S. brasiliensis host predilection, which results in high severe disease in cats, is a striking difference from the epidemics ongoing around the world and in fact has been pivotal to the success of feline outbreaks.
Interestingly, S. schenckii was the prevalent species among humans in areas free of feline sporotrichosis outbreaks.
Although this study did not molecularly identify the phylogenetic species involved, it was most likely S. brasiliensis, as this species is highly prevalent in Rio de Janeiro due to feline sporotrichosis outbreaks [ 1- 3, 10].
If the mutant virus is absent in the gut, it will not be shed in feces, providing an explanation for the seemingly rare incidence of feline infectious peritonitis outbreaks.
When the recent outbreaks of feline sporotrichosis are plotted on the areas sampled for human cases, our data strongly suggest that S. brasiliensis is dependent on its feline host for its epidemic emergence in the South and Southeast.
This has been seen recently in outbreaks of virulent systemic feline calicivirus in cats [ 22] and Streptococcus equi pneumonia in dogs [ 23].
Recently, influenza outbreaks have occurred in species (feline and canine) that historically do not carry influenza virus (3, 4 ), which alerted both regulatory and scientific communities to expansion of the host range of influenza virus.
Strains of feline calicivirus with different pathogenicities obtained from distinct outbreaks did not show conserved changes in virus genomes.
