Abstract:Food safety is one of the most important technical support for Healthy China. The surveillance of food contaminants and harmful factors is the most important technical basis in the whole food safety management in China. The surveillance has been carried out in China for more than 20 years, and 24 million pieces of data have played an important role in food safety risk management in China, such as showing the present status for food safety, indicating trends of contaminants, serving risk assessment activities and the demand of standard formulation/revision, etc. Under the new situation and requirements after the outbreak of COVID-19, this paper summarizes how to improve the efficacy of the surveillance of food pollution and harmful factors and play a greater role in the national food safety risk management,were studied in this paper, and some corresponding advices are proposed.

Abstract:In the recent 10 years, China has carried out the construction of food safety risk assessment system including microbiological risk assessment (MRA) in accordance with the Food Safety Law, and has made significant progress in the work system and technical system of MRA, which has become an important basis for the risk assessment of foodborne pathogens in China. With the change of food supply chain in the global post epidemic era and the rapid development of new technologies as well as the increasing demand for the modernization of food safety management in China, it will become the main challenge for the construction of food MRA to build assessment model based on China's dietary consumption behavior, improve the implementation ability and quality of risk assessment, and realize the application of modern technologies in risk assessment.

Abstract:In order to implement the “most rigorous standard” requirements, a national food safety standard system has been established initially covering the food chain from farm to table that is primarily consistent with the Codex Alimentarius standards and regulations in major developed countries. This article systematically reviews the construction process of the most rigorous food safety standard system from the perspectives of the overview, rule construction, standard formulation, system evaluation and future work prospects. Suggestions are provided on how to achieve the goal of reaching the forefront of food safety standards in the world while the work basis of the “14th Five-Year” food safety standard is clarified.

Abstract:Objective To analyze beauvericin and enniatins concentrations in the culture complex after Isaria cicadae Miquel was inoculated on different media for certain time. Methods One strain of Isaria cicadae Miquel was inoculated on 4 kinds of liquid culture media and 4 kinds of solid culture media. After incubation for 1-7 weeks under 25 ℃, high performance liquid chromatography tandem mass spectrometry was employed to detect beauvericin and enniatins. Results The detection rates of beauvericin in Isaria cicadae Miquel culture on 4 kinds of liquid media ranged between 42.9%-100.0%, and the beauvericin concentrations varied from 1.0 to 94.6 μg/L. The positive rates of beauvericin in Isaria cicadae Miquel culture on 4 kinds of solid media were 100.0%, and the beauvericin concentrations ranged from 60.9 to 44 677.5 μg/kg. Enniatins were negative for Isaria cicadae Miquel on 8 kinds of culture media. Conclusion The strain of Isaria cicadae Miquel used in our study could produce beauvericin in 8 kinds of culture media after incubation for certain time, and the beauvericin concentrations in solid media were much higher than in liquid media. The strain of Isaria cicadae Miquel didn't produce enniatins in 8 kinds of culture media after incubation for certain time.

Abstract:Objective To analyze the serotypes and molecular type of Listeria monocytogenes strains isolated from food, clinical case and environment in Fujian Province, so as to provide reference for the outbreak identification and traceability of foodborne diseases. Methods Using multiplex polymerase chain reaction(PCR) serotyping, immune serum agglutination and pulsed field gel electrophoresis (PFGE) to classify the strains. Results The 117 strains of Listeria monocytogenes strains were divided into 4 PCR serotypes, 67.5%(79/117) of which were 1/2a(3a), 23.1%(27/117) were 1/2b(3b), 5.1%(6/117) were 1/2c(3c) and 4.3%(5/117) were 4b(4d,4e). Among the 9 strains isolated from cases, 6 strains were 1/2a, 2 strains were 4b and 1 strain was 1/2b. 117 Listeria monocytogenes strains were divided into 83 different PFGE types by Asc I restriction endonucleases, and 10 strains of which had unique and single types. Nine clinical case isolates were divided into 8 different PFGE types. Conclusion 1/2a serotype was dominant in Listeria monocytogenes isolated from food and clinical specimens in Fujian Province, and 4b serotype should be concerned.

