Application of moving epidemic method in establishing epidemic intensity threshold of hand, foot, and mouth disease in southern China

Abstract

Objective: To evaluate the incidence intensity of hand, foot, and mouth disease (HFMD) in 2018/2019 season in southern China by Moving Epidemic Method (MEM), and compare the intensity among provinces, so as to provide basis for optimizing the allocation of public health resources. Methods: The weekly incidence data of HFMD of children under 5 years old in 15 provinces of southern China from March 1, 2012 to February 28, 2019 were collected from Disease Surveillance Reporting System of Chinese Center for Disease Control and Prevention, and the epidemic intensity threshold of each province in southern China during this period was calculated and evaluated by MEM. Results: In the first incidence peak of 2018/2019 HFMD season, in 15 provinces in the south China, 6 provinces (Jiangsu, Zhejiang, Jiangxi, Chongqing, Sichuan and Yunnan) reported very high incidence rates in children under 5 years old while Guangdong, Guangxi and Hainan provinces had low incidence level. In the second incidence peak, the incidences in 6 provinces (Shanghai, Jiangsu, Zhejiang, Chongqing, Sichuan and Yunnan) reached very high levels. The incidences in remaining provinces also reached medium or high levels. In most provinces, the thresholds in the first incidence peak were higher than those in the second incidence peak, but Chongqing and Sichuan were different. The results of model validation showed that the sensitivity and specificity of MEM were higher than 70% except for Hainan, Chongqing and Yunnan. Conclusions: For southern provinces with two incidence peaks in HFMD season, MEM can be used to determine the epidemic intensity thresholds of different incidence peaks by dividing the disease season to analyze the incidence intensity of HFMD in different stages. The epidemic intensity threshold established by MEM integrates the historical data, and the province (city) with extremely high epidemic level identified represents that the province (city) has an abnormal increase compared with the historical incidence level, which requires more attention from all areas and timely implementation of prevention and control measures.