[Polyneuropathies in vitamin B1 deficiency in Reunion and Mayotte islands in 70 patients of Maori and Comorian descent].

Beriberi is an uncommon disorder related to thiamine deficiency. It is mainly found in underdeveloped countries among populations with poorly diversified diet, consisting largely of milled white cereals, a poor source of thiamine. In industrialized countries, thiamine deficiency with cardiac failure is more frequently found than the dry beriberi in high risk groups like chronic alcoholics. Nevertheless our attention was drawn to an outbreak of 70 cases of dry beriberi which occurred from 1997 to 2005 in the French territories of Reunion and Mayotte islands. It was characterized by an acute or sub-acute sensorimotor polyneuropathy with axonal lesions, affecting the lower limbs and occasionally the upper limbs, sometimes associated with cardiac beriberi. It affected young, non alcoholic individuals from the Mahoran and Comorian community who were in apparent good health when the illness occurred. Our study highlighted the feeding habits which are partly responsible for the development of the disease due to a chronic lack of thiamine and which probably contributed together with multiple cofactors to trigger off the illness. But many elements and mainly biological ones, also lead us to think that there is a genetic predisposition to develop this neuropathy.