ESCANABA, Mich. (News release) -- A contract worker at a northern Michigan paper mill has died from a fungal infection that has forced the business to temporarily close for deep cleaning.

The death was announced in a release by public health officials in Delta and Menominee counties in the US which said the worker died as a result of blastomycosis infection.

The person's name and date of death were not released.

Company officials said the Billerud Paper Mill in Escanaba, which employs more than 800 people, will close for up to three weeks for scrubbing after authorities confirmed at least 21 cases of blastomycosis among workers since March and dozens more probable cases.

The fungal infection is related to a fungus that grows in moist soil and decomposing wood and leaves, according to the public health department in Delta County. Blastomycosis does not pass from person to person, the department said. Common symptoms are cough, fever, shortness of breath, joint pain and weight loss.

The mill will undergo "deep cleaning in high traffic areas through the mill" as well as other steps, including vent inspections, filter replacements and tests on raw materials, said Kevin Kuznicki, president of Billerud North America.

Billerud said that an industrial outbreak of the fungus has not been "documented anywhere in the US".

The health department in early March first publicly disclosed a number of unusual pneumonia infections among mill workers. About 76 people have been classified as probable blastomycosis cases, according to health officials.

Of the 97 total cases, about a dozen have required hospitalization.

"All 97 of the cases are either employees, contractors or visitors of" the paper mill, the health department said.

The mill produces paper for magazines, catalogues, books and other products. Billerud is based in Sweden.