1. Background Information for Workshop on Revision of USDA Economic Research Service Cost of Foodborne Illness Estimates Sandra Hoffmann U.S. Dept. of Agriculture, Economic Research Service March 29, 2018 Washington, DC
The views expressed herein are those of the author and do not necessarily reflect the views of the Economic Research Service or U.S. Department of Agriculture.

2. Roadmap for Today Focus on current approach and scope
Brief discussion of vision for disease modeling revision

3. ERS Cost Estimates of Foodborne Illness Data Product
Released late 2014
Update plan for 2019/2020
Update
Disease outcome trees
Economics
Medical treatment costs
Treatment of time
VSLs
Expand
To include all specified and unspecified pathogens in Scallan et al. (20011a, 2011b)
Chronic sequellae considered
Treatment of lost time

4. Builds on a decade plus of research on cost of foodborne illness at ERS
The new data product builds on a decade plus of research on cost of foodborne illness at ERS in a very literal sense. Mike, Glenn and I purposefully designed our research to extend and update the existing ERS estimates for Listeria, Salmonella, Campylobacter and E coli O157.

5. Based on more recent publications by Hoffmann, Batz and Morris
Designed to Extend ERS CoI Calculator
Expanded Scope
4 pathogens  15 pathogens
Updated with New CDC Incidence Estimates
Mead et al  Scallan et al. 2011
Updated for Economic Growth
2009 dollars  2013 dollars
VSL updated for income growth and inflation
We updated the estimates for these 4 pathogens taking new incidence estimates, inflation and economic growth in to account and used the same structure and level of detail in developing new estimates for 11 additional pathogens. These 15 pathogens account for 95% of the cases, hospitalizations and deaths that Elaine Scallan and her collaborators could link to a specific pathogen cause.
Bryan is going to tell you more about the specifics of the new ERS data product.

6. Overview of Content: Disease Modelling
Foundation:
Scallan et al Foodborne illness acquired in the United States--major pathogens
Cases, hospitalizations, deaths, by pathogen
ERS estimates include cost for 15 of 31 major pathogens in Scallan et al. 2011
over 95% of cases and hospitalizations, 98% of deaths
More detailed disease outcome trees than Scallan et al. 2011
Severity of hospitalizations/complications
Duration of non-hospitalized and hospitalized cases
Estimate missing state-transition probabilities and calibrate for consistency with Scallan et al. 2011
Additional consequences:
Major chronic sequelae
Congenital outcomes

7. 2013 Estimates: Designed to Complement, Not Replace Existing ERS Estimates
Used ERS models for Listeria, STEC O157:H7, Campylobacter, and Salmonella
Date from 1996 on
Updated with Scallan et al. hospitalization and fatality rates
For 11 other pathogens develop new models
Uncertainty modeling limited to incidence uncertainty
Goal: consistency in treatment across pathogens

8. Information Sources Scallan et al. 2011. Major pathogens
National Inpatient Sample
FoodNet Population Survey (care seeking)
Peer-reviewed literature
Medical textbooks, reviews of clinical characteristics, and other literature for disease duration and symptoms where not included in NIS data
Analogy to other pathogens
E.g., mild diarrheal illness analogized to mild salmonellosis

9. Evidentiary Criteria Used
Primary data where available and representative
High quality systematic reviews or meta-analysis used where available
Scope did not permit new systematic reviews
Used evidentiary criteria similar to that recommended for systematic reviews
Case control preferred to cohort studies
Nationally representative samples and active surveillance preferred to passive surveillance
Sample size
Representativeness relative to U.S. national population
U.S. studies preferred to non-U.S. studies of equal quality

10. Example: Yersinia enterocolitica
Rate of care seeing from FoodNet Population Survey
NIS Data
-- liklihood
-- severity
-- duration

11. Example: Cryptosporidium spp.
Scientific literature

12. Disease Outcomes Vary in Complexity: Ex. Listeria monocytogenes (adult)

13. Disease Outcomes Vary in Complexity: Ex
Disease Outcomes Vary in Complexity: Ex. Listeria monocytogenes (congenital)

14. Economic Burden Estimation
Non-hospitalized cases
Do or don’t seek care
FoodNet population survey
Pathogen-specific rates of bloody and non-bloody diarrhea from outbreak and clinical data + rate of care seeking for each
Lost wages, but not medications
Cost of outpatient visit
Hospitalized cases
NIS data, primary diagnosis using ICD-9-CM code
Lost wages of those ill (we’ll be expanding this)
Deaths
Scallan et al mortality incidence and VSL

15. Detailed Health State Descriptions
Health State Description: non-typhoidal Salmonella
No doctor visit, full recovery.
Mild gastroenteritis with diarrhea, nausea, vomiting, fever and headache, expected to last 1–3 days, and not requiring a doctor visit.
2. Visit doctor, full recovery.
Moderate gastroenteritis, with diarrhea, vomiting, fever and headache expected to last 2–12 days, requiring a doctor visit but not hospitalization.
3. Hospitalized with severe symptoms.
Severe gastroenteritis, with bloody diarrhea, vomiting, fever and headache expected to last 11– 21 days and requiring hospitalization.
4. Post-hospitalization recovery
Mild symptoms such as weakness and dehydration following hospitalization.
5. Death.

