The Evandro Chagas Clinical Research Institute is a referral center for infectious diseases in Rio de Janeiro. Since 1998, the institute has received an increasing number of cases of sporotrichosis in humans, dogs, and cats from the city of Rio de Janeiro and the surrounding areas. Between 1986 and 1997, 13 cases of sporotrichosis in humans were recorded at the institute. Beginning in 1998, the number of cases increased steadily, reaching a total of 759 cases in humans between 1998 and 2004, 83 percent of whom reported contact with cats that had sporotrichosis as a risk factor. Of these, 56 percent reported cat bites or scratches.