Abstract:Objective To understand the prevalence, drug resistance, and virulence gene distribution of foodborne Staphylococcus aureus in northwestern Hubei Province. Methods A total of 303 food samples were collected from Xiangyang City, Shiyan City, and Suizhou City of Hubei Province for Staphylococcus aureus screening. Toxic genes and methicillin-resistant Staphylococcus aureus(MRSA)were detected with PCR method. The drug resistance of Staphylococcus aureus was determined with K-B paper diffusion method. Results Staphylococcus aureus strain was determined from 41 samples with the positive rate of 13.53%. Among them, the highest detection rate was from raw meat products (23.91%, 22/92). Among the enterotoxigenic strains, the strain carrying sea was the most common, accounting for 87.80% (36/41). The strains carrying eta and tst accounted for 97.56% (40/41) and 7.32% (3/41), respectively. Strains carrying three or more enterotoxin genes accounted for 17.07% (7/41). 2.44% (1/41) of strains carry eta and tst simultaneously. The drug susceptibility result showed that the penicillin, tetracycline, erythromycin, and doxycycline accounted for 78.05%(32/41), 43.90%(18/41), 31.71%(13/41)and 21.95%(9/41)respectively. The mecA gene test showed that 19.51% (8/41) of the strains were MRSA strains. Conclusion Foodborne Staphylococcus aureus in northwestern Hubei Province had a higher detection rate, toxic gene carring rate, and multiple drug resistance. Related departments need to strengthen food safety monitoring to control the spread of the strain.

Abstract:Objective To investigate the mechanism of water-soluble propolis (WSP) in relieving dextran sulfate sodium (DSS)-induced intestinal inflammation in ulcerative colitis (UC) rats. Methods SD rats were randomly divided into 5 groups:CON, DSS, L-WSP, M-WSP, H-WSP. By measuring disease activity index (DAI) score, colon length, small intestinal mucosa permeability and histological score (HS) of rats, the degree of intestinal inflammation injury in each group was evaluated. ELISA was used to detect the level of IL-6, IL-9 and TNF-α in colon homogenate of rats. Results Compared with CON group, DSS group experienced severe weight loss, loose stools, and bloody stools, shortened colon length, and increased HS(P<0.05). While compared with DSS group, M-WSP group and H-WSP group were significantly improved (P<0.01,P<0.05). Compared with CON group, the content of proinflammatory cytokines IL-6, IL-9 and TNF-α in colon tissue homogenate in DSS group increased significantly(P<0.05), while decreased significantly in M-WSP group and H-WSP group compared with CON group(P<0.01,P<0.05). Conclusion WSP can improve the intestinal mucosal barrier function and reduce intestinal inflammation by reducing the levels of proinflammatory cytokines IL-6, IL-9 and TNF-α.

Abstract:Objective To construct and compare the methods for correlation analysis of different elements in rice,including barium, vanadium, cadmium, lithium, aluminum, manganese, lead,thallium,antimony,copper, selenium, ehromium, mercury and arsenic. Methods Analyze the correlation among the fourteen elements in rice by two methods:Pearson correlation coefficient and partial correlation coefficient, and compare the two methods. Results Both of the methods can find the correlations among various pollutants from the data and have their own characteristics on computational complexity, information abundancy and other aspects:Pearson correlation coefficient method has less computation, but also provides less information; Partial correlation coefficient provides more information but needs more samples and computing resources. The Pearson correlation coefficient method showed the positive correlation elements including barium-vanadium, barium-lead, vanadium-lithium, aluminum-antimony and copper-thallium. There was no significant correlation between the remaining elements. The partial correlation coefficient method showed strong positive correlation including vanadium-barium, lead-barium,total mercury-barium and antimony-aluminum. There was no significant correlation between the remaining elements. Conclusion Under the current data and software, hardware conditions, the correlation analysis of the partial correlation coefficient is recommended.

