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Probabilistic Supply Chain Risk Model for Food Safety


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  • 1.   Food  Safety?  A  of  the  Supply  Chain:  Probabilis;c   Risk  Model  based  on  the  Agro-­‐Food  Trade  Network                 Ma.eo  Conver;no,  PhD,  PEng  
  • 2. Issues  (WHY?)   1)  Food  Safety  is  steadily  decreasing  à  life  and  economic  losses       2)  Emerging  New  Foodborne  Pathogens  (those  causing  illnesses  that  have  only  recently   appeared  or  been  recognised  in  a  popula;on  or  that  are  well  recognised  but  are  rapidly   increasing  in  incidence  or  geographic  range;  ``secret  bioterrorism  agents’’  included)       3)  Increasing  Human  Mobility,  Social  Contacts,  and  Agri-­‐Food  Trade  (Game  is  considered  in   the  trade  -­‐>  e.g.  avian  infleunza  is  a  poten;al  foodborne  commodity  disease)       4)  Increase  in  An;bio;c  Resistance.  A  poteriori  treatment  is  not  enough.  Desire  to  have  a   whole  control  in  the  food  system’s  state-­‐space     Ins;tute  of  Medicine,  (2012)     Conver(no  et  al.  (2013),  submi9ed   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 3. Issues  (WHY?)   5)  High  uncertainty  (e.g.  unreported  cases),  lack  of  informa;on  (e.g.  trade),  un-­‐op;mized   and  unregulated  dynamics  (trade  and  interna;onal  public  health),  and  lack  of  strategies  for   public  health  controls  based  on  the  sytemic  network.  Surveillance  everywhere  is  not   efficient.     6)  Increased  Complexity  of  the  Food  that  brings  to  mul;ple  Risks  (at  least  4  countries   represented  in  a  food  that  have  2-­‐6  degrees  of  separa;ons  from  the  USA)     7)  Increase  concerns  about  Counterfei;ng  and  Bioterrorism.  A  global  real-­‐;me  inspec;on  is   not  possible     8)  Lack  of  a  Quan;ta;ve  based  and  Integrated  System  Design  (and  Technology  for  such   design)  of  the  Complex  Food  System.  Connec;on  with  Food  Safety,  Water,  Biodiversity,   Economy,  etc.   Conver(no  et  al.  (2013),  submi9ed   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 4. The  case  of  Salmonella  in  Eggs   from  Vietnam   Salmonella  is  the  most  common     Norovirus  is  a  growing  concern   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 5. Normalized  Outbreaksfood   CDC  data  &   Painter  et  al.  2013   Food  Safety  Supply  Chain   Evidence  from  Data   Increase  of  foodborne  outbreaks  in   ;me  (on  average  this  increase   corresponds  to  an  increase  in  the   food  supply  chain  length  and   complexity)     Dependency  of  the  foodborne   incidence  on  the  food  supply  chain         Incidence  Foodborne  Outbreaks   Ma.eo  Conver;no,  PhD  
  • 6. Objec;ves   1)  Iden;fica;on  of  a  Global  Safety  Index  that  consider  both  local  country  proper;es     and  supply  chain  proper;es  (related  to  the  country)     2)  Development  of  a  Food  Supply  Chain  Network  (FSC)  model  for  tracking  exis(ng  risk   sources  (paths,  sources,  food-­‐pathogen-­‐country  triples,  and  their  combina;ons),   predic(ng  poten(al  foodborne  outbreaks,  and  minimizing  the  total  public  health  risk     3)  Create  a  model  for  establishing  the  FS  backbone  network  and  for  making  predic;ons     3)  Global  sensi;vity  and  uncertainty  analyses  of  the  FSC  model  for  a  quan;ta;ve  based   iden;fica;on  of  the  most  important  drivers  of  pubic  health  risk,  and  uncertainty  of  risk   calcula;ons     4)  Quan;fica;on  of  the  what  the  Food  Moderniza;on  Act  states  as  Objec;ves  (we   agree  on  those!)       ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 7. Ercsey-­‐Ravasz  et  al.,  (2012),  PLoS  ONE   FSC  is  a  sub-­‐graph  of  the  IAFTN.  It  is  a  tree  for  a   country  and  food  selected.  Rt  as  a  func;on  of  life-­‐ cycle  risks  of  food  and  FSC  controls     kin     L   Dynamic  Bipar;te  Network   ! Food  Safety  Supply  Chain   Food  Supply  Chain  available  from  data  of  GATS  and  US  Food  Market  Es;mator   (USDA  ERS  and  US  census  for  USA),  FAO  (FAOSTAT),  UN  (ComTrade)   Ma.eo  Conver;no,  PhD  
