Tango icon ravaged by infection (9)

I believe the answer is:

contagion

I'm a little stuck... Click here to teach me more about this clue!

'infection' is the definition.
(synonyms)

'tango icon ravaged' is the wordplay.
'tango icon' can be anagrammed to 'CONTAGION'.
Though, I'm not clear how this is indicated.

'by' acts as a link.

Can you help me to learn more?

(Other definitions for contagion that I've seen before include "Infection" , "Communication of disease by close contact" , "Cognation (anag.)" , "cause of widespread ill-feeling" .)

I've seen this clue in The Hindu.

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