Analysis of epidemiology characteristics of norovirus among diarrheal outpatients in 27 provinces in China, 2009-2013 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the epidemiology characteristics of norovirus among diarrheal outpatients in China.</p><p><b>METHODS</b>Diarrhea cases were monitored at emergency/outpatient departments at 173 hospitals in 27 provinces of China, with clinical and epidemiological data, and fecal specimens collected and sent to 58 network-laboratories to detect norovirus by RT-PCR method, and to analyze the positive rate of norovirus in various regions, population and time during 2009-2013.</p><p><b>RESULTS</b>11.6% of the 34 031 diarrheal cases under surveillance were found with norovirus. Age group of 6-23 month-old children and that of people over 45 years old were found with the highest positive percentage, 13.7% and 12.4% respectively. Positive percentage of norovirus peaks in autumn and winter in a year; it peaks in mid-temperate zones (10.7%) and warm-temperate zones (11.6%) in winter. It peaks in sub-tropical zones in autumn (14.3%). The most prevalent genogroups detected were norovirus G II, accounting for 89.9% of identified strains.</p><p><b>CONCLUSION</b>Norovirus affects all ages and was most prevalent in children and the elderly among diarrhea outpatients. Norovirus' positive percentage showed strong seasonal pattern, and peaks at different times of a year in different climate zones of China. Since no effective preventive measures existed, further study on norovirus epidemiology and intervention strategies should be conducted in future.</p>

Compare the application of flexible spatial statistics and kulldorff scanning window statistics to spatial aggregation of Hepatitis A / 中华预防医学杂志

<p><b>OBJECTIVE</b>To compare the application valuable of flexible spatial scan statistics and kulldorff scanning window in the cluster detection and early warning of hepatitis A.</p><p><b>METHODS</b>The case numbers and incidence data of hepatitis A in 2012 for all the counties (cities, districts)in Yunnan province were collected from China Information System for Disease Control and Prevention and the total number was 1 335. By extracting the time length by month, the flexible spatial scan statistics was tested by retrospective analyses of hepatitis A data in Yunnan in 2012 and compared the results with the Kulldorff circular scan statistic analyses.</p><p><b>RESULTS</b>The results of flexible scanning window showed that there were fifteen hepatitis A spatial clusters in Yunnan province in 2012 and in July, these areas including Gejiu county, Mengzi county and Wenshan county had the strongest clusters (the log likelihood ratio (LLR) = 52.66, P = 0.001). The results of Kulldorff scanning window showed that there were twenty hepatitis A spatial clusters and these areas including Gejiu county, Hekou county, Maguan county, Mengzi county, Pingbian county, Wenshan county had the strongest clusters (LLR = 47.82, P = 0.001). The results of the flexible scanning window were the same as the actual monitoring results. But the results of Kulldorff scanning window showed that in May and June some areas without incidence had the clusters.</p><p><b>CONCLUSION</b>Flexible scanning window can detect the monthly clusters of the Hepatitis A. Flexible scanning window had a higher accuracy than Kulldorff irregular circular scanning window. Flexible spatial scan statistics had the value in the use of spatial aggregation detecting on hepatitis A.</p>