Impact of Health Beliefs during an Stec O157 Outbreak Investigation

BACKGROUND:  An estimated 73% of adults in the United States use social networking sites with most visiting a site daily. Public health is only beginning to understand the role these resources play in introducing bias into data collection and targeted health messaging.  The Tennessee Department of Health (TDH) and Knox County Health Department investigated a STEC O157:H7 outbreak among children who consumed unpasteurized milk from a local cow-share dairy, which generated significant media attention.  Concurrently, there was vigorous communication about the outbreak and the health risks on social media.

METHODS: A health directive was issued by the Knox County Courts, ordering the dairy to stop distributing raw milk and to provide a list of cow-share participants to TDH. Cow-share households were interviewed regarding illness, exposures, and beliefs and attitudes about raw and pasteurized milk. Interview data was captured in Research Electronic Data Capture (REDCap) . Coding of open-ended questions was completed. A review of the social media activity was also conducted.

RESULTS:  Of at-risk, cow-share households, 88 (50%) were interviewed and 74 (84%) agreed to respond to a health belief questionnaire. Sixty-seven (91%) households reported knowing that raw milk can make people sick. The most commonly reported advantages of raw milk were that it was a healthy product (28%), an unprocessed food (28%), helped with digestion issues (26%), and had good bacteria (24%). The most commonly reported disadvantage of raw milk was that it may contain harmful bacteria (47%). Over one-third (36%) of households reported that there were no disadvantages. Half (51%) of all households reported that there were no advantages to drinking pasteurized milk. The most commonly reported disadvantages to drinking pasteurized milk were that it had no nutritional value (30%) and it is a processed food (24%).  Review of social media revealed a larger, well-organized community of ‘farm-to-consumer’ individuals who shared their experiences being interviewed by TDH and offered suggestions about how to respond to the investigation questionnaire.  

CONCLUSIONS:  Despite strong evidence linking the outbreak to the dairy, cow-share participants and the dairy were unwilling to accept the association. Given this and strong beliefs regarding the benefits of unpasteurized milk, TDH attempted follow-up interventions:  disseminating information about the risks of unpasteurized milk and collaborating with the University of Tennessee Agricultural Extension to consult with the dairy. Monitoring social media is especially important for outbreaks with a controversial nature and/or in a community with strongly held beliefs that conflict with public health practice.