Study on epidemiological and pathogenic characteristics of hand, foot, and mouth disease in Yangzhou city from 2012 to 2016

Abstract

Objective To explore the epidemiological and pathogenic characteristics of the hand, foot and mouth disease (HFMD) in Yangzhou city from 2012 to 2016, so as to provide evidences for prevention and control of the disease. Methods Information of the cases was collected by the Chinese national HFMD surveillance system from 2012 to 2016, and was analyzed by descriptive epidemiological methods. Meanwhile, samples of HFMD cases were collected for viral nucleic acid detection from Sentinel hospitals. Results 35 720 cases of HFMD were reported in Yangzhou from 2012 to 2016 and the average annual incidence was 155.30/ 100 000 (35 720/23 000 000), the male-to-female ratio of ordinary cases was 1.54 :1 and the percentage of severe cases was 1.60‰ (56/35 720). There were 2 fatal cases. Children of ≤5 years old were the most susceptible to HFMD (91.83%, 32 800/35 720). Most of the patients were the scatter children (60.18%, 21 498/35 720) and the children in kindergartens and nursery schools (35.93%, 12 834/35 720). There were two peaks in May-July and October-December. The incidences were high in 2012, 2014 and 2016, and were low in 2013 and 2015. Coxsackievirus A16 (Cox A16) (33.28%, 432/1 298) and enterovirus 71 (EV71) (28.58%, 371/1 298) were the major pathogens for HFMD in Yangzhou from 2012 to 2016. EV71 accounted for most of the severe cases (76.79%, 43/56). The positive rate of EV71 among severe cases (1.05%, 13/1 242) was significantly higher than that of ordinary cases (x2=66.62, P<0.01). Conclusions There were significant seasonal and gender, age, occupation and regional differences in the occurrence of HFMD in Yangzhou. The cases showed an alternating trend of high and low incidence peaks in different years. Meanwhile, Cox A16 and EV71 were the major pathogens for HFMD, and EV71 was more common among severe cases. Epidemiology and etiological surveillance of HFMD should be enhanced according to the rules above, especially for the monitoring of EV71. Key words: Hand, foot, and mouth disease; Epidemiology; Severe cases; Pathogenic features