Leptospiral Meningitis

Although research on the leptospiroses was initiated in 1886 with Weil's report on the clinical picture of a disease suspected to be a separate entity, it was not until 1910 that the first cases of what appeared to be meningitis of leptospiral origin were reported in the French medical literature.1-4 In 1915, Inada and Ido, in Japan, and Uhlenhuth and Fromme, in Germany, proved that Weil's disease was caused by a spirochete, which was later classified as Leptospira by Noguchi.1,2,5 Conclusive experimental evidence in support of the role of the Leptospira icterohaemorrhagiae in the production of meningeal manifestations, which frequently accompany the leptospiroses in the icteric and anicteric forms, appeared in 1916.6,7 Physical signs and symptoms of meningitis have been reported in 10% to 33% of large series of cases in the European medical literature.8,9 However, even in the absence of clinical signs pointing to meningeal involvement, significant alterations of