A disease-causing fungus known as histOplasma is in the soil of nearly all US states, a new study suggests. The researchers behind the work say doctors may be relying on outdated risk maps and missing diagnoses of the infections, which can sometimes be deadly.
According to the CDC, histoplasma, or histo, is found in the soils of central and eastern US states, primarily in Ohio and the Mississippi River valleys. But that assumption is based on research from the 1950s and 1960s, says the team behind a new one paper published in Clinical Infectious Diseases. When a person inhales spores of the fungus, they can contract an infection called histoplasmosis.
“Every few weeks I get a call from a doctor in the Boston area — a different doctor each time — about a case they can’t solve,” said study author Andrej Spec, an associate professor of medicine at Washington University in St. Louis. . , in a press release. “They always start by saying, ‘We don’t have histo here, but it looks a bit like histo.’ I say, ‘You call me about this all the time. You have history.’”
Lead author Patrick B. Mazi, a clinical fellow in infectious diseases also at Washington University in St. Louis, and colleagues analyzed more than 45 million Medicare reimbursement-for-service beneficiaries spanning from 2007 to 2016. They looked at diagnoses in the whole country from three fungal diseases: histoplasmosis, coccidioidomycosis and blastomycosis. Histo, the most common, caused clinically relevant morbidity in at least one county in 48 of the 50 states, as well as Washington, DC. The other two infections were each found in more than half of the states.
“Fungal infections are much more common than people realize, and they spread,” Spec said in the release. “The scientific community has underinvested in studying and developing treatments for fungal infections. I think that is starting to change, but slowly.” Climate change can be the driving this spread as warming temperatures make more habitats suitable for the fungi.
While histo can be easily controlled in healthy adults and many people exposed to it never develop symptoms, immunocompromised individuals, infants, and those 55 and older can develop more serious illness, including cough, fever, chest pain, pain in the body and fatigue, according to to the GGD. Symptoms appear within three to 17 days of exposure; most symptoms go away within a month, but if it spreads from a person’s lungs, the disease can become serious and require months of treatment.
Humans can be exposed to histo and other fungal pathogens through activities that disturb the soil, such as farming, landscaping and construction. They can also be exposed in caves and while working in basements and attics. Spec commented, “It’s important for the medical community to realize that these fungi are ubiquitous today and we need to take them seriously and include them when considering diagnoses.”