Cause of sickness reflected in latest estimates (6)
I believe the answer is:
tsetse
'cause of sickness' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'reflected in latest estimates' is the wordplay.
'reflected' is a reversal indicator.
'in' indicates a hidden word.
'estest' is hidden in the letters of 'latest estimates'.
'estest' reversed gives 'TSETSE'.
Can you help me to learn more?
(Other definitions for tsetse that I've seen before include "cause of sleepiness?" , "African transmitter" , "Bloodsucking African fly" , "flies" , "source of sleeping sickness" .)