hi, your father has persistent (pyuria) pus in urine associated with fever , suggests that he has recurrent urinary tract
infections. Possibilities are- 1) he has persistent ureteric obstruction / reflux secondary to tuberculosis
. since he is diabetic , makes him prone to urinary tract infection. 2) he has bladder pathology secondary to tuberculosis or even longstanding diabetes
. 3) his tuberculosis is resistant to treatment.
What you need to do is to consult a urologist
who can evaluate any urinary tract pathology, as well a physician who can evaluate his tuberculosis and diabetes .