Burden of self-reported acute gastrointestinal illness in China: a population-based survey.

BACKGROUND: Acute gastrointestinal illness (AGI) is an important public-health problem worldwide. Previous national studies of the incidence of AGI in China were performed decades ago, and detailed information was not available. This study therefore sought to determine the magnitude, distribution, and burden of self-reported AGI in China. METHODS: Twelve-month, retrospective face-to-face surveys were conducted in 20 sentinel sites from six provinces between July 2010 and July 2011. RESULTS: In total, 39686 interviews were completed. The overall adjusted monthly prevalence of AGI was 4.2% (95% confidence interval, 4.0-4.4), corresponding to 0.56 episodes of AGI per person-year. Rates of AGI were highest in children aged < 5 years. Healthcare was sought by 56.1% of those reporting illness. Of the cases who visited a doctor, 32.7% submitted a stool sample. The use of antibiotics was reported by 49.7% of the cases who sought medical care and 54.0% took antidiarrhoeals. In the multivariable model, gender, age, education, household type, residence, season, province and travel were significant risk factors of being a case of AGI. CONCLUSIONS: This first population-based study in China indicated that AGI represents a substantial burden of health. Further research into the specific pathogens is needed to better estimate the burden of AGI and foodborne disease in China.

[Epidemiologic characteristics of typhoid and paratyphoid fever on related drug resistance and molecular types regarding Salmonella typhi and S. paratyphi, in Jiangsu province].

OBJECTIVE: To explore the distribution of prevalence rates of typhoid and paratyphoid, with drug resistance and molecular types of Salmonella (S.) typhi and S. paratyphi in Jiangsu province. METHODS: Data, collected by the national infectious disease reporting system in Jiangsu province from 2007 to 2011, was analyzed. K-B method was used to test the sensibility to 9 kinds of antibiotics among 210 stains of S. typhi and S. paratyphi. 81 strains of S. typhi were classified by pulse-field gel electrophoresis (PFGE). RESULTS: The annual average incidence of typhoid and paratyphoid was 0.47 per 100 000 in the last five years, showing a decreasing trend. Highest incidence (1.70 per 100 000) was seen in the < 1 year age group, with S. typhi and S. paratyphi A accounted for 66.19% and 23.81% among the 210 stains. The rate of drug resistance to nalidixic acid appeared to be the highest as 66.19%. The drug resistant rates to 6 kinds of antibiotics were on average, lower than 10.00%. The multi-drug resistant rate of S. typhi and S. paratyphi was 30.00%. In the last 3 years, 37 types from 81 S. typhi strains had been classified into 4 clusters by PFGE. The predominant type was JPPX01. JS0027, accounted for 11.11%. JPPX01.JS0001 type had a specific regional distribution, but JPPX01.JS0014, JPPX01.JS0018 and JPPX01.JS0024 strains were widely spread. Results from the clustering analysis showed that cases in the 3 events tended to have a clustering nature. CONCLUSION: The morbidity of typhoid and paratyphoid was in a relatively low level in Jiangsu province. Although S. typhi and S. paratyphi were sensitive to most of the commonly used antibiotics, the resistance rates to some kinds of antibiotics were increasing. The distribution of typhoid was sporadic in Jiangsu and without the dominant strain, it was unlikely that typhoid could become epidemic in the future, in Jiangsu.

Anti-thyroid hormone activity of bisphenol A, tetrabromobisphenol A and tetrachlorobisphenol A in an improved reporter gene assay.

Previously, we transiently transfected Gal4-fused thyroid hormone receptor (TR) expressing vector and the Gal4 response reporter structure pUAS-tk-luc into HepG2 cell, developed a TR beta-1 mediated reporter gene assay to screen for compounds that acted on the TR signaling pathway. In this study, we improved the test efficiency by changing the transfected cell line into CV-1 cell. Triiodothyronine (T3) and thyroxine (T4) induced higher luciferase expression, with the median effective concentration (EC(50)) of 1.16 x 10(-8) and 1.36 x 10(-7)M, respectively. Bisphenol A (BPA) was selected as a positive antagonist, exhibiting weak anti-thyroid hormone activity with the median inhibitory concentration (IC(50)) of 1.64 x 10(-5)M. The assay showed acceptable repeatability to T3 with inter coefficient of variability (CV) of 27.5% and intra CV of 18.6%. Two flame retardants, tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA), were tested for their agonist and antagonist activities. As a result, we found that both of them possessed TR antagonist activity and neither of them showed agonist activity. These results suggested that TBBPA and TCBPA could act as TH antagonists. This assay provided a useful tool for the assessment of environmental chemicals as thyroid system disruptors.

[Study on the application of benchmark dose and biological monitoring indexes of fluorides in drinking water].

OBJECTIVE: By using Benchmark Dose (BMD) approach to explore the relations among drinking water fluoride, urine fluoride, serum fluoride and dental fluorosis; and to evaluate the significance of urine fluoride and serum fluoride in control and prevention of endemic fluorosis. METHODS: 512 children (290 in Xinhuai Village, 222 in Wamiao Village) aged 8-13 years were recruited in the study. Epidemiological methods were used to investigate the prevalence of dental fluorosis, and the levels of urine fluoride, serum fluoride, and drinking water fluoride in superficial well. The children were divided into six subgroups by the concentration of fluoride in drinking water: < 0.5 mg/L, 0.5-mg/L, 1.0-mg/L, 2.0-mg/L, 3.0-mg/L and > or = 4.0 mg/L. RESULTS: There was significant dose-response relationship between the drinking water fluoride and the prevalence of dental fluorosis or the prevalence of defect dental fluorosis. The BMDLs (Benchmark Dose Lower Bound) were 1.01 and 1.30 mg/L, respectively. Urine fluoride and serum fluoride also had significant dose-response relationship to the prevalence of dental fluorosis or defect dental fluorosis. The correlation coefficient between drinking water fluoride and urine fluoride was 0.717, and it was 0.855 between drinking water fluoride and serum fluoride, and 0.617 between urine fluoride and serum fluoride. CONCLUSIONS: The currently national standard of fluoride in drinking water in China is safe and reasonable. As a biological monitoring index, the levels of fluoride in serum may be more useful than that in urine in the control and prevention of endemic fluorosis.