Sanne Charles Bodjo

Monkey CV1 cell line expressing the sheep―goat SLAM protein: A highly sensitive cell line for the isolation of peste des petits ruminants virus from pathological specimens

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.

The first specific detection of a highly pathogenic avian influenza virus (H5N1) in Ivory Coast.

The Virology Laboratory of the Central Laboratory of Animal Diseases in Ivory Coast at Bingerville received samples of wild and domestic avian species between February and December 2006. An RT‐PCR technique was used to test for avian influenza (AI) and highly pathogenic AI subtype viruses. Among 2125 samples, 16 were type A positive; of which, 12 were later confirmed to be H5N1. Fifteen of these 16 type A positive samples were inoculated into the chorioallantoic cavity of 11‐day‐old embryonated hens’ eggs for virus isolation. Eight produced virus with hemagglutination titres from 1/64 to 1/512. The 4/16 M‐RT‐PCR positive samples, which were H5N1 negative, were shown to be H7 subtype negative. The diagnostic efficiency of the laboratory for the surveillance of H5N1 in Ivory Coast was demonstrated. The positive cases of H5N1 were from a sparrowhawk (Accipter nisus); live market poultry and in free‐range poultry, where the mortality rate was approximately 20% (2/10) and 96.7% (29/30) respectively. Currently, investigations into intensive poultry farms have proved negative for H5N1. No human cases have been reported this time.

Specific detection of peste des petits ruminants virus antibodies in sheep and goat sera by the luciferase immunoprecipitation system

Peste des petits ruminants (PPR) is a contagious and often fatal transboundary animal disease affecting mostly sheep, goats and wild small ruminants. This disease is endemic in most of Africa, the Middle, Near East, and large parts of Asia. The causal agent is peste des petits ruminants virus (PPRV), which belongs to the genus Morbillivirus in the family Paramyxoviridae. This genus also includes measles virus (MV), canine distemper virus (CDV) and rinderpest virus (RPV). All are closely related viruses with serological cross reactivity. In this study, we have developed a Luciferase Immunoprecipitation System (LIPS) for the rapid detection of antibodies against PPRV in serum samples and for specific differentiation from antibodies against RPV. PPR and rinderpest (RP) serum samples were assayed by PPR-LIPS and two commercially available PPR cELISA tests. The PPR-LIPS showed high sensitivity and specificity for the samples tested and showed no cross reactivity with RPV unlike the commercial PPR cELISA tests which did cross react with RPV. Based on the results shown in this study, PPR-LIPS is presented as a good candidate for the specific serosurveillance of PPR.

First report and characterization of peste des petits ruminants virus in Liberia, West Africa.

Peste des petits ruminants (PPR) is a contagious and often fatal disease affecting sheep and goats that is currently endemic in Africa, the Middle East, the Indian subcontinent and China. Understanding the molecular epidemiology and evolution of PPR virus (PPRV) can assist in the control of the transboundary spread of this economically important disease. Here we report the isolation of a PPRV from pathological and swab samples collected from goats in Liberia, West Africa in July 2015. The full genome of one of the isolates was sequenced and phylogenetic analysis showed that it clustered within viral lineage II. The full genome revealed a 99.2 % identity at the nucleotide level with the full genome of a PPRV isolated in neighbouring Côte d’Ivoire in 2009 indicating a common origin of the viruses. Peste des petits ruminants (PPR) is a highly contagious infectious viral disease of domestic and wild small ruminants. The control of PPR is considered an important element in the fight for global food security and poverty alleviation and it is for this reason that the disease has been chosen as the next animal disease for global eradication. In April 2015, in Abidjan, Côte d’Ivoire, the Food and Agricultural Organization of the United Nations (FAO) and the World Organization for Animal Health (OIE) met with high-level authorities from affected countries to agree on a global plan to eradicate PPR by 2030 (FAO 2015). The causative agent, the peste des petits ruminants virus (PPRV), is a member of the family Paramyxoviridae, genus Morbillivirus that includes rinderpest virus (RPV), measles virus (MV), canine distemper virus (CDV), phocine distemper virus (PDV), dolphin morbillivirus (DMV) and feline morbillivirus (Woo et al. 2012; Baron et al. 2016). The nonsegmented single-stranded, negative-sense RNA genome of PPRV is 15,948 nucleotides in size and encodes two nonstructural proteins C and V, and six structural proteins arranged in the order: nucleoprotein (N), phosphoprotein (P), matrix protein (M), fusion protein (F), hemagglutinin protein (H) and viral RNA-dependent polymerase (L) (Baron et al. 2016). Based on partial sequences of the N and F genes, PPRV strains have been classified into four genetically distinct lineages (I, II, III and IV) even though the virus is serologically monotypic (Libeau et al. 2014; Parida et al. 2015). PPRV strains that were first identified in Africa belong to lineages I, II and III while viruses belonging to lineage IV have been found in Asia including the Middle East (Libeau et al. 2014; Parida et al. 2015). Although, PPRV has been reported in several West African countries there has been no report of the virus in Liberia to * William G. Dundon w.dundon@iaea.org

Development and validation of an epitope-blocking ELISA using an anti-haemagglutinin monoclonal antibody for specific detection of antibodies in sheep and goat sera directed against peste des petits ruminants virus

Peste des petits ruminants (PPR) is a contagious and economically important disease affecting production of small ruminants (i.e., sheep and goats). Taking into consideration the lessons learnt from the Global Rinderpest Eradication Programme (GREP), PPR is now targeted by the international veterinary community as the next animal disease to be eradicated. To support the African continental programme for the control of PPR, the Pan African Veterinary Vaccine Centre of the African Union (AU-PANVAC) is developing diagnostics tools. Here, we describe the development of a blocking enzyme-linked immunosorbent assay (bELISA) that allows testing of a large number of samples for specific detection of antibodies directed against PPR virus in sheep and goat sera. The PPR bELISA uses an anti-haemagglutinin (H) monoclonal antibody (MAb) as a competitor antibody, and tests results are interpreted using the percentage of inhibition (PI) of MAb binding generated by the serum sample. PI values below or equal to 18% (PI ≤ 18%) are negative, PI values greater than or equal to 25% (PI ≥ 25%) are positive, and PI values greater than 18% and below 25% are doubtful. The diagnostic specificity (DSp) and diagnostic sensitivity (DSe) were found to be 100% and 93.74%, respectively. The H-based PPR-bELISA showed good correlation with the virus neutralization test (VNT), the gold standard test, with a kappa value of 0.947. The H-based PPR-bELISA is more specific than the commercial kit ID Screen® PPR Competition (N-based PPR-cELISA) from IDvet (France), but the commercial kit is slightly more sensitive than the H-based PPR-bELISA. The validation process also indicated good repeatability and reproducibility of the H-based PPR-bELISA, making this new test a suitable tool for the surveillance and sero-monitoring of the vaccination campaign.