Serological prevalence of Leptospira serovars among pigs in Ukraine during the period of 2001–2019

Abstract

Leptospirosis is a widespread infection among pigs throughout the world. In most cases in Ukraine, only the microscopic agglutination test (MAT) is used for the diagnosis of leptospirosis in animals. In general, during the period of 2001–2019, 2 381 163 samples of blood sera from swine were tested in our country and 85 338 positive reactions were received, which is 3.58% [binomial confidence intervals (BCI), 3.56–3.61%]. It was established that the serovars copenhageni – 33.91% (BCI, 33.59–34.23%), bratislava – 14.14% (BCI, 13.90–14.37%), pomona – 8.58% (BCI, 8.39–8.77%), and tarassovi – 7.12% (BCI, 6.95–7.30%) play a leading role in the aetiological structure of swine leptospirosis. A large number of positive reactions to several serovars was observed – 29.78% (BCI, 29.47–30.09%) of the total number of positive cases. In addition, the article presents data according to a retrospective analysis of the eight serovars circulating among pigs in Ukraine. Thus, during the nineteen year period, there was a decrease in the number of positive reactions to bratislava, pomona, and tarassovi and an increase in the number of positive reactions to copenhageni, polonica, and kabura. Mapping Ukraine’s territory for leptospirosis among pigs was carried out. This allows one to identify zones with a risk of leptospirosis infections among swine. The maps show that the highest incidence rates were identified in the eastern and central parts of Ukraine.