Risk factors for cerebrospinal fluid shunt infections during an outbreak: a case-control study

Background: There are few published reports of cerebrospinal fluid (CSF) shunt infection outbreaks. In 2017-2018, British Columbia Children's Hospital (BCCH) experienced an increase in CSF shunt infections co-incident with a move to new operating rooms and a change in shunt catheters used. Aims: To describe how an outbreak was detected, investigations were undertaken to determine the cause, risk factors associated with CSF shunt infection during the outbreak, and changes implemented to attempt to control the outbreak. Methods: Retrospective caseecontrol study. Population included patients who underwent new shunt insertion or revision. Univariate logistic regression models were fitted for each of the variables. Associations with P-values <0.2 were considered of potential interest for further investigation. Findings: There were six cases of CSF shunt infection and 19 controls. The causative organism was different in each case. The only risk factors that met the criteria for further investigation were being a neonate at the time of surgery [odds ratio (OR) 9.0, 95% confidence interval (CI) 0.7-125.3, P=0.10] and the presence of gastrointestinal disease (OR 3.8, 95% CI 0.5-26.2, P=0.18). No association was found with the operating room used or the surgical staff. In response to the outbreak, human traffic through the operating rooms was limited, rigid adherence to the wearing of surgical masks was enforced, and return to the previous CSF shunt catheters used was implemented. Conclusion: No modifiable risk factors were associated with CSF shunt infection. After implementation of surgical protocol changes, no further cases of CSF shunt infection linked to the outbreak were identified. (C) 2019 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.