Sergio López Soria PCVD in 2011:  An update
Historical background of PCV2 and PCVD
Historical background <ul><li>1991  A veterinary practitioner, Dr. John Harding, and a pathologist, Dr. Edward Clark, obse...
Historical background This syndrome was characterized by: <ul><ul><li>↑  postweaning mortality </li></ul></ul><ul><ul><li>...
Historical background <ul><li>1994   more   similar clinical cases  appeared again. </li></ul><ul><li>1996,1997  The disea...
Historical background <ul><li>1996 : A  variant of PCV  was detected in abundance within the lesions observed in lymphoid ...
PCV2 and PCVD
<ul><li>Ubiquitous  in domestic swine </li></ul><ul><li>Small  (17 nm of diameter) </li></ul><ul><li>Circular, single-stra...
PCV2 <ul><li>Resistent in the environment : </li></ul><ul><ul><li>Extreme thermal and chemical resistance  </li></ul></ul>...
<ul><li>PCV2 and  P CVD : </li></ul><ul><ul><li>PMWS </li></ul></ul><ul><ul><li>Subclinical infection </li></ul></ul><ul><...
1960 2009 Natural history of PCV2 and PMWS  First retrospective evidence of PCV2 infection (1962) First retrospective evid...
PMWS distribution <ul><li>The clinico-pathological scope of  PCV2  infection  has expanded  since 1991 (Chae, 2005; Segalé...
PCV2 infection and transmission
PCV2 viral loads (qPCR)  or PCV2 antibody titres Weeks of age PCV2 antibodies PMWS PCV2 infection dynamics  1 3 7-9 21 15 ...
<ul><li>PCV2 has been detected in: </li></ul><ul><ul><ul><ul><li>Nasal cavity </li></ul></ul></ul></ul><ul><ul><ul><ul><li...
sow Boar <ul><ul><li>PCV2 can be excreted by semen </li></ul></ul><ul><ul><li>Semen naturally infected with PCV2  (Opriess...
sow <ul><li>PCV2 intranasal infection of pregnant sows 3 wk PF  (Park et al., 2005; Ha et al., 2008) : </li></ul><ul><ul><...
<ul><li>Controversial paper and impact of PCV2 natural infection in reproductive failure: </li></ul><ul><ul><li>Some  rare...
<ul><ul><li>Pigs held in adjacent pens  (Kristensen et al., 2009) . </li></ul></ul><ul><ul><li>Direct contact more efficie...
PMWS
If PCV2 is ubiquitous, ¿WHY SOME FARMS EXPERIENCE PMWS?
Pig genetics, sex, other Co-infections PCV2 genotype Moment of infection Sow status Management: Madec’s 20 point plan PMWS...
<ul><li>Establishment of zootechnical measures in 10 french farms with PMWS (Guilmoto y Wessel-Robert, 2000): </li></ul><u...
PMWS reduction through zootechnical measures (Guilmoto y Wessel-Robert, 2000) Farm Rate of measures compliance Loss rate b...
PMWS reduction through zootechnical measures (Guilmoto y Wessel-Robert, 2000) Farm Rate of measures compliance Loss rate b...
PMWS reduction through zootechnical measures (Guilmoto y Wessel-Robert, 2000) <ul><ul><li>Where the same measures implemen...
<ul><li>Moment of infection </li></ul>“ Sow effect ” Calsamiglia et al., 2007 Sibila et al., 2004 <ul><li>Sow infection an...
<ul><li>PCV2 genotipe “b” vs “a” : </li></ul>Factors related to PMWS development: The PCV2 genotype Experimental infection...
PCV2 subclinical infection
PCV2 subclinical infection 160 piglets from two PMWS affected farms. Weight and viral load analyses at 3, 9, 15 and 21 wks...
Laboratorial Techniques for PCV2 and PMWS
PCR Laboratorial Analyses: PCR Useful to monitor: Infection dynamic Subclinical infection Sibila et al., 2004 % PCR (serum...
Can PMWS be diagnosed in live animals??? Laboratorial Analyses: qPCR Quantitative PCR Slight Moderate Severe PMWS lesions ...
Not proved to be specific and/or sensitive enough to replace current diagnostic criteria  (Fort et al., 2007; Grau-Roma et...
