Large-Scale International Validation of an Indirect ELISA Based on Recombinant Nucleocapsid Protein of Rift Valley Fever Virus for the Detection of IgG Antibody in Domestic Ruminants
Janusz T. Pawęska,
Petrus Jansen van Vuren,
Veerle Msimang,
Modu Moustapha Lô,
Yaya Thiongane,
Leopold K. Mulumba-Mfumu,
Alqadasi Mansoor,
José M. Fafetine,
Joseph W. Magona,
Hiver Boussini,
Barbara Bażanow,
William C. Wilson,
Michel Pepin,
Hermann Unger,
Gerrit Viljoen
Affiliations
Janusz T. Pawęska
Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham 2131, South Africa
Petrus Jansen van Vuren
Australian Centre for Disease Preparedness, CSIRO Health & Biosecurity, Geelong, VIC 3220, Australia
Veerle Msimang
Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Sandringham 2131, South Africa
Modu Moustapha Lô
Laboratoire National de l’Elevage et de Recherches Vétérinaires, Route de Front de Terre, Dakar Hann 2057, BP, Senegal
Yaya Thiongane
Laboratoire National de l’Elevage et de Recherches Vétérinaires, Route de Front de Terre, Dakar Hann 2057, BP, Senegal
Leopold K. Mulumba-Mfumu
Ministry of Agriculture, Democratic Republic of Congo, Kinshasa 7948, Democratic Republic of the Congo
Alqadasi Mansoor
Central Veterinary Laboratory, General Directorate of Animal Health & Veterinary Quarantine, Ministry of Agriculture and Irrigation, Sana’a 31220, Yemen
National Livestock Resources Research Institute, Tororo P.O. Box 96, Uganda
Hiver Boussini
Direction Generale Des Services Veterinaires, Ministère des Ressources Animales, Ouagadougou 09 BP 907, Burkina Faso
Barbara Bażanow
Department of Pathology, Faculty of Veterinary Science, University of Environmental and Life Sciences, 50-375 Wroclaw, Poland
William C. Wilson
United States Department of Agriculture, Agricultural Research Service, Foreign Arthropod Borne Animal Diseases Research Unit, National Bio- and Agro-Defense Facility, Manhattan, KS 66502, USA
Michel Pepin
Agence Française de Sécurité Sanitaire des Aliments, F-69364 Lyon, France
Hermann Unger
Joint FAO/IAEA Centre for Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, 1400 Vienna, Austria
Gerrit Viljoen
Joint FAO/IAEA Centre for Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, 1400 Vienna, Austria
Diagnostic performance of an indirect enzyme-linked immunosorbent assay (I-ELISA) based on a recombinant nucleocapsid protein (rNP) of the Rift Valley fever virus (RVFV) was validated for the detection of the IgG antibody in sheep (n = 3367), goat (n = 2632), and cattle (n = 3819) sera. Validation data sets were dichotomized according to the results of a virus neutralization test in sera obtained from RVF-endemic (Burkina Faso, Democratic Republic of Congo, Mozambique, Senegal, Uganda, and Yemen) and RVF-free countries (France, Poland, and the USA). Cut-off values were defined using the two-graph receiver operating characteristic analysis. Estimates of the diagnostic specificity of the RVFV rNP I-ELISA in animals from RVF-endemic countries ranged from 98.6% (cattle) to 99.5% (sheep) while in those originating from RVF-free countries, they ranged from 97.7% (sheep) to 98.1% (goats). Estimates of the diagnostic sensitivity in ruminants from RVF-endemic countries ranged from 90.7% (cattle) to 100% (goats). The results of this large-scale international validation study demonstrate the high diagnostic accuracy of the RVFV rNP I-ELISA. Standard incubation and inactivation procedures evaluated did not have an adverse effect on the detectable levels of the anti-RVFV IgG in ruminant sera and thus, together with recombinant antigen-based I-ELISA, provide a simple, safe, and robust diagnostic platform that can be automated and carried out outside expensive bio-containment facilities. These advantages are particularly important for less-resourced countries where there is a need to accelerate and improve RVF surveillance and research on epidemiology as well as to advance disease control measures.