Abstract:Objective To establish a method for determination alpha-solanine in potatoes by liquid chromatography-tamdem quadrupole mass spectrometry. Methods The potato samples were extracted using the mixed solution of acidity water and organic solvent by accelerated solvent extraction. After the purification by MCX solid phase extraction, the eluent was dried-up with nitrogen. The analytes were dissolved by the mobile phase(acetonitrile-water containing 0.1% formic acid,80∶20,V/V)and separated by hydrophilic interaction chromatography(2.1 mm×50 mm,1.6 μm) and determined using multi-reaction monitoring mode. The conditions of the pretreatment solution, liquid chromatography and matrix effect were optimized. Results The limits of detection and quantification were 0.5 and 1.6 μg/kg. The linear range of standard curve were from 0.1 to 100 μg/L. The relative standard deviations of detection were at 3.41%-7.56%(n=6), and the spiked sample recoveries were at 82.8%-99.0%. Conclusion The simplicity, efficiency, sensitivity and accuracy of this method can meet the needs of risk monitoring and poisoning analysis.

Abstract:Objective A ¹³C isotope labeled internal standard-gas chromatography-tandem mass spectrometric (GC-MS/MS) with dispersive solid phase extraction (d-SPE) method was developed for the simultaneous determination of 7 polybrominated diphenyl ethers(PBDEs)residues in milk. Methods After adding¹³C₁₂ isotope internal standard and extracted with 1% acetic acid acetonitrile,purified with the new Z-Sep+C18 dispersive agent, the analytes in the sample solutions were seperated by DB-5 column(30 m×0.25 mm,0.25 μm). Operated by electron impact ion source (EI) with multiple reactions monitoring (MRM) mode, the samples were analyzed by gas chromatography-tandem mass spectrometer.(GC-MS/MS). The quantifications were performed by the isotope internal standard method with matrix-matched calibration standards. Results Good linearity was obtained for 7 PBDEs in the concentration range of 0.500-100 ng/mL with correlation coefficients (r) above 0.999. Recoveries for 7 PBDEs at three spiked levels of 0.1,1.0, and 10 μg/kg were in the range of 89.7%-102.9% with relative standard deviations (RSDs,n=6) of 3.8%-8.3%. The limits of detection and the limits of quantification were in the ranges of 2.4-9.8 and 7.5-30 ng/kg, respectively.Conclusion The established method was simple, efficient and sensitive, and could be applied in the determination of 7 PBDEs in milk.

Abstract:With the increase of risk factors in urban governance in China, traditional fresh food market has become a vulnerable part. In order to avoid the outbreak of public health crisis caused by traditional fresh food, it is necessary to analyze and evaluate the public health risks inherent in it, so as to improve the ability of public health risk management of urban government in China. From the perspective of vulnerability theory, this paper analyzes the public health risks of traditional fresh food market, and discusses the vulnerability of traditional fresh food market in nature, society, management and technical system. On this basis, this paper puts forward some countermeasures for the potential and secondary risks of the traditional fresh food market in China under the fragile system environment.