Non-PMWS affected farms Weeks of age PMWS affected farms Serology   (IPMA, ELISA) Sibila et al., 2004 Percentage Laborator...
<ul><ul><li>2. Moderate to severe  (lymphoid depletion and granulomatous inflammationin lymphoid tissue)  </li></ul></ul><...
<ul><li>Histopathology: </li></ul><ul><ul><li>Optimally 5 live diseased pigs </li></ul></ul><ul><ul><li>Tissue samples: </...
Prevention and control
Prevention and control Prevention and control Initial efforts directed to counteract the known triggering factors Since 20...
<ul><li>According to available data, probably yes… </li></ul><ul><ul><li>Mortality reduction </li></ul></ul><ul><ul><li>In...
PCV2 CReSA Team
 
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  • 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
  • 01 sergio lopez soria

    1. 2. Sergio López Soria PCVD in 2011: An update
    2. 3. Historical background of PCV2 and PCVD
    3. 4. Historical background <ul><li>1991 A veterinary practitioner, Dr. John Harding, and a pathologist, Dr. Edward Clark, observed a new syndrome in Saskatchewan, Canada </li></ul>Edward Clark John Harding
    4. 5. Historical background This syndrome was characterized by: <ul><ul><li>↑ postweaning mortality </li></ul></ul><ul><ul><li>Wasting </li></ul></ul><ul><ul><li>Very specific microscopic lesions in the lymphoid tissue </li></ul></ul>
    5. 6. Historical background <ul><li>1994 more similar clinical cases appeared again. </li></ul><ul><li>1996,1997 The disease was described and the name postweaning multisystemic wasting syndrome (PMWS) was proposed </li></ul><ul><li>(Harding, 1996; Clark, 1996) </li></ul>
    6. 7. Historical background <ul><li>1996 : A variant of PCV was detected in abundance within the lesions observed in lymphoid tissues (Daft et al., 1996) </li></ul><ul><li>1998 - The virus was first isolated from PMWS affected pigs (Allan et al., 1998; Ellis et al., 1998) </li></ul><ul><li>PCV1 and PCV2 are currently recognized as two different species by the International Committee on Taxonomy of Viruses (ICTV) </li></ul>Porcine circovirus type 2 (PCV2) Porcine circovirus type 1 (PCV1) Genus Circovirus PK-15 contaminant PMWS
    7. 8. PCV2 and PCVD
    8. 9. <ul><li>Ubiquitous in domestic swine </li></ul><ul><li>Small (17 nm of diameter) </li></ul><ul><li>Circular, single-stranded DNA (ssDNA) </li></ul><ul><li>Icosahedric, non-enveloped </li></ul><ul><li>(Mankertz et al., 2000) </li></ul>PCV2 PCV2 www.pcvd.eu
    9. 10. PCV2 <ul><li>Resistent in the environment : </li></ul><ul><ul><li>Extreme thermal and chemical resistance </li></ul></ul><ul><ul><li>(O’Dea et al., 2008) </li></ul></ul><ul><ul><li>Resistant to lipid-dissolving disinfectants: based on alcohol, chlorhexidine, iodine and phenol </li></ul></ul><ul><ul><li>(Royer et al., 2001) </li></ul></ul><ul><li>PCV2 can be inactivated by: </li></ul><ul><ul><li>alkaline disinfectants (sodium hydroxide) </li></ul></ul><ul><ul><li>oxidising agents (sodium hypochlorite) </li></ul></ul><ul><ul><li>quaternary ammonium compounds </li></ul></ul><ul><ul><li>(Martin et al., 2008) </li></ul></ul>
    10. 11. <ul><li>PCV2 and P CVD : </li></ul><ul><ul><li>PMWS </li></ul></ul><ul><ul><li>Subclinical infection </li></ul></ul><ul><ul><li>Reproductive disorders </li></ul></ul><ul><ul><li>Porcine dermatitis and nephropathy syndrome (PDNS) </li></ul></ul><ul><ul><li>Enteritis </li></ul></ul><ul><ul><li>Proliferative and necrotising pneumonia (PNP) </li></ul></ul><ul><ul><li>Porcine respiratory disease complex (PRDC) </li></ul></ul><ul><ul><li>Congenital tremor type AII not currently considered a PCVD </li></ul></ul>PCV2 and PCVD
    11. 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
