Thanks for the query
Your child is suufering from CSOM and a tube has been placed one year back,this is clear from your query. But you have not mentioned for how long discharge is coming from his ear.
Now what you can do is just keep his ear dry, put Ciplox
ear drops 1 drop 6 hrly and Syp. Augmentin Duo
5 ml 8hrly. Consult your doctor when you will be back to your town.
I hope this answers your query well
Wish you and your family good health