Survival of leptospires in commercial blood culture systems.

Laboratory diagnosis of leptospirosis depends on the serological findings and, if possible, the isolation of the organisms. During the period 1981-1982 there were 40 blood cultures submitted from serologically positive patients and a successful isolation rate of only 12% was attained. Correct media, method of collection of suspect blood and laboratory technique all contribute to the successful isolation of the organism. Because of the low isolation rate an investigation was undertaken of various blood culturing systems used in Great Britain. Results obtained showed that certain blood culture media were able to maintain the organism better and therefore increase the isolation rates of leptospira. Factors affecting the isolation rate are presented.