Urinary tract infection is a common cause of bacteremia in children. Honkinen and colleagues reviewed the clinical and laboratory features of bacteremic urinary tract infection and compared them with those of nonbacteremic urinary tract infection.
Study subjects were chosen from among children who were being treated in Finnish pediatric hospitals. The medical records of children younger than 16 years with bacteremic urinary tract infection were reviewed. One hundred thirty-four children were identified who had: (1) symptoms of acute illness, such as fever, irritability, vomiting or dysuria; (2) bacterial growth in the suprapubic aspirate or bacterial growth of 100,000 or more in a midstream urine sample or in two urine bag samples; (3) growth of identical pathogen in cultures of the blood and urine; (4) first known urinary tract infection; and (5) no known urinary tract abnormality or other severe underlying disease. The comparison group included children who were hospitalized for symptomatic urinary tract infection whose blood cultures were negative.
Fever was the major sign of illness in both groups. No statistical difference was apparent in the reported incidence of irritability, crying, vomiting or abdominal pain. Feeding problems were the only sign that was reported significantly more often in bacteremic patients. No difference in initial white blood cell count was apparent between the groups. The mean serum C-reactive protein level was significantly higher on admission in the bacteremic group and dropped with treatment.
Escherichia coli accounted for 114 episodes (85 percent) of bacteremic urinary tract infection and for 125 (93 percent) of the urinary tract infections for which blood culture was negative.Staphylococcus aureus caused six bacteremic infections and one nonbacteremic infection. The mean duration of antibiotic treatment was significantly longer in the bacteremic patients, who were also hospitalized longer and took longer to become afebrile. The incidence of vesicoureteral reflux, urinary tract obstruction, or both, on imaging study was significantly higher in the bacteremic patients. All bacteremic patients withS. aureus infection had an abnormality of the urinary tract.
The authors conclude that children with urinary tract infection and bacteremia are often clinically indistinguishable from those with urinary tract infection and negative blood cultures. Because bacteremic children, especially those with infections that are not caused byE. coli, may need earlier imaging to identify abnormalities of the urinary tract, and negative blood cultures may simplify therapy by permitting earlier oral treatment, blood cultures remain useful in the evaluation of hospitalized febrile children with urinary tract infection.