A fungal sexually transmitted infection caused by Trichophyton mentagrophytes type VII (TMvii) has emerged as a growing public health concern in the United States, with at least 30 confirmed cases in Minnesota and additional cases detected in other U.S. cities. The infection spreads through intimate skin-to-skin contact and causes painful, coin-sized rashes on the arms, buttocks, trunk, legs, and genitals. While treatable with oral antifungal medications, the infection can take several weeks to months to clear and may cause scarring if left untreated .

What Is TMvii and Where Did It Come From?

TMvii isn't entirely new, but it's an emerging strain that has only recently been recognized in human outbreaks. The infection was first identified in 2023 among men who had recently traveled in Southeast Asia, suggesting it may have been circulating undetected for some time before being formally characterized. The first U.S. case was reported in New York in 2024, followed by cases in other cities. The Minnesota outbreak, which began in July 2025, represents the largest recorded outbreak in the United States, prompting the state health department to issue a public health alert in February 2026 .

According to infectious disease experts at the Duke Global Health Institute (DGHI), what we're seeing now reflects both improved detection methods and potential spread through connected sexual and social networks. The infection has predominantly been observed among sexually active gay men, though experts emphasize that anyone can contract TMvii.

How Does TMvii Spread, and What Are the Symptoms?

TMvii spreads primarily through direct skin-to-skin contact, including during sexual activity. The infection can also spread through shared items like towels, clothing, or bedding, though this appears to be less common. Because the infection often affects areas of close contact, transmission during intimate encounters is a key driver of spread .

Symptoms can vary significantly from person to person. Some individuals develop mild redness or ringworm-like rashes, while others experience more severe, painful, or pustular lesions. These can appear on the genitals, buttocks, trunk, or extremities. Based on early data, symptoms may develop anywhere from several days to a few weeks after exposure, though researchers are still studying the exact timeline .

Steps to Recognize and Respond to Potential TMvii Infection

• Watch for Unusual Rashes: Pay attention to any persistent or unusual rash, especially in the genital region or areas of close contact. Coin-sized lesions that appear painful or pustular warrant immediate medical attention.
• Seek Prompt Medical Care: If you notice a new rash or lesion, particularly in the genital region, contact a healthcare provider for evaluation. TMvii can resemble other skin conditions or sexually transmitted infections, so proper diagnosis through laboratory testing is important.
• Understand Treatment Timeline: Oral antifungal medications such as terbinafine can treat TMvii, but patients may require up to three months of treatment. Some patients may develop painful and persistent rashes that can lead to scarring and worsening infections without prompt treatment.

"TMvii can resemble other skin conditions or sexually transmitted infections, so proper evaluation is important. The lack of awareness among the highest risk individuals and communities, combined with the lack of wide-scale testing and reporting from clinics, are ingredients for a very serious epidemic to go under the radar," explained Tom Carpino, Hock Postdoctoral Research Fellow at Duke Global Health Institute.

Tom Carpino, Hock Postdoctoral Research Fellow, Duke Global Health Institute

Why Early Detection Matters for Public Health?

From a public health perspective, early recognition and awareness are critical to preventing a wider outbreak. Clinicians need to be educated about TMvii so they can diagnose and treat cases promptly. Strengthening surveillance, particularly in dermatology and sexual health clinics, will help public health officials better understand how widely this infection is circulating and how best to respond .

Carpino recently consulted with the U.S. Centers for Disease Control and Prevention (CDC) to develop information about TMvii infections for clinicians and the public. This collaborative effort aims to improve awareness and response across the healthcare system.

How Can Public Health Officials Reduce Stigma and Encourage Treatment?

Stigma has historically been a barrier to seeking treatment for infections affecting marginalized communities. Public health officials must take deliberate steps to ensure that fear of judgment doesn't prevent people from getting care. This is particularly important for TMvii, which predominantly affects gay men .

"Public health messaging should focus on reducing stigma while providing clear guidance on symptoms and when to seek care," stated Tom Carpino.

Tom Carpino, Hock Postdoctoral Research Fellow, Duke Global Health Institute

Health officials should emphasize that anyone can get TMvii, regardless of sexual orientation or identity. The key message is straightforward: if you have a new rash or lesion, particularly in the genital region, you should seek medical care. Any ringworm-like rash should be taken seriously, and individuals should consult with a medical provider for immediate treatment to prevent complications such as scarring and secondary infections .

As awareness of TMvii grows among healthcare providers and the public, early detection and prompt treatment will be essential to containing this emerging infection and preventing it from becoming a widespread epidemic in the United States.