How Common is Bacterial Meningitis in Patients with Urinary Tract Infection below the Age of 60 Days?

Abstract

IntroductionUrinary tract infection (UTI) is one of the most common pediatric infections. UTI may be associated with bacteremia and even meningitis in small babies, warranting full septic work up including a cerebrospinal fluid (CSF), especially in infants below the age of 60 days. Literature regarding the co-existence of meningitis in infants diagnosed with UTI is conflicting. It is critical to be able to correctly identify and treat any co-existing meningitis, as both the choice and duration of antibiotic used for UTI, is often insufficient to effectively treat meningitis.ObjectiveThe primary objective of this study was to determine the rate of co-existing bacterial meningitis in infants below the age of 60 days with a diagnosed urinary tract infection (UTI) and to determine if age, sex and prematurity and bacteremia were risk factors.MethodA retrospective observational study was conducted at Hamad General Hospital, a tertiary medical institution in the State of Qatar. Patients under the age of 2 months hospitalized with a first episode of UTI from January 1, 2008 to December 31, 2013 were included in the study. UTI was defined as urine culture growing a single organism, with a colony count of greater than 103, where in the urine sample was obtained by either catheterization or supra-pubic aspiration. Infants with pre-exisiting clinical conditions like spina bifida or meningomyelocele and those diagnosed with congenital renal anamolies, were excluded from the study because of their higher likelihood of developing UTI. Infants with a questionable diagnosis of UTI (not in accordance with American Academy of Pediatrics definition of UTI) were also excluded.The study was approved by the Medical Research Center at Hamad Medical Corporation.Results113 patients met the inclusion criteria. 51 patients (44.3%) were neonates (0?28 days old) and 64 patients (55.7%) were between the age group of 29 to 60 days. 43.5% of the infants were male, and most (86.1%) were term. All 113 patients had culture proven UTI. The commonest pathogens causing UTI were Escherichia coli (38%), Klebsiella pneumoniae (15%), Enterococcus faecalis (13%), Group B Streptococcus sp(7%), and Citrobacter (6%). As per the routine practice in our institution, blood culture was ordered in all but one patient. Among these 112 patients, 3 (2.6%) had bacteremia. All 3 patients were Term female babies, 2 of them were neonates and 1 was between 29 to 60 days of age. Of the three pts who had a positive blood culture, CSF study was done in two babies, which was negative and 1 patient's family refused CSF study. A cerebrospinal tap was done in 78 patients i.e. 69% of the sudy population. None of these patients had a postive CSF culture. Physicians were more likely to order a CSF study in babies who were neonates (80% had a CSF study, as opposed to 60.3% of babies in the 29 to 60 day age group).ConclusionOur study demonstrated that in the 78 patients with culture proven UTI, who had a CSF study, none of the patients had co-existing bacterial meningitis. Our results are reflective of several other studies which also show a low risk of meningitis in patients with UTI. We tried to overcome some of the limitations of these studies by maintaining very strict criteria for diagnosing UTI. CSF study is a part of the septic work up in neonates. In contrast for patients between the age group of 29 to 60 days, more selective approach to lumbar puncture is warranted.