Abstract:Objective To understand the contamination pattern of mycotoxin in paddy rice in the main rice-growing regions of Guangdong Province, and analyze the distribution difference of mycotoxin in different areas, so as to provide basis for the implementation of precise prevention and control measures. Methods A total of 120 paddy rice samples were collected from eight cities in the Pearl River Delta, northern, eastern and western Guangdong during 2018 and 2019,and were analyzed for 16 mycotoxins by multiple reaction monitoring mode of ultra performance liquid chromatography-tandem mass spectrometer. Results Among the 120 paddy rice samples, 19.17%(23/120) were positive for mycotoxins, and the main polluants were aflatoxins and fumonisins. FB₁ were detected in 9.17% (11/120) of the samples, followed by 8.33%(10/120) for AFB₁. Two samples had the AFB₁ concentrations above the tolerance limit of 10 μg/kg. The detection values were 73.90 and 18.80 μg/kg, respectively. Among 6 trichothecene mycotoxins, only deoxynivalenol (1.67%,2/120) and its acetyl derivatives [0.83%(1/120) for 3-Ac-DON and 0.83%(1/120) for 15-Ac-DON] were found. ZEN was found in 3.33%(4/120) of the samples. Additionally, 1.67%(2/120) of the paddy rice samples were positive for sterigmatocystin. The ochratoxin A, nivalenol, T-2 and HT-2 mycotoxins were not found in the paddy rice samples. The co-occurrence of two or more mycotoxins was confirmed in 8.33%(10/120) of the paddy rice samples, mainly combination was AFB₁ aflatoxin and other mycotoxins. The contamination patterns were different in the eight cities. The samples from Guangzhou, Qingyuan, Huizhou and Jieyang were grouped into one group, and the level of contamination was lower than other cities. The paddy rice samples from Zhanjiang was mainly contaminated by FB₁, FB₂, DON and 3-Ac-DON. Samples from Heyuan were mainly contaminated by AFB₁, AFB₂, sterigmatocystin, FB₁ and FB₂. The concentration levels of ZEN, DON and 3-Ac-DON were relatively higher in samples from Shaoguan. Conclusion The paddy rice samples from Guangdong Province were contaminated by multiple mycotoxins, and the pollution patterns were different in different areas. In terms of the co-occurence of mycotoxins, some measures should be conducted to assess the exposure risk, reduce the damage, and protect the consumers food safety.

Abstract:Objective To understand the contamination of Bacillus cereus in foodstuff of Jilin Province from 2011 to 2019, and to provide theoretical basis for food safety monitoring and prevention of foodborne diseases. Methods Totally 3 173 samples were collected from the catering service and circulation of nine prefecture (city) levels in Jilin Province from 2011 to 2019. Bacillus cereus in food was detected according to the method of GB 4789.14-2014 national food safety standard microbiological examination of food. The detection rate was analyzed by rate, composition ratio and χ² test. Results Among 3 173 food samples from 2011 to 2019 in Jilin Province, the total detection rate of Bacillus cereus was 23.6%(750/3 173), the highest was in 2015 (38.5%, 62/161), and the lowest was in 2017 (11.8%, 20/170). Baishan City had the highest detection rate (35.8%, 139/388), followed by Yanbian Prefecture (31.4%, 97/309), and Siping City had the lowest detection rate (15.3%, 76/496). The detection rate of egg and egg products was the highest (60.0%, 3/5), followed by milk and dairy products (39.3%, 114/290) and infant food (31.1%, 185/595).Contamination of Bacillus cereus was the highest in department stores (32.4%, 22/68), followed by snack bars and beverage stores (30.9%, 43/139), and fast food stores (29.1%, 25/86).The median (interquartile interval) of the detection result of Bacillus cereus by colony forming units method was 5.8 (2.9,8.7) CFU/g(mL), and the median (interquartile interval) of that by most probable number method was 6.4 (3.2,9.6) MPN/g(mL). Conclusion There were different degrees of Bacillus cereus contamination in foodstuff in Jilin Province. Among the different cities, foodstuff samples collected from Baishan City was much more serious. Eggs and egg products, milk and dairy products were the main contaminated food. Safety monitoring and management of the snack bar, beverage shop and places in department store should be strengthen.

Abstract:Objective To understand the status of microbial contamination in the production of pre-cooked food, provide a basis for the sanitary control of pre-cooked food enterprises, and to make recommendations for the formulation of related product hygiene specifications and standards. Methods From the 70 pre-cooked food enterprises in Hunan Province, 5 samples were stratified to detect the settling microbe in ambient air, the total coliform and the total number of colonies in the contact surface, the adjacent contact surface, and pre-cooked food samples. Results The total coliform and the total number of colonies in the ambient air of medium-sized enterprises and the surfaces and pre-cooked vegetable samples was higher (P＜0.05), and the total number of colonies on each surface of the pre-cooked vegetable production workshop is higher (P＜0.05). It is easier to touch the hands of processing personnel contaminated by microorganisms (P<0.05); the total number of colonies in pre-cooked vegetable products is higher (P<0.05), and the total number of coliforms and colonies in process products are higher than those in finished products(P＜0.05). Conclusion Pre-cooked food enterprises, especially medium-sized enterprises, should strengthen the hygienic requirements of production workshops and the hygienic control of processing. It is recommended that the relevant product standards and hygienic specifications should pay attention to these issues.

