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Microbiology Risk Assessment in China: Current Situation & Challenges. Xiumei Liu Institute of Nutrition and Food Safety China CDC. Risk Analysis. RA A scientifically based process RM The process of weighing policy alternatives, distinct from risk assessment. MRA in the Word.
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Microbiology Risk Assessment in China:Current Situation & Challenges Xiumei Liu Institute of Nutrition and Food Safety China CDC
RA A scientifically based process • RM The process of weighing policy alternatives, distinct from risk assessment
MRA in the Word Foodborne bacteria • Risk Assessment FAO/WHO (JEMRA) • Risk Management Codex (CCFH) Mycotoxins, metabolites of fungi • Risk Assessment FAO/WHO (JECFA) • Risk Management Codex (CCFAC)
China Activities in MRA • CCFH • Since 32nd 1999 • JEMRA • Since 2000, Food hazard, EA, QMRA • CCFAC • Over 10 years, 32nd 2000 in Beijing • JECFA • Expert and data contribution (AF, Fumonisin, DSP)
WTO CODEX / GB FOOD INDUSTRY FOOD SAFETY CONTROL Government Consumers HEALTH PROTECTION Life quality knowledge Why MRA is needed in China?
Risk Assessment Hazard Identification Hazard Characterization Exposure Assessment Risk Characterization
Hazards in Food • Foodborne bacteria • Fungi and mycotoxins • Viruses and parasites • Toxic plants and animals • Potential environmental toxicants
Foodborne bacteria in China Pathogens Mortality (%) • Salmonella 0.1 • Bacillus cereus 0.037 • Burkholderia cocovenenans 40 • Proteus 0.03 • Staphylococcus aureus 0.045 • Clostridium botulinum 7.3 • Escherichia coli 0.1 • Vibrio parahaemolyticus 0.01 (1990-1996)
Case 1BA Food Poisoning Control1933 Indonesia: Fermented coconut food poisoning1960 Pseudomonas cocovenenansBongkrekic acid1950’s China: Unknown causes fermented corn flour poisoning 1979 Flavobacterium farinofermentans nov. sp1984 China: Deteriorated tremella poisoning, 1987 P. cocovenenans subsp. farinofermentans1995 Burkholderia cocovenenans (B. gladiali)
Bongkrekic acidFood Poisoning Caused by Various Food in ChinaFood Provinces Outbreaks Patients Fatal Mortality cases (%)_______________________________________________________________Cereal products 12 78 499 238 62.12Deteriorated tremella 5 22 148 54 36.49 Potato product 3 3 20 9 45.00Total 16 103 667 301 45.13_______________________________________________________________(1985-1994)
Molecular formula C28H38O7 LD50 3.16mg/kg Target Organs Liver Brain Kidney Hazard identification:Bongkrekic acid, BA
Studies on the last 15 yearslIdentification and examination of the foodnorne pathogenlIdentification analysis and detoxication of BAlDiagnosis, monitor and prevention offood poisoning
Risk Manegement in ChinaGB/T 4789.29-94Examination of P. cocovenenans subsp. FarinofermentansGB 11675-89Hygienic Standard of Tremella (BA Detection method)GB WT/12-96Diagnostic Criteria and Principle of Management for P. Cocovenenans subsp. farinofermentans Food Poisoning
BA poisoning control Outbreaks of BA reduced about 80% in 1990’s.
