[Etiological and epidemiological characteristics of Vibrio cholerae in Beijing, 2015-2021].

Objective: To analyze the etiological and epidemiological characteristics of Vibrio cholerae in Beijing during 2015-2021 and provide evidence for the prevention and control of cholera. Methods: The V. cholerae strains isolated in Beijing during 2015-2021 were analyzed by serotyping and virulence genes detection. Pulsed field gel electrophoresis (PFGE) was performed for the molecular typing of the strains. Based on the collected epidemiological and clinical data of cholera cases,the epidemiological characteristics of cholera were analyzed by descriptive epidemiology method. Results: A total of 76 Vibrio cholerae O1 strains were isolated in Beijing during 2015-2021, including 61 strains from human, 10 strains from environment and 5 strains from seafood. The 76 strains consisted of 68 Ogawa strains and 8 Inaba strains. Six Ogawa strains isolated from sporadic cases carried ctxAB. After NotⅠ digestion, 76 strains were divided into 33 PFGE patterns. From 2015 to 2021, a total of 38 cholera epidemics were reported in Beijing, most of them were sporadic ones, accounting for 92.11% (35/38). A total of 45 cases were reported, and the cases occurred during June-September accounted for 97.78% (44/45). Cholera cases occurred in 9 districts of Beijing, and the cases reported in Chaoyang district accounted for 42.22% (19/45) and in Changping district accounted for 31.11% (14/45). The age of the cholera cases ranged from 19 to 63 years. Except for one case with unknown clinical symptoms, 44 cases had diarrhea symptoms with 84.09% (37/44) of the cases reporting diarrhea (3-9 times/day), followed by yellow watery stool (95.45%, 42/44), abdominal pain (68.18%, 30/44), nausea and vomiting (40.91%, 18/44) and fever (36.36%, 16/44). Conclusion: Vibrio cholerae strains isolated in Beijing during 2015-2021 were mainly O1 serotype Ogawa,most of which were non-toxigenic. The PFGE of the strains varied. Cholera epidemics occurred in 9 districts of Beijing, but most were sporadic ones with incidence peak during June-September.

[Epidemiological characteristics of imported COVID-19 cases in Beijing].

Objective: To analyze the epidemiological characteristics of imported COVID-19 cases and the effect of vaccination on virus load and disease severity of the cases in Beijing. Methods: The data of the imported COVID-19 cases in Beijing were collected from the National Notifiable Infectious Disease Reporting System of China Information for Disease Control and Prevention and Epidemiology investigation. The data were processed and analyzed by Excel 2010 and SPSS 22.0. Results: From June 1 to September 30, 2021, a total of 171 imported COVID-19 cases were reported in Beijing, of which 66.67% (114/171) were asymptomatic. The cases were mainly from the Philippines, the United Arab Emirates, the United Kingdom and the Russian Federation, accounting for 67.84% (116/171). The male to female ratio of the cases was 2∶1 (114∶57). The median age M (Q1, Q3) of the cases was 28 (23, 36) years. The cases of Chinese accounted for 80.12% (137/171). The sequencing of the whole genome of the virus in 47 imported COVID-19 cases showed that the proportion of Delta variant was 76.60% (36/47). The COVID-19 vaccination coverage rate in the cases was 60.82% (104/171), but the full vaccination coverage rate was 53.80% (92/171). In the imported COVID-19 cases, 13.53% (23/170) were screened to be SARS-CoV-2 nucleic acid positive on the day when they arrived in Beijing, and all the cases were positive for 2019-nCoV nucleic acid within 28 days. The severity of the disease was higher in the unvaccinated group than in the partially vaccinated group and fully vaccinated group (P<0.001). In the unvaccinated group, there were 1 severe case and 1 critical case. The median Ct values M (Q1, Q3) of N gene and ORFlab gene in unvaccinated group were 32.51 (23.23, 36.06) and 32.78 (24.00, 36.38), respectively. There was no significant difference in the median of double-gene Ct value between the partially vaccinated group and the fully vaccinated group. Conclusions: During the study period, most of the imported COVID-19 cases in Beijing were asymptomatic. No matter vaccinated or not, the viral loads in the COVID-19 cases were similar, but the vaccination could reduce the severity of the disease.

