 In 1984, Eberhard and Orihel redefined the genus "Mansonella" and included the "M. perstans" species in it, so it is currently known as "M. perstans".The adult worms of "M. perstans" were first recovered during "post mortem" examination of two aboriginal Indians in British Guiana from their mesentery and subpericardial fat.While an insect vector was hypothesized, it took many years of investigation before the true vector of "M. perstans" was discovered.