Seroprevalence of leptospirosis in dogs in a city of federal significance

Leptospirosis is a zoonotic disease that occurs worldwide and can cause a variety of symptoms that can be fatal. Bacterial spirochetes of the genus leptospira cause leptospirosis. Dogs become infected through contact with contaminated wildlife urine. Leptospira penetrate mucous membranes and cause endothelial damage in organs such as the liver and kidneys. Pathogenic leptospira persists in the kidneys of mammals and is excreted with their urine for a long time 1. Various wild and domestic animals can act as reservoir hosts for 1 or more serotypes and can excrete the pathogen with urine for months or several years after infection 2.The study conducted monitoring and screening studies to identify the predominant leptospirosis group in dogs. Accounting for foci and outbreaks on the territory of specific municipalities of St. Petersburg, it was found that in the period of 2023 the predominant serogroups L.icterohaemorrhagiae (197 cases), as well as L.cenoptery (24 cases), which is confirmed by high antibody titers up to 1:1600.Analysis of associations with other serovars showed multiple antibody combinations, with L.cynopteryi being the most frequent with 17 findings, followed by l.pomona - 14, followed by L.pyrogenes - 8 findings, L.autumnalis - 4 findings, L.ballum, L.batavia and l.tarasovi - 2 findings each. L.tarasovi - 2 finds each, L.australis , as well as L.javanica 1. The data obtained indicate the need to strengthen preventive measures against leptospirosis. The use of leptospirosis vaccine provides protection against most serogroups of L.icterohaemorrhagiae, L.canicola, L.grippotyphosa, but in the territory of the Russian Federation there are no vaccines against leptospirosis infection of dogs (vaccines of Russian production), which include the following serogroups (Table 1): L.cynoptery, L.pomona, L.pyrogenes, L.autumnalis, L.ballum, L.batavia, L.tarasovi, L.australis, L.javanica. An important aspect of this problem is to conduct and create polyvalent vaccines against leptospirosis with inclusion of the most common serogroups.