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

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.