Viral Central Nervous System Infections in Infants <90 Days Old: A Paediatric Investigators’ Collaborative Network on Infections in Canada (PICNIC) Study

Abstract Background The relative contribution of viruses to central nervous system (CNS) infections in young infants is not clear. For viral CNS infections, there are limited data on features that suggest HSV etiology or that are predictors of unfavorable outcome. Methods In this cross-sectional study, the Pediatric Investigators Collaborative Network on Infections in Canada identified infants <90 days of age with CNS infection proven to be due to viruses. Results Of 174 proven CNS infections, viral causes accounted for 111 (64%) including enterovirus (EV) (N=103; 93%), HSV (N=7; 6%) and human parechovirus (HPeV) (N=1; 1%). All HSV cases and 45 (43%) non-HSV cases presented before 21 days of age. HSV cases were more likely to require ICU admission (p=0.010), present with seizures (p=0.031) and have extra-CNS disease (p<0.001). Three HSV cases (43%) did not have seizures while 4 (57%) HSV and 33 (32%) non-HSV cases lacked cerebrospinal fluid (CSF) pleocytosis. Conclusions Viruses account for about half of proven CNS infections in the first 90 days of life. Empiric therapy for HSV should be considered in suspected CNS infections in the first 21 days even in the absence of CSF pleocytosis unless CSF parameters are suggestive of bacterial meningitis.