Indiana the Detection of Antibodies to Vesicular Stomatitis Virus New Jersey and Vesicular Stomatitis Virus Comparison of the Serum Neutralization Test and a Competitive Enzyme-Linked Immunosorbent Assay for

A competitive enzyme-linked immunosorbent assay (C-ELISA) for the detection of antibodies against vesicular stomatitis virus New Jersey (VSV-NJ) and vesicular stomatitis virus Indiana (VSV-IN) was compared with the serum neutralization test (SNT) using 1,106 serum samples obtained from dairy cattle on sentinel study farms in the Poas region of Costa Rica. Kappa coefficients between the C-ELISA and the SNT were 0.8871 (95% confidence interval [CI]: 0.8587–0.9155) and 0.6912 (95% CI: 0.6246–0.7577) for the VSV-NJ and VSV-IN tests, respectively. These results indicate good to excellent agreement between the 2 tests under these conditions. Vesicular stomatitis (VS), a viral disease which primarily affects cattle, horses, and swine, occurs in endemic and epidemic forms in the tropical and subtropical areas of the Americas.1 In temperate regions of Mexico and the United States, VS causes epidemics at variable intervals, whereas in southern Mexico and throughout Central and South America the disease is considered endemic.9 VS is mainly caused by 2 major serotypes of vesicular From the Posgrado Regional en Ciencias Veterinarias Tropicales (Alvarado, Dolz, Herrero) and the Programa de Investigacion en Enfermedades Tropicales (Dolz, Herrero), Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica, the Centers for Epidemiology and Animal Health, Veterinary Serices, USDA, APHIS, Ft. Collins, CO 80521 (McCluskey), and the Center of Veterinary Epidemiology and the Animal Disease Surveillance Systems, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Ft. Collins, CO 80523-1676 (Salman). Received for publication ?? stomatitis virus, New Jersey (VSV-NJ) and Indiana (VSVIN), of the genus Vesiculovirus in the family Rhabdoviridae and order Mononegavirales.1 Both viruses have a negative sense single-stranded RNA genome and 5 distinct proteins (L, G, N, P, and M). The serum of infected cattle contains high titers of virus-neutralizing antibodies induced by the surface glycoprotein (G). The nucleocapsid (N) protein is highly antigenic, induces a nonneutralizing antibody, and plays a central role in the regulation of transcription and replication of viral RNA.2 Both serotypes cause identical lesions on the epithelia of the mouth and tongue and on the coronary bands of cattle, pigs, and horses. In cattle, the 2 serotypes also affect the teats, making milking difficult. The importance of the disease resides in its clinical resemblance to foot-and-mouth disease (FMD) and the productivity losses it produces through anorexia, lameness, reduced milk yield, and mastitis. In addition, VS viruses infect humans, causing clinical by guest on May 23, 2011 vdi.sagepub.com Downloaded from 241 Brief Communications Table 1. Comparison of serum neutralization test (SNT) and competitive ELISA for detection of antibodies to VSV-NJ. Kappa coefficient 5 0.8871 (95% confidence interval: 0.8587–0.9155).