The spread of cat-transmitted sporotrichosis due to Sporothrix brasiliensis in Brazil towards the Northeast region

Abstract

Background Sporotrichosis is a worldwide subcutaneous mycosis caused by Sporothrix spp. In the past, this infection was associated with armadillo hunting, horticulturists, miners, and gardeners, being considered an implantation mycosis acquired by plant debris injury. Nevertheless, since the late nineties, it has been considered a zoonotic disease in Brazil. Here we report a case series of 121 patients with cat-transmitted sporotrichosis seen in Northeast Brazil. Methodology/Principal findings Patient’s demographic, clinical data, and length of treatment were recorded. In addition, a mycological examination and further PCR confirmation of species identification were performed. One hundred and twenty two patients were diagnosed with subcutaneous sporotrichosis from October 2016 to December 2019, while PCR revealed that 71 of them were due to S. brasiliensis. The majority of the individuals were female (n = 86; 70.5%). Patient’s age ranged from 5 to 87 years old. The clinical forms found were lymphocutaneous (58.2%) and fixed cutaneous (39.4%). Interestingly, 115 patients reported previous contact with cats diagnosed with sporotrichosis. Patients were successfully treated with itraconazole and potassium iodide. Conclusions/Significance Our study adds important contributions for the investigation of the spread of cat-transmitted subcutaneous sporotrichosis in Brazil, specifically towards the Northeast region of a continental-size country. It will also help clinicians to be aware of the existence and importance to accurately diagnose sporotrichosis and treat patients with this infectious disease in the lowest income region of Brazil.

Old and New Insights into Sporothrix schenckii Complex Biology and Identification

“…In feline sporotrichosis, uniquely when compared to the infections caused by other endemic dimorphic fungi (e.g., Onygenales), transmission seems to occur directly through the fungus’s yeast phase that is present at a high burden in the infected animal’s lesions [ 10 ]. Another distinctive feature of sporotrichosis is the supposed high prevalence of animal-to-human transmission, which is consistent with the so far described largest outbreak of cat-transmitted sporotrichosis that has emerged three decades ago and continued to expand in Brazil [ 12 ], involving thousands of humans and cats. Interestingly, some of them were immunocompromised subjects affected by HIV and feline immunodeficiency virus (FIV), respectively [ 10 ].…”

Development and evaluation of a multiplex qPCR assay for rapid diagnostics of emerging sporotrichosis

“…Sporotrichosis is an outlier in fungal epidemiology as it can escalate and produce major epidemics in a short period. Typical examples include epidemics in humans related to sapronoses (Pijper & Pullinger, 1927), animal epizootics in South America (Montenegro et al., 2014; Rodrigues et al., 2016b; Rodrigues et al., 2013) and more recently, zoonoses in endemic areas overlapping feline sporotrichosis outbreaks (de Oliveira Bento et al, 2021; Gremião et al, 2017; Rodrigues et al., 2014b). Judging from these outbreak scenarios, it is essential to develop molecular tools for massive testing, which are sensitive, specific, fast, easy to perform, simple to interpret for identifying emerging agents, such as S. brasiliensis (Rodrigues et al, 2020).…”

“…From a public health perspective, late diagnosis and lack of treatment of infected cats can rapidly spread sporotrichosis among other animals and humans. Usually, the increase in the number of cases in felines is followed by numerous human subjects affected, which poses a significant challenge for control (de Oliveira Bento et al, 2021; Rodrigues et al., 2016b). Therefore, diagnosing and understanding how transmission spreads following host shifts is essential when considering the emergence of Sporothrix in humans and animals.…”

Emerging Animal-Associated Fungal Diseases

“…Cases in humans occur exclusively by zoonotic transmission. An epidemiological relationship has been observed between the number of infected cats in the urban areas of Brazil and diagnosis in humans [ 61 ]. Although cats are the primary vector, Sporothrix brasiliensis also prevails among dogs and rats [ 62 ].…”

“…Alarmingly, the fungus is also insensitive to some antifungal treatments [ 62 , 63 ]. The prevalence of the disease keeps increasing in Brazil and is now spreading to adjacent Argentinian states [ 61 ].…”