Short communication A rapid latex agglutination test for detection of leptospiral antibodies P. Ramadass * , B. Samuel, K. Nachimuthu Department of Animal Biotechnology, Madras Veterinary College, Chennai, India Received 30 December 1997; accepted 19 August 1999 Abstract A rapid semi-quantitative latex agglutination test (LAT) has been standardized for the detection of leptospiral antibodies in serum samples of man and animals. The efficacy of the LAT was compared with the plate enzyme linked immunosorbent assay (ELISA). A total of 276 human serum samples were analyzed by both LAT and ELISA and percentage positives were 84.8 and 85.9%, respectively. Similarly, of 65 animal samples tested, 63.1 and 69.2% positivity were observed in LATand ELISA, respectively. Even though the ELISA test was slightly more sensitive than LAT, the rapidity, simplicity and economics of the LATwere found to fulfill the requirements of a screening test for leptospiral antibodies. # 1999 Elsevier Science B.V. All rights reserved. Keywords: Leptospira sp.; Antibodies; Latex agglutination test; Diagnosis-bacteria 1. Introduction Leptospirosis is a disease of livestock and man caused by Leptospira interrogans. Traditionally, diagnosis of leptospirosis depends on the demonstration of leptospires in clinical samples by dark field microscopy (DFM); by demonstration of leptospiral antibodies by microscopic agglutination test (MAT) or enzyme linked immunosorbent assay (ELISA) or by culturing of leptospires. Anti-leptospiral antibodies are detectable by the 7th day of illness. Detection of leptospires in blood and urine by DFM is not always possible and the possibilities of false positive results are greater with inexperienced workers. Demonstration of leptospiral antibodies by MAT requires good laboratory facilities for maintenance and culturing of different leptospiral strains. ELISA methods Veterinary Microbiology 70 (1999) 137±140 * Corresponding author. Tel.: +91-44-581506; fax: +91-44-560114. E-mail address: ramadass@rocketmail.com (P. Ramadass) 0378-1135/99/$ ± see front matter # 1999 Elsevier Science B.V. All rights reserved. PII:S0378-1135(99)00133-9