Pathogenesis of Leptospirosis: Important Issues

Leptospirosis is a re-emerging tropical infectious disease [1], is an important zooanthroponotic disease spread-worldwide [2]. The spirochetes of the genus Leptospira is responsible of human and animal leptospirosis characterized as mild febrile illness to severe multiorgan failure, especially pulmonary hemorrhage and renal failure [3]. Pathogenic leptospires are highly motile and invasive spirochetes that have the capacity to survive and grow in tissue by escaping natural defense mechanism [4]. The disease is transmitted to humans by direct or indirect exposure to contaminated urine from mammalian reservoir hosts as rodents but also farm, wild, and domestic mammals [5]. Asymptomatic form of leptospirosis with fever, headache, and myalgia that can spontaneously resolve is one of clinical presentations [3]. The most cases are probably inapparent and associated with host-adapted serovars such as Canicola in dogs, Bratislava in horses and pigs, Hardjo in cattle and Australis and Pomona in pigs [6-9].