A fungus that can pass from cats to humans has now been confirmed in Uruguay, raising concern among doctors, veterinarians, and public health experts across South America. The pathogen, known as Sporothrix brasiliensis, was identified after a family outbreak and later linked to sick cats in the departments of Maldonado and Rocha.
The discovery matters because this is not just another skin infection. For the most part, sporotrichosis can be treated, but it may take weeks or months, and experts warn that young children, older adults, and people with weakened immune systems can face more serious complications. So, what should pet owners actually watch for?
A fungus carried by cats
Sporothrix brasiliensis belongs to a group of fungi that can cause sporotrichosis, an infection that usually affects the skin and the tissue beneath it. Unlike the more traditional form sometimes linked to soil, plants, or gardening injuries, this species is strongly associated with infected cats.
The fungus is also thermally dimorphic, which means it changes form depending on temperature. In the environment, at around 77 degrees Fahrenheit, it grows in a filament-like form, but inside a warm mammal’s body, near 98.6 degrees Fahrenheit, it can shift into a yeast-like form.
That switch helps explain why the fungus can survive outside the body and then multiply once it enters an animal or person. It is a small biological detail with a big public health impact.
How Uruguay found the outbreak
The Instituto de Higiene in Uruguay reported the first confirmed presence of S. brasiliensis in the country on February 25, 2026. According to the institute, the finding came after an intrafamily outbreak in 2025, where both people and pets were affected.
At first, investigators linked the outbreak to the adoption of a stray kitten from Brazil. But the story did not stop there. More infected cats were later found in Maldonado and Rocha with no direct connection to the first case, suggesting the fungus may already have been circulating locally.
Dr. Elisa Cabeza, an assistant professor in Parasitology and Mycology at Uruguay’s Instituto de Higiene, said the discovery “has lit up epidemiological surveillance” because the species can cause outbreaks and may be severe in vulnerable groups. In practical terms, that means this is now a medical and veterinary problem at the same time.
Why cats spread it so easily
Cats can develop open sores, scabs, and hairless patches, especially around the face, nose, ears, and paws. These wounds can contain high levels of the fungus, which makes close contact risky for people and other animals.
Transmission can happen through scratches, bites, touching infected wounds, or exposure to fluid from skin lesions. The World Health Organization also notes that scratches from cats are a common source of zoonotic sporotrichosis, while broken skin can allow the fungus to enter the body.
This is where daily life gets tricky. A sick-looking stray cat may seem like it only needs food and a little care, but handling it without protection can create a route for infection. Gloves, caution, and a call to a veterinarian are not overreactions.
Symptoms to watch for
In people, sporotrichosis often begins as small red bumps or plaques on exposed skin, usually on the arms, legs, or face. These spots can ulcerate and, in some cases, spread in a line along the lymphatic vessels.
In cats, the warning signs are often more dramatic. Wounds that do not heal, crusted lesions, hair loss, and eye irritation can all appear, especially in animals that live outdoors or fight with other cats.
Most cases remain skin-related, but doctors do not dismiss the infection. The WHO warns that rare deep forms can cause arthritis, respiratory infection, or meningitis, particularly in people with underlying health problems.
A wider South American concern
The Uruguayan case is part of a broader regional pattern. The WHO says S. brasiliensis has caused cat-linked infections in South America, mainly Brazil, where more than 11,000 human cases have been reported in affected areas over the past 10 years.
Recent scientific work also describes the spread of cat-transmitted sporotrichosis from Brazil into other Latin American countries, including Argentina, Paraguay, and Chile. That does not mean every cat is a threat, but it does show how easily an unnoticed animal reservoir can keep an outbreak alive.
The hard part is control. Stray cats may go untreated, infected pets may be handled before anyone realizes what is happening, and diagnosis is not always easy in areas with limited resources.
Treatment and prevention
The good news is that sporotrichosis is treatable. The WHO lists oral antifungal drugs such as itraconazole and terbinafine as effective options, although cat-acquired infections may require longer treatment courses, often around three to four months.
For pet owners, the safest move is simple. Do not touch wounds on a cat with bare hands, avoid rough play with sick animals, and seek veterinary care if a cat has sores that do not heal.
At the end of the day, this outbreak is a reminder that public health does not stop at the clinic door. It also lives in neighborhoods, shelters, vet offices, and those quick moments when someone decides to pick up a stray animal without thinking twice.
The official statement was published on Instituto de Higiene’s website.
