Diagnosis of Zoonotic Diseases

 

It is the goal of this project to assist the Government of South Africa to protect the public against the threat of rabies and bovine spongiform encephalopathy (BSE). Zoonotic diseases are of a global public and veterinary health threats. This is achieved through the provision of a national diagnostic service of high quality (accurate, rapid). Zoonosis is a disease that can be transmitted from animals to humans. In the case of rabies, this assists with the medical management of contact victims and with control in animal vectors. In addition, it is mandated to conduct research into the epidemiology of rabies and non-rabies lyssaviruses, as well as acting as the OIE Rabies Reference Laboratory.

Transmission usually occurs when an animal infected with either bacteria or virus encounters humans. The diagnostic of zoonotic diseases project primarily focuses on rabies and rabies related viruses, Bovine spongiform encephalopathy (BSE) and pathology. The project has two main responsibilities, diagnostic services and research. 

Rabies is a globally distributed zoonotic disease. The aetiological agent of the disease is a single stranded negative sense RNA virus and a member of the genus Lyssavirus. The disease causes thousands of human deaths every year predominately in Asia and Africa where the virus circulates endemically in domestic dogs. The burden of rabies in Africa is second globally behind Asia with around 24 000 human deaths estimated each year despite the availability of effective vaccines. Rabies is endemic in South Africa and the main maintenance hosts include domestic dogs, jackal species, bat eared fox (canid rabies biotype) and/or yellow mongoose (mongoose rabies biotype). The clinical signs vary from animal to animal but generally include aggression, biting of unusual objects, excessive salivation, paralysis and/or wild animals appear tame.

Bovine spongiform encephalopathy (BSE) is a progressive neurological disorder of cattle that results from infection by an unusual transmissible agent called a prion. The nature of the transmissible agent is not well understood. Currently, the most accepted theory is that the agent is a modified form of a normal protein known as prion protein. For reasons that are not yet understood, the normal prion protein changes into a pathogenic (harmful) form that then damages the central nervous system of cattle. To date, no BSE positive cases have been confirmed in South Africa. Zoonotic Diseases is therefore involved in an annual surveillance programme and receives a targeted number of samples from all provinces of South Africa. ​

Meet our Staff

1.       DIAGNOSTIC SERVICES

The OIE Rabies Reference Laboratory provides diagnostic services for rabies diagnosis using direct fluorescent antibody test (FAT) from the rabies suspected animal cases in South Africa and the SADC region. The laboratory also provides fluorescent antibody virus neutralisation test (FAVNT) [serological test] critical for the movement of pets and/or wildlife from the region and/ other parts of the world. It is noteworthy that the OIE Rabies Reference Laboratory is the only laboratory to provide such a service on the African continent. All the methods used for diagnosis of rabies and serology tests are recommended and prescribed by the World Organisation for Animal Health (OIE) and World Health Organisation (WHO) and are ISO 17025 accredited. The laboratory also supports regional laboratories with diagnostic reagents such as anti-rabies conjugate and other controls required for diagnostics and research. In addition, the laboratory maintain a virus and serum banks for future research and other applications.

The BSE laboratory offers a serological test that is able to detect the infectious agent known as prion. The objective of the laboratory is to assist the national Department of Agriculture, Forestry and Fisheries (DAFF) for surveillance of BSE with a view to certify the disease-free status of South Africa. The ELISA method is also SANAS accredited.  The pathology section covers a wide field and include most disease conditions that are being studied in the animal trials by other departments of the ARC-OVR and private clients. The section also offers pathology and post mortem services to private clients.

