A leptospiral isolate from a bovine kidney was found to be antigenically different from all previously recognized serovars of Leptospira interrogans based on the cross-agglutinin absorption test. The new serovar belongs to the Sejroe serogroup, and the name Leptospira interrogans serovar unipertama is proposed for it, with strain K2-1 as the reference strain.
A cross-sectional bacteriological survey of cattle in West Malaysia revealed 14.4% (32/222) had leptospiral infection. Isolates were obtained from all except one herd with prevalence of infection in herds ranging from 0-44.8%. A small number of buffalo urine samples were examined and all of them were found to be negative. A leptospiral isolate obtained from a bovine kidney proved to be a new serovar of Leptospira interrogans and the name unipertama was assigned to it. Six other leptospiral serovars were isolated, namely canicola, australis, javanica, ballum, pomona and hardjo. All six serovars were isolated for the first time in cattle in Malaysia. Cattle in Malaysia appear to be the maintenance host for serovar hardjo. The presence of the other serovars in cattle was probably due to contact with the maintenance hosts, pigs for serovar pomona and rodents for the other three serovars. It appears that the epidemiology of leptospiral infection in cattle in Malaysia is similar to that reported overseas.
This paper reviews the literature on leptospirosis in Malaysia from its first description in 1928 until the present day. Most of the early reports were on investigations of leptospirosis in wildlife and man and up-to-date, thirty-seven leptospiral serovars from thirteen serogroups have been bacteriologically identified. The thirteen serogroups are: Australis, Autumnalis Bataviae, Canicola, Celledoni, Grippotyphosa, Hebdomadis, Icterohaemorrhagiae, Javanica, Pomona, Pyrogenes, Sejroe and Tarassovi. Rats have been ascribed as the principal maintenance host of leptospires in Malaysia. However, serovars from the Pomona, Pyrogenes and Sejroe serogroups have yet to be isolated from rats. It is considered that the majority of leptospirosis cases in man were due to association of man with an environment where rats were plentiful. Recent investigations on domestic animals disclosed a high prevalence of infection in cattle and pigs and they were suspected as being the maintenance host for serovar hardjo and pomona respectively. There is ample scope for research in leptospirosis, particularly in the epidemiology and control of the disease in domestic animals. The strategy to control the infection in domestic animals and man in Malaysia is bound to be different from that of the temperate countries, basically due to the presence of a large number of leptospiral serovars in wildlife, further confounded by geographical and financial constraints.
Pathogenic leptospiras (1,424) isolated from natural waters and wet soils in Malaysia comprised 29 different serovars (synonym serotypes). All except two of the serovars had been found previously in Malaysia. The exceptional serovars were werrasingha, an Autumnalis serogroup member originally isolated in Ceylon, and a new serovar designated evansi. Serovar evansi had serological affinities with serovar ranarum which was isolated from the kidney of a frog in Iowa. The large variety of serovars found in jungle areas was consistent with similar previous findings of diverse serovar infections in troops who had operated in Malaysian jungles.