Seasonal variation in the prevalence of leptospirosis in stray dogs in the citv of S. Paulo (Brazil)

Utilizando a técnica da soroaglutinação microscópica para o diagnóstico de leptospirose, 308 (21,6%) de 1428 soros de cães errantes da cidade de São Paulo (Brasil) mostraram-se reagentes. Na população canina estudada, a infecção leptospirótica sofreu influência sazonal. Verão (24,2%) e outono (24,9%) foram as estações do ano com maior número de soros reatores, em oposição à primavera (18,3%) e inverno (18,3%). Estas diferenças foram significantes, estatisticamente. Ô sorotipo canicola é o principal causador da leptospirose na população estudada (50,7%), seguido do icterohaemorrhagiae (25,5%); grippotyphosa (7,8%); pomona (6,7%) e ballum (4,4%).One thousand, four hundred and twenty-eight sera from stray dogs from the city of S. Paulo were examined using agglutination microscopic testing. Of the total of 1428 sera, 308 (21.6%) showed positive. Seasonal influence was observed in the leptospiral infection of the canine population studied in that the largest number of the reagent sera was verified in the summer (24.2%) and autumn (24.9%). In contrast, spring (18.3%) and winter (18.3%) prevalence levels were lower. These differences were considered significant from the statistical point of view. The canicola serotype was found to be the main cause of leptospirosis in the population examined (50.7%), followed by icterohaemorrhagiae (25.5%), grippetyphosa (7.8%), pomona (67%), and ballum (4.4%)