[Seroprevalence of the newer enterovirus types A71, A90 and B87 in healthy individuals in Shandong Province, China].

This study aimed to investigate antibody levels of the newer human enteroviruses (EV) A71, A90, and B87 in the population of Shandong Province, and provide a scientific basis for the development of prevention and control measures. In this study, serum specimens were collected from 400 individuals living in Yantai city, Shandong Province in 2010. EV-A71, A90, and B87 antibodies were detected using neutralization tests, and the results were analyzed by statistical methods. It was found that the positive neutralizing antibody rates of EV-A71, A90 and B87 in the population were 46.0%, 8.8%, and 47.0%, respectively. Their geometric mean titers (GMT) were 1 : 5.20, 1 : 1.49, and 1 : 4.02, respectively. Positive antibody rates for EV-A71 and EV-B87 were lowest in the 1-yr and 7-mo age groups, respectively. Positive rates increased gradually with age, and become consistent in the population aged >5 years. Positive antibody rates of EV-A90 were consistent across all age groups. Maternal antibody levels of EV-A71 declined rapidly after birth, and the increase in seroprevalence among 3-7 years old children implied that most EV-A71 infections occurred in preschool and early elementary school children. High positive antibody rates of EV-B87 in healthy individuals, especially children, implied that there may be an immune barrier within the general population. The population monitoring of EV-A90 should be strengthened, as its positive antibody rate is low.