[Investigation on Norovirus prevalence in catering companies and train station in Beijing during non-epidemic season in 2019].

Objective: To study the prevalence of Norovirus infection among kitchen workers in Beijing, and the contamination status of Norovirus in catering companies and train station. Methods: A cross-sectional survey was conducted to collect anal swab specimens and environmental specimens from catering companies in 16 districts of Beijing and in 3 big train stations. Norovirus nucleic acid was detected by fluorescence quantitative PCR. The contamination status of Norovirus in the environment and the asymptomatic infection status of kitchen workers was analyzed in this study. Results: A total of 650 catering companies were investigated. 1 302 anal swabs or stool specimens and 2 600 environmental swabs were collected and tested. Among the 644 catering companies out of train stations, 1 290 anal swabs or stool specimens and 2 576 environmental swabs were collected and tested. The asymptomatic infection rate of Norovirus was 0.85% (11/1 290) among kitchen workers of the catering companies out of the train stations, while the positive rate of norovirus contamination in the environment was 0.04% (1/2 576). Norovirus was not detected in the specimens collected from the kitchen workers and the environment of the catering companies in train stations. Conclusion: During the non-epidemic season of Norovirus in 2019, the infection rate of Norovirus among kitchen workers in Beijing is low, and the environment is contaminated by Norovirus.

[Analysis of pathogenic composition and clinical characteristics of viral acute gastroenteritis in children under five years old in Beijing].

Objective: To understand the epidemiological characteristics and clinical features of rotavirus-, norovirus-, adenovirus-and astrovirus-associ ated acute gastroenteritis in children under 5 years old in Beijing from Octorber, 2015 to March, 2017. Methods: In the intestinal clinic of 6 hospitals in 6 districts of Beijing, information and stool samples of the first 30 patients with acute gastroenteritis who are under the age of 5 years are collected monthly.Rotavirus, norovirus, adenovirus and astrovirus are identified by PCR.Descriptive epidemiological method was used to describe the epidemiological characteristics of diarrhea caused by rotavirus, norovirus, adenovirus and astrovirus in Beijing. One-way analysis of variance was used to analyze the Vesikari clinical severity score of of acute gastroenteritis caused by each virus. Unconditional logistic regression analysis was used to analysis the associated factors of clinical features. Results: Of the 2 052 samples, 709 (34.6%) were non-mixed infections: the positive rate of rotavirus, norovirus, adenovirus and astrovirus were 20.0%, 7.5%, 4.2% and 2.9%, respectively. A total of 135 cases (6.6%) were mixed infection. The mean and standard deviation of Vesikari clinical severity score was 8.0±3.1 for rotavirus associated acute gastroenteritis, which was significantly higher than norovirus (6.4±2.4, P<0.001), adenovirus (6.2±2.1, P<0.001) and astrovirus (6.1±2.0, P<0.001). The comparison of clinical features showed that compared with astrovirus, the children under 5 years old infected with rotavirus were more likely to have a diarrhea ≥5 days (OR=3.334), have vomiting ≥3 times within one day (OR=8.788), have vomiting≥1 day (OR=3.963), have a Vesikari clinical severity score ≥11 severe cases (OR=13.194). Norovirus infected cases were prone to have vomiting≥3 times in 1 day (OR=5.710).Adenovirus infected cases were prone to have a diarrhea≥5 days (OR=2.616). When using rotavirus as a reference, children under 5 years of age were less likely to develop fever≥38.4 ℃ after infection with norovirus (OR=0.397) or adenovirus (OR=0.280). Conclusions: The results of this study showed that the characteristics of acute gastroenteritis caused by different viruses are different. The clinical symptoms caused by rotavirus are more serious. Children under 24 months of age are at high risk of rotavirus infection. Effective preventive measures such as vaccination should be taken as soon as possible.

[Analysis on influencing factors for acute gastroenteritis outbreaks caused by norovirus in Beijing, 2014-2018].

