[Etiology surveillance of hand-foot-mouth disease in Henan province between 2008 and 2011].

OBJECTIVE: To understand etiological types and distribution features of hand-foot-mouth disease (HFMD) in Henan province between 2008 and 2011. METHODS: A total of 30 486 specimens of feces, rectal swabs or throat swabs from HFMD patients were collected by each Municipal CDC in Henan from 2008 to 2011. The enterovirus 71 (EV71), coxsackie virus A16 (CA16) and other enterovirus (EV) were detected by RT-PCR or real time RT-PCR. The VP1 gene of EV71 was amplified and the sequences were analyzed by bioinformatics software. A genetic evolution tree of the sequence was constructed as well. RESULTS: The positive rates of EV71, CA16 and other EV were 62.70% (11 209/17 876), 12.03% (2150/17 876), 25.27% (4517/17 876) in 17 876 laboratory diagnosed cases, respectively. The differences were statistically significant (χ(2) = 157.17, P < 0.05). The positive rates of EV71, CA16 and other EV were 63.40% (7370/11 624), 11.58% (1346/11 624) and 25.02% (2908/11 624) in male patients and 61.40% (3839/6252), 12.86% (804/6252) and 25.74% (1609/6252) in female patients, respectively. The differences were statistically significant (χ(2) = 4.06, P < 0.05). The children under 5 years old were high-risk population of HFMD, accounting to 97.67% (17 459/17 876) of the laboratory-diagnosed patients.86.92% (15 537/17 876) cases were children between 1 to 3 years old. Constituent ratio of EV71 changed seasonally during a year, there was a high infection ratio of EV71 between April and June, especially in May, the infection ratio reached 69.34% (2384/3438). The positive rates of EV71, CA16 and other EV were 82.48% (5715/6929), 1.76% (122/6929) and 15.76% (1092/6929) among the 6929 laboratory-diagnosed severe cases, respectively. The positive rates of EV71 was higher than CA16 and other EV (χ(2) = 9259.17, 6170.81, P < 0.05, respectively). There were 117 deaths because of severe HFMD, 55 (47.01%) of which were laboratory confirmed. 50 death cases were infected by EV71, and according to the genetic evolution analysis, the VP1 gene of EV71 strain was belonged to subtype C4 of gene C. CONCLUSION: The EV71 and CA16 were the main pathogens which caused HFMD in Henan province, and EV71 virus was the dominant strain, belonging to C4 subtype of gene C.

[Analysis on clinical and epidemiological characteristics of severe cases infected by EV71].

OBJECTIVE: To explore the clinical and epidemiological characteristics of serious cases of hand-foot-and-mouth disease (HFMD) infected by EV71, in order to provide scientific evidence for prevention and control of HFMD. METHODS: Information was collected by questionaires through consulting medical cases. Data was input by Epidata, and analysed by software SAS 9.13. RESULT: 201 severe cases were investigated. 84.65% of the cases were below 3 years old. The youngest one was 5 months and the oldest one was 8 years old. The ratio for male and female was 2.2: 1.85. 08% of the cases were distributed sporadically. 51.74% of them lived in rural, 29.36% of them lived in urban and 19.9% of them lived at the fringe area of rural and urban. 81.59% of the cases became serious between 1 and 4 days after infected. 100% cases had fever and 99.95% of them had a rash. 96.52% of them had nerve system symptoms. The main complications were virulent spinal encephalitis, pneumonia and breathing exhaustion. 98.01% of the patients were recovered or cured. CONCLUSION: The cases aged below 3 years old are high risk persons. Rural area and the fringe area of rural and urban are the key area for disease control. 1-4 days after onset is the key period to prevent complications.