Antibiotics Do Not Prevent Urinary Tract Infections, May Cause Treatment Resistance

11/30/2007


Children's Hospital investigators have found that daily antibiotics after a first urinary tract infection (UTI) may not prevent another such infection, and may actually increase the risk that the next UTI is caused by resistant bacteria.

UTIs are common in children, with 70,000 to 180,000 having an infection by 6 years of age. The American Academy of Pediatrics recommends children have an imaging study after a first UTI to evaluate the presence and degree of vesicoureteral reflux (VUR). If the child has VUR, daily antibiotic treatment is recommended in an attempt to prevent recurrent UTIs.

VUR occurs when urine in the bladder flows back into the ureters or kidneys during urination. Approximately 30 to 40 percent of children who have had a UTI have VUR, and it is thought that a child who has VUR is at risk of developing recurrent kidney infections, which, over time, can cause damage to the kidneys.

In the first large study of children diagnosed with UTI in a primary care pediatric setting, investigators led by Patrick Conway, M.D., M.Sc., reviewed the electronic health records of 74,974 children with at least two clinical visits in the Children's Hospital pediatric healthcare network between July 2001 and May 2006. The researchers found that 611 children had a first UTI and 83 had a recurrent UTI.

The majority of children with first UTI were female, Caucasian and 2 through 6 years old. Most did not have an imaging study performed and did not receive daily antibiotics to prevent infections. Children between ages 3 and 5, Caucasians and those with severe VUR had the highest risk of recurrent UTI, according to the study published recently in the Journal of the American Medical Association.

Receiving a daily dose of preventative antibiotics was not associated with a lower risk of recurrent UTI, but it was associated with an increased risk of resistant infections.

"The majority of children have lower-grade VUR, and this lower-grade VUR was not associated with an increased risk of recurrent UTI in our study," says Dr. Conway, who conducted the research while at Children's Hospital and a Robert Wood Johnson Clinical Scholar at the University of Pennsylvania.

More definitive studies, such as clinical trials, are needed, but according to the authors, it is appropriate for pediatricians to discuss with families the risks and unclear benefits of daily preventative antibiotic treatment after a child has had a first UTI.

Grants from the National Institutes of Health, the Robert Wood Johnson Foundation Clinical Scholars Training Program, and the University of Pennsylvania Center for Education and Research on Therapeutics supported this study. Dr. Conway's co-authors were Ron Keren, M.D., M.P.H., Avital Cnaan, Ph.D., Theoklis Zaoutis, M.D., M.S.C.E., Brandon V. Henry, and Robert W. Grundmeier, M.D., all of Children's Hospital and the University of Pennsylvania School of Medicine.