Thank you for your query.
He is suffering from infective endocarditis
This is one of the complications of valve replacement
The antibiotic therapy is prolonged in this case.There isn't any other option .
Please have faith in the doctors.The fever
is coming down...so he should be OK after the completion of the course.
If you have any further queries you are free to consult me.
Hope this answers your query.
Wishing a speedy recovery.
Have a nice day.