Colorado Integrated Food Safety Center of Excellence

Innovations in Routine Investigations and Surveillance

Text Messaging Projects

With the success of the online case investigation projects, the CO Food Safety CoE explored other innovative projects to help with case investigation and piloted several text-based projects.

In 2021, Colorado began sending Campylobacter cases a pre-text message before contacting them for a telephone interview. Cases were randomized to receive a pre-text message or phone call as usual. While the pilot found that pre-texting cases did not increase response rates, it did result in faster interview completion. This pilot was repeated in 2022 with an updated protocol and included both Campylobacter and Salmonella cases. Results from this repeat pilot are pending. The general pre-texting protocol is available below.

In 2022, Colorado began offering pre-text Campylobacter cases the option to opt in to the online survey directly from the pre-text message. To date, approximately 25% of cases have opted in for the online survey, with completion rates over 80%. This has resulted in significant time savings to public health. The combined pre-texting and online case investigation protocol is available below.

When is pre-texting a good tool to supplement telephone interviews?

  • If you have time for an additional pre-texting step
  • If your agency has funds to support text messaging
  • If the case has a cell phone

When should pre-texting NOT be used?

  • If the case has a landline

In 2021, Colorado also piloted a text-only protocol for Giardia where cases were only sent a message asking them to complete an online survey (no telephone contact). While response rates for this pilot have been low (approximately 20%), these are cases that would not have otherwise been interviewed since Giardia is not routinely interviewed in Colorado. The general text-only online case investigation protocol is available below.

When is a text-only online survey a good tool?

  • If you have a high number of cases
  • If you have limited staffing
  • For surge capacity
  • For lower priority pathogens that may not be interviewed otherwise

When should a text-only online survey NOT be used?

  • If your agency has the time or resources to conduct the interview by phone
  • If a case works as a foodhandler or healthcare worker, or if a case is a childcare worker or attendee
  • If a case is suspected to be part of a cluster or outbreak investigation
  • If a case is unwilling to do an interview online, or if they do not have access to internet
  • If a lot of education is necessary
  • For higher priority pathogens that are more likely to be associated with an outbreak

Getting Started


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