Blastomycosis, a fungus found in soil and decaying wood, is believed to have infected more than 90 employees at a paper mill in Escanaba, Mich., according to an April 8 report from the Detroit Free Press.
Officials from the CDC, the state health department and local health department are investigating the fungal outbreak at the Billerud paper mill, in the state's Upper Peninsula. Nineteen cases of blastomycosis were confirmed among employees at the plant, while 74 are thought to have probable cases based on symptoms.
Approximately a dozen of those affected have required hospitalization, Gerald Kell, president of the United Steel Workers Local 21 Union, which represents about 670 of the mill's 900 employees, told the news outlet. Some employees began experiencing symptoms in early March, according to Mr. Kell. Those who were hospitalized early were first treated for bacterial pneumonia and when symptoms did not improve, they underwent additional testing.
"It's not something they would typically test for," Mr. Kell said. "Now, people are getting identified quickly and are getting more effective treatment."
Treatment involves antifungal medications and can take between six months to a year. Blastomyces lives in moist soil and decomposing matter and is found in areas surrounding the Great Lakes. People can become infected from breathing in spores, usually after activities that disturb the soil. While most people who breathe in the spores do not become sick, some develop flu-like symptoms and those with weakened immune systems are at risk of the fungus spreading from their lungs to other parts of the body.
Because it is highly unusual for the fungal disease to affect large numbers of people, employees at the Billerud mill were likely infected from working with the materials containing the spores, though the source of infection has not been established, according to the report.
"The health and safety of our Escanaba employees is our first priority," Brian Peterson, operations vice president at the Billerud Escanaba Mill, said in a statement. "Although the source of the infection has not been established, we continue to take this matter very seriously and are following recommendations from health and government officials and implementing numerous, proactive steps to protect the health and safety of our employees, contractors and visitors."