More people might have contracted Legionnaires' disease than originally thought

Jun 22, 2017

New data suggest people who have tested negative for Legionnaires' disease may actually have been infected and not known it.

That's according to research by University of Michigan professor Michele Swanson.

Swanson's research shows only one type of Legionella, "serotype 1," shows up positive on the traditional Legionnaires' disease diagnostic test. 

Serotype 1 is associated with about 80 percent of Legionnaires' disease cases. Serotype six and all other forms of Legionella will only show positive in a pricey lab test.

Swanson says not many clinics have the resources to administer that test.

"To culture Legionella takes longer. It takes some special media and special training, and that's why our clinical microbiologists just are not investing the time and money to do that," she said.

Twelve Genesee County residents died of Legionnaires' disease during the Flint water crisis. Five current and former state and city officials have been charged with involuntary manslaughter in relation to the outbreak.