Objective: To analyze the influencing factors of acute gastroenteritis outbreaks caused by norovirus in Beijing from 2014 to 2018. Methods: Data of acute gastroenteritis events caused by norovirus in Beijing from April 2014 to March 2018 were collected. Unconditional logistic regression model was conducted to identify the risk factors of the outbreaks. Results: A total of 765 acute gastroenteritis epidemics caused by norovirus were reported in Beijing, in which 85.88% (657/765) were cluster events and 14.12% (108/765) were outbreaks. Among the outbreaks, 70.37% (76/108) were reported in 2017; 84.26% (91/108) were reported in winter and spring; 88.89% (96/108) were reported in kindergartens, primary or secondary schools; 81.48% (88/108) were through person-to-person transmission; 93.52% (101/108) were caused by norovirus GⅡ infection. The risk of outbreaks in suburban and out suburb area were 1.84 times (95%CI: 1.13-3.02) and 3.78 times (95%CI: 1.62-8.82) as high as that in urban area, respectively. The risks of outbreaks in primary, secondary schools and other institutions were 6.26 times (95%CI: 3.53-11.10), 14.98 times (95%CI: 6.23-36.01) and 8.71 times (95%CI: 3.07-24.71) as high as that in kindergartens, respectively. The risk of outbreak in which patients having lower hospital visiting rate than the median rate of all events was 2.29 times than that in the context of having higher hospital visiting rate (95%CI:1.42-3.68). The risk of foodborne outbreak was 14.55 times as high as that transmitted through person-to-person (95%CI: 3.15-67.07). Conclusion: Measures such as strengthening the prevention and control of norovirus outbreaks in suburbs, primary schools, secondary schools and other institutions, promoting patients to visit the hospital actively, improving the management of foodborne events and kitchen workers should be taken to reduce the incidence of acute gastroenteritis outbreaks caused by norovirus.

[Systematic review on the characteristics of acute gastroenteritis outbreaks caused by sapovirus].

Objective: To understand the epidemiological and etiological characteristics of outbreaks on acute gastroenteritis caused by sapovirus (SaV) worldwide. Methods: Literature about the outbreaks on acute gastroenteritis caused by SaV were retrieved from the databases including WanFang, CNKI, PubMed and Web of Science after evaluation. Time, geography, setting and population distributions of outbreaks, transmission mode, SaV genotype and clinical characteristics of the patients were analyzed. Results: A total of 34 papers about SaV were included, involving 146 outbreaks occurred between October 1976 and April 2016. In these papers, 138 outbreaks were reported on the related months. All these outbreaks occurred in northern hemisphere. SaV outbreaks occurred all year around, but mainly in cold season, the incidence was highest in December (25 outbreaks) and lowest in in August (2 outbreaks). Most outbreaks were reported by Japan, followed by Canada, the United States of America and the Netherlands. There were 141 outbreaks for which the occurring settings were reported, child-care settings were most commonly reported setting (48/141, 34.04%), followed by long-term care facility (41/141, 29.08%) and hospital (16/141, 11.35%). Clinical symptoms of 1 704 cases in 31 outbreaks were reported, with the most common symptom was diarrhea (1 331/1 704, 78.12%), followed by nausea (829/1 198, 69.20%), abdominal pain (840/1 328, 63.25%), vomiting (824/1 704, 48.36%) and fever (529/1 531, 34.53%). Genotypes of SaV were determined for 119 outbreaks. GⅠ(51/119, 42.86%) and GⅣ (45/119, 37.82%) were predominant. The outbreaks of GⅣ SaV increased suddenly in 2007, and the outbreaks of GⅠ SaV mainly occurred in 2008 and during 2011-2013. Conclusions: SaV outbreaks were reported mainly by developed countries, with most outbreaks occurred in cold season, in child-care settings and long term care facility. GⅠ and GⅣ were the most common genotypes of SaV. Prevention and control of SaV outbreak in China seemed relatively weak, and it is necessary to conduct related training and to strengthen the SaV outbreak surveillance in areas where service is in need.

Serological survey of 2009 H1N1 influenza in residents of Beijing, China.

