Prophylaxis does not prevent recurrent UTI
Current guidelines suggest that children under the age of six who present with urinary tract infections (UTIs) should be investigated by renal imaging to determine if they have scarring or reflux. Those with scarring or high degrees of reflux are then prescribed prophylactic antibiotics to prevent further infection.
A large study from the US challenges this advice.
The authors identified 611 children aged six years or younger, from a total population of nearly 75,000, who had been diagnosed with a UTI.
Time to event analyses were used to determine risk factors for recurrent UTI and effectiveness of antibiotic prophylaxis.
The results were surprising. Prophylactic antibiotics seemed to have no effect on whether or not a child had a recurrence of UTI. If the child had been treated with antibiotics and then developed a recurrence, it was more likely that this would be caused by an antibiotic-resistant organism.
The study found that children aged between three and five of white racial background were most likely to have a recurrent UTI. Gender seemed to make no difference.
As one would expect, children who had more significant vesicoureteric reflux were more at risk of subsequent infections.
One drawback of this study is that only 35% of the children studied had a micturating cystogram, so the degree of reflux cannot be accurately stated in the majority of participants. Another issue is that the study excluded results from children who had evidence of renal scarring on imaging.
From a practical point of view I would hesitate in stopping antibiotic prophylaxis in a child with proven renal scarring, but where there is just reflux I wonder if those repeat prescriptions are really in the child's best interest.
Conway PH, Cnaan A, Zaoutis T et al. Recurrent urinary tract infections in children: risk factors and association with prophylactic antimicrobials. JAMA 2007;298:179-186Reviewer
Dr Peter Saul
GP, Wrexham and hospital practitioner in paediatrics (asthma and allergy)