Beriberi in a well-nourished Amazonian population.

Beriberi is an endemic disease among the Naporuna indigenous people of Ecuadorean Amazonia (annual morbidity rate of 1.5%). A total of 47 patients with dry beriberi were seen at the Franklin Tello Hospital, Napo, during 1995-1996; a similar incidence was observed in previous years. No wet beriberi was found. Although the diagnosis of the disease was made clinically, an effective and quick response to thiamine treatment excluded other differential diagnoses, such as tropical ataxic neuropathy. Although indigenous people have several possible dietetic risk factors, none of them adequately explain the disease's high incidence. Some suggestions are made for the high incidence of beriberi among this Amazonian people but its cause remains unknown.