Thursday, 1 December 2011

Circovirus may render pigs liable to CSF and other diseases


So circovirus decreases the efficiency of CSF- Classical Swine Fever vaccine!

Now let’s go back to 2000. Britain was suffering, a more or less undeclared even, secret, PMWS-PDNS (Circovirus) epidemic and the real thing - CSF, the dreaded Classical Swine Fever, not a vaccine, arrived in Britain.

So circovirus would presumably reduce any natural defences against CSF (and perhaps the follow up FMD – Foot and Mouth epidemic too)

The cheekily named "Gardiner Hypothesis" see above, suggested circovirus renders pigs more liable to other diseases and the extraordinary personal story told  in Stop the World is now explained. 

Porcine Circovirus is a very nasty virus and it has been present in Britain since 1999 rendering the pigs liable to other diseases. It rivals the British government veterinarians for sneaky behaviour and it caught them out in 2000 and 2001.

The CSF and FMD (Foot and Mouth) epidemics were major national disasters, with consequential  animal cruelty, human anguish and huge national financial losses.

This report makes the connection clear:

This PCV2-derived interference may not only allow the invasion of wild-type CSFV in pig farms but also increases the difficulty of CSF prevention and control in CSF endemic areas.”




Abstract here and provisional  full report here.

Porcine circovirus type 2 (PCV2) infection decreases the efficacy of an attenuated classical swine fever virus (CSFV) vaccine

Yu-Liang Huang, Victor Fei Pang, Chun-Ming Lin, Yi-Chieh Tsai, Mi-Yuan Chia, Ming-Chung Deng, Chia-Yi Changand Chian-Ren Jeng
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Veterinary Research 2011, 42:115 doi:10.1186/1297-9716-42-115
Published: 1 December 2011

Abstract (provisional)

The Lapinized Philippines Coronel (LPC) vaccine, an attenuated strain of classical swine fever virus (CSFV), is an important tool for the prevention and control of CSFV infection and is widely and routinely used in most CSF endemic areas, including Taiwan. The aim of this study was to investigate whether PCV2 infection affects the efficacy of the LPC vaccine. Eighteen 6-week-old, cesarean-derived and colostrum-deprived (CDCD), crossbred pigs were randomly assigned to four groups. A total of 105.3 TCID50 of PCV2 was experimentally inoculated into pigs through both intranasal and intramuscular routes at 0 days post-inoculation (dpi) followed by LPC vaccination 12 days later. All the animals were challenged with wild-type CSFV (ALD stain) at 27 dpi and euthanized at 45 dpi. Following CSFV challenge, the LPC-vaccinated pigs pre-inoculated with PCV2 showed transient fever, viremia, and viral shedding in the saliva and feces. The number of IgM+, CD4+CD8-CD25+, CD4+CD8+CD25+, and CD4-CD8+CD25+ lymphocyte subsets and the level of neutralizing antibodies against CSFV were significantly higher in the animals with LPC vaccination alone than in the pigs with PCV2 inoculation/LPC vaccination. In addition, PCV2-derived inhibition of the CSFV-specific cell proliferative response of peripheral blood mononuclear cells (PBMCs) was demonstrated in an ex vivo experiment. These findings indicate that PCV2 infection decreases the efficacy of the LPC vaccine. This PCV2-derived interference may not only allow the invasion of wild-type CSFV in pig farms but also increases the difficulty of CSF prevention and control in CSF endemic areas.