Leptospirosis in south-american camelids. A study on the serological prevalence in different regions of Argentina

Abstract

Leptospirosis is a zoonotic infectious disease, affecting wild and domestic animals and human beings, caused by pathogenic spirochetes, spread world wide, belonging to the genus Leptospira. It is transmited by direct contact with infected animal urine or tissues, and indirectly through contaminated water and soil. 
Leptospirosis has a negative economic impact on porcine and bovine productions. It causes abortions, stillbirths, placental retention, infertility and chronical renal deficiency, causing disturbance of flow milk and quality in dairy cattle. Studies on south-american camelids productive aspects, have increased during the last decades, in order to promote alternative regional economies. 

There exist three species in Argentina, llama (Lama glama), guanaco (Lama guanicoe) and vicuña (Vicugna vicugna). The knowledge of physiological parameters and susceptibility and immune response to infectious agents of these animals, are required to improve their breeding efficiency.  Leptospirosis is an infectious disease, which may affect reproduction efficiency.

Leptospira antibody prevalence in 494 sera obtained from healthy non vaccinated llamas, vicuñas and guanacos from different geographic zones in Argentina,  was evaluated. The serovar specific microaglutination test (MAT) was applied, using live serovares of Leptospira spp.

This study revealed prevalence results between, 47.3% and 96.2% in llamas, 0 and 13% in guanacos and  9 and 62.8% in vicuñas. The more frecuently reactive serovares were copenhageni (serogroup Icterohaemorrhagiae), and castellonis (serogroup Ballum), serogroups which have already been isolated from humans and domestic or wild animal infections, in our country (Dorta de Mazzonelli y col., 1997; Rosetti y col., 2000). From these results, it might be inferred  that urine of domestic or wild species which lived with studied camelids,  could have been the contagious source.