Sleeping sickness – human African trypanosomiasis

INTRODUCTION One of the great advantages of working with veterinary colleagues is the insight they often bring to the pathogenesis of human disease through their studies of natural animal diseases and animal models. In 1988 Professor Max Murray of the University of Glasgow Veterinary School introduced me to the problem of African trypanosomiasis in animals, its close relationship to its human counterpart that is known as sleeping sickness, and the unsolved problems of neurological involvement in that condition. We have now been investigating the neuropathogenesis of human African trypanosomiasis (HAT) in the laboratory and the African field for the last 16 years (Fig. 1). Neurologists will realize of course that HAT is not to be confused with the other ‘sleeping sickness’ known as encephalitis lethargica, famous for the pandemic during the first quarter of the 20th century, and which still occurs sporadically. While the cause of the latter disease has