Equine leptospirosis: results of laboratory control in the Russian Federation

Abstract

An analysis of the results of equine leptospirosis diagnostics by methods used in practice in state veterinary laboratories of the Russian Federation (bacteriological, serological (microagglutination reaction and enzyme-linked immunosorbent assay (ELISA)), molecular genetic (polymerase chain reaction method) for the period 2018-2020 is presented in the article. The veterinary laboratories of the Russian Federation received 225,582 horses blood serum samples for research on leptospirosis, for which research was carried out in the microagglutination reaction – 1,516,087, in ELISA – 1,039, 12,770 samples reacted positively. The analysis of the reported data for the last three years in the 4-vet form showed that the epizootic situation in equine leptospirosis in the Russian Federation remains difficult. The level of infection of horses with Leptospira averaged 5.7%. In 2020, the largest number of positive responders in microagglutination reaction were detected in 9 regions; among the studied animals, specific leptospirotic antibodies were found from 1.6% to 65.0% of cases. The dominant serogroups of leptospira in horses in the Russian Federation are Icterohaemorrhagiae and Grippotyphosa, up to 34% and 19.7%, respectively. Over the past three years, 1,907 urine samples from horses have been examined by dark-field microscopy; live leptospira have been found in only 1 case. To improve the epizootic situation in horses leptospirosis in Russia, it is necessary to increase the number of bacteriological and molecular biological studies for the timely detection of the causative agent of the disease – L. interrogans. In disadvantaged regions, it is necessary to use antileptospirosis vaccines in accordance with the specific etiological structure of animal leptospirosis, which is relevant for a specific territory.