ABSTRACT In 2006, the International Organization for Standardization (ISO) published two standard protocols for the detection and enumeration of Campylobacter spp. in foods: the ISO 10272-2(direct method) and the ISO 10272-1 (enrichment method). The aim of this study was to compare the efficiency of these two methods in the detection of Campylobacter spp. and propose a modification in the enrichment method. Compared with the enrichment method, the direct method yielded a higher number of positive results for Campylobacter spp. and, consequently, presented higher sensitivity percentage. The isolation of Campylobacter spp. was more difficult when 10 mL of rinse was used in the enrichment method, which is currently recommended by the ISO protocol. Therefore, different rinse volumes were tested (2.5 and 5 mL). The most efficient recovery of Campylobacter spp. occurred when 2.5 mL of rinse were used in the enrichment method, most likely due to a lower number of microbial contaminants than that present in the 5 or 10 mL rinses. The proposed modification of the enrichment method will contribute to the food analysis by improving the detection of Campylobacter spp. in chicken carcass.

Introducción. El foco enzoótico del subtipo ID del virus de la encefalitis equina venezolana en la región del Magdalena Medio produce esporádicamente casos en humanos. El registro de un caso en una niña de tres años en el caserío de Chingalé, municipio de Puerto Wilches, Santander, motivó este estudio. Objetivo. Evaluar el caserío de Chingalé como probable sitio de infección. Materiales y métodos. En junio de 2005 se recolectaron mosquitos con trampas de luz CDC dentro y fuera de las casas; también se colocaron trampas Trinidad y hámster centinela alrededor de las viviendas. Resultados. En 107 muestreos se recolectaron 14.423 mosquitos distribuidos en 35 especies. La abundancia relativa de los posibles vectores del subtipo ID del virus de la encefalitis equina venezolana encontrados, Culex (Melanoconion) pedroi y Cx. (Mel) ocossa, en general, fue baja (<4%). Estas dos especies fueron más frecuentes en el exterior de las viviendas que en los dormitorios: Cx. ocossa en las trampas CDC y Cx. pedroi en las Trinidad. C. ocossa fue más frecuente en las viviendas. Además, este estudio detectó Psorophora confinis, considerado posible vector de subtipos epidemo/epizoóticos y una alta frecuencia de Mansonia indubitans en las viviendas. Los hámster expuestos no se infectaron. Conclusiones. La niña pudo infectarse en su casa o cerca de ella, aunque el ciclo epidemiológico del virus no tiene lugar en el casco urbano de Chingalé. Posiblemente ocurre en un lugar cercano y Culex (Melanoconion) infectados llevan el virus al caserío, en donde algunos mosquitos incursionaron a alimentarse.

Introduction. The enzootic focus of subtype ID of Venezuelan equine encephalitis (VEE) virus in the Central Magdalena region (central Colombia) occasionally produces human cases. The report of a VEE infection in a three-year-old girl in the small Chingalé, municipalitype of Puerto Wilches, Santander, motivated this study. Objective. The village of Chingalé was evaluated as the probable site of infection. Materials and methods. In June 2005, mosquitoes were collected with CDC light traps in and outside of dwellings in the village. Trinidad traps were placed in nearby vegetation, and hamsters were used as sentinel animals near homes. Results. One hundred and seven samples, consisting of 14,423 mosquitoes of 35 species were collected. The relative abundance of incriminated vectors of subtype ID of VEE, Culex (Melanoconion) pedroi and Cx. (Mel.) ocossa, was generally low (<4%), but both species were more frequent outside of dwellings than indoors. Cx. (Mel.) ocossa was collected in CDC traps and was more frequent indoors,whereas Cx. (Mel.) pedroi was found in the Trinidad traps. In addition, Psorophora confinnis was present, recognized as a potential vector of the epidemo/epizootic subtype. Mansonia indubitans, another recognized vector, was present at high frequency within dwellings. The exposed hamsters did not become infected. Conclusion. The child may have been infected in or near her home, although the epidemiologic cycle of the virus was not demonstrated within the village of Chingalé. Possibly, infected Culex mosquitoes of the subgenus Melanoconion carried the virus into the village from a neighboring habitat.