Leptospirotic etiology in pulmonary and upper respiratory tract pathology.

A number of 3,200 febrile patients who presented upon admission to hospital primary pulmonary or upper respiratory tract impairment either as single forms of manifestation or associated to other syndromes were tested. The cases were screened by the rapid slide agglutination reaction with heat inactivated Patoc antigen and leptospirotic etiology was confirmed by the ultramicroscopic agglutination reaction with 18 live circulating pathogenic antigens. 64 leptospirosis cases with pulmonary impairment were confirmed and in 52 cases the upper respiratory tract was involved. Particular aspects of leptospirosis with pulmonary impairment: 71.8% of cases had a clinical diagnosis of interstitial pneumonia; 89% of cases presented important chest x-ray modifications; in an approximately equal number of cases the pulmonary involvement was the single manifestation or was associated with other syndromes; icterohaemorrhagiae, wolffi and pomona were the frequently encountered infecting serotypes. Particular aspects for leptospirosis involving the upper respiratory tract: 84.6% of cases had a clinical diagnosis of acute rhino-pharyngotracheitis; in 86.5% of cases the upper respiratory tract impairment was the single feature; the infecting serotypes were in decreasing order of frequency as follows: icterohaemorrhagiae, pomona, wolffi, canicola, grippotyphosa.