Research Article Leptospirosis in Vellore: A Clinical and Serological Study G. Vimala, 1 A. Mary Josephine Rani, 1 and V. Raja Gopal 2 1 Department of Zoology, Auxilium College, Vellore, Tamil Nadu 632006, India 2 Zonal Entomological Team, Vellore, Tamil Nadu 632001, India Correspondence should be addressed to A. Mary Josephine Rani; josephineanto@yahoo.com Received 17 February 2014; Accepted 9 June 2014; Published 23 June 2014 Academic Editor: Sudarsan Mukhopadhyay Copyright © 2014 G. Vimala et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Leptospirosis is a severe spirochetal zoonosis in the world. It is considered an occupational disease of persons engaged in agriculture, sewage works, forestry, and animal slaughtering. A study was conducted with an objective of assessing the seroprevalence of leptospirosis in and around Vellore district, Tamil Nadu. Te study was based on the signs and symptoms of the patients reporting fever in Vellore Municipal Clinic (Urban Malarial Scheme). Blood samples were collected from 129 patients. Animal studies were conducted from 24 rodents captured form the market place of the Vellore municipality. In the ZET (Zonal Entomological Team, Vellore) Laboratory the sera were examined by macroscopic slide agglutination test (MSAT). In the MAST, totally 10 positive leptospiral cases from human beings and 10 positive leptospiral cases from rats (Rattus rattus and Rattus norvegicus) were found out. Ten both positive cases of leptospiral vials were labeled, sealed, and sent to the Leptospirosis Research Laboratory, Madhavaram, Chennai, for further serovars examination. Among the various serovars identifed autumnalis was more prevalent. Our fndings showed that the age groups between 15 and 55 years showed more susceptibility. Particularly the adults were more infected. Te majority of seropositive individuals in the cases had only subclinical infection. Rodents were abundant and contributed to enzootic and endemic prevalence of leptospirosis. 1. Introduction Leptospirosis is a common zoonosis worldwide that afects mammals, including human beings. Infection is endemic and occurs with greatest frequency in tropical and subtropical regions. It is emerging as an important public health problem in India [1–3]. Both humans and animals can be directly infected through contact with infected tissue or urine or indirectly through contact with contaminated soil and water [4, 5]. In humans, typical symptoms can include fever, headaches, chills, vomiting, sore muscles, jaundice, red eyes, abdominal pain, diarrhea, and rashes. Leptospirosis can become considerably dangerous if not treated, potentially leading to kidney damage, meningitis, liver failure, and respiratory problems [5]. Leptospirosis has been recognized as an important occu- pational hazard of agriculture manual laborers, sewage work- ers, animal handlers, forestry workers and other outdoor workers who work in wet conditions, and butchers. Te transmission cycle involves interaction between one or more animal hosts harboring leptospires, an environment favorable for its survival, and human beings. Leptospirosis in human occurs in two courses: anicteric or benign (between 85 and 90% of cases) and icteric or serious, also known as Weil’s diseases (between 10 and 15% of cases). Te wide spectrums of clinical symptoms that characterize leptospirosis make its diagnosis easily confused with other febrile diseases [6]. Leptospira interrogans, which causes human leptospirosis, consists of over 24 serogroups made up of a large and expanding number of serovars. Serogroups and their member serovars causing leptospirosis difer from region to region. Tese are identifed by specifc laboratory tests like isola- tion of organism by culture, specifc antigen detection by gene amplifcation by polymerase chain reaction (PCR), or antibody detection by microscopic agglutination test (MAT). MAT uses whole leptospire as antigen and detects both lgM and lgG antibodies. IgM antibodies may disappear afer six months and IgG antibodies persist for two to 10 years afer Hindawi Publishing Corporation International Journal of Microbiology Volume 2014, Article ID 643940, 5 pages http://dx.doi.org/10.1155/2014/643940