Online foodborne illness surveillance and visitor data entry patterns:

Building and strengthening public health infrastructure

Holly Wethington, MSPhD Candidate, Sociology

National Food Safety & Toxicology CenterMichigan State University

American Public Health Association Annual Meeting Washington DCNovember 2004

Foodborne Disease Epidemiology

Changes in demographics, food preferences, food distribution systems, microbial adaptationNewly identified pathogens have emerged in the USImmunosuppressed population increasing$23 billion dollar annual cost (Hedberg, MacDonald, and Shapiro, 1994)

76 million illnesses, 320,000 hospitalizations, and 5,000 deaths annually (Mead et al., 1999)

© Nature publishing group 2003

Current Foodborne Disease Surveillance

3 main purposes of surveillance (Olsen et al., 2000):

– disease prevention and control, – knowledge of disease causation, – administrative guidance

Limitations (Olsen et al. 2000):

1. not all outbreaks are included (e.g. cruise, water)

2. outbreaks not included if indirect route of transmission

3. determining a causal food vehicle is problematic

4. deficiency in standard criteria for classifying a death as foodborne disease related

© Dennis Kunkel Microscopy, Inc.

Burden of Illness Pyramid. (CDC, FoodNet Data Sources)

Burden of Illness

The current system requires laboratory confirmation

Underreporting remains a problem:– Estimated 1-2% incident

report rate (CD Summary, 1998)

One MI survey found a mean 35 day interval between onset date and report completion: – no opportunity for

preventive efforts

No surge capacity

Culture-confirmed case

Reported to Health Department/CDC

Lab tests for organism

Exposure in the general population

Person becomes ill

Person seeks care

Specimen obtained

RUsick2 Foodborne Disease ForumWe designed a syndromic surveillance system to augment existing laboratory-based surveillanceOvercomes several limitations:– Can increase rate of reporting so that small and

medium sized outbreaks no longer escape detection– Can hasten investigation so preventive measures can

occur– Capacity in event of large outbreak

Original RUsick2 operated from November 2002 - October 2004Enabled people who suspected food poisoning to come to our website, report their illness, and see if others became sick from the same food from the same place around the same time.

Several pages of data inputOutput reports towards the end:– displayed percentages of other RUsick2 visitors that

entered the same symptom or food item or food source

– kept personal information confidential from other RUsick2 visitors

– kept full names of food establishments confidential from other RUsick2 visitors

– output intended to motivate people coming to the web site

Password given so visitors could return and modify their report or view reports at a later date

RUsick2 Foodborne Disease Forum

Methods

Pilot counties; nationwide

Data input section (follows CDC’s Standard Foodborne Illness Questionnaire)

The individual goes through several entry levels as shown on the right

DATA COLLECTED1: Case ID assigned2: Personal Characteristics (age, gender)3: County, city4: Symptoms 5: Identifiers (name, email, phone)6: Suspected Foods and Food Sources 7: Suspected Food(s) 8: Suspected Food Source(s)9: Non-food Exposures 10: Four Day Food History11: Food Sources12: Contact Information (last name, address)13: First Summary Report (tallies on other

visitors who reported eating the same foods)14: Source Matching (asked to match up which

foods came from which food sources)15: Match foods to food sources16: Second Summary Report (can view reports)17: Comparison Report (compare target period to

comparison period)

Designed so people could leave at any point, different “options” for period of time spent on the websiteNov. 1, 2002 - Dec. 1, 2003Entry Level 4 (Symptoms & Onset date entered)3,693 visitors total; 2,044 reached at least level 4

RUsick2 Visitors by Entry Level

564

10411171143915241604

204421482261

2711

3693

1113903

589729 714

0

500

1000

1500

2000

2500

3000

3500

4000

Entry Level

No.

RU

sick

2 Vi

sito

rs

Key Entry Levels: 4 = Symptoms5 = Personal Identifiers7 = Suspected Foods10 = Food History13 = 1st Summary Report14 = Food Sources Matching

Results (restricted to Entry Level 4 and beyond; n=2,044)

18.3% from pilot counties

11.7% from MI, not pilot counties

70% outside MI

60% female

Mean age = 36 years (SD=14.24y)

Median age = 34 years

17% >50 years

6% >60 years

Results (restricted to Entry Level 4 and beyond; n=2,044)

13.5% sought medical attentionMean no. food items = 9.97 (SD=7.81)– Greater number than telephone reports

(mean = 4.4; n=87)Mean no. food sources = 1.81 (SD=1.24)– Slightly greater number than telephone

reports (mean = 1.65; n=87)59%: email address54%: at least one phone number61%: willing to leave some sort of contact information

Discussion

Gender breakdown consistent with literatureMedian age not surprisingThe percentage that sought healthcare was smallGeographic location: mostly outside of MINearly 2/3 were willing to leave contact infoOnline food history reports were more complete than telephone reports

Limitations of RUsick2

Web-based – Excluded those

without web accessDifficult to convince individuals to report foodborne illness.Difficult to identify clusters because low rate of participation due to minimal national advertising

Online food histories more complete than telephone food historiesCan save LHD timeThe pilot test found that it can increase the rate of reporting 4 fold in a geographic location if well advertised

Strengths of RUsick2

The “new and improved” RUsick2 …

a conduit to the health dept. reporting system

a website for people to create their own report to be given to LHD

gives instructions and links for visitors to contact their local health department

does not offer any output reports

helps people remember their food histories without any time pressure– Visitors still given a password to

modify their report

Online reporting to health departments has potential

Electronic reporting lessens the amount of time LHD employees need to stay on the phone with individuals trying to remember what they ate

Electronic reporting has better capacity in the event of a large outbreak

Conclusions

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