Epidemiological characteristics of clustered cases of hand, foot, and mouth disease in Beijing, 2013 -2017

Objective To describe the epidemiological characteristics of clustered cases of hand, foot, and mouth disease (HFMD) in Beijing from 2013 to 2017. Methods The epidemiological data of clustered HFMD cases were collected, and the pathogens were detected afterwards. Results From 2013 to 2017, the total number of clusters was 4 813, and (926.6±247.9) per year. The clusters showed a periodicity of two years. The main peak was from May to July, and the secondary peak was through September to November. The top-three districts with the most clusters were Chaoyang (184.6±83.8), Daxing (100.8±43.7) and Fengtai (91.2±22.2). Childcare facilities reported most of the clusters (75.25%, 3 662/4 813), followed by households (17.16%, 826/4 813), schools (6.17%, 297/4 813), as well as other places (1.58%, 76/4 813). The attack rate in childcare facilities was 10.00%, higher than that of schools 7.10% (Z=10.540, P<0.01). The positive rate of enteroviruses among all clusters was 67.17% (3 281/4 813). Amongst these, Cox A16 took the largest part (36.39%, 1 194/3 218), followed by other enteroviruses (32.92%, 1 080/3 218), EV71 (28.68%, 941/3 218) and Cox A6 (15.57%, 511/3 218). Among the clusters, 13.23% (434/3 218) was caused by 2 or more types of viruses. Conclusions The disease prevention and healthcare institutions should provide health education and instructions to students and teachers in childcare facilities and schools before summer and at the beginning of autumn semester. At the initial period of clusters, samples of patients should be collected as early as possible to detect pathogens and to determine its scale, so as to take timely and effective control measures. Key words: Hand, foot, and mouth disease; Clustered cases; Epidemiological characteristics