Brazil’s Growing Sporotrichosis Epidemic: How a Cat-Transmitted Fungus Is Evolving
A disfiguring fungal infection, spread primarily by cats, is sweeping across Brazil—and scientists are racing to understand its rapid adaptation and spread.
The Face of an Outbreak
A cat in Rio de Janeiro, its nose marked by ulcerated lesions, shows the telltale signs of Sporothrix brasiliensis infection. This highly contagious fungus causes sporotrichosis, a disease that attacks the skin, lymph nodes, and sometimes even internal organs. Transmitted through scratches, bites, or contact with contaminated secretions, it has fueled Latin America’s largest and longest-running sporotrichosis epidemic.
Unraveling the Fungus’s Secrets
A study led by Dr. Anderson Messias Rodrigues (Federal University of São Paulo) analyzed 104 Sporothrix strains, uncovering surprising genetic diversity in the 3-carboxymuconate cyclase (CMC) gene, a key player in the fungus’s survival. Researchers found:
79 unique CMC variants, suggesting rapid evolution.
High mutation rates in S. brasiliensis and S. schenckii, possibly driven by environmental pressures.
A potential link to urban pollutants like benzene and toluene, which the fungus may metabolize for growth.
Why Is This Fungus Spreading So Fast?
S. brasiliensis is more aggressive than other Sporothrix species, with:
✔ Higher virulence (causing more severe disease).
✔ Increased transmission between cats—and from cats to humans.
✔ Growing antifungal resistance, complicating treatment.
The outbreak, which began in Rio in the 1990s, has now spread across Brazil and into neighboring countries. Stray cat populations, limited healthcare access, and poor disease tracking have worsened the crisis.
A New Tool for Tracking—And Fighting—The Disease
The CMC gene has emerged as a superior marker for identifying strains, improving outbreak monitoring. Researchers also pinpointed potential vaccine and drug targets within the fungus’s proteins, offering hope for future control measures.
A Call to Action
“Understanding these adaptations is critical for diagnosis, surveillance, and treatment,” says Dr. Rodrigues. With cases rising, experts urge:
🔹 Stronger fungal tracking systems in affected regions.
🔹 Better guidelines for veterinarians and doctors.
🔹 Research into new therapies to curb transmission.
As S. brasiliensis continues to evolve, this study provides a crucial step toward containing a worsening public health threat—one that bridges the gap between animal and human medicine.
Key Takeaways:
Sporotrichosis, spread by cats, is surging in Brazil.
The fungus is evolving rapidly, possibly aided by pollution.
New genetic insights could lead to better diagnostics and treatments.
Improved surveillance is urgently needed to control the outbreak.
