CDC reveals rare fungus in Wisconsin killed one person and hospitalized two

One person died and two were hospitalized after an outbreak of a rare fungal infection in Wisconsin last year.

The cluster of cases was caused by Blastomyces, a microscopic fungal species which lives in moist soil and decomposes wood and leaves. 

The Centers for Disease Control and Prevention (CDC) – which revealed the outbreak last week – has told doctors in the Midwest and South to be ‘alert’ for the infection.

Blastomyces – which infects around 6,700 Americans and kills 60 each year – causes a lung infection that can trigger fever, coughs, chest pain, fatigue and night sweats.

In severe cases, the spores can spread from the lungs to other areas of the body, including bones, joints and even the brain and spinal cord.

In total, four people and five dogs were diagnosed with the infection in St Croix County, in western Wisconsin, in February 2022. 

The CDC was first alerted to the cases when four dogs living within a mile of each other all tested positive for the fungal infection.

Officials then sent an alert to physicians, veterinarians and people living in the neighborhood to watch out for symptoms of Blastomycosis.

They noted the disease was often diagnosed in people who engaged in physical activities near waterways.

Investigators linked the infections to a rural path running through the neighborhood where the cases were spotted.

The fungal alert, revealed in the Morbidity and Mortality Weekly Reports (MMWR), comes amid concerns over rising cases of the deadly fungus C. auris in the United States — with hospital infections tripling in recent years.

The World Health Organization (WHO) has also warned that fungal infections are becoming a ‘major threat’ to public health.

Some experts claim fungi are becoming more common worldwide as the changing climate makes environments more suitable for them. 

Blastomycosis is caused by the fungus blastomyces which typically hides in damp areas of woodland across the eastern half of the United States. 

It is most common around the Mississippi river valleys, great lakes, Ohio and St Lawrence river.

People may become infected after breathing in spores released when they disturb soil or leaf litter, with the first symptoms appearing three weeks to three months later.

Mild cases tend to resolve on their own, but in serious infections doctors may treat patients with antifungals — such as itraconazole — which disrupt the wall of fungus cells, causing cell leakage and eventual death. 

Patients prescribed these drugs, however, will need to take them for up to a year to clear the infection.

The fungus causes about 6,700 cases and 60 deaths annually. Up to one in ten cases are fatal in some states, data shows.

But in recent years there have been signs that outbreaks of the fungus are growing in the United States.

Minnesota is one of the states to report that while cases are up its fatality rate has also risen from nine to 23 percent of patients between 1999 and 2021.

The most recent outbreak marked the first to strike Wisconsin in more than a decade.