Sleeping sickness of an unusual type in Sierra Leone and its attempted control

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene Vol. 41; no. 4; pp. 481 - 512
• Main Authors: Harding, R.D., Hutchinson, M.P.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 1948; Royal Society of Tropical Medicine and Hygiene
• Subjects: Animals; Biomedical Research; Humans; Old Medline; Sierra Leone; Trypanosomiasis - epidemiology; Trypanosomiasis - prevention & control; Trypanosomiasis - statistics & numerical data; Trypanosomiasis, African; TRYPANOSOMIASIS/prevention; TRYPANOSOMIASIS/epidemiology and statistics
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1016/S0035-9203(48)90747-0

1. A short history is given of the outbreak of an epidemic of sleeping sickness of unusual type which resisted control by standard methods. 2. Infected cases have been kept under observation for periods up to 9 months without treatment. The observations indicate that in many cases a state of equilibrium exists between parasite and host over long periods, and suggest that spontaneous cure may occur. 3. The strain has been isolated and its behaviour studied in monkeys and guineapigs. In vivo tests of its resistance to normal human serum and to tryparsamide are described. 4. The suppressive effect of antrypol and pentamidine in various doses on peripheral trypanosomes in already infected cases has been studied. 5. An interim report is made on the results after 7 months of mass prophylaxis with antrypol and pentamidine in part of the area affected by the atypical strain. 6. For comparison, the results after 10 months of prophylaxis in two small areas affected by the normal Sierra Leone strain are described. 7. No overt infections have been discovered after pentamidine in any of the areas, and those after antrypol have been very few. Practical considerations are mentioned which indicate that pentamidine is to be preferred to antrypol in a mass prophylactic campaign. 8. The possibility of the occurrence after prophylaxis of cryptic new infections is considered, but at this stage no conclusion is possible. Observations are continuing, and it is hoped to publish a later report dealing with this question and summarizing the results of mass prophylaxis after 1 year in a much larger area than is dealt with in this report.