Human African trypanosomiasis

Human African trypanosomiasis, also known as African sleeping sickness,  is an illness caused by one of two parasitic zoonoses: Trypanosoma brucei gamiense or Trypanosoma brucei rhodesiense. 

Epidemiology

African trypanosomiasis is a disease endemic to sub-Saharan Africa. Within this region the disease is harbored mainly in rural areas ¹, where access to medical imaging is often nonexistentnon-existent.Trypanosoma brucei gambiense accounts for the vast majority of reported cases of African trpanosomiasistrypanosomiasis. The incidence and prevalence have varied widely over the last two centuries. Under 3,000 cases were reported in 2016, and the incidence is declining ².

Clinical presentation

In the initial stage of African trypanosomiasis, many symptoms of the disease are nonspecificnon-specific, such as fever and malaise. Untreated, the disease progresses to include various neurological manifestations, including encephalitis, coma, and ultimately death.

Pathology

Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense are transmitted by certain species of tsetse flies, although other transmission routes are possible ³.

Radiographic features

There have been only small case series and case reports of brain MRI of patients with African trypanosomiasis at stage II (central nervous system involvement) ^4,5,6-6. 

MRI

• T2-FLAIR
  • ​symmetric high signal intensity in the supratentorial deep white matter (all cases) ⁵
  • high signal intensity in the basal ganglia, cerebellum, and/or brainstem (around half of cases)
• DWI: restricted diffusion may be seen in white matter tracts such as the posterior limbs of the internal capsules and splenium of the corpus callosum ⁵
• SWI/GRE/T2^*: parenchymal microhemorrhages may be seen ⁵