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.

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

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

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.

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. 1999  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.

Overview of Content: Disease Modelling Foundation: Scallan et al. 2011. 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

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

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

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

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

Example: Cryptosporidium spp. Scientific literature

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

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

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. 2011 mortality incidence and VSL

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.

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

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

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. 2011 major pathogens and incidence from Scallan et al. 2011 unknown pathogens Other changes in scope?

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

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

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

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

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?

Questions? Discussion.

Contact Information Sandra Hoffmann USDA Economic Research Service shoffmann@ers.usda.gov (202) 694-5354