Hand, foot, and mouth disease in Changsha City, China, 2009?2017: a new method to analyse the epidemiological characteristics of the disease

Objectives: By adopting a new method, this study aimed to analyse the epidemiological characteristics of hand, foot, and mouth disease (HFMD) in nine districts and counties (cities) of Changsha City, China, from 2009 to 2017. Methods: The reported HFMD cases were collected in Changsha from 2009 to 2017. The traditional descriptive method and a new method (index system) including six indices (richness index N, Simpson diversity index D, Shannon diversity index H, Berger-Parker dominance index d, Shannon evenness index E, and Morisita?Horn similarity index C) were used to describe the epidemiological characteristics of HFMD in Changsha. Results: There were 214155 HFMD reported in Changsha during the study period. The incidence of the disease was higher in even-numbered years (2010, 2012, 2014, and 2016) than in uneven-numbered years (2009, 2011, 2013, 2015, and 2017), with two peaks in May to June and October to November every year. The age of onset was mainly from 0 to 5?years old, and the death was mainly from 0 to 2?years old. According to occupational classification, districts and counties (cities) had a high degree of similarity of the composition of HFMD, and there was no regional difference. Conclusions: Changsha had a yearly increasing trend of HFMD from 2009 to 2017, and the key population for prevention and control was children aged in 0?5?years old. Seasonal distribution of high incidence and peak incidence were occurred in even-numbered years. The sub-regions of the city shared moderate diversity and high similarity of occupational distribution of HFMD.