Ringworm warning: Drug-resistant fungus’ detection in NZ prompts caution to GPs

Researchers have identified a new strain of drug-resistant fungus, T. indotineae, in New Zealand.

• A recently-emerged, treatment-resistant fungal species called T. indotineae has become a growing health concern as it’s spread across the globe
• Researchers today report a small number of cases have been detected in New Zealand, cautioning clinicians to be aware of it
• Like other types of ringworm, T. indotineae is spread through physical contact, personal items like clothing or towels, or from changing room floors

Researchers have identified a new strain of drug-resistant fungus in New Zealand, prompting an alert to GP clinics to watch out for ringworm cases potentially caused by it.

Dermatophytosis - also known as ringworm or tinea – is a fungal infection of the skin, hair and nails and is estimated to affect up to a quarter of the global population.

One of its main causes, the fungal species T. rubrum, has long been behind common infections like athlete’s foot and nail fungus in New Zealand.

But a closely related, recently-emerged species called T. indotineae has become a growing health concern as it’s spread across the globe.

Since large outbreaks were first described across the Indian subcontinent, it’s been confirmed in countries across Europe, North America, the Middle East and Asia.

Months after it was reported for the first time in Australia, researchers have described a small number of local cases in an article in today’s New Zealand Medical Journal.

The researchers analysed 960 dermatophyte samples collected between 2017 and August 2024 from Auckland City Hospital’s National Mycology Reference Laboratory and elsewhere.

Of those, 85 were confirmed or strongly suspected cases of T. indotineae, with most affecting the groin, feet and arms.

More than a third of the infections were resistant to terbinafine, which has traditionally been used as a first-line treatment.

“While the numbers are small, they have increased, and the possibility of resistance may not be known,” said study co-author Dr Arthur Morris, a clinical microbiologist at LabPLUS.

Like other types of ringworm, T. indotineae spreads through physical contact, personal items like clothing or towels, or from the changing room floor, Morris said.

“Without quick recognition and proper treatment, this fungus can spread easily, particularly between households.”

The researchers suggested Itraconazole, rather than terbinafine, remained the most effective agent, with nearly all T. indotineae isolates testing susceptible to it.

They said clinicians should be aware of the possibility of the new ringworm in patients – particularly among those of Indian or other South Asian ethnicity - who had extensive or long-standing tinea.

“There are no ongoing or planned studies, however, LabPLUS is the national reference laboratory and will continue to follow the numbers and notify practitioners in the future as required,” Morris said.

“Long-term travel to or from the Indian sub-continent is a risk factor for having this emerging fungal skin infection.”

Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.

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