Disease obtained from insects? Not primarily (7)
I believe the answer is:
rickets
'disease' is the definition.
(rickets is a kind of health problem)
'insects? not primarily' is the wordplay.
'insects?' becomes 'crickets' (cricket is a kind of insect).
'not primarily' means to remove the first letter.
'crickets' with its initial letter taken away is 'RICKETS'.
'obtained from' acts as a link.
(Other definitions for rickets that I've seen before include "Children's disease" , "Bone-distorting disease" , "Childhood disease caused by a deficiency of vitamin D" , "Bone disease, caused by vitamin D deficiency" .)