    12. 13. PMWS distribution <ul><li>The clinico-pathological scope of PCV2 infection has expanded since 1991 (Chae, 2005; Segalés et al., 2005a; Opriessnig et al., 2007); </li></ul>Countries in red mean that they have described at least one case of PMWS (based on available literature) PCV2 Infection worldwide
    13. 14. PCV2 infection and transmission
    14. 15. PCV2 viral loads (qPCR) or PCV2 antibody titres Weeks of age PCV2 antibodies PMWS PCV2 infection dynamics 1 3 7-9 21 15 PCV2 viremia
    15. 16. <ul><li>PCV2 has been detected in: </li></ul><ul><ul><ul><ul><li>Nasal cavity </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Oro-tonsillar secretions </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Bronchial secretions </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Salivary secretions </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Ocular secretions </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Faeces </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Urine </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Milk </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Semen </li></ul></ul></ul></ul>PCV2 horizontal transmission Oro-nasal route: principal horizontal transmission Segalés et al., 2005 PMWS Affected Wasted Non-PMWS Healthy PMWS affected pigs harbour higher PCV2 amounts in those secretions/locations
    16. 17. sow Boar <ul><ul><li>PCV2 can be excreted by semen </li></ul></ul><ul><ul><li>Semen naturally infected with PCV2 (Opriessnig et al., 2007) : </li></ul></ul><ul><ul><ul><li>Intraperitoneal inoculation of piglets : seroconversion and vireamia </li></ul></ul></ul><ul><ul><ul><li>Artificial Insemination in sows: no infection </li></ul></ul></ul>Semen <ul><li>Naïve sows inseminated with PCV2 spiked semen (Madson et al., 2009) : </li></ul><ul><ul><li>Reproductive failure </li></ul></ul><ul><ul><li>Foetuses infection </li></ul></ul>PCV2 transmission by semen <ul><ul><li>Is the amount of PCV2 naturally shed in boar semen sufficient to infect sows or their fetuses? </li></ul></ul><ul><ul><li>Is it a frequent situation in the field? </li></ul></ul><ul><ul><li>Unfortunately it remains unknown </li></ul></ul>
    17. 18. sow <ul><li>PCV2 intranasal infection of pregnant sows 3 wk PF (Park et al., 2005; Ha et al., 2008) : </li></ul><ul><ul><li>PCV2 present in aborted and live-born piglets </li></ul></ul>PCV2 vertical transmission <ul><ul><li>Can PCV2 be transmitted from sow to foetus? </li></ul></ul> Yes <ul><li>In utero infected foetuses (92-104 days of gestation) and allowed to live postnatally until 35 days PI (Sanchez et al., 2004) : </li></ul><ul><ul><li>PMWS-like histological lesions </li></ul></ul><ul><ul><li>but not PMWS </li></ul></ul>
    18. 19. <ul><li>Controversial paper and impact of PCV2 natural infection in reproductive failure: </li></ul><ul><ul><li>Some rare event </li></ul></ul><ul><ul><li>(Ladekjaer-Mikkelsen et al., 2001; Maldonado et al., 2005) </li></ul></ul><ul><ul><li>Others 13% of infected aborted fetuses and stillborns (Kim et al., 2004) </li></ul></ul>sow PCV2 vertical transmission <ul><ul><li>Is the role of PCV2 in aborted foetuses and still born piglets clear nowadays? </li></ul></ul><ul><ul><li>Is it frequent in the field? </li></ul></ul>X Unfortunately it remains unknown
    19. 20. <ul><ul><li>Pigs held in adjacent pens (Kristensen et al., 2009) . </li></ul></ul><ul><ul><li>Direct contact more efficient than in separate pens (Andraud et al., 2008) . </li></ul></ul>PCV2 and PMWS horizontal transmission <ul><ul><li>Inter-mingling PMWS affected and healthy pigs (Dupont et al., 2009; Kristensen et al.,2009) </li></ul></ul><ul><ul><li>Can PCV2 be transmitted between piglets? </li></ul></ul><ul><ul><li>And PMWS? </li></ul></ul> Obviously Yes  Yes
    20. 21. PMWS
    21. 22. If PCV2 is ubiquitous, ¿WHY SOME FARMS EXPERIENCE PMWS?