Abstract:Objective To understand the contamination status of microorganisms and pathogenic factors in 19 kinds of food in Zhoushan City, so as to provide basic data for food safety risk monitoring and early warning. Methods A total of 1 246 food samples were collected from 2017 to 2019 according to the requirements of the national risk monitor manual of food contamination and harmful factors from 2017 to 2019. The samples were tested for food microbial pathogenic factors. Results A total of 243 pathogenic factors were detected and the total detection rate was 19.50%(243/1 246). Among them, The detection rate of Salmonella in raw meat was 41.67%(30/72), the detection rate of Vibrio parahaemolyticus in bivalve shellfish was 31.58%(48/152), the detection rate of Anisakid in fresh marine fish was 27.00%(27/100), and the detection rate of Staphylococcus aureus in cold-made pastry was 16.25%(13/80). The detection rate of microorganism and its pathogenic factors in bulk food was higher than that in pre-packaged food. The difference was statistically significant(χ²=92.333,P<0.05). In different sampling locations, the highest detection rate of pathogenic factors was found in farmers' markets (32.54%,150/461), followed by online stores (25.44%,29/114) and small restaurants (23.88%,16/67). Conclusion From 2017 to 2019,19 types of food on sale in Zhoushan City were contaminated by microorganisms and pathogenic factors at varying degrees. The contamination of microorganisms and pathogenic factors in take-out meals,raw animal meat and bivalve shellfish products was relatively serious. It is suggested to strengthen hygiene supervision on these types of food to prevent the occurrence of foodborne diseases.

Abstract:Objective To understand the epidemic trend and characteristics of foodborne diseases caused by specific pathogens in Pudong New Area of Shanghai,so as to provide scientific evidence for disease prevention and control. Methods From 2015 to 2018, the infectious cases with diarrhea as the main complaint were collected from the sentinel hospital of foodborne disease active monitoring in Pudong New Area of Shanghai. Stool or anal swab samples were collected and tested for Vibrio parahaemolyticus, Salmonella, Shigella, diarrheogenic Escherichia coli, Campylobacter jejuni and Norovirus. At the same time, the profiles were collected and analyzed. Results In 2015-2018,2 871 stool or anal swab samples of diarrhea cases were monitored and collected. The positive rate of pathogens was 23.55%(676/2 871), including Norovirus 20.04%(97/484), diarrheogenic Escherichia coli 11.84%(340/2 871), Campylobacter jejuni 7.21%(68/943), Vibrio parahaemolyticus 4.01%(115/2 871), Salmonella 3.27%(94/2 871)and Shigella 0.28%(8/2 871).The positive rate was higher in the third quarter, showing a significant peak in summer and autumn. Suspicious food was mainly mixed food (41.12%,278/676), followed by aquatic animals and their products (22.19%,150/676) and meat and meat products (10.95%,74/676). Conclusion Norovirus and diarrheogenic Escherichia coli were the main pathogens of diarrhea cases in Pudong New Area of Shanghai. We should further improve the foodborne disease active monitoring system, carry out detailed epidemiological case investigation for specific pathogen positive cases, and provide technical support for effective prevention and control.

