Serological monitoring of vesicular stomatitis New Jersey virus in enzootic regions of Costa Rica
Fecha
1990-03
Autores
Rodríguez, Luis L.
Vernon, Suzanne
Morales, Ana I.
Letchworth, Geoffrey J
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Editor
American Society of Tropical Medicine and Hygiene
Resumen
Se monitoreó la actividad de los virus de la estomatitis vesicular en 3 tambos de Costa Rica. Se midieron los niveles de anticuerpos y se controló la enfermedad clínica en 165 bovinos durante un período de 20 meses (1986-1988). Se demostró que el virus de la estomatitis vesicular de Nueva Jersey (VS NJ) es enzoótico en estas granjas con una prevalencia del 94,2% de anticuerpos neutralizantes; esto no varió significativamente entre rebaños. La prevalencia media de anticuerpos contra el virus de la estomatitis vesicular Indiana (VS IN) fue del 15,2%, pero fue significativamente mayor en 1 rebaño. Se informó un total de 25 casos (tasa de incidencia anual del 9%) de estomatitis vesicular clínica (EV). El virus VS NJ se identificó como el agente causal mediante la detección de antígenos del virus VS NJ mediante la prueba de fijación del complemento. El virus VS NJ se aisló en 11 casos. Todos los episodios de enfermedad ocurrieron entre noviembre y enero, inicio de la estación seca. La mayoría de los animales mantuvieron títulos de anticuerpos neutralizantes estables durante todo el estudio, y todos los animales enfermos fueron previamente seropositivos al virus VS NJ. Un total de 31 animales con anticuerpos neutralizantes contra el virus VS NJ tuvieron una respuesta IgM específica del virus VS NJ, y 6 animales tuvieron respuestas IgM que persistieron durante hasta 6 meses. No hubo relación entre las respuestas de IgM y la aparición de enfermedades clínicas. El virus VS NJ persistió predominantemente como una infección subclínica en bovinos durante todo el año en áreas enzoóticas de Costa Rica. La respuesta humoral no evitó la reinfección por el virus VS NJ.
The activity of vesicular stomatitis viruses was monitored on 3 dairy farms in Costa Rica. Antibody levels were measured and clinical disease monitored in 165 cattle during a 20 month period (1986–1988). Vesicular stomatitis New Jersey (VS NJ) virus was shown to be enzootic on these farms by a 94.2% prevalence of neutralizing antibody; this did not vary significantly between herds. The mean prevalence of antibody to vesicular stomatitis Indiana (VS IN) virus was 15.2%, but was significantly higher in 1 herd. A total of 25 cases (annual incidence rate of 9%) of clinical vesicular stomatitis (VS) was reported. VS NJ virus was identified as the causal agent by detection of VS NJ virus antigens by the complement fixation test. VS NJ virus was isolated in 11 cases. All episodes of disease occurred between November and January, the beginning of the dry season. Most animals maintained stable neutralizing antibody titers throughout the study, and all diseased animals were previously seropositive to VS NJ virus. A total of 31 animals with neutralizing antibodies to VS NJ virus had a VS NJ virus-specific IgM response, and 6 animals had IgM responses that persisted for as long as 6 months. There was no relation between IgM responses and clinical disease occurrence. VS NJ virus persisted predominately as a sub-clinical infection in cattle throughout the year in enzootic areas of Costa Rica. The humoral response did not prevent reinfection with VS NJ virus.
The activity of vesicular stomatitis viruses was monitored on 3 dairy farms in Costa Rica. Antibody levels were measured and clinical disease monitored in 165 cattle during a 20 month period (1986–1988). Vesicular stomatitis New Jersey (VS NJ) virus was shown to be enzootic on these farms by a 94.2% prevalence of neutralizing antibody; this did not vary significantly between herds. The mean prevalence of antibody to vesicular stomatitis Indiana (VS IN) virus was 15.2%, but was significantly higher in 1 herd. A total of 25 cases (annual incidence rate of 9%) of clinical vesicular stomatitis (VS) was reported. VS NJ virus was identified as the causal agent by detection of VS NJ virus antigens by the complement fixation test. VS NJ virus was isolated in 11 cases. All episodes of disease occurred between November and January, the beginning of the dry season. Most animals maintained stable neutralizing antibody titers throughout the study, and all diseased animals were previously seropositive to VS NJ virus. A total of 31 animals with neutralizing antibodies to VS NJ virus had a VS NJ virus-specific IgM response, and 6 animals had IgM responses that persisted for as long as 6 months. There was no relation between IgM responses and clinical disease occurrence. VS NJ virus persisted predominately as a sub-clinical infection in cattle throughout the year in enzootic areas of Costa Rica. The humoral response did not prevent reinfection with VS NJ virus.
Descripción
Palabras clave
ESTOMATITIS, BOVINOS, ENFERMEDADES EN BOVINOS, COSTA RICA, VIROSIS, STOMATITIS, BOVINE, DISEASES IN BOVINE, COSTA RICA, VIROSIS