Non-polio Enterovirus Aseptic Meningitis

Background: Non- polio enterovirus aseptic meningitis (NPE-AM) is a self-limiting illness that can mimic serious bacterial infection (SBI) in infants < 90-days-old.

Methods: Included febrile infants < 90-days-old hospitalized between 2010-2019. Infants with underlying illnesses, preterm infants, or ill-appearing infants were excluded. Data were compared between NPE-AM, SBI and non-bacterial infections (NBI).

Results: Overall 1250 infants were included; 206 (16.5%) SBI, 203 (19.4%) NPE-AM, 1044 (83.5%) NBI. The median age was 33.9 days (21.5-51.8). NPE-AM was documented in 25.4% of infants < 29 days and 9.8% of infants aged 29-90 days. Infants with NPE-AM were more likely to have a history of maternal perinatal fever (5.4% vs 2.1%, p=0.011) and high-grade fever > 39oC on admission (23.2% vs 10%, p<0.001) compared to NBI. Duration of fever > 2 days was less frequent, 3.4% vs 18.9% in SBI and 26.3% in NBI (p<0001); rash in 37.4% in NPE-AM compared to 4.6% and 13.6% in NBI and SBI respectively (p<0.001). CRP > 3mg/dL was more common in NPE-AM than NBIs. Viral symptoms in family members were 3-times more common in NPE-AM than in SBI. Infants with NPE-AM were more likely to be treated with antibiotics than infants with NBIs (88.7% vs 50%, p<0.001) and as infants with SBIs (p=0.571).

Conclusions: Infants with NPE-AM were more likely to have clinical findings suggestive of bacterial infection, a history of perinatal fever, higher fever on admission, and elevated CRP. However, fever was of short duration and viral symptoms in family members were common.