Dynamics and epidemiological characteristics of hand, foot and mouth disease in Shaanxi province, 2009-2018

Abstract

Objective: To understand the dynamics and epidemiological characteristics of hand, foot and mouth disease (HFMD) in Shaanxi province during 2009-2018 and provide evidence for prevention and control of HFMD. Methods: Information on HFMD was collected from the Chinese Disease Prevention and Control Information System in Shaanxi Province during 2009-2018 and was analyzed by descriptive, dynamic geometric series averaging and circular distribution methods. Results: The annual average incidence rate of HFMD was 140.04/100 000 in Shaanxi province during 2009-2018. The highest incidence rates were seen in age groups as 1-year olds (3 494.24/100 000), 2-year olds (2 734.79/100 000) and 3-year olds (2 608.58/100 000). The highest reported mortality rates appeared in: 1-year olds as 1.42/100 000, 2-year olds as 0.77/100 000) and 0-year olds (0.53/100 000). The incidence rate increased most rapidly in the 1-year olds and the 0-year olds groups. The top three incidence rates were reported in Xi'an (251.34/100 000), Weinan (161.21/100 000) and Xianyang (123.73/100 000) cities in Guanzhong area of Shaanxi province. In the whole province, incidence rate was on the rise, and the average increases of incidence rates were all greater than zero in these cities. The proportion of severe cases in most cities somehow declined. Results from the circular distribution method estimated that the peak incidence would appear in April 10-11 each year, and the high incidence season was from April to July. In 2018, the composition of enterviruses (EV) 71 was 26.47% (1 303/4 922). In 2014 to 2018, the proportion of Coxsackie virus A16 (Cox A16) was between 20.06%(753/3 753) and 23.08% (855/3 705). The proportions of other EVs increased from 6.09% (14/230) to 51.91% (2 555/4 922) during 2009-2018. Conclusions: The overall incidence rate of HFMD was increasing, with high risk population appeared in children under 3 year olds, in Shaanxi province during 2009-2018. However, both mortality and fatality rates were declining, with severe cases also showing a downward trend in most of the areas. Composition of pathogens was changing over time.