[Clinical stages and outcomes of severe cases on hand, foot and mouth disease].

Objective: To understand the characteristics and relation of clinical stage and outcome of severe cases on hand, foot and mouth disease (HFMD) and to establish the evaluation method for understanding severity of this disease. Methods: According to factors as geographical location, economic and epidemic levels, five provinces (Henan, Shandong, Yunnan, Zhejiang and Sichuan provinces) were selected. Reported severe cases of HFMD from the National Notifiable Diseases Reporting System were selected randomly in the five provinces. Basic epidemiological information, clinical data, and pathogen testing results in the involved hospitals were collected. Clinical stages on all the patients were decided in accordance with"the clinical expert consensus on diagnosis and treatment for severe case of enterovirus type 71 (EV71) infections (2011 edition)" . Data were analyzed using SPSS software 18.0 and other epidemiological methods. Results: A total of657 severe HFMD cases were investigated, with 326 cases positive of EV71, accounting for 91.3 % (326/357) among all the laboratory-confirmed cases. Of the 657 cases, 542 cases (82.5 % , 95 %CI : 79.4 %- 85.3 % ) were diagnosed as in stage 2 (with nervous system involvement), 99 cases (15.1 % , 95 %CI : 12.4 %- 18.0 % ) in stage 3 (early phase of function failure on heart and lung), and 16 cases (2.4 % , 95 %CI : 1.4 %- 3.9 % ) were in stage 4 (function failure of heart and lung). 11 cases (1.7 % , 95 %CI : 0.9 %- 3.0 % ) were with squeal when discharged from hospital with 8 cases (1.2 % , 95 %CI : 0.6 %- 2.3 % ) died. When comparing the proportions among stage 2, stage 3 and stage 4, significant differences were found between age groups ( χ (2)=22.632, P =0.012). The younger the patient was the lower the proportions of stage 2 and the more proportion of stage 3 appeared. When comparing the proportions of clinical stages among the five provinces, significant differences ( χ (2)=41.481, P =0.000) were noticed. Proportions of different clinical stages in gender, ethnicity, occupation, place of residence types and the type of pathogen appeared no significant differences, respectively. However, the proportions of squeal and death in stage 2, stage 3 and stage 4 showed significant differences (sequela: χ (2)=12.960, P =0.001; Death: χ (2)=16.850, P =0.001), respectively. Conclusions: The percentage of clinical stages of severe HFMD patients related to the rate of squeal and death. Clinical staging can be used for assessing the clinical severity of complications and the effectiveness of treatment, of HFMD.