By Ethan Covey
A recently published report describes a feline sporotrichosis cluster and zoonotic transmission between one of the affected cats and a technician at a Kansas veterinary clinic.
Sporotrichosis is a rare implantation mycosis caused by fungi in the genus Sporothrix that can affect other humans and mammals (Emerg Infect Dis 2024;30[5]:1053-1055).
“The report highlights the potential severity of this disease in cats, and discusses the need for prompt diagnosis and antifungal treatment to improve outcomes and reduce transmission risk,” said Ian Hennessee, PhD, a Epidemic Intelligence Service officer with the CDC’s Mycotic Diseases Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases.
“[The report] also raises awareness about the potential for zoonotic transmission of this disease to veterinary professionals or others who have close contact with affected cats, emphasizing considerations for reducing zoonotic transmission risk,” Dr. Hennessee added.
In August 2022, the first cat was brought to the veterinary clinic with an ulcerated lesion on her paw. Despite treatment, the wound eventually worsened and the cat was humanely euthanized. An impression smear conducted by the veterinarian revealed cytology consistent with Sporothrix.
During November 2022, a technician caring for the cat received a puncture wound from the cat’s infected paw. A blister appeared on the technician’s arm, which quickly ulcerated, and developed into sporotrichoid lymphadenopathy. Cultures were positive for
Sporothrix spp. and CDC testing confirmed S. schenckii. The technician recovered after an eight-month course of antifungal treatment.
Three months later, during February 2023, the owners of the first cat brought in a second indoor-outdoor cat from the same property who was experiencing similar lesions. Cytology revealed Sporothrix, and the cat recovered after a four-month treatment regimen.
“Although cat-transmitted sporotrichosis is an increasing concern in Latin America due to the emerging and highly virulent species Sporothrix brasiliensis, cat-transmitted sporotrichosis has only rarely been documented in the U.S.,” Dr. Hennessee told Infectious Disease Special Edition. “The Kansas cluster, therefore, initially raised concerns that it could be caused by S. brasiliensis. Whole-genome sequencing later confirmed that the infections were due to S. schenckii, the species found domestically,” he said.
“Nevertheless,” Dr. Hennessee added, “these cases underscore the potential for cat-transmitted sporotrichosis in the U.S. Increased awareness of sporotrichosis and the potential for zoonotic transmission could help veterinary professionals manage feline cases and take precautions to prevent human acquisition.”
Accurately estimating the burden of the disease is challenging, as sporotrichosis is not reportable, and there is currently no national surveillance for it in animals or humans.
“This report therefore raised questions about how common feline sporotrichosis is,” Dr. Hennessee said. “It also raised questions how often zoonotic transmission occurs if cases are not always reported to public health.
“To help answer some of these questions, CDC is collaborating with veterinary associations and veterinary professionals to improve our understanding of the epidemiology of animal sporotrichosis and zoonotic transmission in the U.S.,” Dr. Hennessee said. “We are also working together to raise awareness among veterinary professionals about feline sporotrichosis and precautions for preventing zoonotic transmission in the veterinary setting.”
Dr. Hennessee reported no relevant financial disclosures.
