Microbiology Risk Assessment in China: Current Situation

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Microbiology Risk Assessment in China Current
Situation Challenges

• Xiumei Liu
• Institute of Nutrition and Food Safety
• China CDC

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Risk Analysis
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• RA A scientifically based process
• RM The process of weighing policy
  alternatives, distinct from risk assessment

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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)

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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)

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Why MRA is needed in China?

• WTO
• CODEX / GB
• FOOD INDUSTRY
• FOOD SAFETY CONTROL
• Government
• Consumers
• HEALTH PROTECTION
• Life quality
• knowledge

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Risk Assessment
Hazard Identification
Hazard Characterization
Exposure Assessment
Risk Characterization
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Hazards in Food

• Foodborne bacteria
• Fungi and mycotoxins
• Viruses and parasites
• Toxic plants and animals
• Potential environmental toxicants

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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)

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Case 1 BA Food Poisoning Control1933 Indones
ia Fermented coconut food poisoning1960 Pseudom
onas cocovenenans Bongkrekic
acid1950s China Unknown causes fermented
corn flour poisoning 1979 Flavobacterium
farinofermentans nov. sp1984 China
Deteriorated tremella poisoning, 1987 P.
cocovenenans subsp. farinofermentans1995 Burkhol
deria cocovenenans (B. gladiali)
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Bongkrekic acid Food Poisoning Caused by
Various Food in China Food 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 45.00
Total 16 103 667 301 45.13__________________
_____________________________________________
(1985-1994)
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Hazard identificationBongkrekic acid, BA

• Target Organs Liver Brain Kidney

• Molecular formula
• C28H38O7
• LD50
• 3.16mg/kg

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Studies on the last 15 years l       
Identification and examination of the foodnorne
pathogen  l        Identification analysis and
detoxication of BA l        Diagnosis, monitor
and prevention of food poisoning
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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
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• BA poisoning control
• Outbreaks of BA reduced about 80
• in 1990s.

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Prevalence in fly feces
Mean 11.9 5th-95th 10.7-13.1
Prevalence
Fig Distribution for E.coli prevalence in fly
feces Beta(235,1988-2351)
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Number of houseflies

• Month Average flies density
• (no. of flies/cageday)
• Mar 21
• Apr 63
• May 125
• June 221
• July 314
• Aug 341
• Sep 257

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No. of ingested bacteria
Mean 310 cfu/meal 5th-95th 23875cfu/meal
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Exposure probability
Mean 63.5 5th-95th 59.567.4
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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

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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

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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

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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

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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)

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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

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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

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Characteristics of 34 MSP Cases Age 3 to
27 years oldIncubation period 10 minutes to 8
hoursManifestations Vomiting Dystonia S
tare on one side Convulsion Carpopedal
spasm Coma Electroencephalogram Sequ
elae
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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

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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

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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

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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!

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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

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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