A Retrospective Analysis of Suramin Treatment for Stage 1 TBR

Inclusion Criteria: * Suramin-treated cohort: * Patient records must meet all the following criteria to be included in the suramin-treated cohort: * Male or female of any age; age or sex must be included. * Treatment with at least four full doses of suramin (not including the test dose). * Onset date or duration of symptoms associated with S1 TBR HAT is available. * An outcome is required; any mention of a clinical outcome is acceptable. * Must live in an area endemic for TBR HAT * Documented HAT diagnosis * Positive parasitology for HAT (observed in blood sample or a standard test). Natural History cohort: * Treatment records from a cohort of approximately 200 patients who were hospitalized between 1901 and 1910 during the 1900-1920 HAT epidemic * Treatment records must have sufficient information for analysis including: * Demographic data: age or sex must be included * Diagnosis: HAT diagnosis is confirmed by blood or lymph gland fluid analysis and parasites observed or HAT symptoms during the epidemic. For example, if the records state that a lymph node biopsy was performed, any result of the biopsy (e.g., documentation that trypanosomes were observed), a documentation of the HAT diagnosis, or mention of HAT symptoms such as sleepiness or excess sleeping are all acceptable. Symptoms alone are not sufficient, but a notation of biopsy and mention of HAT symptoms is acceptable. * Outcome: An outcome is required; any mention of a clinical outcome is acceptable. Exclusion Criteria: Patient records that meet any of the following criteria will be excluded from the suramin-treated cohort: * Reported duration of symptoms for more than 2 months at time of presentation at a healthcare facility. * Stage 2 TBR HAT as determined by examination of cerebrospinal fluid (CSF) using WHO criteria, which classify patients with the presence of trypanosomes in the CSF and/or a WBC count \>5 cells/mm3 as Stage 2 TBR HAT at time of presentation to a healthcare facility. * Evidence of Stage 2 TBR HAT symptoms at time of presentation to a healthcare facility. * Required medication treatment for Stage 2 illness (melarsoprol) prior to time of presentation to a healthcare facility. * Known to have had Trypanosoma Brucei Gambiense (TBG) HAT or became ill while travelling from an area known to be endemic for TBG HAT * Duration of HAT symptoms for more than 6 months. Survival for more than 6 months with TBR HAT is unlikely.