Seroprevalence and associated risk factors for brucellosis and leptospirosis in swine raised in small-scale farms from rural communities of Tandil county (Buenos Aires province, Argentina)

Abstract

Brucellosis and leptospirosis are zoonoses that cause reproductive diseases in pigs. Small-scale pig farming in rural communities represents a significant economic activity in Buenos Aires province, Argentina. The aims of this work were to determine the seroprevalence of leptospirosis and brucellosis in pigs reared in small-scale farms from rural areas of Tandil county, to analyze the associated risk factors, to describe the prevalent Leptospira serogroups and to determine the spatial distribution of both diseases. A total of 340 serum samples were obtained. Buffer Plate Agglutination Test, Rose Bengal Test, and Fluorescence Polarization Assay were used to detect antibodies against Brucella spp. Microscopic Agglutination Test was applied for serological diagnosis of leptospirosis. Statistical methods were used to evaluate the factors associated with the infections. Seroprevalences of 0% and 22.6% were observed for brucellosis and leptospirosis, respectively. The most prevalent Leptospira serogroups identified were Canicola, Ballum, Icterohaemorrhagiae and Pomona. The main risk factors associated with leptospirosis infection were the higher number of pigs, the presence of horses and wild boars near or within the farms. The use of milling by-products of cereal grains as animal feed and the presence of weaning cage were also associated. A relevant spatial cluster of seropositivity to Leptospira spp. was identified in a low altitude area. Our results suggest that brucellosis probably was controlled in these productions but leptospirosis was present. Knowledge of leptospirosis and brucellosis seroprevalence, spatial distribution, and associated risk factors can be useful for prevention and control of endemic zoonotic diseases in the region.