Cluster of Legionellosis Cases Associated with Manufacturing Process, South Carolina, USA, 2022

Emerg Infect Dis. 2025 Jan;31(1):41-49. doi: 10.3201/eid3101.240916.

Abstract

Evolving technology and the development of new devices that can aerosolize water present a risk for new sources of Legionella bacteria growth and spread within industrial settings. We investigated a cluster of legionellosis among employees of a manufacturing facility in South Carolina, USA, and found 2 unique equipment sources of Legionella bacteria. The cluster of cases took place during August-November 2022; a total of 34 cases of legionellosis, including 15 hospitalizations and 2 deaths, were reported. Legionella pneumophila was isolated from 3 devices: 2 water jet cutters and 1 floor scrubber. L. pneumophila sequence type 36 was identified in environmental isolates and 1 patient specimen, indicating that those devices were the likely source of infection. Remediation was ultimately achieved through the development and implementation of a device-specific water management program. Manufacturing facilities that use aerosol-generating devices should consider maintaining updated Legionella water management programs to prevent Legionella bacterial infections.

Keywords: Legionella pneumophila; Legionnaires’ disease; South Carolina; United States; bacteria; legionellosis; manufacturing facilities; occupational health; respiratory infections; water.

MeSH terms

  • Disease Outbreaks
  • Humans
  • Legionella pneumophila* / isolation & purification
  • Legionnaires' Disease* / epidemiology
  • Legionnaires' Disease* / microbiology
  • South Carolina / epidemiology
  • Water Microbiology*