Mamadou Lelenta

Enzyme-linked immunosorbent assay (ELISA) techniques for the detection of antibodies are now widely used throughout the world for the diagnosis of infectious diseases in veterinary medicine. Although many laboratories have independently developed ELISA techniques for their own purposes, little progress has been made with respect to the international standardisation and validation of these techniques. This lack of international conformity is of major concern to organisations such as the Office International des Epizooties (OIE), the United Nations Food and Agriculture Organisation (FAO), the World Health Organisation (WHO) and the International Atomic Energy Agency (IAEA) which are involved in the establishment of international guidelines and programmes for the control, surveillance and/or eradication of infectious diseases. In this regard, a Joint FAO/IAEA Meeting of Consultants was convened in Vienna in January 1992 to review aspects of ELISA data expression, primary reference standards, quality assurance and diagnostic validation. Based on the consensus derived from this meeting, the authors describe procedures which are recommended as a platform on which to build definitive guidelines for international standardisation of ELISA protocols and reagents, in cooperation with the OIE and the OIE Reference Laboratories.

Peste des petits ruminants (PPR) is an important economically transboundary disease of sheep and goats caused by a virus which belongs to the genus Morbillivirus. This genus, in the family Paramyxoviridae, also includes the measles virus (MV), canine distemper virus (CDV), rinderpest virus (RPV), and marine mammal viruses. One of the main features of these viruses is the severe transient lymphopaenia and immunosuppression they induce in their respective hosts, thereby favouring secondary bacterial and parasitic infections. This lymphopaenia is probably accounted for by the fact that lymphoid cells are the main targets of the morbilliviruses. In early 2000, it was demonstrated that a transmembrane glycoprotein of the immunoglobulin superfamily which is present on the surface of lymphoid cells, the signalling lymphocyte activation molecule (SLAM), is used as cellular receptor by MV, CDV and RPV. Wild-type strains of these viruses can be isolated and propagated efficiently in non-lymphoid cells expressing this protein. The present study has demonstrated that monkey CV1 cells expressing goat SLAM are also highly efficient for isolating PPRV from pathological samples. This finding suggests that SLAM, as is in the case for MV, CDV and RPV, is also a receptor for PPRV.