In order to determine the prevalence of antibody against 2009 H1N1 influenza in Beijing, we conducted a serological survey in 710 subjects, 1 month after the epidemic peak. We found that 13·8% of our cohort was seropositive. Subjects aged ≥60 years recorded the lowest seroprevalence (4·5%). The age-weighted seroprevalence of 14·0% was far lower than the supposed infection rate at the epidemic peak, derived from the basic reproduction number for 2009 H1N1 virus. For subjects who had received the pandemic vaccine seroprevalence was 51·4%. In subjects aged ≥60 years the seasonal influenza vaccination was not significantly associated with being seropositive. Our study suggests that many factors, and not just the immunological level against 2009 H1N1 influenza in the community, affected the spread of the virus within the population of Beijing.

How to simplify the diagnostic criteria of hypertension in adolescents.

Diagnosis of hypertension in adolescents is complicated because blood pressure values vary with age, gender and height. How can we simplify the diagnostic criteria for hypertension in adolescents? In 2006, anthropometric measurements were assessed in a cross-sectional population-based study of 3136 Han adolescents aged 13-17 years. Hypertension was defined according to the 2004 National High Blood Pressure Education Program Working Group definition. The following equations for blood pressure-to-height ratio (BPHR) were used: systolic BPHR (SBPHR)=SBP (mm Hg)/height (cm) and diastolic BPHR (DBPHR)=DBP (mm Hg)/height (cm). Receiver-operating characteristic curve analyses were performed to assess the accuracy of SBPHR and DBPHR as diagnostic tests for elevated systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively. After the cutoff points were determined, hypertension was defined by SBPHR/DBPHR, and the sensitivity and specificity were calculated. The accuracy of SBPHR and DBPHR (assessed by area under the curve) for identifying elevated SBP and DBP was >0.85 (0.989-1.000). The optimal thresholds of SBPHR/DBPHR for defining hypertension (stages 1 and 2) were 0.75/0.48 for boys and 0.78/0.51 for girls, and for defining hypertension (stage 2) were 0.81/0.57 for boys and 0.84/0.63 for girls. In identifying hypertension, the sensitivity and specificity were both >90% (91.0-99.1%). In identifying stage 2 hypertension, when the sensitivity was 100%, the specificity was 98.6% for boys and 99.1% for girls. BPHR is a simple, accurate and non-age-dependent index for screening hypertension in Han adolescents, especially for stage 2 hypertension.

Regulating colored textile wastewater by 3/31 wavelength ADMI methods in Taiwan.

The wastewater from textile dyeing facilities is difficult to treat satisfactorily because of high compositional variability and high color intensity. To reduce colored effluents discharged into watercourses, the government of Taiwan adopted the Effluent True Color Standard in 1998. The true color discharge limit is 400 American Dye Manufactures Institute (ADMI) units. The adopted analytical method is the ADMI Tristimulus Filter Method (3 wavelength (WL) method), and the 31 WL ADMI method might be also adopted as an alternative for color value measurement. The refractory nature of textile dyes and the introduction of this new regulation present an environmental challenge to the Taiwanese textile industry. The main objectives of this study were to (1) evaluate the efficacy of current wastewater treatment systems for controlling the colored textile wastewater discharges, and (2) evaluate the correlations between 3 and 31 WL ADMI methods. Ten representative textile wastewater treatment facilities employing biological and chemical coagulation treatment technologies were selected to perform a 10-consecutive-day effluent sampling and analysis. Results show that a significant difference between 3 and 31 ADMI methods was observed. These two ADMI methods cannot be substituted for each other, and the discharge standard should be determined based on the selected testing method. Investigation results also suggest that the commonly used wastewater treatment technology (biological + chemical coagulation) fails to effectively remove dye from the colored textile wastewater. Sodium hypochlorite (NaOCl) addition was applied by most facilities as the temporary post-polishment step to comply with the color discharge standard.

Apolipoprotein C-III can specifically bind to hepatic plasma membranes.

