Serostatus of echovirus 11, coxsackievirus B3 and enterovirus D68 in cord blood: The implication of severe newborn enterovirus infection

Background: Maternal transplacental antibody is an important origins of passive immunity against neonatal enterovirus infection. Echovirus 11 (E11) and coxsackievirus B3 (CVB3) are important types causing neonatal infections. There were few investigations of enterovirus D68 (EVD68) infection in neonates. We aimed to investigate the serostatus of cord blood for these three enteroviruses and evaluate the factors associated with seropositivity. Methods: We enrolled 222 parturient (gestational age 34–42 weeks) women aged 20–46 years old between January and October 2021. All participants underwent questionnaire investigation and we collected the cord blood to measure the neutralization antibodies against E11, CVB3 and EVD68. Results: The cord blood seropositive rates were 18% (41/222), 60% (134/232) and 95% (211/222) for E11, CVB3 and EVD68, respectively (p < 0.001). Geometric mean titers were 3.3 (95% CI 2.9–3.8) for E11, 15.9 (95% CI 12.5–20.3) for CVB3 and 109.9 (95% CI 92.4–131.6) for EVD68. Younger parturient age (33.8 ± 3.6 versus 35.2 ± 4.4, p = 0.04) was related to E11 seropositivity. Neonatal sex, gestational age and birth body weight were not significantly different between the seropositive group and the seronegative group. Conclusion: Cord blood seropositive rate and geometric mean titer of E11 were very low, so a large proportion of newborns are susceptible to E11. The circulation of E11 was low after 2019 in Taiwan. A large cohort of immune naïve newborns existed currently due to lack of protective maternal antibodies. It is imminent to monitor the epidemiology of neonates with enterovirus infections and strengthen the relevant preventive policies.