Abstract:Objective To understand the epidemic characteristics and drug resistance of Salmonella I4, [5], 12∶I∶- in Maoming City. Methods Salmonella I4, [5], 12∶I∶- were identified by serological method, and then antibiotic sensitivity of isolated Salmonella I4, [5], 12∶I∶ - was tested by broth microdilution method. Results Among 476 strains of Salmonella from patients' feces, 143 strains of Salmonella I4, [5], 12∶I∶- were detected, and the detection rate was 33.81%. The feces of patients were mainly from infants <3 years old, the peak period mainly occurred from June to August. The rate of resistance to doxycycline was the highest (97.90%,140/143), followed by tetracycline (95.10%,136/143), sulfamethoxazole (93.71%,134/143), ampicillin (90.91%,130/143), streptomycin (86.71%,124/143), minocycline(83.22%,119/143), ampicillin/sulbactam (58.74%,84/143), chloramphenicol (58.74%,84/143) and sulfamethoxazole/trimethoprim (53.85%,77/143). Amikacin and meropenem were the most sensitive antibiotics, and no drug-resistant strains were found, followed by polymyxin B(99.30%,142/143), imipenem (99.30%,142/143), cefoxitin (97.20%,139/143), colistin (93.01%,133/143), ceftazidime(92.31%,132/143),azithromycin (92.31%,132/143), cefotaxime (81.82%,117/143), cefepime(79.72%,114/143)and aztreonam (79.72%,114/143). 97 kinds of drug resistance spectrum were identified, and the multi drug resistance rate was 100.00%. Conclusion Salmonella I4, [5], 12∶I∶- infection rate in infants is high, drug resistance is serious, and it is harmful to infants. It is necessary to expand the scope of sentinel hospitals and strengthen the surveillance of Salmonella, especially Salmonella I4, [5], 12∶I∶-. Salmonella I4, [5], 12∶I∶- was more sensitive to carbapenems and the second, third and fourth generation of cephalosporins which could be used as the first choice for treatment.

Abstract:Objective To understand the microbial contamination during the production and processing of prepackaged cooked meat products in Henan, find out the high-risk links and key control points of contamination, reduce theprobability of food contamination, and incidence of foodborne diseases. Methods Sample collection and detection were performed according to the National Manual for Risk Monitoring of Food Contamination and Hazardous Factors, serotyping and molecular typing of positive strains were all performed according to the National Manual for Foodborne Disease Surveillance. Results A total of 168 samples were monitored, including 104 environment samples (4 in the raw area and 100 in the cooked area), 8 strains of Listeria monocytogenes were detected. A total of 24 strains of Listeria monocytogenes and 2 strains of Salmonella were detected from 60 cooked meat-related samples. 2 strains of Salmonella were Salmonella Enteritidis and had 2 molecular patterns with similarity of 92.9% by digestion with XbaⅠand pulsed field gel electrophoresis. The 32 strains of Listeria monocytogenes were classified into six serotypes (1/2a, 1/2b, 1/2c, 4ab, 3a and 4b), and the dominant serotype was 1/2a. 32 strains were divided into 17 molecular patterns by digestion with AscⅠand pulsed field gel electrophoresis, and each pattern contains 1-10 strains with similarity ranged 55.8%-100.0%. There were 4 water samples, and the total number of colonies and the coliform was all less than 1 CFU/mL, which met the requirements according to the national standard for drinking water. Conclusion There were common sources or cross-contamination in the environment and foods, microbial contamination could be effectively controlled after cooking, however, there were still deficiencies in other aspects. Therefore, it is suggested to further strengthen the management of product division, strengthen the disinfection treatment of ground and operators, and stipulate reasonable production processing and storage period.

Abstract:Objective This paper aim to investigate dibutyl phthalate(DBP) concentration level in edible vegetable oil sold in Shanghai, and to evaluate the dietary exposure risk of local residents. Methods By combining monitoring data of DBP in edible vegetable oil sold in Shanghai from 2015 to 2019 with the dietary consumption data of residents, the dietary exposure of DBP in edible vegetable oil was assessed via point assessment method. Results A total of 1 248 DBP samples in edible vegetable oil were tested from 2015 to 2019, the overall unqualified rate was 3.4%(43/1 248), and the mean concentration was (0.34±2.15) mg/kg. According to the annual statistics, the unqualified rate showed an upward trend of fluctuation and reached 4.4%(13/295) in 2019. According to the statistics of edible vegetable oil varieties, DBP contamination levels in walnut oil, sesame oil and rapeseed oil were relatively serious, with the unqualified rate of 28.6%(6/21), 10.5%(20/190) and 9.2%(8/87), respectively. The mean and 97.5 percentile daily DBP intake from edible vegetable oil in general population were 0.23 and 0.40 μg/kg BW, accounting for 2.3% and 4.0% of tolerable daily intake(TDI, 10 μg/kg BW), respectively. Conclusion The health risk of DBP intake from edible vegetable oil was relatively low and acceptable for Shanghai residents.