  • 8. Example  of  Cereals  Trade   ! The  size  of  circles  is  related  to  the  trade  from  the  expor;ng  countries  to  the  USA  and  the  blue   links  are  the  backbone  of  the  Interna;onal  Agro-­‐Food  Trade  network   Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 9. Path  Length:  L    the  length  traveled  by  a  selected  food  commodity  on  average   Network     Variables   Connec;vity  (In-­‐degree):  kin  is  defined  as  the  number  of  incoming  links  to  a  node   Edge  weight:  importance  of  an  edge  related  to  the  total  transport   (Betweenness)  Centrality:  is  a  measure  that  rates  the  importance  of  the  posi(on  of  a  node   or  an  edge  in  the  network  with  respect  to  transport  through  the  whole  network.  αmn(i)   denotes  the  number  of  highest  total  weighted  paths  from  node  m  to  n  that  are  passing   through  i,  and  αmn  denotes  the  total  number  of  highest  total  weighted  paths  running  from   node  m  to  n   Node  Relevance  (Salience):  the  sum  of  all  L  divided  by  the  number  of  connec;ons   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 10. Topological  Proper;es  of   the  Food  Supply  Chain   for  the  USA   Log-­‐normal  epdf   ! Food  Safety  Supply  Chain   Exponen;al  epdf   Ma.eo  Conver;no,  PhD  
  • 11. Topological  Proper;es  of   the  Food  Supply  Chain   for  the  USA   A  sta;c  assessment  is   not  enough;  a   dynamical  system   model  that  considers   both  SC  and  risk   factors  is  needed  for:   (1)  understanding   system  drivers;  (2)   surveillance  (of  system   drivers);  and  (3)   op;mal  management   considering  driver   interac;on  and   importance   Ercsey-­‐Ravasz  M  et  al.,  2012,  PLoS  ONE   Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 12. Data   QALY  =  Quality  Adjusted  life-­‐year   Just  a  sta;s;cal  characteriza;on  is  not   enough  but  it  is  necessary  for  informing  the   model!       Need  of  a  complex  systems  transdisciplinary   approach  that     assesses  the  causa8ve  factors,  their  importance   and  interac8on  for  food  safety   to  prevent  foodborne  illnesses.  SC  factors!     Batz  et  al.,  2011  (UF  and  CDC),  2012,  EID;  Morris  et  al.,  2011   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 13. ! Data,  and  Input  Variables     12  food  categories  (complex  food,  poultry,  eggs,  fruits  and  vegetables,  dairy,  seafood,   beef,  pork,  other  meats,  bakery/cereals,  game,  and  beverages),  77  food  commodi;es,   and  187  expor;ng  countries  to  the  USA.  We  considering  six  degrees  of  separa;on    from   source  countries  to  USA  and  connec;vity  from  IAFTN  (this  is  a  safe  assump;on)     We  consider  8  types  of  complex  foods  (bread/pasta,  cookies,  cereals,  canned  soups,   typical  first  coarse  and  second  coarse  meals,  ice  cream,  fast  food  meals)  that  are  the  best   selling  and  riskiest  in  the  USA  according  to  popular  rankings     UNcom  Trade,  USDA  Global  Agricultural  Trade  System  (GATS),  and  Food-­‐Pathogen  Risk   from  Batz  et  al.  (2012).  Other  various  data  complement  the  characteriza;on  of  IF.   Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 14. Topological  Proper;es  &  Safety  Indices   ! from  Rapid  Alert  System  For  Food  and  Feed   Nepusz  et  al.  (2009,2012),  PLoS  ONE     Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 15. Model  Keywords:  Food  Life  Cycle,  Supply  Chain  Network,  Risks   Source  (Adjacency)  Matrix   Composi;onal  Food  Matrix   Food  Matrix   Food     Life  Cycle   Port  of  Entry   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 16. Total  Health  Risk  for  the  USA   Ranking  of  the  riskiest  food-­‐pathogen-­‐country  triples.  Monte  Carlo  filtering  allows  to  assess   the  combina;on  of  food-­‐pathogen-­‐country  that  contribute  the  most  to  selected  total  risk   value  ranges   Conver(no  et  al.  (2013),  submi9ed   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 17. Total  Health  Risk   for  each  food     commodity   Disentangling  the  total  health   risk  for  each  food  commodity   by  selec;ng  only  the   respec;ve  food  commodi;es   paths  along  the  FSC     Our  ranking  is  similar  (but  not   the  same)  of  the  one  of  Batz   and  Morris  (2012)   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 18. Model  Valida;on   Slope=0.76   R2=0.72   NSC=0.79   We  believe  that  the  model  underes;mates  the  risks  due  to  the   large  ignorance/variability  of  FSC  and  risk  factors;  however,  the   model  certainly  gives  a  good  assessment  of  the  total  health  risk   for  a  country  considering  small  scale  risks  and  FSC  controls.   