SHOPPER HISTORY - AFDO

ideally be consolidated and managed centrally by a federal agency. Centralized shopper history datacollection conducted by a federal agency can be initiated based on requests from state partners,industry partners, or federal agencies. Federal agencies should ensure that shopper history obtainedas part of a centralized effort is shared with applicable state partners in a timely fashion.c. Reviewing/Analyzing the DataThe responsible party varies depending on the agency and the step in the collection process. Theindividual requesting the information from the retailer is often responsible for verifying whichproducts are listed on the shopper history documents through follow up questions with the retailer.The epidemiology staff are often responsible for verifying that a certain ill individual is the consumerof a certain product in question. Compilation and analysis of the data is most often done by state orfederal epidemiology staff, depending on the jurisdictions involved in an outbreak.4. Acquiring Information from Case-Patients during Interviewsa. Identifying potential sources of shopper historyDuring initial and follow-up case-patient interviews, investigators should:Ask prompting questions about grocery stores and other sources of food prepared/served athome (including meal delivery, etc.);Ask specifically about grocery chains in the area where the case-patient resides;Remind case-patients during the first interview to hold onto any records or receipts; andAsk about other records of food purchases such as receipts or credit/debit card statements. b. Obtaining case-patient permission and explaining confidentialityAsking explicitly for permission to obtain shopper history data can be done during: The initial interview – The interview would include the explanation that records will onlybe requested in the event of an outbreak investigation.At a follow-up hypothesis-generating interview – The interview would occur when a casepatient has been included in a cluster (e.g., through molecular lab testing) but a commonexposure has not been identified.During a focused outbreak interview – This interview would take place when the casepatient has been included in a cluster and the exposure has been narrowed to a limitednumber of common exposures.Examples of how shopper history is currently requested in various existing questionnaires are: National Hypothesis Generating Questionnaireo “May we have permission to retrieve purchases based on your member cardinformation? This information will be kept confidential. May we share thisinformation with other public health officials to help with this outbreakinvestigation?”CDC Listeria Initiative Case-Patient Report Formo “Would you be willing to release your shopper card information so we can get anexact list of your foods and when they were purchased?”Oregon Hypothesis Generating (Shotgun) Surveyo “If necessary—say, because of an outbreak investigation—would you be willing tolet us ask the store(s) to provide us with shopping records?”6

During the request, communicate with the case-patient or their household member(s) that shopperhistory will only be shared on a need-to-know basis with local, state, or federal staff during theinvestigation. All personal identifiers will be redacted (e.g. name, shopper card number, credit ordebit card number, phone number, etc.). Communicate with the case-patient that this informationcould help solve the outbreak and prevent additional illnesses. Additionally, the case-patient may beable to access their own shopper history through an online account.The time frame and scope of the shopper history request may vary based on the details of theinvestigation. It is important to discuss this with the case-patient or their household member(s).Examples of ways to ask this include: We are investigating foods you purchased from January 2019 to February 2019. Wouldyou be willing to provide us your shopper card number so we can obtain this informationfor that specific timeframe?Would you allow us to request all shopper card data or just particular types of food?c. Obtaining clarifying details about use of the purchase methodThe following questions can be asked during a case-patient interview to obtain permission torequest shopper history information and to help clarify who may have consumed the food listed onthe shopper history records: Is this shopper card or online account in your name or someone else’s name? Do you havethe authority to give permission to obtain records?Do you share your shopper card with any family members, friends, or other customers onoccasion?Do you always use this card when you shop at this particular store?Can you review your bank records to confirm the purchase date(s)?5. Requesting Information from the RetailerThis section explains the various steps and considerations behind requesting shopper history from afood establishment.a. Considerations Specific to Various Types of Shopper Historyi. Shopper/Loyalty and Warehouse/Club Membership AccountsThese types of shopper history records typically require a membership number and a name torequest information from the retailer.ii. Credit/Debit Card RecordsThere are various options for obtaining detailed food transaction records using credit/debit cardsthat were used for the purchase. These options are detailed in Appendix 1: Obtaining FoodTransaction Records from Credit/Debit Cards. This includes: Asking the case-patient to reprint a receipt by going to the retail storeAsking stores to find itemized transaction information in their digital systems using detailsfrom the case-patient’s bank statements, including location of purchase, time of purchase,or a transaction number.Requesting that the case-patient calls a retailer to obtain their shopper history7

