It was originally thought that rodents were the main reservoir for O. tsutsugamushi and that the mites were merely vectors of infection: that is, the mites only transferred the contagion from the rodents to humans.
Pensábase orixinalmente que os roedores eran o principal reservorio natural de O. tsutsugamushi e que os ácaros simplemente funcionaban como vectores da infección, é dicir, que os ácaros limitábanse a transmitir a infección desde os roedores aos humanos.