microbiology risk assessment in china: current situation & challenges
DESCRIPTION
Microbiology Risk Assessment in China: Current Situation & Challenges. Xiumei Liu Institute of Nutrition and Food Safety China CDC. Risk Analysis. RAA scientifically based process RMThe process of weighing policy alternatives, distinct from risk assessment. MRA in the Word. - PowerPoint PPT PresentationTRANSCRIPT
July 25,2002 1
Microbiology Risk Assessment in Microbiology Risk Assessment in China:China:
Current Situation & ChallengesCurrent Situation & Challenges
Xiumei Liu
Institute of Nutrition and Food Safety
China CDC
July 25,2002 2
Risk AnalysisRisk Analysis
Risk assessment Risk management
Risk communication
July 25,2002 3
RA A scientifically based process
RM The process of weighing policy alternatives,
distinct from risk assessment
July 25,2002 4
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 )
July 25,2002 5
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)
July 25,2002 6
Why MRA is needed in China ?
WTO CODEX / GB FOOD INDUSTRY
FOOD SAFETY CONTROL Government Consumers
HEALTH PROTECTION Life quality knowledge
July 25,2002 7
Risk AssessmentRisk Assessment
Hazard Identification
Hazard Characterization
Exposure Assessment
Risk Characterization
July 25,2002 8
Hazards in FoodHazards in Food
Foodborne bacteria
Fungi and mycotoxins
Viruses and parasites
Toxic plants and animals
Potential environmental toxicants
July 25,2002 9
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)
July 25,2002 10
Case 1Case 1 BA Food Poisoning Control
1933 Indonesia: Fermented coconut food poisoning1960 Pseudomonas cocovenenans Bongkrekic acid
1950’s China: Unknown causes fermented corn flour poisoning
1979 Flavobacterium farinofermentans nov. sp
1984 China: Deteriorated tremella poisoning,
1987 P. cocovenenans subsp. farinofermentans1995 Burkholderia cocovenenans (B. gladiali)
July 25,2002 11
Bongkrekic acid Food Poisoning Caused by Various Food in China
Food Provinces Outbreaks Patients Fatal Mortality cases (%)_______________________________________________________________Cereal products 12 78 499 238 62.12
Deteriorated tremella 5 22 148 54 36.49
Potato product 3 3 20 9 45.00 Total 16 103 667 301 45.13_______________________________________________________________
(1985-1994)
July 25,2002 12
Hazard identification:Bongkrekic acid, BA
Molecular formula C28H38O7
LD50
3.16mg/kg
Target Organs
LiverBrainKidney
July 25,2002 13
Studies on the last 15 years Identification and examination of the foodnorne pathogen
Identification analysis and detoxication of BA Diagnosis, monitor and prevention of food poisoning
July 25,2002 14
Risk Manegement in China
GB/T 4789.29-94 Examination of P. cocovenenans subsp. Farinofermentans
GB 11675-89 Hygienic Standard of Tremella (BA Detection method)
GB WT/12-96 Diagnostic Criteria and Principle of Management for P.
Cocovenenans subsp. farinofermentans Food Poisoning
July 25,2002 15
BA poisoning control
Outbreaks of BA reduced about 80%
in 1990’s.
July 25,2002 16
Prevalence in fly feces
Prevalence
Fig Distribution for E.coli prevalence in fly feces
——Beta(235,1988-235+1)
Mean: 11.9%
5th-95th: 10.7%-13.1%
July 25,2002 17
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
July 25,2002 18
No. of ingested bacteria
0
0. 05
0. 1
0. 15
0. 2
0. 25
0. 3
0. 35
0 1000 2000 3000Number of i ngested bacteri a
Frequency
Mean: 310 cfu/meal
5th-95th:
23 ~ 875cfu/meal
July 25,2002 19
Exposure probability
0
0. 02
0. 04
0. 06
0. 08
0. 1
0. 12
0. 14
0. 16
0. 54 0. 59 0. 64 0. 69 0. 74Exposure probabi l i ty
Frequency
Mean: 63.5%
5th-95th: 59.5% ~ 67.4%
July 25,2002 20
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
July 25,2002 21
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
July 25,2002 22
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
July 25,2002 23
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
July 25,2002 24
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)
July 25,2002 25
Case 2 Case 2 The Control of the Deteriorated The Control of the Deteriorated Sugarcane Food Poisoning in ChinaSugarcane 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
July 25,2002 26
Sugarcane poisoningSugarcane 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
July 25,2002 27
Characteristics of 34 MSP Cases
Age: 3 to 27 years old
Incubation period: 10 minutes to 8 hoursManifestations: Vomiting
DystoniaStare on one sideConvulsionCarpopedal spasm ComaElectroencephalogram
Sequelae
July 25,2002 28
Etiology and risk assessmentEtiology 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
July 25,2002 29
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
July 25,2002 30
Prevention and control measuresPrevention 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
July 25,2002 31
Good resultsGood 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!
July 25,2002 32
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
July 25,2002 33
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