Deslocamento horizontal do carrapato amblyomma sculptum (acari: ixodidae): bases para a prevenção de picadas

Abstract

For the prevention of diseases transmitted by ticks, it is essential to know their bioecology, especially their ability to move horizontally. This ability defines the range of the parasite from infested places to humans and can be important to define strategies for preventing bites. The Amblyomma sculptum tick, a very aggressive species for humans, found a favorable environment and host (capybara) in urban green areas in Southeast and Midwest Brazil. In a few locations, this tick is a vector of Brazilian spotted fever, a highly lethal disease caused by the bacterium Rickettsia rickettsii. In this work, the ability of nymphs and adults of the tick A. sculptum to move horizontally was studied, to define safety distances to be adopted in infested places. Subsequently, CO2 traps were set up to recapture released ticks at variable distances and times. Among others, it was possible to observe that adults and nymphs of the A. sculptum tick can move horizontally at distances of 3 meters at a maximum speed of, respectively, 30 min/meter and 20 min/meter. Dispersion of A. sculptum tick adults in the absence of chemical stimulus is low, with a tendency to disperse at most a distance of 5 meters. Horse and human odors increase the attraction exerted by CO2. This information can be used to establish bite prevention actions in areas where the parasite occurs in urban areas.