Disease from India caught by traveller to the East (5)
I believe the answer is:
polio
'disease' is the definition.
(polio is a kind of disease)
'india caught by traveller to the east' is the wordplay.
'india' becomes 'i' (phonetic alphabet: alpha, bravo, charlie etc.).
'caught by' is an insertion indicator.
'traveller to the east' becomes 'polo' (Marco Polo).
'i' inserted inside 'polo' is 'POLIO'.
'from' is the link.
(Other definitions for polio that I've seen before include "Viral disease causing paralysis" , "Acute viral disease" , "rarely seen complaint" , "Paralysing disease" , "Viral disease which can cause paralysis ( 5)" .)