Pyuria is another name for pus in urine. A diagnosis for a urinary tract infection may have been made but pyuria may mean that the infection was caused by chlymadia or mycoplasma which can be transmitted via intercourse. It would mean that the treatment of the patient would be required as would the patient's partner or partners.
The presence of Pus is a sign that your body is fighting a bacterial infection, and pus is usually means that further steps need to be taken to fight the infection.
Pus in your urine is an indication that you may have an infection. The only way to really tell is for the lab to culture the pus and grow more of it. Once they have a quantity they can sample; the lab will tell your doctor if you are positive.