ABSTRACT
Objective:To investigate the prevention and control effect of hand， foot and mouth disease （HFMD） after entervirus （EV） 71 vaccine immunization， evaluate economic benefit of EV71 vaccine immunization，and provide evidence for developing HFMD vaccine immunization strategies． Methods:Descriptive analysis was performed on comparing epidemiological characteristics of HFMD before and after EV71 vaccine immunization. Cost-benefit analysis was conducted， in which disease burden of HFMD， coverage of EV71 vaccine immunization， and costs of EV71 vaccine immunization were collected to evaluate the benefit-cost ratio （BCR）. Results:The average incidence of HFMD was 202.17/10 million from 2017 to 2018， which decreased by 43.8% compared with the average of the previous six years（χ2 = 395.49，P<0.05）； the average proportion of severe case decreased by 88.7%（χ2=40.84，P<0.05）. The prevalence of EV71 in the outpatients from 2017 to 2018 were 2.56%（18/704）， which decreased by 88.7% compared with the previous six years（χ2=124.74，P<0.05）. The severe and fatal cases were mainly caused by EV71 （84.5% -100.0%）. The average cost of EV 1 vaccine immunization was RMB 526， which was approximately 30.2% of the average cost of HFMD diagnosis and treatment. Coverage of EV71 vaccine was 40.12% from 2017 to 2018 in Minhang. The total costs of EV71 vaccination in Minghang from 2016 to 2018 was 174.89 million RMB. It was estimated that EV71 vaccination strategies had prevented 2 491 outpatients， 232 ordinary inpatients and 54 severe cases. The BCR was determined to be 0.35∶1. Conclusion:EV71 vaccine may reduce the incidence of HFMD， the incidence of severe cases， and the disease burden. It is highly recommended to reduce the immunization costs to increase the immunization coverage.
ABSTRACT
Objective To analyze the epidemic characteristics of the hand-foot-mouth disease (HFMD) in four years before and after EV71 vaccine inoculation, and to provide a basis for better EV71 vaccination and prevention and control of HFMD. Methods The descriptive epidemiology method was used to analyze the monitoring data of HFMD from 2013 to 2020 and EV71 vaccination from 2017 to 2020 in Xinwu District of Wuxi City. Results A total of 9 589 HFMD cases including 104 severe cases (accounting for 1.08%) were reported in four years before EV71 vaccination, and the reported average annual incidence rate was 431.15/100 000. A total of 7 396 HFMD cases including 21 severe cases (accounting for 0.28%) were reported in four years after vaccine inoculation, and the reported average annual incidence rate was 325.28/100,000. Annual incidence rate and severe illness rate decreased significantly before and after vaccine inoculation. The HFMD incidences displayed two epidemic peaks, from May to June and from October to November. The three streets with the highest average annual incidence were Jiangxi, Meicun, and Shuofang. The HFMD cases were mainly children under 5 years old, and there were more men than women. A total of 394 samples were sent for examination from 2013-2020, and 231 were positive, with a total positive rate of 58.63%. There were significant changes in the etiological composition before and after vaccine inoculation. The composition of EV71 virus decreased significantly (χ2=69.70, P2=22.35, P<0. 05). From 2017 to 2020, a total of 12 472 people were inoculated with EV71 vaccine in Xinwu District of Wuxi City, with estimated annual vaccination rates of 3.78%, 10.96%, 8.40% and 7.63%, respectively. Conclusion There is no significant change in time, region and population distribution of HFMD before and after EV71 vaccination in Xinwu District of Wuxi City, but the annual incidence rate and severe illness rate show a decreasing trend, and the dominant intestinal pathogens have changed. It is suggested to strengthen the use of EV71 vaccine and the development of multivalent HFMD-related vaccine.