P462 Spread of sporothrix brasiliensis from the sneeze of infected cats: a potential novel route of transmission

Abstract

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM Objectives Cat-transmitted sporotrichosis (CTS), caused by Sporothrix brasiliensis, is an emerging fungal disease that has become a major public health concern in Brazil. Transmission of CTS usually occurs through the implantation (e.g., scratches or bites) of infectious yeast from feline Sporothrix lesions. Recent reports on transmission events have suggested that S. brasiliensis might be transmitted through feline respiratory droplets created while sneezing. The aim of our study is to determine whether infectious respiratory secretions are expelled when cats with sporotrichosis sneeze. Methods We collected respiratory secretions expelled while sneezing from 28 cats diagnosed with sporotrichosis. We placed a Mycosel agar plate, a fungal culture medium, in front of the animals’ nostrils and used a nasal swab to stimulate sneezing (Fig. 1). Samples were incubated at 28-30°C for 4 weeks in the Mycology laboratory of Hospital de Clinicas. Molecular identification of the isolates was performed by sequencing the calmodulin gene. The infected cats enrolled in the study were subsequently treated at the School Veterinary Clinic of the Pontifical Catholic University of Paraná, a referral hospital for the treatment of feline sporotrichosis. Results Out of the 28 respiratory samples collected, 20 (70%) had evidence of fungal growth morphologically consistent with Sporothrix. Sequencing of all isolates identified Sporothrix brasiliensis (Fig. 2). Conclusion We identified a possible novel route of transmission of Sporothrix spp. through infectious feline respiratory secretions expelled during sneezing. The respiratory droplets created by a sneeze could contain viable Sporothrix yeast that could infect humans and other animals after mucosal exposure. One health partner and collaborator such as veterinarians, physicians, health authorities, epidemiologists, and fungal disease researchers should be made aware of the potential spread of Sporothrix through respiratory droplets and sneezing to prevent and control the further spread of CTS. To prevent cat-to-human transmission of Sporothrix brasiliensis, personal protective equipment (PPE) should be worn while handling a cat with suspected sporotrichosis. Veterinarians, veterinary clinic employees, students, and pet shop owners are at increased risk due to their professions. Veterinary care frequently involves procedures that encourage respiratory droplets (e.g., nasal swabs); restraint and other close contact may directly expose staff to infectious secretions. Because this study identified viable yeast in respiratory droplets from sneezing, decontamination and disinfection of exposed surfaces is increasingly important, as surfaces and objects can serve as fomites for Sporothrix. Physicians who diagnose and treat human cases of sporotrichosis should be aware of this new transmission method to improve clinical suspicion, diagnosis, and treatment for sporotrichosis. Approximately half of the human patients with conjunctival sporotrichosis did not report experiencing traumatic injury from cats; mucosal exposure to infectious yeast is a likely alternative transmission method.