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

Abstract

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.

The Age-Related Risk of Co-Existing Meningitis in Children with Urinary Tract Infection

“…Since the publication by Bergstrom et al , several other studies have investigated co-existing meningitis in children with UTI [3], [7], [11]–[19]. However, the majority are limited by the size of the study population, which in most instances comprised fewer than 200 patients with UTI who had a lumbar puncture [4], [14], [17], [19], or even less than 100 patients [6], [13], [15], [16], [18].…”

“…The authors reported that co-existing bacterial meningitis was present in six (19.4%) of the 31 infants with UTI who had a lumbar puncture. Subsequent studies have reported considerably lower estimates for the risk of co-existing meningitis in children presenting with UTI [3]–[7], [11]–[19]. However, the majority of studies have significant limitations, including small sample size [4], [6], [13], [15]–[19] and absence of a precise definition for UTI [12], [17].…”

Question 1 How common is co-existing meningitis in infants with urinary tract infection?

“…Between 1% and 15% of young children presenting with fever in the outpatient setting have an underlying UTI 16 17. In comparison to older children, UTI in infants is more commonly associated with bacteraemia, occurring in 4–12% of cases 1 3 5 6 10 11. It has been postulated that infants with UTI are therefore at higher risk of co-existing meningitis as a result of bacterial dissemination to the central nervous system (CNS).…”

“…Consequently, as infants with meningitis (ie, those appearing sicker) would have been more likely to be subjected to a lumbar puncture, this is likely to have skewed the estimate of co-existing meningitis even further. This important limitation also applies to some other studies included in this review in which a considerable proportion of participants did not undergo lumbar puncture 4 6 8 10 11 14…”

“…It is noteworthy that aseptic meningitis, which was addressed in only some studies,1 2 4 6 8 9 11 12 15 was identified in 5–18% of patients. Importantly, in only one study did the investigators exclude patients who had received antibiotics prior to presentation by analysing urine samples for antimicrobial activity 2.…”