    22. 23. Pig genetics, sex, other Co-infections PCV2 genotype Moment of infection Sow status Management: Madec’s 20 point plan PMWS: a multifactorial disease
    23. 24. <ul><li>Establishment of zootechnical measures in 10 french farms with PMWS (Guilmoto y Wessel-Robert, 2000): </li></ul><ul><li>Facilities </li></ul><ul><li>Management </li></ul><ul><li>Hygiene </li></ul>PMWS reduction through zootechnical measures Measures directed to diminish the dissemination infectious agents and their infectious pressure
    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
    25. 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
    26. 27. PMWS reduction through zootechnical measures (Guilmoto y Wessel-Robert, 2000) <ul><ul><li>Where the same measures implemented in those “improved” farms and the “non-improved” ones? </li></ul></ul><ul><ul><li>REMEMBER: </li></ul></ul><ul><ul><li>PMWS is a multifactorial disease! </li></ul></ul>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
    27. 28. <ul><li>Moment of infection </li></ul>“ Sow effect ” Calsamiglia et al., 2007 Sibila et al., 2004 <ul><li>Sow infection and immune status : </li></ul>Factors related to PMWS development <ul><ul><li>The earlier the PCV2 infection, the higher the risk of developing PMWS </li></ul></ul><ul><ul><li>Higher mortality in piglets from: </li></ul></ul><ul><ul><li>▪ Viraemic sows </li></ul></ul><ul><ul><li>▪ Sows with lower antibody titres </li></ul></ul>0 50 100 PCV2 prevalence Weeks of age 1-5 PMWS affected farms Non-PMWS affected farms 6-10 11-15 16-20 21-25
    28. 29. <ul><li>PCV2 genotipe “b” vs “a” : </li></ul>Factors related to PMWS development: The PCV2 genotype Experimental infections 50% PMWS with “b” (20 studies) 35% PMWS with “a” (75 studies) PMWS with “b” 3,45 times > “a” (Tomás et al., 2008)
    29. 30. PCV2 subclinical infection
    30. 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).
    31. 32. Laboratorial Techniques for PCV2 and PMWS
    32. 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
    33. 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
    34. 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?
    35. 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
    36. 37. <ul><ul><li>2. Moderate to severe (lymphoid depletion and granulomatous inflammationin lymphoid tissue) </li></ul></ul><ul><ul><li>3. Detection of moderate to high PCV2 amount within microscopic lesions in lymphoid tissues </li></ul></ul><ul><ul><li>1. Compatible clinical signs: </li></ul></ul><ul><ul><li>growth retardation </li></ul></ul>(Sorden, 2000; Segalés, 2002) PMWS diagnosis H/E PCV2 ISH
    37. 38. <ul><li>Histopathology: </li></ul><ul><ul><li>Optimally 5 live diseased pigs </li></ul></ul><ul><ul><li>Tissue samples: </li></ul></ul><ul><ul><ul><li>Lymphoid tissues: (Lymph nodes, tonsil, ileum [Peyer’s patch], timus) </li></ul></ul></ul><ul><ul><ul><li>Lung </li></ul></ul></ul><ul><ul><ul><li>Liver </li></ul></ul></ul><ul><ul><ul><li>Kidney </li></ul></ul></ul><ul><ul><ul><li>Other… </li></ul></ul></ul>Laboratorial Analyses: Sample collection for histopathology Non essential for PMWS diagnosis
    38. 39. Prevention and control
    39. 40. Prevention and control Prevention and control Initial efforts directed to counteract the known triggering factors Since 2004 onwards  PCV2 vaccination
    40. 41. <ul><li>According to available data, probably yes… </li></ul><ul><ul><li>Mortality reduction </li></ul></ul><ul><ul><li>Increase of ADG </li></ul></ul><ul><ul><li>Batch homogeneity </li></ul></ul><ul><ul><li>Reduction of antibiotics use </li></ul></ul><ul><ul><li>Reduction of infection pressure </li></ul></ul><ul><li>Of course, to be coupled with: </li></ul><ul><ul><li>Good management practices </li></ul></ul><ul><ul><li>Control of concurrent diseases </li></ul></ul><ul><ul><li>Rational use of antibiotics </li></ul></ul>Prevention and control Is PCV2 vaccination the solution for PMWS and PCV2 subclinical infection?
    41. 42. PCV2 CReSA Team

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