Zoonotic Sporotrichosis in Paraguay: A Public Health Alert.

BACKGROUND: Cat-transmitted sporotrichosis caused by Sporothrix brasiliensis is increasingly reported in the last three decades within Brazil. Recently, other South American countries like Argentina and Chile also reported cases, while the number of reported cases in Paraguay, a Brazilian neighbour, remains quite limited with 10 feline and three human cases. Importantly, early diagnosis and disease awareness facilitate effective treatment and allow strategies to prevent spread. OBJECTIVES: Here, we describe two previously reported and 11 novel human sporotrichosis cases by S. brasiliensis from Paraguay, diagnosed from 2017 to 2025. METHODS: Clinical and epidemiological data of patients were collected, fungal isolates were phenotypically analysed with microscopy, and short tandem repeat (STR) genotyping was used for species identification and to determine genetic relatedness between isolates. RESULTS: From the 13 human patients, 11 were diagnosed with sporotrichosis after contact with cats, while two reported ant bites as the source. All patients reported subcutaneous lesions with lymphocutaneous spread and were treated successfully, resulting in complete resolution of the lesions, despite late recognition of the disease and prior antibiotic treatment. STR genotyping revealed a unique genotype for four cases, all imported from Brazil, including the two ant-associated isolates, all patients had a history of first symptoms while still in Brazil, but later after moving to Paraguay the diagnosis was made. All other isolates were allocated to the previously identified Rio de Janeiro (RJ) clade, originating from Brazil and known to be more widespread in Brazil. CONCLUSIONS: Altogether, we report the probable first two cases of transmission by ants for S. brasiliensis , and all cases result from direct import or spread from Brazil.