The strain was isolated from a blood sample of a patient on the east coast of Sumatra, Indonesia, by Wolff in 1937 and studied by agglutination and absorption tests against many strains available at the time, from all of which it was found to differ (Walch-Sordrager et al., 1940). They named the strain Benjamin. The serovar represented by strain Benjanin first appears in the list of serovars of 19590 (WHO, 1959), with the serovar name benjamini. The strain was submitted to factor analysis and it was suggested that it should be placed in the subgroup Schueffneri (Kmety, 1967).