Porcine Circovirus Type 2 (PCV-2) Coinfections in US Field Cases of Postweaning Multisystemic Wasting Syndrome (PMWS)

Abstract

The prevalence of different pathogens detected in combination with porcine circovirus type 2 (PCV-2) was studied retrospectively in field cases of postweaning multisystemic wasting syndrome (PMWS) diagnosed at the Iowa State University Veterinary Diagnostic Laboratory, Ames, Iowa, between January 2000, and September 2001. The presence of PCV-2 antigen in lymphoid tissues and/or lung, demonstrated by immunohistochemistry, together with moderate to severe lymphoid depletion and/or granulomatous lymphadenitis, was used as the criteria for the diagnosis of PMWS. A total of 484 cases fulfilled these criteria. Most of the cases (294/369) of PMWS occurred in pigs between the ages of 8 and 18 weeks, with a peak at 10 weeks of age. Porcine reproductive and respiratory syndrome virus was detected in 51.9% of the cases, Mycoplasma hyopneumoniae in 35.5%, bacterial septicemia in 14.0%, bacterial pneumonia in 7.6%, swine influenza virus in 5.4%, and PCV-2 alone in 1.9%. In cases with bacterial septicemia the most frequently isolated pathogen was Streptococcus suis. In cases with bacterial pneumonia, Pasteurella multocida was the most prevalent.

Micoplasma hyopneumoniae associado ao circovírus suíno tipo 2 em plantéis não vacinados para micoplasmose

“…A ocorrência de coinfecções do PCV2 com outros agentes virais ou bacterianos é bem estabelecida e tem sido relatada em diversos estudos (CARRASCO et al, 2000;PALLARÉS et al, 2002;ALLAN et al, 2004;GRAU-ROMA et al, 2011).…”

“…Em estudo realizado nos EUA durante os anos de 2001 e 2002, 19% dos suínos com PCVAD foram diagnosticados como coinfectados com PCV2 e M. hyopneumoniae, antecedido em número de casos apenas pelo vírus da síndrome reprodutiva e respiratória suína (PRRSV) (PALLARÉS et al, 2002). No Brasil, não há, ainda, notificação de doença provocada pelo PRRSV (BRASIL, 2015), nem ocorrência de anticorpos em soro de suínos, conforme estudo sorológico realizado (CIACCI-ZANELLA et al, 2013); todavia, é frequente a ocorrência de enfermidade pelo M. hyopneumoniae (MORÉS et al, 2015).…”

“…Apesar de a infecção concomitante de micoplasma com PCV2 já ter sido descrita na literatura sob as formas experimental (OPRIESSNIG et al, 2004) e mesmo de forma natural (PALLARÉS et al, 2002;MORÉS et al, 2015), até o presente momento, entretanto, ela não foi relatada no estado de Goiás.…”

Associação entre otites bacterianas e infecção pelo circovírus suíno tipo 2 (PCV2) em suínos

“…bronchiseptica e A. pleuropneumoniae (Madec et al 2000, Kim et al 2002, Pallarés et al 2002, Segalés et al 2005. No presente estudo, uma alta percentagem (23,5%) de animais com a SMDS apresentou lesões purulentas no ouvido médio.…”

Exploratory Epidemiological Study on Porcine Circovirus Type 2 Infection and Postweaning Multisystemic Wasting Syndrome in the Czech Republic

“…The causes of different clinical expression of PMWS have not yet been clarified, however, their association with other infectious and non-infectious factors was suggested (Pogranichniy et al 2002;Krakowka et al 2007;Kyriakis et al 2002;Pallares et al 2002) as well as the impact of different pathogenicity among PCV2 isolates (Grau-Roma et al 2008;Dupont et al 2008). The combined effect of these factors might enhance the replication ability of PCV2 resulting in dysfunction of the host immune system and more severe clinical manifestation of the disease (Vincent et al 2005;Krakowka et al 2002;Segales et al 2004b).…”