Portal de Pesquisa da BVS Veterinária

Acta sci. vet. (Impr.); 40(1): Pub. 1014, 2012. tab

Artigo em Inglês | VETINDEX | ID: biblio-1373513

Resumo

Background: The group A rotavirus is the most important ethiological agent that causes diarrhea in newborn humans and animals. They belong to the Reoviridae family and have a genome consisting of 11 segments of double-stranded RNA enclosed in a triple-layered capsid. Rotaviruses are classified in six groups (A to G) based on the VP6 capsid protein or on the migration pattern of genomic segments in polyacrylamide gel. Groups A, B, and C were found either in humans or in animals, while groups D to G were found only in animals. The outer layer is formed by two proteins, VP7 and VP4, which elicit neutralizing antibody responses and form the basis of the current dual classification system in G (VP7) and P (VP4) types. The early diagnostic of this viral infection in raising farms is crucial for preventing the dissemination of the disease among the animals. Latex agglutination tests (LAT) are quick and easily done, and require low financial investments. Materials, Methods & Results: The present study evaluated the Rotavirus Latex® kit (Richmond Immunosystems Diagnostics) currently used with humans for detecting the presence of rotavirus antigen in diarrheic feces of piglets. In order to confirm the results obtained with the LAT, samples were analyzed by EIA with the Ridascreen rotavirus® kit (R-Biopharm). The results were compared with the rotavirus determination test by polyacrylamide gel electrophoresis (PAGE). During March 2007 and March 2008, 328 excrement samples of diarrheic piglets were collected at a hog-raising farm in the state of Rio Grande do Sul, Brazil. Results showed that the rotavirus was present in 38 samples (11.6%) assayed with LAT, while PAGE detected the virus in 26 samples (7.9%). This means that 15 positive cases (4.6%) were not identified by PAGE. This difference shows the higher sensitivity of LAT against PAGE. LAT showed 88.5% of sensitivity, 95% of specificity, 60.5% of positive predictive value, 99% of negative predictive value and 94.5% of accuracy. Discussion: Latex agglutination is easy to perform in a short time and does not require expensive equipment or skilled personnel, and the reagents have long shelf lives. These factors make the LAT suitable and highly efficient for use in a clinical laboratory and a small farm as a rapid screening test for piglet rotavirus. A test used for detecting the etiological agent of gastroenteritis should be fast, easy to use, and specific for anticipating the disease treatment, thus minimizing unnecessary expenses and establishing prophylactic measures to protect the entire flock. The most important factor in choosing the method is the number of samples that should be collected, the qualification of the analysis laboratory, and the type of pathogen that has contaminated the flock. The diagnostic methods most easily applied are based on detecting viral particles or RNA from fecal samples. Most kits available in the market for detecting rotaviruses are designed for humans and are not adequate for use in veterinary diagnosis. Therefore, the results obtained herein presented high sensitivity and specificity for LAT, showing to be a valuable tool for diagnosing rotaviruses in pig feces. This system used in clinical laboratories might also be used in intensive animal farming systems or by small-scale pig raisers in a cooperative system.

Biblioteca responsável: BR68.1