Epidemiology and Infection


Serological titres to Leptospira fainei serovar hurstbridge in human sera in Australia

R. J. CHAPPEL a1c1, D. A. KHALIK a1, B. ADLER a2, D. M. BULACH a2, S. FAINE a2a3, P. PEROLAT a4 and V. VALLANCE a2
a1 Agriculture Victoria, Victorian Institute of Animal Science, Attwood, Victoria 3049, Australia
a2 Department of Microbiology, Monash University, Clayton, Victoria 3168, Australia
a3 MediSci, Armadale, Victoria 3143, Australia
a4 Institut Pasteur, Ho Chi Minh City, Vietnam


A set of 723 diagnostic sera from human patients, submitted for the microscopic agglutination test (MAT) for antibodies to a group of 6 leptospiral serovars, was also tested by MAT for antibodies to the recently-discovered Leptospira fainei serovar hurstbridge. MAT titres of [gt-or-equal, slanted]128 to serovar hurstbridge were detected in 13·4% of these sera, and titres of [gt-or-equal, slanted]512 in 7·2%. In contrast, none of 62 sera obtained from a control population of laboratory staff gave titres of [gt-or-equal, slanted]128. The difference between the number of titres of [gt-or-equal, slanted]128 given by the two groups of sera was highly significant (P<0·01). The titres observed may have been due to cross-reactions with other leptospiral serovars, but this could not be demonstrated. An alternative explanation is that serovar hurstbridge is present in the human population.

(Accepted April 15 1998)

c1 Author for correspondence.