SI's Role in Stopping Legionnaires' Disease

For Everyone

At a glance

By eliminating weeks of manual effort, TowerScout gives investigators the data they need in minutes — allowing for faster source identification, fewer infections, and saved lives.

Scientists

The Challenge

Legionnaires' disease, a severe pneumonia caused by Legionella bacteria, can spread through devices such as improperly maintained cooling towers.

  • Legionnaires' disease is deadly — about 1 in 10 people who get sick will die from complicationsA.
  • Traditional investigations, especially for outbreaks not associated with a hotel or hospital, can be complex, labor-intensive, and possess unique challenges related to identification of potential sources of exposure.
  • $835 million lifetime economic burden, including $412 million in productivity losses caused by premature deaths and $21 million in productivity losses caused by absenteeismB.

The Solution

Finding the source of a Legionnaires' disease outbreak can take days or weeks — time that public health agencies can't afford to lose, especially in peak summer months when multiple outbreaks occur. TowerScout uses computer vision, a subfield of SI, to analyze satellite imagery, automatically detecting cooling towers that may harbor Legionella bacteria.

  • Reduces cooling tower identification time by 98% (from 4 hours to 5 minutes).
  • Saved over 280 hours in investigative time annually.

Public Health Impact

  • Enhances outbreak response by precisely identifying cooling tower locations.
  • Helps jurisdictions build cooling tower registries to prevent future outbreaks.
  • Supports near-real-time decision making for public health agencies.
  • Allows public health investigators to focus their time and effort on preventing Legionnaires' disease infections.

Scalable and Ready for the Future

  • Enterprise-ready solution with automated model retraining.
  • Adaptable for new challenges – TowerScout is adaptable to solve different public health problems; the system can be retrained to find any object visible from satellite imagery.
  • Free to use and improve – TowerScout code is expected to be open sourced to the extent possible, so public health partners can use it locally.
  • Locally implemented versions are already in use in Los Angeles County and other jurisdictions.
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Content Source
Office of Public Health Data, Surveillance, and Technology
About This Page
Published: March 12, 2026
Updated: October 20, 2026

This page was last updated on this date. Updates may include minor edits, image changes, or other modifications to page content.

Reviewed: March 13, 2026

The information on this page was last reviewed by subject matter experts to ensure accuracy.

  1. Centers for Disease Control and Prevention. (n.d.). Legionella (Legionnaires' disease and Pontiac fever). https://www.cdc.gov/legionella/about/index.html
  2. Baker-Goering, M., Roy, K., Edens, C., & Collier, S. (2021). Economic Burden of Legionnaires' Disease, United States, 2014. Emerging Infectious Diseases, 27(1), 255-257. https://wwwnc.cdc.gov/eid/article/27/1/19-1198_article#;