16. Cost of Illness by Analogy
Hospital costs:
Done where NIS data had insufficient coverage
STEC non-O157 = STEC O157
Cyclospora = Cryptosporidium perfringens
Vibrio other = Salmonella
Vibrio vulnificus = Listeria adjusted for ICU use rates
All pathogens: non-inpatient costs of hospitalized cases = those for salmonellosis
Outpatient: mild and moderate cases health care utilization and costs = those for salmonellosis

17. Chronic Sequelae Campylobacter (GBS), STECs (ESRD)
Cryptosporidium (diarrhea relapse)
Listeria (congenital cases  disabilities)
Both disease outcome trees and costs based on prior studies

18. Plan for 2020 Update
Update disease outcome trees and cost estimates for:
Listeria, STEC, Campylobacter, and Salmonella
Revise state transition probabilities, where needed
Update acute complications, where needed
Expand chronic sequellae, where appropriate
Expand pathogens covered
31 pathogens from Scallan et al major pathogens and incidence from Scallan et al unknown pathogens
Other changes in scope?

19. Pathogens Currently Included Plan to Include
> 95% of cases, hospitalizations, deaths
Provides estimate of full economic burden
Currently Included
Plan to Include
15 pathogens
FoodNet pathogens
Campylobacter
Cryptosporidium parvum
Cyclospora cayetanensis
STEC O157
Listeria monocytogenes
Salmonella enterica (non-typhoidal)
Shigella
Vibrio vulnificus
V. parahaemolyticus
V. other non-cholerae
Yersinia enterocolitica
plus
STEC non-O157
Norovirus
Toxoplasma gondii
15 pathogens currently included plus:
Astrovirus
Bacillus cereus
Brucella spp.
Clostridium botulinum
Cryptosporidium spp.
Cryptosporidium cayetanensis
ETEC
E. coli, diarrheagenic other than STEC and ETEC
Giardia intestinalis
Hepatitis A
Mycobacterium bovis
Rotavirus
Salmonella enterica serotype Typhi
Sapovirus
Staphylococcus aureus
Streptococcus spp., Group A
Trichinella spp.
Vibrio cholerae, toxogenic
Unspecified pathogens

20. Acute Complications Currently Included
Pathogen
Acute Complication
Campylobacter
Appendicitis
STEC O157 and non-O157
HUS (kidney failure, seizure, stroke)
Listeria
Placental infection (pregnant women), meningitis (adult or newborn)
Toxoplasma gondii
Adult: encephalitis, pneumonia, myocarditis, hepatitis, blurry vision
Congenital: folded into chronic
Yersinia
Misdiagnosed appendectomy
Listeria (congenital), Vibrios (all), Yersinia
Sepsis
Campylobacter, Clostridium perfringens, STECs, Listeria (congenital), Norovirus, Salmonella enterica (non-typhoidal), Shigella, Vibrio parahaemolyticus
Bloody diarrhea

21. Chronic Sequellae Currently Included
Pathogen
Chronic sequellae
Campylobacter
Guillan Barré
Cryptosporidium parvum
Diarrheal relapse
STEC O157 and non-O157
ESRD
Listeria monocytogenes
Miscarriage, stillbirth, newborn death
Mild: seizure disorder, hearing impairment; moderate to severe disability; total physical or mental impairment
Toxoplasma gondii
Modeled, but not valued
Adult: chronic vision impairment
Congenital: vision impairment, intercranial calcification, hydrocephalus, hemiplegia, mild retardation

22. Issues for Workshop Discussion (1)
Scope
Certainly parallel with CDC incidence
What changes are expected in CDC incidence estimates?
What would be the value of adding other hazards?
Allergens
Food toxins, e.g., seafood toxins
Food intolerances, e.g., lactose, gluten, fructose
Managing increase in scope
Are there pathogens that have analogous health outcomes?
What information sources should be used to support this decision?
What criteria should be used to decide on analogies?
How best to deal with foodborne illness of unidentified etiology
How to model severity and duration

23. Issues for Workshop Discussion (2)
Changes in Acute Disease Outcomes
Where have advances in treatment or diagnostics led to shorter or less severe outcomes?
Have changes in the effectiveness of antibiotics led to longer or more severe outcomes?
Is it time yet to worry about modeling uncertainty about the effectiveness of antibiotic therapy?
Acute Complications
Are we missing any major complications?
Do any of the pathogens we’re adding have significant complications?
Chronic Sequelae (a major focus of the workshop)
What are we missing and how strong is the evidence to support inclusion?
Have treatments or diagnostics of any of the sequelae currently included reduced incidence, severity or duration?

24. Questions? Discussion.

25. Contact Information Sandra Hoffmann USDA Economic Research Service (202)