All Rabies related enquiries​

Dr Claude Sabeta

Tel:+27 (0)12 529 2439/2451

E-mail: sabetac@arc.agric.za​

 
2.       MAIN RESEARCH ACTIVITIES

2.1. Validation of lyssavirus diagnostic methods

2.2. Antigenic and genetic characterisation of lyssaviruses using a panel of monoclonal antibodies and phylogenetic analysis

2.3. Characterisation, isolation and long term storage of lyssaviruses [through the European Virus Archive goes global project, EVAg]

2.4. Production and supply of a polyclonal conjugate for rabies diagnosis in the region and elsewhere.

3.       COLLABORATORS

3.1. Canadian Food Inspection Agency (CFIA): OIE and National Rabies Reference Laboratory

3.2. French Agency for Food, Environmental and Occupational Health & Safety (ANSES): European Rabies Reference Laboratory.

3.3. Friedrich Loeffler Institute (National Institute for Animal Health, Germany): OIE and National Reference Laboratory for Rabies; WHO Collaborating Centre for Rabies Surveillance and Research

3.4. Animal and Plant Health Agency, United Kingdom: OIE and National Reference Laboratory for Rabies; WHO Collaborating Centre for Rabies Surveillance and Research

3.5. University of Pretoria: Department of Microbiology and Plant Pathology

3.6. National Institute of communicable diseases: Special pathogen unit

4.       RECENT PUBLICATIONS

Wonhyo S., Prehaud, C., Khan, Z., Sabeta, C. and Lafon, M. Investigation of Rabies virus glycoprotein carboxy terminus as an in vitro predictive tool for rabies virus neurovirulence. Microbes and Infection. http:/dx.doi.org/10.1016/j.miinf.2017.05.006.

Seo, W., Servat, A., Cliquet, F., Akinbowale, J.  Prehaud, C., Lafon, M., and Sabeta, C. Comparison of G protein sequences of South African rabies virus isolates showing distinct progression of the disease in a mouse model of experimental rabies. Microbes and Infection.  http:/dx.doi.org/10.1016/j.miinf.2017.05.005.

 Coetzer, A., Anahory I., Dias PT., Sabeta, CT., Scott, TP., Markotter W. and Nel, LH. (2017). Improved diagnosis of rabies and molecular evidence for the transboundary spread of the disease in Mozambique. Journal of the South African Veterinary Association. 88 (0): a1397.

Coertse, J., Markotter, W., Le Roux, K., Stewart, D., Sabeta, C.T. and Nel, L.H. (2017). New isolations of the rabies-related Mokola virus from South Africa. BMC Veterinary Research:  13:37.

Troupin, C., Dacheux, L., Tanguy, M., Sabeta, C., Blanc, H., Bouchier, C., Vignuzzi, M., Holmes, E.C. and Bourhy, H. (2016). Large scale phylogenetic analysis reveals the complex evolutionary trajectories of rabies virus among different carnivore hosts. Plos Pathogens. DOI: 10.1371/journal.ppat.1006041.

Tsekoa, T.L., Lotter-Stark, T., Buthelezi, S., Chakauya, E., Stoychev, S.H., Sabeta, C., Shumba, W., Phahladira, B., Hume, S., Morton, J., Rupprecht, C.E., Steinkellner, H., Pauly, M., Zeitlin, L., Whaley, K. and Chikwamba, R. (2016). Efficient in Vitro and in Vivo Activity of Glyco-engineered Plant-Produced Rabies Monoclonal Antibodies E559 and 62-71-3.  Plos One. DOI:10.1371/journal.pone.0159313.

Eggerbauer, E., DeBenedictis, P., Hoffmann, B., Mettenleiter, T.C., Schlottau, K., Ngoepe, E.C., Sabeta, C.T., Freuling, C.M. and Müller, T. (2016). Evaluation of six commercially available rapid immunochromatographic tests for the diagnosis of rabies in brain material. Plos Neglected Tropical Diseases. DOI:10.1371/journal.pntd.0004776.

Sabeta, C. (2015). Role of the glycoprotein in lyssavirus pathogenicity. Future Virology, 10.2217/fvl.15.84.

Sabeta, C., Phahladira, B., Marston, D.M., Wise, E.L., Ellis, R. J. & Fooks, A.R. (2015). Complete genome sequences of six southern African lyssaviruses. Genome Announcement, Volume 3 Issue 5 e01085-15. 

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