If there had been only a single exposure, one might expect antibody titers to peak within 6 months and then decline unless re-exposure occurs (26)

If there had been only a single exposure, one might expect antibody titers to peak within 6 months and then decline unless re-exposure occurs (26). titers in 2012C2013 from comparably aged children. Rate of seronegativity was highest (15.3%) for B2 computer virus. Multivariate analysis revealed an association between asthma and higher titers against B2 and D viruses. EV-D68 seems to have circulated during 2014C2017. Keywords: enterovirus, EV-D68, neutralizing antibody, children, seroprevalence, asthma, viruses, B1 clade, B2 clade, D clade, Kansas City, Missouri, USA Enterovirus D68 (EV-D68) rose to prominence because of its association with acute flaccid myelitis (AFM) (1,2) and the US outbreak of severe respiratory disease among children in 2014 (381 cases in Kansas City, Missouri, USA; 1,153 confirmed cases nationally). Severe disease affected children with a history of atopic disease, asthma, or reactive airway disease (3C6). Even though 2014 EV-D68 outbreak in the United States was caused predominantly by a clade B1 computer virus, 2 less frequent viruses, clades B2 and D (previously A2), were also detected. In the United States, EV-D68 activity varies 12 months to 12 months and regionally; some areas show a biennial pattern and others do not (7), yet EV-D68 seems to be seasonal (primarily late summer time through fall). Before 2014, sporadic small regional/local EV-D68 outbreaks were reported in the United States (8) and globally. However, during 2014C2016, EV-D68 was the most frequently reported enterovirus in the United States (9). Prevalence of nonoutbreak cases is unclear; however, new B clade viruses emerged in 2012 and 2013 (10C12), and new B subclade and D clade viruses emerged in 2016C2019 (12). In contrast to other US regions, activity in Kansas City was minimal in 2015 (7), 2016, and 2017 (R. Selvarangan, unpub. data). Prospective EV-D68 surveillance has recently been undertaken by the New Vaccine Surveillance Network (NVSN, https://www.cdc.gov/surveillance/nvsn/index.html), which includes Kansas City. NVSN reported an uptick in activity in July and October 2018 (13) in not only Missouri (54 detections in Kansas City, Serpinf2 clade B3 [14]) but also Ohio, Tennessee, Pennsylvania, Texas, Washington, and New York. Clade B3 computer virus in Kansas City was similar to the computer virus that caused a 2016 outbreak associated with AFM in nonmidwestern US areas. Nevertheless, increased worldwide attention Demethoxycurcumin has led to seroprevalence and genotyping reports from multiple countries (15C20). EV-D68 community blood circulation remains underrecognized because clinically used multiplex respiratory PCR assays do not specifically identify EV-D68. We previously evaluated EV-D68 neutralizing antibodies in serum collected in Demethoxycurcumin Kansas City during 2012C2013 from persons 2C85 years of age (21). Despite no prior documented EV-D68 outbreaks or outbreaks of EV-D68 compatible illnesses in Kansas City, all samples experienced neutralizing antibodies to the B1 computer virus, suggesting EV-D68 blood circulation before the major outbreak in 2014. Our goals with this study were to use the same assay that we used previously to evaluate neutralizing EV-D68 antibodies to the 2014 clade B1, B2, and D viruses in serum collected during 2017 from children 6 months to 18 years of age, including those given birth to after 2014, and to examine associations of antibody titers with demographic and medical history factors. This study was approved by the institutional review table at Childrens Mercy Hospital Kansas City. Methods We examined deidentified serum from 300 nonimmunocompromised children 6 months to 18 years of age in Kansas City for EV-D68 neutralizing antibodies. Samples were taken from extra serum after standard-care phlebotomy Demethoxycurcumin during AprilCMay 2017 (Appendix). We matched age, sex,.