Serological Study of Neutralizing Antibodies Against Enterovirus D68 Among Healthy Population in Xiamen, China

Abstract Background: Enterovirus D68 (EV-D68) infections poses a serious public health threat, which caused outbreaks of severe respiratory illness and has been closely associated with "polio-like" central nervous system disease. The patterns of immune responses to EV-D68 have not been fully understood. This study was performed to investigate the level of neutralizing antibody against EV-D68 among the healthy population in Xiamen City.Methods: A total of 515 serum samples from healthy people were selected by stratified random sampling in Xiamen City in 2016, and the titer of neutralizing antibody against EV-D68 was detected by an efficient micro-neutralization assay.Results: The overall seroprevalence of neutralizing antibody against EV-D68 was 81.9%, and the overall geometric mean titers (GMT) was 248.0. The positive rates were 42.2%, 49.3%, 71.9%, 94.2% and 98.5%, respectively, in groups of <1, 1-3, 4-6, 7-19 and 20-39 years old, and were up to 100% in the 40-59 and ≥ 60 age groups. The GMTs in these seven groups were 1:39.8, 1:80.6, 1:133.2, 1:283.7, 1:253.3, 1:308.1 and 1:405.0, respectively. The seroprevalence and GMT of EV-D68 showed an increased trend with age, while gender and geographic area didn’t show significant impact.Conclusions: EV-D68 infection was prevalent in Xiamen City. Children are the high-risk groups for EV-D68-related illnesses, especially those aged ≤ 3 years. It is necessary to establish preventive measures and strengthened the surveillance on EV-D68 to prevent disease outbreaks.