Clinical observation and treatment of leptospirosis.

The epidemiological and clinical observations of 240 patients with Weil's disease and 10 patients with canicola fever, and these observations in two epidemics of canicola fever, are presented. Early diagnosis is most important for the prognosis of patients with the severe form of leptospirosis. It depends on the clinical features, clinical laboratory findings, and the epidemiological situation. The most characteristic clinical signs for early diagnosis were febrile illness of sudden onset, severe general malaise, muscular pain, and conjunctival congestion. Proteinuria, leukocytosis with neutrophilia, and raised erythrocyte sedimentation rate were the most indicative clinical laboratory findings for early diagnosis. Although jaundice and hemorrhage are the most important signs of the severe form of leptospirosis, Weil's disease, these are rarely useful in early diagnosis. Of a variety of antibiotics used, penicillins and cephems had the lowest minimal inhibitory concentration against leptospires. However, it became apparent from basic studies in vitro and in vivo that streptomycin showed the best bactericidal action against leptospires and that it was the most effective anti-leptospiral antibiotic. Gentamicin, tobramycin, and isepamicin are also effective as alternatives to streptomycin. Although penicillins, cephems, tetracyclines, and macrolides are also effective for the treatment of leptospirosis, when these antibiotics with inadequate bactericidal activity are used for the treatment of the disease, long-term therapy with sufficiently large doses may be required from an early stage of the disease until the appearance of antibodies.