Leptospira Laboratory

In addition to its research function, the laboratory also performs a diagnostic serology service for human leptospirosis for the state of Victoria, with an annual throughput of approximately 1000 sera. It is accredited for testing by the National Association of Testing Authorities and by the Royal College of Pathologists of Australasia.

The Microscopic Agglutination Test (MAT) is the World Health Organisation (WHO) gold standard test to diagnose infection with Leptospira.

Attempts to culture the organism have an extremely low success rate and are therefore not useful for individual diagnosis.

The IgM ELISA can sometimes become positive slightly earlier than the MAT, but suffers from both false positive and false negative problems and gives no indication of the infecting serovar and therefore of potentially important epidemiological information. Reliance on ELISA alone is not recommended.

Attempts to detect leptospiral DNA by PCR is meaningless if negative and gives no information on infecting serovar. Additionally, the WHO recommends MAT confirmation of all PCR-positive sera.

In general, blood for serology should be taken as soon as possible in the illness. A second specimen should be taken 5-7 days later if the clinical picture and history indicate significant possibility of infection, and repeated at similar intervals if necessary. The test may be negative in the early stages, but the second specimen may be positive or show a rise in titre compared with the first. A third or later successive specimen usually shows a rise in titre to a peak in 2-3 weeks. Sometimes antibodies do not appear until 3-4 weeks after infection, or rarely, even longer.

When infection with Leptospira is present, a significant titre (400 or higher) will generally remain for many months, so a significant titre can mean a current or previous infection. A rising titre of 4-fold or greater is highly suggestive of recent infection.

The laboratory may be contacted at:

Telephone: +61 3 9902 9193
Facsimile: +61 3 9902 9224
Email: med-lepto@monash.edu

Address:  Leptospirosis Laboratory, Department of Microbiology, Level 2 Building 76,  Wellington Road, Clayton, Victoria, 3800

For a list of publications on Leptospira and leptospirosis.

Clinical laboratory diagnosis of leptospirosis