12. 1960 2009 Natural history of PCV2 and PMWS First retrospective evidence of PCV2 infection (1962) First retrospective evidence of PMWS occurrence (1985) First description of PMWS in NA (1991) – sporadic First description of PMWS in EU (1995-97) Major epizootic PMWS outbreaks in EU and Asia (1998-2004) Major epizootic PMWS outbreaks in North and South America (2004-07) First PCV2 vaccine available (2004) PCV2 vaccines
22. If PCV2 is ubiquitous, ¿WHY SOME FARMS EXPERIENCE PMWS?
23. Pig genetics, sex, other Co-infections PCV2 genotype Moment of infection Sow status Management: Madec’s 20 point plan PMWS: a multifactorial disease
24.
25. PMWS reduction through zootechnical measures (Guilmoto y Wessel-Robert, 2000) Farm Rate of measures compliance Loss rate before (%) Loss reduction 1 81% 18.3 -13.7 2 86% 14.7 -12.7 3 59% 19.0 -9.3 4 84% 11.2 -5.8 5 79% 15.3 -6.4 6 70% 12.7 -4.7 7 82% 11.5 -4.4 8 55% 12.3 -3.5 9 54% 17.6 0.4 10 72% 11.3 0.7 Media 66% 13.1 -5.4
26. PMWS reduction through zootechnical measures (Guilmoto y Wessel-Robert, 2000) Farm Rate of measures compliance Loss rate before (%) Loss reduction 1 81% 18.3 -13.7 2 86% 14.7 -12.7 3 59% 19.0 -9.3 4 84% 11.2 -5.8 5 79% 15.3 -6.4 6 70% 12.7 -4.7 7 82% 11.5 -4.4 8 55% 12.3 -3.5 9 54% 17.6 0.4 10 72% 11.3 0.7 Media 66% 13.1 -5.4
31. PCV2 subclinical infection 160 piglets from two PMWS affected farms. Weight and viral load analyses at 3, 9, 15 and 21 wks of age. Area under the curve for weight and viral load was calculated. The higher the AUCqPCR during the postweaning period, the lower AUCW (ρ=-0.203; p=0.010).
33. PCR Laboratorial Analyses: PCR Useful to monitor: Infection dynamic Subclinical infection Sibila et al., 2004 % PCR (serum) Weeks of age Non-PMWS affected farms Percentage PMWS affected farms PCV2 is ubiquitous Not useful for PMWS diagnosis
34. Can PMWS be diagnosed in live animals??? Laboratorial Analyses: qPCR Quantitative PCR Slight Moderate Severe PMWS lesions a b c Olvera et al., 2004 PMWS Subclinical PCV2 infection
35. Not proved to be specific and/or sensitive enough to replace current diagnostic criteria (Fort et al., 2007; Grau-Roma et al., 2009) Inter-laboratory and inter-assay variation (Harding et al., 2009; Hjulsager et al., 2009) qPCR suggested applications for PMWS herd diagnosis. Can qPCR be used as a diagnostic tool for PMWS?
36. Non-PMWS affected farms Weeks of age PMWS affected farms Serology (IPMA, ELISA) Sibila et al., 2004 Percentage Laboratorial Analyses: Serology Useful to monitor: Maternal immunity transfer Infection dynamic Seroconversion to vaccination PCV2 is ubiquitous All piglets seroconvert Not useful for PMWS diagnosis
40. Prevention and control Prevention and control Initial efforts directed to counteract the known triggering factors Since 2004 onwards PCV2 vaccination
Aquí tenemos dos ejemplos de la dinámica de infección (PCR) y el perfil serológico de animales procedentes de granjas con (en verde) y sin CP (en amarillo). Como podeis ver tanto las granjas con CP como las sin CP estan infectadas con el virus, aunque las que sufren la enfermedad tiene un mayor porcentage de animles infectados. En cuanto a la serología, vemos que no diferencias en el perfil serológico entre granjas con y sin CP
