Minnesota reports largest U.S. outbreak of TMVII; health officials warn of sexually transmitted fungal infection
Minnesota is facing the largest known U.S. outbreak of TMVII — a sexually transmitted Trichophyton mentagrophytes genotype VII — with more than 30 cases in the Twin Cities, prompting public health alerts for clinicians and residents and targeted guidance.
- Outbreak size: Over 30 confirmed or suspected cases in the Twin Cities since July 2025, making this the largest U.S. cluster to date.
- Presentation: Round, red, often painful or itchy genital and perianal rashes that can resemble eczema or other dermatologic conditions.
- Diagnosis and treatment: Laboratory fungal culture and DNA sequencing confirm TMVII, but clinicians are urged to begin oral terbinafine based on clinical suspicion.
- Public health actions: Enhanced surveillance, reporting instructions, partner notification and guidance on avoiding sexual and skin-to-skin contact while symptomatic.
Overview
TMVII refers to Trichophyton mentagrophytes genotype VII, a dermatophyte recently linked to genital infections and sexual transmission in U.S. cases. Minnesota health authorities have issued advisories after patients in the Twin Cities presented with characteristic rashes and reported sexual contacts. Public health guidance and national reporting stress rapid recognition, specimen submission and empiric therapy when clinically indicated.
What is TMVII?
TMVII is a genotype of the fungus Trichophyton mentagrophytes, a group commonly responsible for dermatophyte infections (often called ringworm, athlete’s foot or jock itch). Despite the colloquial name, ringworm is caused by fungi, not worms. TMVII has been associated with sexual transmission and genital infections in recent reports and health advisories.
For official guidance see the Minnesota Department of Health advisory and a national summary at CIDRAP.
Symptoms and clinical appearance
Patients with TMVII typically develop round, coin-shaped red lesions that can be itchy, painful and persistent. When sexually transmitted, lesions most commonly affect the genitals, perianal area, buttocks, thighs and abdomen. Because lesions may resemble eczema, psoriasis or other dermatoses, clinical suspicion and laboratory testing are important for accurate diagnosis.
Timeline and geographic spread
The first U.S. genital infection linked to TMVII was identified in New York City in June 2024. Minnesota confirmed its first TMVII case in July 2025; since then, more than 30 confirmed or suspected cases have been reported across the Twin Cities metro area. The CDC has been informed of sporadic TMVII infections among men who have sex with men in several large U.S. cities; current reporting describes Minnesota as the largest known outbreak to date.
See coverage at NBC Montana and reporting at CBS News.
Who is at risk
Clusters have most frequently involved men who have sex with men, but transmission is via direct skin-to-skin contact and potentially contaminated clothing or bedding, so anyone with relevant exposures could be at risk. Public health guidance emphasizes partner notification and avoiding shared personal items.
Diagnosis and testing guidance
Confirmatory testing requires fungal culture and DNA sequencing of isolates. The Minnesota Department of Health advisory instructs clinicians to submit skin scrapings for culture and to forward isolates to the MDH Public Health Laboratory for confirmatory testing. Importantly, clinicians are advised not to delay treatment while awaiting lab results if clinical signs and risk factors suggest TMVII.
Treatment and clinical advice
Recommended systemic therapy is oral terbinafine 250 mg daily, typically continued until two weeks after symptom resolution. Courses usually last six to eight weeks, sometimes up to 12 weeks. Providers should:
- Discuss terbinafine side effects and monitor liver function as indicated.
- Avoid topical corticosteroids on suspected TMVII lesions, because steroids can worsen fungal infections.
- Begin empiric oral therapy when clinical suspicion is high rather than waiting for sequencing confirmation.
Guidance sources include the Minnesota Department of Health advisory and reporting summarized by NBC Montana.
Prevention steps and public health response
Minnesota implemented enhanced surveillance after multiple patients reported genital rashes and contacts. The MDH issued a health advisory asking providers and the public to report suspected cases via an online form or by phone at 651-201-5414. Recommended prevention actions:
- Avoid sexual and skin-to-skin contact while symptomatic.
- Do not share clothing, towels or bedding; wash affected items on high heat.
- Notify recent sexual partners so they can seek evaluation and treatment if needed.
“Avoid sexual contact while symptomatic and seek care early; partner notification and prompt antifungal therapy are key to controlling spread,” public health advisories emphasize.
Implications for San Diego
Health care providers in San Diego — including sexual health clinics and dermatologists — should consider TMVII for genital and perianal rashes, collect skin scrapings for culture and begin treatment based on clinical judgment. Coordinate with county public health labs and the CDC for confirmatory testing when isolates require sequencing.
Public health surveillance: San Diego County should monitor unusual or persistent genital rashes and communicate with state and federal partners if clusters appear; enhanced local surveillance may detect introductions early.
Community impact: Outreach organizations serving men who have sex with men and other at-risk groups should incorporate TMVII awareness into education: avoid sex while symptomatic, don’t share personal items, wash clothing on high heat and seek care promptly.
Practical guidance for residents: Residents who notice round, red, itchy rashes on the genitals, buttocks or nearby areas should seek medical care, avoid sexual contact while symptomatic, and refrain from using topical steroids on suspicious rashes.
Service considerations: Clinics may see increased visits for genital rashes if TMVII spreads; plan for lab capacity, oral antifungal access and patient education materials.
Expert perspective
Infectious disease specialists note that TMVII symptoms can resemble more common dermatophyte infections such as ringworm or jock itch and that lesion appearance varies by body site. One expert described the lesions as round, itchy spots that may look rough and be mistaken for eczema. Prompt recognition and appropriate antifungal therapy are critical to limiting transmission.
