The strain was isolated in Sumatra, Indonesia, in 1923 by Baermann from the blood of a patient (Rachmat) suffering from "leptospirosis febrilis". Baermann (1923) differentiated it from other available strains. Subsequently Schffner (1939) found that the strain behaved serologically as the 'incomplete biotype' of Akiyami A, and in his publication he named the strain Rahmat. Gispen et al. (1939) confirmed these findings.
In the list of 1959 (WHO, 1959) it is quoted as a 'subserotype' named autumnalis (A). As the taxon 'subserotype' was abolished in 1966, it appears in the list of 1967 (WHO, 1967) as a separate serovar named rachmati, with reference strain Rachmat.