When is pus not pus?

There is perhaps a small but important error in the statement in the CMAJ article by Ajayi and Radhakrishnan on urinary tract infection in older adults in long-term care facilities: “Findings of bacteriuria or pyuria alone are insufficient to diagnose urinary tract infection; clinical symptoms must also be present.”¹ Surely not. If pathogenic bacteria are growing in the urinary tract and killing white cells, that is by definition a urinary tract infection.

The authors show clearly that these are common in long-term care facilities, and only some infections require treatment. But does this mean the others are mythical?