Does antibiotic therapy after a first infection decrease recurrence rates? What about antibiotic resistance?
For years we have been prescribing prophylactic antibiotic therapy for children with a first-time urinary tract infection (UTI) before obtaining imaging studies—as is recommended in the 1999 American Academy of Pediatrics' practice parameter1—and for those with vesiculoureteral reflux (VUR). Although many pediatricians have raised questions about the efficacy and safety of this practice, the risks and benefits of antibiotic prophylaxis have not been well studied.
In a study recently published in JAMA, Conway and colleagues2 examined risk factors for recurrent UTI, the relationship between antibiotic prophylaxis and recurrent UTI, and risk factors for resistance. Using a network of pediatric primary care practices in urban, suburban, and semirural areas with almost 75,000 children, the authors identified a group of children younger than 6 years with a first UTI who made at least 2 clinic visits during the 5-year study period. (The practices involved in the study shared an electronic health record system, so the charts were easily accessible.) The authors also had access to records at some emergency departments and hospitals and from 2 private laboratories.
After excluding children who were observed for less than 24 days and those with comorbid conditions that might affect infection rates (such as immunodeficiencies and renal anomalies), the authors had a cohort of 611 children. Most of these children were white girls aged 2 to 6 years. Eighty-three of the 611 children had a recurrent UTI during the study period. The risk of recurrence was increased in white children, in those aged 2 to 6 years, and in those with grade 4 to 5 VUR. There was also an increase in recurrence among uncircumcised males, but circumcision status was not recorded in many of the charts.
Of the 611 children with first-time UTIs, 483 received antibiotic prophylaxis. However, when the authors compared children who received prophylaxis with those who did not, there was no significant difference in rates of recurrent UTI. Unfortunately, the children who received prophylaxis and who experienced a recurrent infection had a significant increase in resistance compared with children with recurrent infections who had not received prophylaxis. The increase in resistance persisted even when other factors, such as the presence of VUR, were controlled for.
The authors point out several limitations of their study, such as lack of data from outside of their network, the absence of imaging studies from 65% of the children, lack of circumcision data, and the assumption that prescriptions written for prophylaxis were taken as prescribed. With additional information, there may have been a shift in the relationships observed: antibiotics may have had more of an effect on recurrence rates, or there may have been a change in the effect of antibiotics among children with different grades of reflux.
While there is clearly a need for further investigation of risks and benefits of prophylaxis, the study by Conway and colleagues indicates that antibiotic prophylaxis should not be a reflex reaction undertaken in every child with a UTI. The risks and benefits should be discussed with families to determine on an individual basis which children should receive prophylaxis and which can be watched closely. With further examination, we can look forward to gaining more information to provide guidance in our management of UTI. *