Answer:
The white blood cells pictured here can be associated with urinary tract infections.  Vesicoureteral reflux (VUR) is an abnormal flow of urine from the bladder back into the ureters.   It is most commonly diagnosed in infancy and childhood after the patient has a urinary tract infection.  Vesicoureteral reflux can lead to continual infections because urine that remains in the child's urinary tract provides a place for bacteria to grow.  Hence the child's previous diagnosis of pyelonephritis and the increased presence of white blood cells in her urine.