A highly contagious fungus that causes angry red rashes on the genitals is surging in Minnesota in what officials say is the nation’s ‘largest known outbreak.’
State health officials have reported 40 confirmed or suspected cases of ringworm, a sexually transmitted infection spread by skin-to-skin contact that triggers round, coin-shaped rashes on the buttocks, trunk, arms and legs.
All the infections are due to a new strain of the ringworm fungus called Trichophyton mentagrophytes genotype VII (TMVII), which causes painful and persistent rashes that may leave scars on the body.
CDC officials say infections with this strain are often in men who have sex with men, which is because the fungus has spread into these sexual networks.
All the patients were infected over the last seven months and were in the Twin Cities, or Minneapolis-Saint Paul, metropolitan area, health officials said. The first case was recorded in July 2025 in a Twin Cities resident who sought treatment after suffering from a genital rash.
No deaths have been reported, and the infection is very unlikely to cause a fatality. Doctors warn, however, that it is highly contagious and those with weak immune systems may struggle to clear the infection.
Officials revealed the outbreak on Wednesday in a health alert, and are urging anyone who has symptoms of the infection to contact their doctor immediately. Physicians are being urged to treat patients immediately rather than wait for confirmatory testing before offering them prescription medications to reduce the spread of the disease.
The Minnesota Department of Health believes this is the ‘largest known outbreak’ of TMVII in the US since the fungus was first detected in New York in 2024.
Officials in Minnesota are warning about the nation’s largest ever outbreak of Trichophyton mentagrophytes genotype VII (TMVII) (stock photo)
Despite its name, ringworm is not caused by a worm but by a fungus that is closely related to the disease behind athlete’s foot and jock itch.
It is spread via direct skin-to-skin contact with infected areas and fungal spores that may spread from infected skin to razors, sex toys and linens.
Patients suffer symptoms within four to 14 days of infection. In TMVII infections, rashes may also have bumps or pimples, and can be mistaken for other conditions such as eczema or psoriasis.
To treat the infection, patients may be prescribed antifungal lotions or tablets to help clear the infection. There is no vaccine against the disease.
In cases of TMVII, individuals may also receive antibiotics because the strain can cause a worsening bacterial infection.
In mild cases, ringworm can be cleared in two to four weeks. In more serious cases, however, it can take six to 12 weeks to resolve.
According to officials in Minnesota, of the infections, 13 cases have been confirmed and 27 are suspected, reports infectious diseases website CIDRAP based on an official document it said was shared with reporters.
In its alert, the department said: ‘More than 30 confirmed or suspected cases have been reported in the metro area, resulting in the largest known outbreak of [ringworm] in the United States.’
Ringworm can be spread sexually and via skin-to-skin contact (stock image)
Minnesota Department of Health officials told Daily Mail that there was no link between the cases and migrants in the area.
TMVII was first detected in the US in 2024 in a man who had sex with men and had returned to New York City from a recent trip to Europe.
Since then, the CDC has detected sporadic cases among men who have sex with men, primarily in larger cities in the US. Normally, there are no more than a handful of cases.
The strain TMVII is rare, but is most likely to be detected in Southeast Asia and Europe, particularly among men who have sex with men.
It was first reported in 2017 in travelers who had returned to Switzerland from Thailand. Since then, cases have emerged in a number of neighboring countries including France.
Online, the Minnesota Department of Health says that fungal spores can be killed with common disinfectants such as diluted chlorine bleach. It says potentially infected linens should be laundered on high heat.
It recommends that those with new rashes should cover them with bandages or clothing to minimize unintentional infection or spread.
To prevent an infection, people in Minnesota are being advised to avoid skin-to-skin contact if they or their partner has a new rash.
Individuals are also being advised to consider pausing or limiting sexual activity if there are individuals in their network who have recently reported a new rash.
Those who have a new rash are being advised to inform sexual partners and to consider covering the rash with bandages or clothing to minimize the risk of unintentional spread.
They are being urged to contact their doctor immediately.
