Co-detection in the pathogenesis of severe hand-foot-mouth disease.

It still needs to be elucidated whether co-detection of EV71 with other intestinal tract viruses plays a role in the pathogenesis of severe hand-foot-mouth disease (HFMD). A total of 680 stool specimens collected from clinically diagnosed mild and severe-HFMD patients were tested for EV71, CA16, norovirus, bocavirus and rotavirus. The results showed that EV71 was significantly associated with severe-HFMD patients. Co-detection of EV71 with norovirus and rotavirus was also significantly associated with severe-HFMD patients: The OR (95 % CI) value was 6.466 (2.735, 15.283) and 7.561 (3.560, 16.057), p < 0.001, respectively. Co-detection of EV71 with rotavirus or norovirus is probably associated with severe HFMD.

Changing profiles of bound water content and distribution in the activated sludge treatment by NaCl addition and pH modification.

Currently the dewatering of activated sludge from wastewater treatment plants is a problem not well solved. Extracellular polymeric substances (EPS), including loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS), are highly hydrated biopolymers and play important roles in sludge dewatering. In the present work, two types of treatments, i.e., salt addition and pH modification, were proposed to evaluate the effects of bound water content and its distribution on the dewatering performance of activated sludge. Results show that the bound water content in activated sludge was deeply related to the floc structures and EPS compositions. Both salt addition and acid treatment altered the flocculated matrix and increased the contents of LB-EPS, resulting in the release of trapped water and reduction in sludge volume. In addition, the chemical treatments also affected the distribution of bound water. The internal water content increased upon the dose of NaCl, leading to a decreased water content trapped in EPS. Hence, salt addition caused a slower filtration rate, but did not effectively decrease the total water content, although the EPS were decomposed. Under acidic conditions, cell lysis helped to release the intracellular water and further enhance the sludge dewatering performance. In contrast, conditioning with low-dosage alkali increased the bound water content and deteriorated the sludge dewaterability. Therefore, an in-depth investigation into the mechanisms is useful to optimize the activated sludge dewatering process.

[Spatial clustering and changing trend of hand-foot-mouth disease during 2008-2011 in China].

OBJECTIVE: The purpose of this study was to explore the spatial clustering, specific clustering areas, as well as changing trend of clustering areas of hand-foot-mouth disease (HFMD). METHODS: Exploratory spatial data analysis (ESDA) was used to conduct spatial statistical analyses for the HFMD using 2008 - 2011 data at both provincial and county/district levels. RESULTS: The Global Moran's I coefficients appeared to be 0.3336, 0.6074, 0.3372, 0.4620 and 0.4367 for 2008 - 2011 and for the combined 4 years, respectively. The corresponding P-values were 0.002, 0.001, 0.004, 0.001 and 0.001 respectively, when using the Monte Carlo tests with all the P-values less than 0.05. Moran's I coefficients ranged between 0.3 and 0.7, showing the appearance of moderate or higher clustering nature. Based on the results from nationwide analyses on clustering areas at the county/district levels between 2008 and 2011 (Moran's I = 0.5198, P = 0.001), it appeared a moderate clustering nature. When local autocorrelation analysis was applied at the provincial level, 3 hot spot areas in Beijing, Tianjin and Shanghai cities in 2008; 7 hot spot areas in Beijing, Tianjin, Hebei, Shanxi, Shanghai, Jiangsu and Shandong in 2009; four hot spot areas: Beijing, Tianjin, Guangdong and Guangxi; five hot spot areas: Fujian, Jiangxi, Hunan, Guangdong and Guangxi in 2011, were discovered. 390 hot-spot counties/districts were found through local autocorrelation analyses using the three-year data of 2008 to 2010. CONCLUSION: Spatial clustering nature of HFMD incidence between 2008 and 2011 in China appeared to be moderate or high, with the clustered areas a north to south shifting trend. However, further investigation was in need to address this changing trend.