WAUSAU, Wis. (WSAU) – Three field investigators from the U.S. Centers for Disease Control and Prevention are helping local and state health officials learn why there's been an increase in the number of blastomycosis cases in Marathon County.
“We don't know how [many] of the cases is due to a change in environmental factors or something else,” said Monika Roy, a public health officer in the CDC's mycotic diseases branch. Roy and her team has spent the last two weeks interviewing healthy residents and those with blastomycosis to understand their outdoor activities.
The team is also looking at weather patterns and water conditions since blasto is more frequently found in acidic, sandy soils, decaying wood and other vegetation, and by waterways with fluctuating water levels.
“There's still a lot that's unknown about blastomycosis, both about the environment and the ecological niche, where it likes to live in the environment,” Roy said. But the fungus is more commonly found in the Mississippi and Ohio River valleys and Wisconsin has been identified as a hyperendemic state because the disease is so prevalent here.
“Our interest stems from the subject area where all our research is currently being done,” Roy said. Her branch performs two to three field investigations like this one each year. County and state officials asked the CDC to get involved because of the increase in cases.
But investigators are finding that blasto is hard to isolate from the environment because of the perfect storm of conditions needed to produce it. Another complicating factor is that different people show symptoms of the disease more quickly than others.
Symptoms can take one to three months to develop and most outbreaks occur in the spring and fall. Health officials say some blasto cases do not fit the profile because residents contracted the disease in the winter. Officials have also noticed more women and younger people than usual who have contracted the illness.
Once the field investigation is over, the CDC will analyze the results and continue to work with local and state officials, Roy said. She said the full investigation could take another month or two before they have any probable findings.
