Dig in remains of fruit said to bring disease (8)
I believe the answer is:
beriberi
'disease' is the definition.
(beriberi is a kind of disease)
I can't explain the remainder of the clue.
(Other definitions for beriberi that I've seen before include "Asian disease caused by a dietary deficiency" , "Tropical vitamin deficiency disease" , "Lack-of-vitamin-B disease" , "Disease (lack of vit. B1)" , "Tropical disease caused by lack of vitamin B1" .)