Apo C-III plays an important role in the metabolism of plasma triglyceride, which can delay the catabolism of triglyceride-rich lipoproteins by interfering with apo E-mediated receptor clearance of remnant particles from plasma. The mechanism of the interference has not yet been defined. To further explore the role of apo C-III, we first injected mice with 125I-apo C-III. The measurement of radioactivity showed that liver took up 3.3-10 fold as much radioactivity as other organs such as heart, spleen, lung, kidney, stomach, large intestine, small intestine, and muscle. This was confirmed by incubating the tissue homogenates of the organs with 125I-apo C-III that the radiolabeled apo C-III specifically bound to only hepatic homogenate. To investigate which subcellular part or parts of hepatic cells play the role of binding to apo C-III, hepatic cell components of nucleus, mitochondria, microsomes and plasma membranes were then incubated with 125I-apo C-III. The radiolabeled apo C-III could specifically bind to only hepatic plasma membranes. Finally hepatic plasma membranes were purified to study the characteristics of the specific binding with apo C-III. Addition of increasing concentration of 125I-apo C-III to human hepatic plasma membranes revealed saturable binding to membranes with a Kd of 0.31 +/- 0.07 micromol/l. The maximum specific binding capacity was 1.74 +/- 0.45 microg apo C-III/mg membrane protein. In competition studies using unlabeled apo C-III and isolated lipoproteins HDL, LDL and VLDL, only apo C-III and VLDL effectively competed with 125I-apo C-III for membrane binding. The binding of 125I-apo C-III to human liver plasma membranes was Ca2+-independent, and was abolished when plasma membranes were treated with trypsin. The characteristics of 125I-apo C-III binding to mouse liver plasma membranes were similar to those of human liver plasma membranes with the exception of a binding maximum of 1.52 +/- 0.39 microg apo C-III/mg membrane protein. We conclude that apo C-III exhibits high-affinity binding to hepatic plasma membranes, which is saturable, reverse and specific.

Oxidative modification of lipoproteins in hypertriglyceridemic patients and hypercholesterolemic rabbits in vivo.

Many lines of evidence suggest that LDL is oxidized in vivo and that Ox-LDL is present in the artery wall. But the oxidation of VLDL and HDL in vivo has not yet been reported. In this study, the oxidative modification of serum LDL, VLDL, and HDL in patients with endogenous hypertriglyceridemia (HTG) and in serum of rabbits fed on high cholesterol diet were made. The serum LDL, VLDL and HDL were isolated by the density gradient ultracentrifugation. The oxidative modification of LDL, VLDL and HDL were identified by agarose eletrophoresis, absorbance at 234 nm and fluorescence of TBARS. The results showed that serum TC, TG and TBARS in the HTG group (n = 25) and in rabbits fed with a high fat diet (for 12 weeks, n = 8) were significantly higher than those of the corresponding control groups (normal subjects, n = 25; rabbits fed with a normal diet, n = 8; p < 0.01). The electrophoretic mobilities of LDL, VLDL and HDL were increased when compared with the controls, and absorbance at 234 nm and TBARS of LDL, VLDL and HDL in the HTG group and in the high fat diet rabbits were significantly higher than those of the controls (p < 0.01). These results suggest that not only LDL but also VLDL and HDL were oxidatively modified in vivo in the patients with HTG and in the rabbits fed with a high cholesterol diet.

Common genetic variants of lipoprotein lipase and apolipoproteins AI-CIII that relate to coronary artery disease: a study in Chinese and European subjects.

The large ethnic differences in prevalence of coronary artery disease between China and Europe may relate to both genetic and environmental differences. To assess possible genetic factors we have therefore studied the frequencies of disease-related variants of genes involved in lipid transport in 69 hypertriglyceridemic Chinese subjects and 74 healthy Chinese controls. The loci studied include lipoprotein lipase (Asp9Asn, Asn291Ser, Ser447Ter, and Thr361Thr); apolipoprotein A1 (restriction sites at MspI, XmnI, and PstI); and apolipoprotein (apo) CIII (G3175C). All these variants have been shown in previous literature publications to relate to either dyslipidemia and/or premature coronary heart disease in Caucasians. Two disease-related genetic variants in Europeans (Asp9Asn and Asn291Ser) were not found in the Chinese sample. The apo CIII G3175C variant was found more frequently in the upper tertile distributions for apolipoprotein CIII, apolipoprotein E, and plasma triglyceride/HDL ratios (P < 0.05). The rare allele of the apo AI MspI restriction site polymorphic variant was also found more frequently in the upper tertiles for apo CIII, apo E, and plasma triglyceride/HDL ratios (P < 0.04). Eleven of the most lipaemic Chinese subjects (with fasting plasma triglycerides >700 mg/dl) were analyzed for DNA sequence variation. One novel mutation was observed C1338A (which is a silent mutation at Thr361) and two others that are also found in European subjects (Ala261Thr and Ser447Ter). We conclude that genetic differences between Chinese and Europeans may have an effect on the prevalence of coronary artery risk factors involved in lipid transport, and further extended study is warranted.

