Clinical presentation of human African trypanosomiasis in Zambia is linked to the existence of strains of Trypanosoma brucei rhodesiense with varied virulence: two case reports

INTRODUCTION: Trypanosoma brucei rhodesiense typically causes acute and severe human African trypanosomiasis in Zambia and other countries in Eastern and Southern Africa. Although a few atypical cases of chronic and mild forms of this disease were reported in Zambia more than 40 years ago, no such cases have been diagnosed over the last four decades. CASE PRESENTATIONS: For the first case, a 19-year-old Black African woman from the Eastern Province of Zambia presented with symptoms and signs of an atypical chronic and mild form of the disease for a period of 2 years. For the second case, a 16-year-old Black African boy from the Northern Province presented with symptoms and signs of a typical acute and severe form of the disease for 3 weeks. CONCLUSION: Two strains of T. b. rhodesiense with varying degrees of virulence still do exist in Zambia. This has implications for control strategies at the national level.