2026-02-17 ミネソタ大学
A water sample collected from Grand Rapids’ water system in 2024 tests positive for Legionella pneumophila, the bacterium that causes Legionnaires’ Disease. Photo provided by Tim LaPara, University of Minnesota
＜関連情報＞
- https://cse.umn.edu/college/news/strategic-changes-water-treatment-could-prevent-disease-outbreaks
- https://wwwnc.cdc.gov/eid/article/32/1/25-1232_article#;
ミネソタ州における地域水道システムのクロラミン消毒がレジオネラ症の流行に及ぼす影響（2024年） Effect of Chloramine Disinfection of Community Water System on Legionnaires’ Disease Outbreak, Minnesota, USA, 2024
Molly E. Bledsoe, Apoorva Goel, Maya Adelgren, Timothy M. LaPara, and Raymond M. Hozalski
Emerging Infectious Diseases
Original Publication Date: January 15, 2026
DOI: 10.3201/eid3201.251232
Abstract
The Minnesota Department of Health identified an outbreak of Legionnaires’ disease in a city in northern Minnesota, USA, in April 2023 that continued until chloramine disinfection of the community water system was implemented. Before chloramine disinfection was implemented, Legionella pneumophila was detected in 1 of 16 samples from the drinking water distribution system and in 5 of 10 premise plumbing samples using both cultivation-dependent (Legiolert) and cultivation-independent (digital PCR) assays in this independent investigation. Approximately 11 weeks after disinfection was implemented, all distribution system samples tested negative; however, 1 of 6 Legiolert-tested and 3 of 6 digital PCR–tested premise plumbing samples were positive. After 24 weeks of disinfection, all samples collected from the distribution system and premise plumbing tested negative. Our results show that a community water system supplied by groundwater supported substantial growth of L. pneumophila in premise plumbing and that chloramine disinfection halted the outbreak.
