The strain was isolated in 1967 from a patient in Ceylon and described as a new serovar of the Autumnalis group named lanka, reference strain R 740 (Nityanada, Sulzer, 1971).
Serovar lanka waas recognized by the TSC in 1986 and was placed according to the suggestion of Dikken and Kmety (1978) within the new Lousiana seroroup. It appears as such in the Revised List of 1988 (Kmety, Dikken, 1988).