Sporotrichosis is an endemic mycosis caused by the dimorphic fungus Sporothrix schenckii sensu lato. It has gained importance in recent years due to its worldwide prevalence, recognition of multiple cryptic species within the originally described species, and its distinctive ecology, distribution, and epidemiology across the globe. In this review, we describe the current knowledge of the taxonomy, ecology, prevalence, molecular epidemiology, and outbreaks due to S. schenckii sensu lato. Despite its omnipresence in the environment, this fungus has remarkably diverse modes of infection and distribution patterns across the world. We have delved into the nuances of how sporotrichosis is intimately linked to different forms of human activities, habitats, lifestyles, and environmental and zoonotic interactions. The purpose of this review is to stimulate discussion about the peculiarities of this unique fungal pathogen and increase the awareness of clinicians and microbiologists, especially in regions of high endemicity, to its emergence and evolving presentations and to kindle further research into understanding the unorthodox mechanisms by which this fungus afflicts different human populations.

BackgroundThere have been several recent changes in the taxonomy of Sporothrix schenckii as well as new observations regarding the clinical aspects of sporotrichosis. In this study, we determined the identification of the Sporothrix species associated with both classic and unusual clinical aspects of sporotrichosis observed in the endemic area of sporotrichosis in Rio de Janeiro, Brazil.Methodology/Principal FindingsTo verify whether S. brasiliensis is associated with clinical manifestations of sporotrichosis, a cross-sectional study was performed in which Sporothrix isolates from 50 patients with different clinical manifestations were analyzed and their isolates were studied by phenotypic and genotypic methods. Data from these patients revealed a distinct clinical picture and therapeutic response in infections caused by Sporothrix brasiliensis (n = 45) compared to patients with S. schenckii sensu stricto (n = 5). S. brasiliensis was associated with disseminated cutaneous infection without underlying disease, hypersensitivity reactions, and mucosal infection, whereas patients with S. schenckii presented with less severe and more often localized disease, similar to the majority of previously described sporotrichosis cases. Interestingly, S. brasiliensis-infected patients overall required shorter durations of itraconazole (median 16 weeks) compared to the individuals with S. schenckii (median 24 weeks).Conclusions/SignificanceThese findings suggest that Sporothrix species are linked to different clinical manifestations of sporotrichosis and that S. brasiliensis is effectively treated with oral itraconazole.

Sporotrichosis has significantly increased in Brazil in the last decade, particularly in the state of Rio de Janeiro, with the occurrence of an epidemic related to zoonotic transmission from cats to humans. Recently, four new phylogenetic species were incorporated into the Sporothrix species complex based on the phenotypic and molecular characteristics, and a new species name (Sporothrix brasiliensis) was proposed for some of the Sporothrix isolates from this epidemic. This study describes the characterization of 246 isolates obtained from patients attending the Laboratory of Infectious Dermatology, IPEC-FIOCRUZ, between 1998 and 2008, together with one environmental sample. Two hundred and six of the isolates (83.4%) were characterized as S. brasiliensis, 15 (6.0%) as S. schenckii, and one (0.5%) as S. mexicana. Twenty-five isolates (10.1%) could not be identified according to their phenotype and were classified as Sporothrix spp. The calmodulin gene was sequenced to confirm the identity of these isolates. The molecular analysis demonstrated that 24 of the isolates were S. brasiliensis, with the remainder being a S. globosa isolate. The isolate characterized phenotypically as S. mexicana was clustered on the S. schenckii clade. The correlation between molecular data and phenotypic characteristics described in this study is fundamental to the identification of the Sporothrix complex.

Sporotrichosis is endemic in Rio de Janeiro, Brazil, and cases have been reported to be associated with HIV. This article describes the clinical manifestations and evolution of sporotrichosis in HIV-positive patients and constitutes the largest case series reported to date. There were 21 HIV-positive patients with sporotrichosis diagnosed by the recovery of the etiologic agent from 1999-2009. Sixteen patients (76.2%) were men and five (23.8%) were women, with a mean age of 41.2 years. Seven of these individuals were previously unaware of their HIV infection. Mean CD4 count was 346.4 cells/μl. The most frequent clinical presentations of sporotrichosis in these patients were the lymphocutaneous and disseminated form (seven patients each, 33.3%), followed by the widespread cutaneous form in five (23.8%), and fixed form in the remaining two (9.5%). In patients with the disseminated forms, clinical manifestations involved the skin in six, mucosa (nasal, oral, or conjunctival) in four, bone in two, and meninges in two. Eleven (52.4%) patients received itraconazole and eight (38.1%) amphotericin B contributing to an overall cure rate of 81%. Spontaneous cure was observed in one patient. The clinical forms of sporotrichosis varied according to the patients' immune status. The results demonstrate the importance of sporotrichosis as an opportunistic infection associated with AIDS in countries where the mycosis occurs.