English: Common warthogs (Phacochoerus africanus) and bushpigs (Potamochoerus larvatus), were
experimentally infected with classical swine fever virus (CSFv) following the diagnosis of classical
swine fever (CSF) subtype 2.1 in 2005 in domestic pigs in South Africa. At that time, no data
regarding their susceptibility or the potential lesions in these wild suids were available. Seven
sub-adult warthogs and six bushpigs were captured, taken to the high containment facilities of the
Transboundary Animal Diseases Programme of the Agriculture Research Council (ARC) -
Onderstepoort Veterinary Research Institute, and infected intranasally with the South African
isolate. In each experiment, two in-contact control animals of the same species verified intraspecies
transmission, while two domestic pigs were used to demonstrate virus virulence and
viability. Surviving animals were euthanized 44 days post infection. Formalin-fixed tissue samples
collected from all experimental animals were evaluated for histological lesions. The warthogs,
which remained clinically normal throughout the study, developed histological lesions that were
inconsistently present and sometimes subtle. Three warthogs, including one in-contact control,
developed distinct perivascular lymphoplasmacytic cuffing in their brains. Subtle lesions included
scant lymphoplasmacytic infiltration of various organs, occasionally accompanied by perivascular
cuffing. In contrast, the bushpigs developed overt clinical signs similar to CSF in domestic pigs.
Four animals out of six, including two in-contact controls, died or were euthanized during the trial.
On post mortem examination, intestinal necrosis and ulceration, purulent rhinitis and pneumonia were present. Acutely affected animals developed lymphoid necrosis and depletion whilst
surviving individuals showed perivascular lymphoplasmacytic cuffing in multiple organs.
Immunohistochemical demonstration of CSFv antigen using a commercially available mouse
monoclonal antibody, WH303, revealed intense, widespread labelling in most tissues of all the
warthogs and bushpigs as well as the four domestic pigs used as controls during the trial. A wide
range of cell types and tissues reacted with the antibody. These included: mononuclear cells
(monocyte-macrophages, lymphocytes and plasma cells), follicular reticular cells, epithelial cells,
vascular endothelial cells, mesothelial cells, smooth muscle cells and fibroblasts.
Tissues that were labelled included tonsil, lymph nodes, spleen, third eyelid, adrenal gland,
urinary bladder, skin, liver, kidney, lung, certain cells within central nervous tissue like the choroid
plexus, various parts of the gastro-intestinal tract as well as glandular tissue like the pancreas
and salivary gland.
The tonsils were the most consistently labelled tissue, while no labelling was noted in myocytes of
skeletal or cardiac muscle.
From the present work, it was concluded that these wild Suidae are susceptible to CSFv and
intra-species transmission under experimental conditions can occur. / Afrikaans: Wilde Afrika varke, nl. vlakvarke (Phacocoerus africanus) en bosvarke (Potamochoerus larvatus)
was eksperimenteel infekteer met europese varkpes virus nadat die siekte in kommersiële mak
varke diagnoseer is in 2005 (dit was tipeer as subtipe 2.1). Geen inligiting oor die vatbaarheid of
potensiële letsels weens europese varkpes infeksie in hierdie wilde varke was beskikbaar nie.
Sewe wilde onvolwasse vlakvarke en ses bosvarke is gevang, na die isolasie eenheid van die
Onderstepoort Veterinêre Instituut se oor-grens siekte afdeling geneem en intranasal geïnfekteer
met die Suid-Afrikaanse isolaat van 2005. Twee in-kontak kontrole diere van dieselfde spesie is
gebruik in elke eksperiment om intra-spesie oordraging vas te stel en twee mak varke om virus
lewensvatbaarheid en virulensie te demonstreer. Oorlewende diere is uitgesit na 44 dae.
Formalien gefikseerde weefsel monsters is versamel van hulle, sowel as van diere wat uitgesit is
tydens die eksperiment. Die vlakvarke was klinies normal regdeur die eksperiment, maar het wel
histologiese letsels ontwikkel wat subtiel was en ook nie altyd teenwoordig in alle gevalle nie.
Drie vlakvarke, waarvan een ‘n in-kontak dier was, het prominente limfo-plasmasitiese
perivaskulêre flensing in hul breine ontwikkel. Subtiele letsels het klein hoeveelhede limfoplasmasitiese
infiltrasies in verskeie organe en somtyds perivaskulêre flensing ingesluit. In teenstelling, het die bosvarke uitgesproke kliniese tekens soortgelyk aan Europese varkpes in
mak varke, ontwikkel. Vier uit die ses diere, insluitend twee in-kontak diere is dood of uitgesit
tydens die eksperiment. Met nadoodse ondersoek is daar intestinale nekrose en ulserasie,
purulente rinitis en pneumonie gevind. Diere wat dood is, het limfoïede nekrose en limfoïede
uitputting getoon, terwyl die oorlewende bosvarke perivaskulêre flensing met limfo-plasma selle in
verskeie organe ontwikkel het.
Immunohistochemiese demonstrasie van Europese varkpes virus antigen deur gebruik van ‘n
kommersieël beskikbare muis monoklonale teenligaam, WH303, het duidelike wydverspreide
kleuring in meeste weefsel van die die vlakvarke, bosvarke en mak varke getoon. ‘n Wye reeks
van weefsel en sel tipes het met die teenliggam reageer naamlik: mononukliêre selle (monosietmakrofage
en limfo-plasma selle), follikulêre retikulêre selle, epiteel, vaskulêre endoteel,
mesoteel, gladde spier selle en fibroblaste.
Weefsel wat gemerk is met die teenliggaam het ingesluit: mangels, limfknope, milt, derde ooglid,
adrenaal klier, urienblaas, vel, lewer, nier, long, sekere selle in die sentrale senuwee stelsel, soos
die koroïed pleksus, verskeie dele van die gastro-intestinale stelsel sowel as klier weefsel soos
die pankreas en speekselklier.
Die mangels was die mees konsekwent gemerkte weefsel, terwyl geen kleuring gevind is in
miosiete van skelet of hartspier nie.
Uit hierdie werk kon daar afgelei word dat vlakvarke en bosvarke vatbaar is vir Europese varkpes
en dat intra-spesie oordraging plaasvind onder eksperimentele omstandighede. / Dissertation (MMedVet)--University of Pretoria, 2011. / Paraclinical Sciences / Unrestricted
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:up/oai:repository.up.ac.za:2263/31364 |
| Date | 19 October 2011 |
| Creators | Gers, Sophette |
| Contributors | Williams, Mark C., sophetteg@elsenburg.com |
| Publisher | University of Pretoria |
| Source Sets | South African National ETD Portal |
| Detected Language | Unknown |
| Type | Dissertation |
| Rights | © 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
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