[Syndrome differentiation in traditional Chinese medicine in chronic aplastic anemia; T-lymphocyte subpopulation in peripheral blood and erythrocyte C3b receptors].

UNLABELLED: In this paper, the Syndrome Differentiation in TCM and the determination on T-lymphocyte subpopulation and RBC C3b receptor were carried out by using indirect SPA assay and RBC C3b receptor ring test among 51 chronic aplastic anemia patients. RESULT: The OKT3, OKT4 and OKT4/OKT8 ratio in groups of Kidney-Yin Deficiency group were lower, while the OKT8 was higher than that of controls. In the group of both Kidney-Yin and Yang Deficiency, OKT4 and OKT4/OKT8 ratio were lower. and the value of OKT8 is higher than that of controls. The OKT8 in the Kidney-Yang Deficiency group was higher. and the ratio of OKT4/OKT8 was lower than that of controls. The OKT8 in the Kidney-Yin Deficiency group among three groups increased higher than that of other two groups. while the OKT4/OKT8 ratio reduced. The OKT4/OKT8 ratio in the group of both Kidney-Yin and Yang Deficiency was higher than that of Kidney-Yang Deficiency group. Among the three groups, the rosette rates of RBC C3b receptor were lower than controls. The above-mentioned data were statistically significant. These characteristic changes could be used as a reference of microcosmic Syndrome Differentiation and also a guide for how to apply the immunosuppressant and immunopotentiator.

[Quantitation of human serum apolipoprotein CII by radial immunodiffusion assay].

A radial immunodiffusion assay (RID) for quantitation of human serum apolipoprotein CII (apoCII) was developed. Antiserum to apoCII was raised in goats with purified apoCII. The antibody-gel plate was prepared with 1% agarose. 5 microliters of each sample or standard serum was added in a well. Diffusion was performed at 25 degrees C or 37 degrees C for 48 h. The standard curve with a working range of 0.8-4.5 mg/dl was plotted. The minimum measurable concentration of apoCII was 40 ng. The intra-assay and inter-assay CV were 1.4-3.5% and 1.3-3.6% respectively. The recovery of the assay was 92.38-104.35%. The concentrations of apoCII for healthy adults and patients with hyperlipidemia were 3.9 +/- 1.7 mg/dl (M +/- SD, n = 67) and 5.9 +/- 2.5 mg/dl (n = 43) respectively.

[Preparation and identification of monoclonal antibodies against Echinococcus granulosus hydatid cyst fluid antigen].

McAbs were prepared by fusing SP2/0 cells with spleen cells of BALB/c mice immunized with hydatid cyst fluid (HCF) antigen. Antibodies in hybrid culture supernatant were detected by ELISA, and positive hybrids were cloned by technique of limiting dilutions. Numbers of chromosomes of five hybridoma cell lines (1D1, 1D8, 2D6, 4B10, 4F4) were demonstrated in the range of 99-108. The immunoglobulin class/subclass of McAb 4F4 was IgM and the others belonged to IgG1. IHA, ELISA and I-ELISA were used for identifying titer and specificity of five McAbs. The titers of two McAbs (1D1, 1D8) reached 1:10(6)-10(7) in IHA and ELISA. Two of these McAbs (1D1, 4F4) with other parasitic antigens revealed cross-reactions. This indicated that the McAbs 1D1 and 4F4 were against common antigen determiners of different parasitic antigens and the McAbs 1D8, 2D6, 4B10 against specific antigen determiners of HCF.