Between November 1, 2022 and May 15, 2023, paper mill workers in Michigan were part of the largest blastomycosis outbreak in US history, with 162 cases of the fungal disease identified among 645 mill workers.
This outbreak was the largest documented blastomycosis outbreak in the United States, and the first associated with a paper mill or an industrial setting.
“This outbreak was the largest documented blastomycosis outbreak in the United States, and the first associated with a paper mill or an industrial setting,” the authors said.
Though rare, fungal infections are usually linked to inhaled spore exposure from moist soil or decaying wood and leaves in the midwestern and southeastern United States.
Medical surveys were conducted among all plant workers, and officials estimated blastomycosis case prevalence was 20%.
The largest blastomycosis outbreak in US history affected paper mill workers in Michigan between November 1, 2022, and May 15, 2023. Of the 645 mill workers, 162 cases of the fungal disease were found.
The largest known outbreak of blastomycosis in the US was also the first to be linked to an industrial setting, such as a paper mill.
“This outbreak was the first linked to a paper mill or an industrial setting, and the largest documented blastomycosis outbreak in the United States,” the authors stated. Fungal infections are uncommon, but in the midwestern and southeastern regions of the United States, they are typically associated with inhaled spore exposure from moist soil or decomposing wood and leaves.
A number of atypical pneumonia cases among employees at a nearby paper mill in Delta County, Michigan, were reported to Public Health Delta and Menominee Counties (PHDM) at the end of February 2023, informing officials of the outbreak. In January and February of 2023, the patients began to exhibit respiratory symptoms, and Blastomyces was detected in their urine.
Yesterday, the team’s findings were published in the most recent edition of the Morbidity and Mortality Weekly Report.
18 hospitalized, 1 death.
The median age of the workforce was 46 years, and the majority of workers were male (83 percent), white (94 percent), and non-Hispanic (98 percent), according to the authors. Of patients who tested positive for infection, 90% had a cough, 76% had both exhaustion and dyspnea, 73% had fever, and 63% had abnormal lung findings on chest imaging.
Hospitalization of 18 (12 percent) workers with blastomycosis resulted in one patient’s death. All plant employees participated in medical surveys, and authorities calculated that 20% of cases were of blastomycosis.
