Fungal Outbreak Affects Over 90 Workers at Michigan Paper Mill

A medical illustration of Blastomyces, the fungus that causes blastomycosis. (Courtesy of CDC)

Nineteen confirmed cases of blastomycosis, a type of fungal infection, have been linked with a northern Michigan paper mill, with a further 74 people believed to be probable cases, according to local health authorities.

Public health officials said on April 7 that both confirmed and probable cases are workers at Escanaba Billerud Paper Mill infected with Blastomycosis after showing symptoms. A probable case is a person with symptoms with a positive antigen or antibody test.

Blastomycosis is an infection caused by a fungus called blastomyces that live in soil and decaying wood.

Earlier on Feb. 28, the Public Health Delta and Menominee Counties (PHDM) was first alerted of several atypical pneumonia infections in individuals employed at the mill.

On March 3, the mill learned of the infections from the PHDM.

The exact source of the fungus has not yet been found. However, it is believed that it arrived on damp and rotten wood at the mill.

“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,” Brian Peterson, the mill’s vice president of operations, said in a statement.

An investigation into an outbreak of blastomycosis is ongoing and includes health and safety officials at the local, state, and federal levels.

Experts said that an outbreak that affects a large number of people is highly unusual as the fungal disease is not usually transmitted from person to person.

Workers at the mill are now being asked to wear company-provided N95 masks. Deep cleaning of ventilation systems in the plant is underway, as advised by health officials, to avoid disease spreading.

Billerud AB, an American subsidiary of the Swedish pulp and paper manufacturer, operates the mill.

About Blastomycosis

According to the U.S. Centers for Disease Control and Prevention (CDC), the Blastomyces fungus lives in moist soil and decomposing matter.

People can get blastomycosis after breathing in fungal spores from the air, which can infect the lungs.

Most people who breathe in the spores don’t get sick, but some might experience the following symptoms: cough, fever, chest pain, difficulty breathing, night sweats, fatigue, weight loss, muscle aches, and joint pain.

In severe cases, the fungus spreads from the lungs to other organs, including the muscles, bones, and brain. It can take anywhere from three weeks to three months for symptoms to appear after exposure to the fungus, the CDC says.

States that track blastomycosis report only about one or two cases per 100,000 of the population yearly. Deaths from the disease are similarly rare, with the CDC finding 1,216 blastomycosis-related deaths occurred in the United States from 1990 to 2010.

“These infections are exceedingly rare. On average over the past five years, only 26 cases have been reported for the entire State of Michigan annually,” PHDM wrote in a statement published March 9. “However, the Upper Peninsula (UP) of Michigan is a known risk area for blastomycosis infection.”

There is no vaccine that can prevent blastomycosis, but the disease can be treated with prescription antifungal medications.

“Depending on the severity of the infection and the person’s immune status, the course of treatment can range from six months to one year,” the CDC states.