Twelve people who live or work in Hopkins, Minn., have contracted Legionnaires' disease, and no source has been detected, according to a WCCO report.
The Minnesota Department of Health announced Sept. 9 it was investigating a "cluster" of five confirmed cases of Legionnaires' disease. Since then, the number of confirmed cases has grown.
The 12 people infected range in age from 20s to 80s, according to WCCO.
Minnesota typically sees 50 to 60 cases of Legionnaires' disease each year, and this year the cases total more than 60, "mirroring a national increase in cases in 2016," according to MDH.
Legionnaires' disease is caused by Legionella bacteria, which thrive in some water environments. The pneumonia illness is not spread person to person, and outbreaks in other cities have been linked to cooling towers, cooling misters, decorative fountains or plumbing systems.
More articles on Legionnaires' disease:
4th patient infected in Legionnaires' outbreak at UW Medical Center
McLaren-Flint Hospital alleges state cover up preceding Flint water crisis
How many more have to die before regulators take action on Legionnaires' disease?