Aseptic meningitis in infants younger than six months of age hospitalized with urinary tract infections

Background. Aseptic meningitis associated with urinary tract infection (UTI) in young infants has not been described in detail in the literature. We performed a retrospective study to determine the incidence and clinical features of aseptic meningitis accompanying UTI. Methods. We retrospectively reviewed the medical records of all infants younger than 6 months of age hospitalized with a UTI at Miller Children's Hospital from March 1995 through March 2000. UTI was defined as a urine culture growing greater than or equal to10 000 colony-forming units/ml of a single organism from a catheterized. specimen or 2:100 000 colony-forming units/ml of a single organism from a bagged urine specimen. Meningitis was defined as a positive cerebrospinal fluid culture or cerebrospinal fluid with > 35 white blood cells/ mm(3) in infants less than or equal to30 days of age or with > 10 white blood cells/mm(3) in infants >30 days of age. Results. Of 386 infants with UTI, a lumbar puncture was performed in 260, and 31 (11.9%) had aseptic meningitis. One infant had bacterial meningitis. None of the 26 infants with UTI and bacteremia had aseptic meningitis. Two infants with meningitis had confirmed enteroviral infections, but aseptic meningitis did not occur more frequently in any particular month or during times of peak enteroviral activity. Conclusions. A cerebrospinal fluid pleocytosis is relatively common in hospitalized infants <6 months of age who have a UTI and usually does not reflect bacterial meningitis. Knowledge of this may prevent unnecessary courses of antibiotics for presumed bacterial meningitis and lead to evaluation for other possible causes of aseptic meningitis including viral or congenital infections.