iii. Accounts for Online Ordering or Delivery ServicesFor grocery delivery services, sometimes there is no account number identifying either the casepatient or their account. The name or account username of the individual who owns the accountand their email address may need to be provided to the retailer. Alternately for this type of shopperhistory, the account holder may have the option of checking their purchase history online andproviding it to investigators.b. Gathering Information about the RetailerObtain a corporate point of contact for the retailer you are requesting information from: Consider whether others in your organization may have a history with this retailer and ifthere is already a point of contact established. This may be the case for recall coordinatorsin your state.Consider reaching out to other agencies that have had experience working with aparticular retailer. This may include neighboring states, districts, or federal agencies. TheAssociation of Food and Drug Officials (AFDO) directory of state and local officials is auseful resource to obtain contact information for other public health or regulatoryagencies: http://dslo.afdo.org/.Look on the company website for a phone number and ask to be directed to theappropriate person. Typically, the point of contact is a director/manager of food safety orquality assurance.c. Gathering Information about your Case-PatientBefore requesting purchase data from the retailer, consider the purchaser’s exposure date, illnessonset date, pathogen incubation range, details about suspect product frequency of purchase, datespurchased, and product characteristics, such as product expiration date, shelf life, and likelihoodthat consumers will freeze this product, to make an appropriate timeframe request.d. Sending a Request to the Retaileri.Mode of CommunicationsThe mode of communications with a retailer to request shopper history varies based onpreference, including phone or email, depending on the preference of the requesting agency andretailer. See Appendix 3 for template emails and Appendix 4 for a suggested phone script.ii. Determining Dates of Shopper History Information RequestedThe timeframes requested will vary in each investigation depending on pathogen and the state ofthe suspected food (frozen, canned, fresh, etc.). See the table below for guidance behind selectinga timeframe.Food ItemsTimeframe Details8

Canned, frozen, andshelf-stable foodThe timeframe for the shopper history request can be very broad. For thesetypes of food, it is vital to obtain as much customer information as possibleabout the dates the suspect food was purchased.Fresh food items,like produce and raw(non-frozen) meatsThe timeframe for the shopper history request will be narrow as the productwill have a short shelf life. Particularly, consider the shelf life for that particularitem. For example, items like cilantro, basil, and lettuce will have much shortershelf lives (about one week) compared to apples, grapes, and cherries whichcan last several weeksDeli meats, cheeses,salads, or antipastosThe timeframe of purchase data requests could span several months since it isnot uncommon for individuals to keep some types of deli items, such asunopened chubs of salami, olives, or aged cheeses, in their refrigerators forone or more months. For deli meats, the use by dates, best-by dates, and sellby dates can be considered but should not be a final deciding factor forselecting purchaser data timeframes as businesses and buyers do not alwaysadhere to these recommendations. Different brands of deli meats, cheeses,and salads will have a wide range of date suggestions depending upon how themeat is processed and packaged.iii. Requesting Preferred FormatWhen requesting purchaser data from the retailer, ask them what type of format they are able toprovide the data in. If possible, obtain the customer data in Excel. Data in Excel are easilysearchable, formatted, and are compatible with most analytical software packages like SAS, R, andEpi Info. Receiving data in Excel is ideal, but if it is not an option, accept the available format andrequest the information be legible. PDF formats work well for keyword searches, but if morecomplex analytics are required, the data would need to be converted into another softwarepackage.iv. Communicating ExpectationsThe retailer should send shopper/loyalty card data back to the requester as soon as possible, butwithin 48 hours. Communicate to the retailer that a timelier response can greatly help to identifythe source of illnesses, reduce illness transmission in the community, and significantly reduce theoverall impact of the outbreak. Communicate that you may reach out with questions to clarifyproduct codes and identify products purchased.Explain to the retailer that documentation may be shared, if requested, as part of aninvestigational file. This may vary state-to-state due to confidentiality laws. Request they redactany sensitive business information on the shopper history record, such as. prices for bulkproducts, etc.Let retailers know that non-relevant, non-food purchases may be excluded from the records (e.g.alcohol, prescriptions, etc.).v. Coordinating Requests with Investigation PartnersIf feasible, while ensuring timeliness, batch the shopper/loyalty card data requests (instead ofsending individually) by coordinating requests with investigation partners to lessen the burden onretailers, as well as encouraging continued retailer cooperation (see IV. Responsibilities).9