Prevalence in fly feces Mean: 11.9% 5th-95th: 10.7%-13.1% Prevalence FigDistribution for E.coli prevalence in fly feces ——Beta(235,1988-235+1)
Number of houseflies Month Average flies density (no. of flies/cage·day) Mar 21 Apr 63 May 125 June 221 July 314 Aug 341 Sep 257
No. of ingested bacteria Mean: 310 cfu/meal 5th-95th: 23~875cfu/meal
Exposure probability Mean: 63.5% 5th-95th: 59.5%~67.4%
Natural toxicants--Actual and potential effects in humans • Acute effects • liver illness, poisoning, death Aflatoxin, DON, 3-NPA, Ergot Microcystin, Saxitoxins, Domoic acid,Solanine • Chronic effects • Carcinogenic, genotoxic & endemic illness Aflatoxins,Fumonisins, Deoxynivalenol, Zearalenone, Ochratoxin A,Patulin, T-2 toxin, Moniliformine, Sterigmatocystin Microcystin, Domoic acid,Cyanogenic glycosides
Example: Aflatoxin B1 • Animal toxicity data showed: it could cause primary liver cancer in most species studied • Epidemiological studies found an association between consumption of food contaminated with aflatoxin B1 and liver cancer • Is a genotoxic carcinogen
Quantitative risk assessment at 49th JECFA Meeting • HBsAg (+) :0.3 liver cancer/year/100,000/ ng AF/ kg bw/day • HBsAg (-) :0.01 liver cancer /year /100,000 / ng AF/kg bw/day
HBsAg(+) 1%; European Cont. level & Dietary Pattern AFB1 intake Risk (ng/day) (Cancer/year/100,000) AFB1 limit 20 µg/kg 19 0.0041 (0.0006-0.01) AFB1 limit 10 µg/kg 18 0.0039 (0.0006-0.01) 2 cancers/year/billion
China cont. level and far east dietary pattern AFB1 intake Risk (ng/day) (Cancer/year/100,000) AF limit 20 µg/kg 125 0.17 (0.03-0.3) AF limit 10 µg/kg 103 0.14 (0.02-0.3) 300 cancers/year/billion *The mortality of liver cancer was 20/100,000 in the period of 1990-1992. (20.03/100,000)
Case 2 The Control of the Deteriorated Sugarcane Food Poisoning in China • Fresh sugarcane grown in southern area of China • Usually shipped to northern parts of China, stored and sold through the winter season • Contaminated sugarcane can cause fatal food poisoning when sold in the next spring
Sugarcane poisoning • The first outbreak of sugarcane poisoning with unknown causes occurred in Henan Province in 1972 • From 1972 to 1989: • No. of outbreak: 217 • No. of cases: 884 • No. of deaths: 88 • Average fatality: 10% • Identified as a priority to assess and control
Characteristics of 34 MSP CasesAge: 3 to 27 years oldIncubation period: 10 minutes to 8 hoursManifestations: VomitingDystoniaStare on one sideConvulsionCarpopedal spasm ComaElectroencephalogram Sequelae
Etiology and risk assessment • Etiology: the Chinese Academy of Preventive Medicine studied on the etiology of this specific food poisoning since 1984 and found: • Arthrinium spp.was the pathogenic fungus; • 3-nitropropionic acid (3-NPA) produced by A. spp. was proved to be the causative compound • Assessment was made according to case-based studies, epidemiological and laboratory studies
Decision making and management activities • Based on discovery and assessment, MOH promulgated: • Diagnostic criteria and principles for the management of deteriorated sugarcane poisoning (WS/T10-1996); • Methods for the isolation and identification of Arthrinium strains and analyzing 3-nitropropionic acid (GB47689.16) • At the same time, MOH issued a notification on the prevention and control of DSP to all provinces of China • A national health campaign for prevention and control of the poisoning was launched
Prevention and control measures • The main measures adopted by local health inspectors: • Fresh sugarcane shipped to northern China should not be stored for more than 3 weeks • The deteriorated sugarcane with unpleasant smell and mold growing should not be sold in market • When poisoning outbreak occurred, the suspected left-over sugarcane should be immediately sealed and destroyed • During the outbreak, food inspectors and clinical doctors should work closely to identify and treat patients
Good results • As a result of these efforts, sugarcane poisoning has been satisfactory controlled • No typical cases were reported in China in the last 10 years!
Challenges: Areas for Strengthening • Knowledge • Team (National level) • Practice (Data, Modeling) • Food consumption / dietary intake • Effects of processing • QMRA (Quantitative method) • Analytical methods • Sampling protocols
FAO/WHO Activates in China • Workshop on Microbiological Risk Assessment • Sponsored by FAO/ ILSI /WHO/ MOH • May 10-11, 2002 Beijing • Quantitative Microbiological Risk Assessment Training Course (David Vose) • Sponsored by WHO/INFS • May 13-24, 2002 Beijing