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 19. Total  Health  Risk  versus  FSC  and  safety  variables     A  mul;factor  characteriza;on  of  the  total  health  risk  is  necessary.  GSI  is  a  good   index  to  characterize  countries  based  on  their  safety  level  and  on  their  features   along  the  FSC.  The  risk  is  related  to  some  risk  factors  and  FSC  variables.   Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 20. Driving  Factors  of  the  Total  Health  Risk   Global  Sensi;vity  and  Uncertainty  Analyses  –  Morris  Test,  Monte  Carlo  Simula;ons  &  Filtering   Saltelli  (2004)   N = 10 (k + 1) Supply  Food  Chain   Network  Variables   Food  Pathogen  Risks   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 21. Management  Strategies  of  the  Total  Health  Risk   44%  decrease   of  Rt  (by  keeping  countries   with  GSI  higher  than  0.25  or   higher  than  0.50  the  risk   reduces  from  0.43  to  0.24)   53%  decrease   of  Rt  (from  six     to  2-­‐4  degrees  of     separa;on)   ! Food  Safety  Supply  Chain   46  %  increase   of  Rt  (with  removal  of   countries  has  been   performed  randomly  by   excluding  from  the   importa;on  25%-­‐50%   of  the  connected   countries  without  any   risk  considera;on   Ma.eo  Conver;no,  PhD  
  • 22. Management  Strategies  of  the  Total  Health  Risk   GSI-­‐  and  L-­‐based  management  change  the  FSC  in  a   small  world  network  that  minimizes  the  risk  and  likely   maximizes  the  trade       ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 23. Rank  based  on  the  GSI   The  hubs  in  term  of  trade  are  not  always  the  Achille’s  hell  because  they  have  very  high  SI     Countries  with  high  SI  but  very  high  L  ,  b,  and  k  are  unsafe  (e.g.  Singapore)     Countries  with  very  low  SI  are  unsafe     Ma.eo  Conver;no,  PhD  
  • 24. Global  Management  on  the  FSC  Network   Because  of  the  strong  dependence     of  the  Health  Risk  on  the  FSC   network  we  explore  the     Health  Risk  as  a   func;on  of  the  network     topology  considering  all     possible  topologies     The  current  FSC  for  the  USA   does  not  minimize  the  risk     The  small  world  FSC     network  minimizes  the     Total  Health  Risk     This  analysis  does  not   consider  Economical   and  Poli;cal  Constraints   among  countries,  thus  some   networks  may  be  unfeasible     Conver(no  et  al.  (2013),  submi9ed   ! Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 25. Number  of  Observers  for   Different  Knowledge  Level   of  the  Supply  Chain   ! Ma.eo  Conver;no,  PhD  
  • 26. Needs  and  What  can  be  done  with  the  FSC  model   Despite  the  Need  of:   -­‐  assessment  of  the  factors  à  Needs  of  Transdisciplinary  Connected  Research   (Engaging  Stakeholders);   -­‐      Track  of  the  informa;on  about  the  intermediate  countries  along  the  Agri-­‐Food  trade   and  within  the  USA  (within  countries);  and,   -­‐  Verifica;on  of  the  predictability  of  the  model  for  real  foodborne  disease  outbreaks   We  have  a  model  for:   (i)  Poten;al  early  iden;fica;on  of  emerging  incidents  (real  ;me  traceability)       (ii)  Informa;on  about  surveillance  of  cri;cal  countries,  trades,  and  supply  chain  paths       (iii)  Food  policy  evalua;on  at  any  scale,  from  the  interna;onal  to  the  town  scale       (iv)  FSC  for  the  design  of  a  resilient  (random  or  targeted  a.ack  that  affect  food  safety)   and  sustainable  FSC  (Environmetally  (Water,Biodiversity)  –  Economically  –  Socially   (Food  Security  &  Quality)).  Op;miza;on  constrained  to  economical  &  poli;cal   constraints  can  be  performed     (v)  GSI  is  a  great  metric  to  assess  country  safety  for  food   Conver(no  et  al.  (2013),  submi9ed     Food  Safety  Supply  Chain   Ma.eo  Conver;no,  PhD  
  • 27.   Thanks!                 Ma.eo  Conver;no,  PhD,  PEng     (