Serological survey of leptospirosis in calves in Tehran suburb

Leptospirosis is one of the main causes of acute febrile illness and is presumed to be the most widespread zoonotic disease in the world. Cattle populations may be infected with serovars Hardjo، Pomona and Grippotyphosa. Infection with Icterohaemorrhagiae، Bratislava، Hebdomadis، Autumnalis، Australis، Sejroe، Canicola and Bataviae serovars also occurs. In this study، 200 serum samples were collected from calves of 2-8 months-age from Tehran suburbs farms during October 2009 and May 2010. Sera were tested for antibodies against 6 serovars of Leptospira interrogans including: Hardjo، Pomona، Canicola، Grippotyphosa، Icterohaemorrhagiae and Ballum using standard microscopic agglutination test (MAT) and titers of ≥ 1/100 were considered to be positive. The results of this study showed that 58 (29%) of the calves were MAT positive، mainly to serovar Pomona. In October the most prevalent Leptospira serovar was Pomona and in May the most prevalent Leptospira serovar was Grippotyphosa. The aim of this study was to evaluate the presence of leptospiral antibodies in calves which did not show any clinical symptoms of leptospirosis and comparing two months in our study zone. It is concluded that the managers and veterinarians must pay more attention to the herd’s health because of biosecurity، specially in rainy months for preventing calves from becoming a source of continues infection in the herds.