Virus del síndrome reproductor y respiratorio porcino (PRRSV) en granjas porcinas tecnificadas del Estado de México.

Porcine reproductive and respiratory syndrome virus (PRRSV) in technified pig farms from the State of México.

PORCINE reproductive & respiratory syndrome; EPIDEMICS; LEUCOPENIA; MENTAL depression; LYMPHOID tissue

Se realizó un estudio transversal por conglomerados en una etapa, de abril a septiembre de 2011, en cerdos de más de 11 semanas de edad, de 11 granjas, para analizar la situación de PRRSV en granjas tecnificadas del Estado de México. Se colectaron muestras de suero (n=220) para ELISA y sangre (n=80) para transcripción en reversa y reacción en cadena de la polimerasa en tiempo real en un solo paso (RTqPCR) para PRRSV, e hisopos nasales (n= 425) para el aislamiento de posibles bacterias patógenas de la enfermedad del complejo respiratorio porcino (CRP). También se aplicó un cuestionario. ELISA mostró una seroprevalencia verdadera de 30.67 %, siendo mayor la probabilidad de ser seropositivos en granjas con antecedentes y calendario de vacunación y de ubicación urbana-semiurbana; los cerdos fueron seroreactivos en 7/11 granjas (63.63 %). RTqPCR mostró viremia en 2/80 (2.5 %) cerdos analizados, de 2/11 granjas (18.18 %); una cerda infectada con PRRSV norteamericano que mostró signos clínicos de la enfermedad y una cerda infectada con PRRSV europeo que no mostró ningún signo clínico evidente de infección. Dos granjas no mostraron cerdos seropositivos o virémicos, no tienen antecedentes ni calendario de vacunación y están ubicadas en una zona semirural. En todas las granjas se aisló Staphyloccus aureus y Streptococcus suis; en algunas granjas y con menos frecuencia Actinobacillus spp (4/11) y Pasteurella spp (3/11). Es el primer reporte en México de infección por PRRSV europeo. [ABSTRACT FROM AUTHOR]

A cluster cross sectional study in a single stage was carried out from April to September 2011 on pigs over 11 wk old from 11 farms, to analyze the viral porcine reproductive and respiratory syndrome (PRRSV) status of technified farms of the State of Mexico. Sera samples (n=220) for ELISA, blood samples (n=80) for one step real-time quantitative reverse transcriptase--PCR (RTqPCR), nasal swabs (n=425) for bacterial isolation of possible porcine respiratory disease complex syndrome (PRDC) pathogens were collected. Additionally information about individuals and farm condition was gathered for further analysis. ELISA shows a 30.67 % PRRSV true seroprevalence been more as likely to be seropositives in farms with PRRSV background and vaccination schedule and of urban-semiurban location; pigs were seroreactive for PRRSV in 7/11 farms (63.63 %). Viremia was found through RTqPCR in 2/80 (2.5 %) of the total of pigs sampled for it, and was in 2/11 farms (18.18 %). We found a sow infected with a European PRRSV that did not show any evident clinical signs of infection, and a sow with a North American PRRSV who displayed clinical signs of the disease. Two farms didn´t show seropositive or viremic pigs; these two farms had no PRRSV background or PRRSV vaccination schedule and are located in a semirural area. Staphyloccus aureus and Streptococcus suis where isolated from all the farms and Actinobacillus spp (4/11) or Pasteurella spp (3/11) where found less frequently in some farms. This is the first report in México of a European type PRRSV infection. [ABSTRACT FROM AUTHOR]

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