Risk of meningitis in young infants with suspected urinary tract infection: a Systematic Review
Background:
Urinary tract infections (UTI) are the most common severe bacterial infections in infants. Young infants are at higher risk of both severe and invasive bacterial infections, such as meningitis. A minority of children with UTI have been reported to have co-existing meningitis. Early diagnosis of co-existing meningitis has important implications with respect to treatment and outcome. Its prevalence in infants younger than 3 months with a suspected UTI has not been rigorously evaluated. There is currently no consensus on which infants should undergo a lumbar puncture when a UTI is suspected in the emergency department.
Objectives:
To systematically review the risk of co-existing meningitis in febrile infants with suspected UTI and identify patients’ characteristics of low/high risk of co-existing meningitis.
Methods:
We systematically searched PubMed, EMBASE, the Cochrane Library to identify studies reporting data on the frequency of co-existing meningitis in infants ≤ 3 months evaluated in the emergency department with a suspected UTI, based on urine collected by sterile methods. Two investigators independently reviewed identified articles for inclusion, and extracted relevant data. Our main outcomes were the diagnosis of any bacterial meningitis, and the identification of characteristics of low or high risk of meningitis.
Results: Of the 2,085 studies screened, the 22 that met inclusion criteria included 4,730 children with suspected or confirmed UTI who successfully underwent a lumbar puncture. Only four studies (18%) were prospective and 18 were retrospective. Four studies were multicenter, three included only neonates and six only infants younger than 2 months. The percentage of lumbar punctures performed varied between 24.3 % and 100 % in the included studies. Overall a bacterial meningitis was finally diagnosed in 26 infants with suspected or confirmed UTI, with a prevalence ranging from 0% to 0,05% in the different studies. Characteristics of patients with co-existing bacterial meningitis were inconsistently reported. 11/14 patients for whom clinical data were available were neonates < 28 days. Only two studies focused on the development of low risk criteria for co-existing meningitis (i.e. well-appearing infants, > 21 days of age, procalcitonin ≤ 0.5 ng/ml, C reactive protein ≤ 20 mg/L)
Conclusions: the presence of a co-existing bacterial meningitis in young infants with a suspected UTI is rare. While it seems safe to avoid lumbar puncture in infants meeting low risk criteria, a case by case assessment should be made in patients not meeting low risk criteria.
