OIE Reference Laboratory Reports
Activities in 2010
Name of disease (or topic) for
which you are a designated OIE
Reference Laboratory:
Address of laboratory:
Lumpy skin disease
ARC-Onderstepoort Veterinary Institute
Private Bag X05
Onderstepoort, 0110
SOUTH AFRICA
Tel.:
(+27-12) 529.91.17
Fax:
(+27-12) 529.94.18
E-mail address:
LubisiA@arc.agric.za
Website:
http://www.arc.agric.za
Name of Head of Laboratory
(Responsible Official):
Dr Baratang Alison Lubisi
Name of OIE Reference Expert:
Dr Baratang Alison Lubisi
Name of writer of this report
(if different from above):
Dr Baratang Alison Lubisi
Annual reports of OIE Reference Laboratories and Collaborating Centres, 2010
1
Lumpy skin disease
Part I: Summary of general activities related to the disease
The OIE Lumpy Skin Disease (LSD) reference laboratory at ARC-OVI aligns its activities with the Agricultural
Research Council’s (ARC) strategic objective of enhancing the ability of the agricultural sector to manage and mitigate
agricultural risks. Activities for the report period include the provision of diagnostic services, disease certification of
ruminants for breeders and exporters of susceptible live animals, conducting serological tests for studies aimed at
understanding the prevalence of the disease in certain geographical areas and vaccine quality assurance, and performing
research aimed at improving the currently utilised vaccines.
1.
2.
Test(s) in use/or available for the specified disease/topic at your laboratory
Test
For
Specificity
Total
Serum Neutralisation (SN)
Antibody
Group
777
Electron Microscopy (EM)
Virus
Group
11
PCR
Genomic material
Group
20
CFT cell culture
Virus isolation
Group
7
Production and distribution of diagnostic reagents
Type of reagent
Amount supplied nationally
(including for own use)
Amount supplied to other
countries
Control positive serum
None
10 ml
Immunofluorescent conjugate
None
None
Antigens for SNT
None
20 ml of LSDV (cell culture
propagated)
Part II: Activities specifically related to the mandate of
OIE Reference Laboratories
3.
International harmonisation and standardisation of methods for diagnostic testing or the
production and testing of vaccines
ARC-OVI was unable to find an inter-laboratory or a proficiency test scheme to participate in for LSD.
4.
Preparation and supply of international reference standards for diagnostic tests or vaccines
Virulent cell culture propagated LSD virus (LSDV) and antisera in quantities of 20 and 10 millilitres (in 1 ml
vials) respectively, were supplied to Dr Pious Makaya, Central Veterinary Laboratory, Harare, Zimbabwe, for
diagnostic purposes.
5.
Research and development of new procedures for diagnosis and control
The Institute has a project on developing and evaluating a marker-free LSDV-RVF recombinant vaccine construct
in progress, led by Dr Wallace.
2
Annual reports of OIE Reference Laboratories and Collaborating Centres, 2010
Lumpy skin disease
In 2010, animal trials were conducted with the following objectives:
i.
to develop a new infection model for RVF pathogenesis in 6-month old Merino sheep and determine a
suitable challenge titre using the M35/74 virulent field isolate of RVFV;
ii.
to evaluate the protective ability of the marker-free LSDV-RVF construct using a dose titration regime and a
single vaccination against virulent RVFV challenge (strain M35/74) in sheep.
Results showed that high titres of the virus inoculated intra-venously induced clinical signs comparable with those
observed in the field, and a high titre would thus be chosen for future vaccine evaluation work. On the second
objective, preliminary results indicated that the highest titre fully protected the sheep against RVF.
A project led by Mr, Pravesh Kara and aimed at improving immune-responsiveness to LSDV vaccines in target
hosts was implemented during the report period. It was made possible by the availability of the genome sequences
of the Onderstepoort Biological Product’s (OBP) LSDV vaccine strain (OBP LSDV) and that of the virulent
Warmbaths (South Africa) field isolate. Gene knock-out technology was employed in the study. A number of
putative immuno-modulatory genes were identified, of which two were targeted. The knock-out recombinant
constructs have been generated and will be evaluated at a later stage in cattle.
The mRNA expression levels of the putative immuno-modulatory genes identified in the OBP LSDV vaccine
strain and the virulent Warmbaths field isolate were determined in infected foetal calf ear cells. Most of the genes
from the LSDV OBP vaccine strain are down-regulated as compared to the virulent LSDV Warmbaths isolate.
A pilot study was also conducted to determine the suitability of rabbits for use as small animal models in LSDV
infection studies. The rabbits were injected with 107pfu/ml of LSDV via the intra-muscular, intravenous and
subcutaneous routes respectively. Clinical signs were not observed during the course of the infections and it was
concluded that rabbits were not suitable for the intended purpose.
The Institute has a project on developing and evaluating a marker-free LSDV-RVF recombinant vaccine construct
in progress, led by Dr Wallace.
In 2010, animal trials were conducted with the following objectives:
iii.
to develop a new infection model for RVF pathogenesis in 6-month old Merino sheep and determine a
suitable challenge titre using the M35/74 virulent field isolate of RVFV;
iv.
to evaluate the protective ability of the marker-free LSDV-RVF construct using a dose titration regime and a
single vaccination against virulent RVFV challenge (strain M35/74) in sheep.
Results showed that high titres of the virus inoculated intra-venously induced clinical signs comparable with those
observed in the field, and a high titre would thus be chosen for future vaccine evaluation work. On the second
objective, preliminary results indicated that the highest titre fully protected the sheep against RVF.
