Brief History of the Causative Agents of Sporotrichosis
Sporothrix species are the etiological agents of human and animal sporotrichosis, a chronic, subcutaneous mycosis with frequent lymphatic involvement (Rodrigues et al. 2016b). On November 30, 1896, the American physician Benjamin Robinson Schenck, working at Johns Hopkins Hospital in Baltimore, Maryland (USA), examined a patient with an infection in his right arm.
The patient had a primary infection in the index finger that had spread to his arm via the lymphatic system. Schenck isolated the causative agent and sent a sample to the mycologist Erwin F. Smith, who classified the fungus in the genus Sporotrichum (Schenck 1898) (Fig. 10.1).In 1900, Hektoen and Perkins, also in the USA, reported the second case of the disease when they isolated the pathogen from a skin lesion of a child who had injured her index finger with a hammer (Hektoen and Perkins 1900). Based on experimental studies with laboratory animals, they described the pathogen morphology in detail and named the fungus Sporothrix schenckii.
In 1910, in France, Matruchot also encountered this species. Several similar cases began to occur in the USA and Europe, first in France (Beurmann and Ramond 1903), where it became a rather common disease, and later in England (Walker and Ritchie 1911; Adamson 1911). Several reports of cutaneous mycosis, and even of the rare, disseminated form of the disease, were published by experts of that time (Beurmann and Ramond 1903; Beurmann and Gougerot 1912).
Animal sporotrichosis was first described in 1907 in Sao Paulo (Brazil) by Lutz and Splendore, who isolated pathogenic microorganisms of the genus Sporothrix from the buccal mucosa of rats (Lutz and Splendore 1907). Several attempts to classify and name the pathogen were made until 1921, when Davis, studying the samples isolated in France and the Americas, concluded that they were identical and classified the etiological agent found in Brazil as Sporotrichum schenckii (Davis 1921).
However, Sporotrichum is of basidiomycetous nature, and therefore Carmichael (1962) recommended Sporothrix schenckii as the correct name for the causative agent of sporotrichosis.After these initial findings, cases of human sporotrichosis were described in the Americas (Dixon et al. 1991), Asia (Song et al. 2013), Europe (Bachmeyer et al. 2006), and Africa (Vismer and Hull 1997), with Brazil, South Africa, and China considered highly endemic areas. The first sporotrichosis epidemic in South Africa was described by Pijper and Pullinger (1927) and affected 14 native miners, but the source of infection was not identified. The largest epidemic in humans occurred in the early 1940s, with approximately 3000 cases identified in 3 years, at the same place in South Africa where the first cases were diagnosed. The infection occurred when miners touched untreated wood beams supporting the mine shafts; transmission ceased after the wood was treated with antifungals (Helm and Berman 1947).
In all the scenarios described above, sporotrichosis is characterized as a disease acquired through direct contact between the human host and the environment. Sporothrix was first described in cats in the mid-1950s (Singer and Muncie 1952), and three decades later, the first case of zoonotic transmission was reported (Read and Sperling 1982). In recent years (1998-2016), large epizootics have occurred in domestic cats in South and Southeast Brazil, with an increasing number of zoonotic
Fig. 10.1 Chronological order of the main facts and pioneering events that contributed to the epidemiological studies on human and animal sporotrichosis. Despite a century of history, the emergence of Sporotlirix brasiliensis that cause large outbreaks in humans and animals in South and Southeast Brazil has only been observed in the last few decades
transmissions (Montenegro et al. 2014; Gremiao et al. 2015; Sanchotene et al. 2015). Due to the negligence of human and animal cases, it is difficult to estimate the true magnitude of this epizootic/epidemic (Fig. 10.1).
10.2