Abstract:Objective To explore the blood arsenic exposure levels of preschool children and analyze the factors of blood arsenic. Methods By the multi-stage cluster and simple randomized method, six districts of Shanghai City was chosen and the preschool children in the selected village were asked to fill in the questionnaire and have blood sampling. Inductively coupled plasma mass spectrometry(ICP-MS)was used to detect blood arsenic, of which the data was analyzed by multiple linear regression models. Marine fish, freshwater fish, freshwater shrimp and shellfish were grouped as follows:≤3 times per month, 1-3 times per week, and 4-6 times per week. Rice, noodles and milk were grouped as <50,50-100, and ≥100 g/d. Results 2 263 preschool children were recruited. The range of blood arsenic was 0.12-27.94 μg/L. The median (P25,P75) were 2.26(1.63,3.09) μg/L. Statistical analysis showed that the more intake of rice, wheaten food, and sea fish and shrimp, the more arsenic in children's blood(P<0.05). Whereas highter intake of freshwater fish and shrimp group showed decreased blood arsenic(P<0.05). Conclusion Most preschool children's blood arsenic levels(92.4%, 2 091/2 263) were at normal level (<5 μg/L). There was a positive correlation between blood arsenic concentration and the intake of rice, wheaten food, and sea fish and shrimp, while negative correlation with high freshwater fish and shrimp consumption.

Abstract:Objective To obtain the comprehensive evaluation from stakeholders by carrying out special follow-up evaluation on national food safety standards, so as to provide reference for further improvement of China's national food safety standards system. Methods Questionnaire was designed, and the opinions of stakeholders were collected through National Food Safety Standards Follow-up Evaluation and Feedback Platform. Excel 2013 was used to sort out the original data and make descriptive statistical analysis. Results The analysis of 5 467 questionnaires showed that more than 90% of the respondents thought that the food classification in the current national food safety general standards was clear and the limits were scientific and reasonable. The food products could be covered by the corresponding food safety standards and code of practice standards. The comprehensive score of food safety product standards was 4.37 (out of 5), and the comprehensive score of code of practice standards was 4.42 (out of 5). Conclusion China's current food safety standards system framework is basically perfect, and the convergence between standards is smooth. The coverage rate of general standards, product standards and code of practice standards for all kinds of food products exceeds 90%, and the system setting is reasonable and perfect. It is suggested to further improve the national food safety standard system, make full use of the result of food safety standard follow-up evaluation, and continue to actively explore follow-up evaluation method to be brought in line with international practice.

Abstract:Objective To investigate a food poisoning events occurred in multiple schools at the same time,and analyze pathogenic factor, contaminated food and source, in order to guide clinical treatment and preventive measures. Methods Based on the investigation of clinical characteristics and epidemiological distribution of patients, homology analysis of Salmonella from different sources was carried out with the combination of pulsed field gel electrophoresis(PFGE) in the laboratory. Results Totally 37 suspected cases were found from 4 school in different districts, 19 cases were diagnosed. The main clinical features of the patients were diarrhea (70.27%, 26/37), fever (54.05%,20/37), abdominal pain (51.35%,19/37) and vomiting (37.84%,17/37). A total of 24 strains of Salmonella Enteritidis were isolated in the laboratory, of which 19 strains were from cases and 5 strains were from sandwiches and their dried meat floss. According to PFGE, 24 strains of Salmonella Enteritidis were clustered to 100.00%. The drug resistance rate of 19 cases was 100.00% to nalidixic acid and 5.26%(1/19) to cefoxitin and imipenem. Conclusion Combined with the clinical feature, epidemiological investigation and laboratory test results, it was confirmed that the main cause of the incident was the raw material of the sandwich which was contaminated by Salmonella Enteritidis. It is suggested that the regulatory department should strengthen the supervision of the school catering company, improve the food safety awareness and prevent the foodborne disease.