e. Additional Information that May Be HelpfulIf needed, consider asking the retailer to also provide the following items: The market share for the food item of interest to help assess baseline usage of theproduct (e.g., what percentage of your bagged salad is Brand A or what percentage ofshoppers purchased bagged salad Brand A during the outbreak period?).A redacted random sample of other shopper history records from the same time periodand location as the case-patient records to serve as a control group.f. Overcoming Barriers at the Retaileri. Notary and Other Legal Requirements by RetailersSome retailers require a notarized signature from the cardholder before they are willing to releaseshopper/loyalty card records: Disclosure is required by law per Public Health Service Act Section 301;If a retailer requests notarized signatures, contact CDC at outbreakresponse@cdc.gov orthe assessment epidemiologist for the cluster to request assistance (see example inAppendix 2).Some retailers might prefer a letter on agency letterhead noting permission from the cardholder(see Appendix 3 for letter templates for both verbal and written consent from the consumer).Review existing state laws and determine if retailers are required to share this information withoutadditional consent from the cardholder during an outbreak investigation; consult with your state’slegal counsel if this is unclear. A compilation of state laws can be found online at:www.afdo.org/purchase-history.ii. Credit/Debit Card Data RecordsAlthough there are additional sensitivities with using credit/debit card data during foodborne illnessinvestigations, in many instances, it is possible for the retailer to provide a record of purchases forpurchases made using this method; can be assessed on a case-by-case basis.g. Limits and Caveats of Shopper/Loyalty Card DataThere can be some limitations to shopper/loyalty/credit/debit card data if the cards are not used asintended. Some limits are described in the table below.LimitationOutcomeThe shopper mayhave usedanother person’scard or thecashier’s“courtesy card”behind theregister.This prevents a clear picture of what was purchased and may have beenconsumed due to multiple shoppers’ histories tied to one card.The shopper mayhave multipleThough less common, a shopper may have multiple loyalty cards for anindividual store if they have forgotten or lost a card and elect to open a10

loyalty cards forthe same store.second card. Missing purchases made with the “forgotten” card may alsoprevent a clear record of shopper history.The shopper mayhave forgotten touse the card.If the shopper did not use the card the data needed would not be available.The shopper mayhave paid in cash.Paying in cash eliminates the method of retrieving credit/debit cardpurchase data and may eliminate the ability to track purchases made with ashopper/loyalty card. Purchase with a credit/debit card allow the ability totrack what, where, and when an item was purchased. Note that a shoppermay pay in cash but still use a shopper/loyalty card.The consumermight not havepurchased foodthemselves.There are various reasons why consumers might not purchase foodthemselves which can make traceback difficult. It might not be possible totrack down the shopper or the shopper might not recall needed informationbecause they were not shopping for themselves.Data from theshopper cardcannot be pulleddue toencryption.With the increased use of credit cards with chips, retailers are facingdifficulty retrieving records because all the purchase history information isencrypted.6. Reviewing and Analyzing the DataThis section reviews best practices for verifying and analyzing shopper history records once theyhave been obtained.a. Verifying the ProductsIf the meaning of codes and abbreviations for food items on the receipt are not obvious, confirmthese by asking the retailer or the case-patient for additional detail. Different retailers will usedifferent abbreviations for products on their receipts. For example, both ground beef and greenbeans may be abbreviated with “GB”. If it is not clear exactly what the product is, this will need tobe verified by the retailer and/or case-patient. The retailer will likely be able to provide more detailon the specific product such as lot numbers, weight, and source. Most retailers use a numeric codefor the product. This number may be present on the receipt and providing this information to theretailer can be helpful in obtaining the exact product details for products that come in a variety ofselections from a variety of brands. Pay attention to the quantity purchased as well as specificity ofitem (e.g., whole

c. Appendix 3- Template Letters—Shopper History Request Examples (Tennessee, New York, . store loyalty programs, and records of purchases made with credit or debit cards, can provide a . household’s shopper card number, credit/debit card number (or l