progressive mental deterioration. Without effective treatment, the disease usually leads to death. A lumbar puncture is needed to differentiate between stages in order to choose the appropriate treatment. Current treatments are difficult to administer, and stage-specific:
TREATMENT OF STAGE 1 HAT
T. b. rhodesiense
Epidemic Endemic
T. b. gambiense is endemic in
Pentamidine (1940) for g-HAT and suramin (1920s) for r-HAT, require injections and are ineffective for stage 2.
TREATMENT OF STAGE 2 HAT
24 countries
NECT – nifurtimox-eflornithine combination therapy (2009): for stage 2 g-HAT, requires 14 slow intravenous infusions of eflornithine of 2 hours each over 7 days, together with three times a day oral nifurtimox for 10 days. Requires specialized hospital administration and trained staff. Since its addition to the EML, NECT is first-line treatment for stage 2 g-HAT. Eflornithine (1981): today seldom used alone, requires an extended stay in hospital during administration (56 intravenous infusions – four times per day, over 14 days). Melarsoprol (1949): No longer used for g-HAT. Remains the only drug available for stage 2 r-HAT – a toxic arsenic derivative that causes pain and fatal encephalopathy in up to 5% of patients who receive it.
of West and Central Africa • Less than 3,000 new cases reported (2015)
T. b. rhodesiense is endemic in
13 countries
of Eastern and Southern Africa • 117 cases (2014)
WHAT IS DNDi DOING TO ADDRESS UNMET TREATMENT NEEDS?
