Tickborne Disease Metadata: Near Real-Time Emergency Department Visits for Suspected Tick Exposure


Near real-time emergency department visits for suspected tick exposure are from the Maine CDC Infectious Disease Program’s syndromic surveillance system.

Dates Available:

2023 to date, 2022, 2021, 2020, 2019, 2018; by week.

Geographic Resolution:



The Maine EPHT program receives daily counts of emergency department visits for suspected tick exposure from syndromic surveillance data collected by the Infectious Disease Program at the Maine CDC.

The dataset contains the following measure:

     1. Total suspected tick-related emergency department visits, by week (Statewide)


This data set supports efforts to improve public health in Maine and contributes to the U.S. CDC’s National Environmental Public Health Tracking (EPHT) Network. A key activity of participants in this network is to track and make available environmental health measures on state and national data portals. Measures derived from the data set described here can be used to compare tickborne disease incidence across the state, and over time.

The Maine Tracking Network, a member of the National EPHT Network, connects communities, public health professionals, policy makers, state agencies, and others to the data they need to monitor public health, respond to health concerns, prioritize resources for public health action, and evaluate prevention activities. Maine tracks certain health effects, exposures, and environmental hazards that have known relationships, as well as some health effects and environmental hazards that have suspected relationships. By making health and environmental data available through the Maine Tracking Network, more people have access to data they need to think critically and hypothesize about health outcomes and their relationships to conditions in the environment.

Supplemental Information:

The Maine CDC Infectious Disease Program operates a near real-time “syndromic surveillance” system. Syndromic surveillance is the collection and analysis of medical data in near real time to detect health events such as disease outbreaks, exposures, and bioterrorism. The Maine CDC system receives emergency department visit information directly from all hospitals in Maine, conveyed one or more times per day via secure, electronic messaging. The Maine CDC searches relevant fields in each record, including the chief complaint, reason for visit, and discharge diagnosis, for key words or codes, and categorizes the visit record into defined syndromes or events.

“Tick-related” visits are defined as any visit with a tickborne disease diagnostic code, or where the chief complaint field includes the text string “tic,” “insect bite,” “Lyme,” or related terminology, while excluding non-tick-related strings such as “betic” (as in “diabetic”). 

Maine residents and non-Maine residents seen at Maine hospitals are included in these data.

Entity and Attribute Overview:

The dataset includes the following fields: Week number (starting with January 1 to January 7 as week 1), ending date of week (e.g., January 7), state of residence, and weekly sum of suspected tick-related emergency department visits.

Data Limitations:

  • Automated coding is imperfect and will include some non-tick-related ED visits, while also excluding some true tick-related ED visits. Spelling variations and alternative terminology can result in tick-related visits that are excluded (false negatives), while the broad syndrome definition of “tick-related” includes insect and bug bites, and so will include some non-tick-related visits (false positives).
  • Data are considered preliminary and subject to change.

Access Constraints:


More Information:

Suggested Citation for Data Displays:

Maine Center for Disease Control and Prevention, Maine Tracking Network. Tickborne Disease: Near Real Time Data. Available online: https://data.mainepublichealth.gov/tracking/. Accessed on [date accessed].