ESCANABA — Public Health Delta and Menominee Counties is still investigating a string of fungal pneumonia cases associated with the Escanaba Billerud Paper Mill as the number of cases continues to climb.

According to PHDM, 14 cases have been confirmed of blastomycosis, an infection caused by the blastomyces fungus, with an additional 39 probable cases.

A confirmed case is a person with symptoms of blastomycosis and where the fungus has either been grown from a culture or seen by microscope in a specimen. Probable cases are when the individual has the symptoms of blastomyocosis and has had a positive antigen or antibody test identifying the fungus.

The number of confirmed and probable cases is an increase from what was reported by PHDM late last week. As of March 17, there were 35 confirmed or probable cases of blastomycosis associated with the mill. PHDM was first made aware of the cluster of atypical pneumonia infections among mill employees Feb. 28, though some mill workers developed symptoms in January.

Over the past five years, an average of 26 cases of blastomycosis have been reported annually in the entire state of Michigan.

At the request of Billerud, the National Institute for Occupational Safety and Health, an OSHA research agency, will perform a health hazard evaluation focused on studying the health and safety of Escanaba mill employees. A team of experts from NIOSH, the Centers for Disease Control and Prevention, the Michigan Department of Health and Human Services, and PHDM will perform a site visit to tour the mill. During the tour, the team will meet with members of management, the mill’s occupational health and safety team, and union representatives.

The evaluation is expected to continue after the onsite visit is complete, as the NIOSH team works to analyze data and review the case investigation collected by PHDM.

PHDM is still interviewing patients identified by health care providers as potentially having blastomycosis. Information from those interviews is being shared with MDHHS and NIOSH.

Billerud has taken a number of steps to help protect the workers, including providing N95 masks, inspecting ventilation systems, changing filters, and deep cleaning common areas.

“Though no causal link to our mill has been confirmed, we continue to take this matter very seriously,” said Brian Peterson, operations vice president at the Billerud Escanaba Mill.

The fungus that causes blastomycosis grows in moist soils and decomposing matter, such as wood and leaves. A specific source of the fungus causing the outbreak at the Escanaba paper mill has not been identified, but because the fungus is common in the environment in the U.P., identifying a specific source of exposure can be difficult.

“The addition of an independent review by NIOSH will deepen the investigation. We continue to work with OSHA, PHDM and an industrial hygienist to determine common areas where affected employees have been,” Peterson said.

People can get blastomycosis infections by breathing in the fungal spores; however, most people who inhale the spores do not get sick. Those who do get sick can develop a cough, which sometimes presents with blood, as well as fever, chest pain, difficulty breathing, night sweats, fatigue, weight loss, muscle aches and joint pain.

There is no vaccine for blastomycosis and the disease cannot be spread between people or between people and animals.

Blastomycosis is treated with anti-fungal medications. Treatment for the disease is most effective when started as soon as possible after diagnosis by a health care provider.