A project led by Mr, Pravesh Kara and aimed at improving immune-responsiveness to LSDV vaccines in target
hosts was implemented during the report period. It was made possible by the availability of the genome sequences
of the Onderstepoort Biological Product’s (OBP) LSDV vaccine strain (OBP LSDV) and that of the virulent
Warmbaths (South Africa) field isolate. Gene knock-out technology was employed in the study. A number of
putative immuno-modulatory genes were identified, of which two were targeted. The knock-out recombinant
constructs have been generated and will be evaluated at a later stage in cattle.
The mRNA expression levels of the putative immuno-modulatory genes identified in the OBP LSDV vaccine
strain and the virulent Warmbaths field isolate were determined in infected foetal calf ear cells. Most of the genes
from the LSDV OBP vaccine strain are down-regulated as compared to the virulent LSDV Warmbaths isolate.
A pilot study was also conducted to determine the suitability of rabbits for use as small animal models in LSDV
infection studies. The rabbits were injected with 107pfu/ml of LSDV via the intra-muscular, intravenous and
subcutaneous routes respectively. Clinical signs were not observed during the course of the infections and it was
concluded that rabbits were not suitable for the intended purpose.
Annual reports of OIE Reference Laboratories and Collaborating Centres, 2010
3
Lumpy skin disease
6.
Collection, analysis and dissemination of epizootiological data relevant to international disease
control
Not done.
7.
Provision of consultant expertise to OIE or to OIE Members
Dr Wallace was an invited expert at the event below, where he presented a talk:
Wallace, D., 2010. LSDV (CPX) - Past, present and future. DISCONTOOLS workshop on "Capripoxviruses - gap
analysis for diagnosis and control", Presentation Brussels, Belgium, 15 and 16 November 2010.
8.
Provision of scientific and technical training to personnel from other OIE Members
Ms. Hope Kekana, a technologist in the laboratory, trained Dr Barbara Bhembe of the Central Veterinary
Laboratory, Harare, Zimbabwe, on how to perform LSD serum and virus neutralisation tests between 14 and 25
June 2010.
9.
Provision of diagnostic testing facilities to other OIE Members
Country
No. of
specimens
Test
Tentative
Confirmatory
Results
Positive results
reported to OIE
Botswana
11
Yes
No
Positive
N/A
Mauritius
Various
Yes
No
Positive
N/A
Namibia
5
Yes
No
Negative
N/A
1
No
Yes
Negative
N/A
Oman
1
No
Yes
Positive
N/A
United Arab
Emirates
Various
Yes
No
Positive
N/A
Zimbabwe
80
Yes
No
Negative
N/A
N/A - not applicable ; Various – a single submission containing numerous lesions for electron microscopy
10. Organisation of international scientific meetings on behalf of OIE or other international bodies
Not done.
11. Participation in international scientific collaborative studies
None.
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Annual reports of OIE Reference Laboratories and Collaborating Centres, 2010
Lumpy skin disease
12. Publication and dissemination of information relevant to the work of OIE (including list of
scientific publications, internet publishing activities, presentations at international conferences)

Presentations at international conferences and meetings
Drs. D. Du Plessis and D. Wallace attended the final/closure meeting of the French government-funded
LABOVET Project, in Bamako, Mali, 27-29 January 2010. Their areas of involvement in the project were
molecular characterisation of field strains of capripoxvirus; development of recombinant knockout viruses of
LSDV towards an improved vaccine; and use of LSDV as a vector for a recombinant LSDV-CBPP vaccine.
The topics listed below were presented orally:
i)
Wallace, D. Development of new Capripoxvirus immunodiagnostics
ii)
Wallace, D. Capripoxvirus sequencing
iii) Wallace, D. and Phosiwa, M. Construction of CBPP-CPX recombinants
iv)
Wallace, D. and Kara, P. Development & in vitro characterisation of mutant strains of Capripoxvirus (KO)
v)
Wallace, D., Mather, A. and Totte, P. Immune characterisation of a CBPP-LSDV construct in sheep
(presented by Dion Du Plessis)
The ARC-OVI team also contributed to the following talk at the same meeting:
vi)

Niang, M., Totte, P., Mather, A. and Wallace, D. Evaluation of protective properties of a CBPP-LSDV
construct in cattle
Scientific publications in peer-reviewed journals
LAMIEN, C.E., LELENTA, M., SILBER, R., LE GOFF, C., WALLACE D.B., GULYAZ, V., TUPPURAINEN,
E., MADANI, H., CAUFOUR, P., LUCKINS, A.G., ALBINA, E. and DIALLO, A. (2010). The capripoxvirus
homologue of the vaccinia virus 30 kd RNA polymerase subunit (RPO30) gene is suitable for genus member
differentiation. Journal General Virology, 90, 1967-77.
TUPPERAINEN, E., STOLTSZ, H., TROSKIE, M., WALLACE D.B., OURA, C., MELLOR, P.S., COETZER,
J.A.W. and VENTER, E.H. A potential role for hard (ixodid) tick vectors in the transmission of lumpy skin
disease virus in cattle. Transboundary and Emerging Diseases (Epub, ahead of print, available online).
13. Inscription of diagnostic kits on the OIE Register
i)
Did you participate in expert panels for the validation of candidate kits for inscription on the
OIE Register? If yes, for which kits?
No.
ii)
Did you submit to the OIE candidate kits for inscription on the OIE Register? If yes, for
which kits?
No.
_______________
Annual reports of OIE Reference Laboratories and Collaborating Centres, 2010
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