BACKGROUND: In 2010, China experienced the largest outbreak on record of Enterovirus 71 (EV71)-associated Hand Foot and Mouth Disease (HFMD) with more than 1.7 million cases, 27,000 patients with severe neurological complications and 905 deaths. Understanding of the seroprevalence of neutralizing antibodies (NAb) against EV71 and their protective role against HFMD in children is crucial for the implementation of future therapeutic and prophylactic intervention. OBJECTIVES: To correlate the prevalence of NAb against EV71 genotype C4a in children prior to the 2011 epidemic season with severe EV71-associated HFMD disease during the subsequent 2011 epidemic season. STUDY DESIGN: 614 sera samples were collected from children without HFMD. EV71 NAb were tested by a quantitative PCR assay. Samples with NAb ≥1:8 were scored as positive. RESULTS: 122 (19.9%) of 614 sera were EV71-seropositive. The NAb seroprevalence was highest in infants 0-5 months of age (28.6%) and lowest in children 1-1.9 years of age (13.4%). 64.1% of severe EV71-associated HFMD occurred in children 1-2.9 years. CONCLUSIONS: Despite the large 2010 outbreak, the overall seroprevalence of EV71 in children is relatively low. The seropositive rate of EV71 NAb prior to the 2011 season was inversely correlated with the number of EV71-infected severe cases in 2011. Loss of maternal antibodies in infants and lack of acquired anti-EV71 immunity are responsible for increased proportion of severe HFMD in the 1-2 years age group. Our data suggest that future vaccination campaigns should be initiated as early as 6 months. Copyright Â
BACKGROUND: In 2010, China experienced the largest outbreak on record of Enterovirus 71 (EV71)-associated Hand Foot and Mouth Disease (HFMD) with more than 1.7 million cases, 27,000 patients with severe neurological complications and 905 deaths. Understanding of the seroprevalence of neutralizing antibodies (NAb) against EV71 and their protective role against HFMD in children is crucial for the implementation of future therapeutic and prophylactic intervention. OBJECTIVES: To correlate the prevalence of NAb against EV71 genotype C4a in children prior to the 2011 epidemic season with severe EV71-associated HFMD disease during the subsequent 2011 epidemic season. STUDY DESIGN: 614 sera samples were collected from children without HFMD. EV71 NAb were tested by a quantitative PCR assay. Samples with NAb ≥1:8 were scored as positive. RESULTS: 122 (19.9%) of 614 sera were EV71-seropositive. The NAb seroprevalence was highest in infants 0-5 months of age (28.6%) and lowest in children 1-1.9 years of age (13.4%). 64.1% of severe EV71-associated HFMD occurred in children 1-2.9 years. CONCLUSIONS: Despite the large 2010 outbreak, the overall seroprevalence of EV71 in children is relatively low. The seropositive rate of EV71 NAb prior to the 2011 season was inversely correlated with the number of EV71-infected severe cases in 2011. Loss of maternal antibodies in infants and lack of acquired anti-EV71 immunity are responsible for increased proportion of severe HFMD in the 1-2 years age group. Our data suggest that future vaccination campaigns should be initiated as early as 6 months. Copyright Â
Authors: Bingyi Yang; Peng Wu; Joseph T Wu; Eric H Y Lau; Gabriel M Leung; Hongjie Yu; Benjamin J Cowling Journal: Pediatr Infect Dis J Date: 2015-12 Impact factor: 2.129
Authors: Nguyen Thi Thanh Thao; Celeste Donato; Vu Thi Huyen Trang; Nguyen Trung Kien; Ph M Mai Thuy Trang; Tran Quoc Khanh; Dang Thi Nguyet; October M Sessions; Hoang Quoc Cuong; Phan Trong Lan; Vu Thi Que Huong; H Rogier van Doorn; Dhanasekaran Vijaykrishna Journal: J Infect Dis Date: 2017-12-12 Impact factor: 5.226