Epidemiology of Meningitis in Canadian Neonatal Intensive Care Units

Background: Meningitis is a serious disease that occurs more commonly in the neonatal period than in any other age group. Recent data from large national cohorts are needed to determine if the epidemiology of neonatal meningitis (NM) has changed. Aim: To assess the rates, causative organisms, risk factors, temporal trends and short-term outcomes of NM in Canadian Neonatal Intensive Care Units (NICUs). Methods: A retrospective review of newborn infants admitted to NICUs participating in the Canadian Neonatal Network between January 2010 and December 2016. Patients with meningitis were reviewed. Outcomes of patients with meningitis were compared with 1:2 matched (for gestation, sex and birth weight) neonates without meningitis. Results: Rates of NM ranged between 2.2 and 3.5/1000 NICU admissions during the 7-year study period with the majority of patients (87%) having late-onset meningitis (at >3 days after birth). The most common bacterial organism for both early- and late-onset meningitis was Escherichia coli followed by group B streptococci. Only 31% [95% confidence interval (CI): 24.06-38.63) of neonates with meningitis had simultaneous bacteremia. NM was associated with increased seizures [odds ratio (OR): 8.63; 95% CI: 4.73-15.7], retinopathy of prematurity (OR: 3.23; 95% CI: 1.30-8.02), bronchopulmonary dysplasia (OR: 1.93; 95% CI: 1.11-3.35), days of mechanical ventilation (OR: 1.03; 95% CI: 1.02-1.04) and length of hospital stay (OR: 1.02; 95% CI: 1.01-1.02), but not with mortality before discharge (OR: 1.29; 95% CI: 0.74-2.23). Conclusions: The rate of NM remains largely unchanged in Canadian NICUs. NM was associated with increased major morbidities and longer hospital stay but not with mortality before discharge.