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.