External Quality Assurance: Subregional experiences on RVF

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Regional Seminar for OIE National Focal Points for Veterinary Laboratories Towards a culture of safety and quality External Quality Assurance: Subregional experiences

1 Regional Seminar for OIE National Focal Points for Veterinary Laboratories Towards a culture of safety and quality External Quality Assurance: Subregional experiences on RVF Gian Mario Cosseddu, Istituto Zooprofilattico Sperimentale dell'abruzzo e del Molise «G. Caporale» - IZSAM g.cosseddu@izs.it Tunis, Tunisia, September 2018

2 The performance of the different techniques applied to the diagnosis of infectious pathogens may vary during the time or between laboratories. External quality assurance (EQA), allows the determination of a laboratory s performance by testing specimens of undisclosed content. EQA allows the laboratories to monitor the quality of their diagnosis, evaluate their capacities and, eventually, identify the possible weaknesses in order to put in place corrective actions

3 In the framework of the Animal Health Mediterranean Network (REMESA) activities IZSAM in collaboration with FAO and OIE organized the first ring trial to detect RVF infection in animals. The aim of the ring trial was the preliminary evaluation of the diagnostic capabilities of the participating laboratories to detect antibodies and viral genome from clinical samples.

4 Call for participation An invitation letter was sent to the REMESA partners in June 2012

5 Call for participation Logistical and technical organization of EQA was discussed to REMESA members during a meeting in Tunis in May 2013 Ten laboratories from six Countries (Algeria 3, France 2, Mauritania 1, Morocco 2, Spain 1 and Tunisia 1) expressed their willingness to participate Six laboratories participated to both the viral genome detection and the specific IgG and IgM antibodies detection schemes. Four laboratories participated exclusively to serological trial

6 Specimen preparation Two different test panels were prepared: i) sample panel for viral genome detection by RT-PCR ii) sample panel for antibodies detection (IgG and IgM detection) by ELISA Due to biosecurity/biosafety reasons, all the samples included in the trial were treated in order to avoid the presence of live virus and the success of the inactivation confirmed before the shipment.

7 Samples for viral genome detection Each participant received a coded panel of 15 samples composed of 5 negative and 10 positive : RVFV Namibia 2010 cell culture was inactivated and spiked into negative bovine serum at dilutions 1:2, 1:10, 1:50, 1:100, 1:200 the viral load of positive samples was evaluated by qrt-pcr homogeneity and stability of spiked samples were assessed

8 Samples for antibodies detection Each participant received a panel of 15 ruminant sera composed of 5 negative and 10 positive samples. The positive samples were sera from domestic and wild ruminants: 5 sera from RVFV vaccinated sheep (n = 4) and goats (n =1) seropositive for IgG 5 sera from springboks (Antidorcas marsupialis), RVF seropositive for both IgG and IgM Samples were heat inactivated and evaluated for homogeneity and stability.

9 EQA details The participants were asked: to analyze the panels by using the diagnostic procedures routinely used in their laboratories. to provide details about the tests, namely: the serological assay(s) used, the protocols for RT-PCR procedure, the manufacturer of the RT-PCR instrument and the chemicals for the RNA extraction. The results provided by each participant were classified as correct or incorrect on the basis of the known samples results. Bayesian approach analysis (Beta distribution)

10 Participating laboratories Algeria France Mauritania Morocco Spain Tunisia Institut National de la Médecine Vétérinaire, Laboratoire Central Vétérinaire d'alger,; Institut National de la Médecine Vétérinaire, Laboratoire Vétérinaire Régional de Laghouat, Institut National de la Médecine Vétérinaire, Laboratoire Vétérinaire Régional de Tlemcen, ANSES, Virology Unit, Laboratory of Lyon, France; CIRAD, Montpellier, France; Centre National d'elevage et de Recherches Vétérinaires, laboratoire de Virologie, Nouakchott Office National de Sécurité Sanitaire des Produits Alimentaires (ONSSA), Laboratoire Régional d'analyses et de Recherches d'agadir Office National de Sécurité Sanitaire des Produits Alimentaires (ONSSA), Laboratoire Régional d'analyses et de Recherches de Casablanca CISA-INIA, Laboratory of Emerging and Transboundary Diseases, Valdeolmos (Madrid) Institut de la Recherche Vétérinaire de Tunisie

assays Drosten et al., 2007 (3) Bird et al.

11 Virus genome detection Participants: 6/10 laboratories; Different PCR machines and RNA extraction methods used Real-time RT-PCR assays Drosten et al., 2007 (3) Bird et al., 2002 (3) LaBeaud et al., 2011 (1) Labeaud et al., 2011 Drosten et al., 2002 Bird et al., 2007

12 Virus genome detection

13 Virus genome detection

14 RVF antibodies detection (IgG/IgM) Participants: 10/10 IgG detection assays ID Screen Rift Valley Fever Competition multi-species (Idvet) (10) INgezim FVR DR (Ingenasa) (1) in-house IgG-ELISA assays (lysate RVFV cell culture) (1) in-house IgG-ELISA assays (recombinants RVFV proteins) (1) VNT (1) IgM detection assays ID Screen Rift Valley Fever IgM Capture (IDvet) (10)

15 RVF antibodies detection (IgG)

16 RVF antibodies detection (IgM)

17 RVF antibodies detection (IgG/IgM)

18 Conclusions EQA provided a good overview on the laboratory capacities for the diagnosis of RVF in animals in the Western Mediterranean Region. The participating laboratories were able to perform the tests and provide the results in time. The use of a limited set of diagnostic assays indicated that harmonized procedures are already being applied, allowing the comparison of results and indicating that an efficient regional surveillance system may be put in place.

19 Conclusions The use of the same tests by all participants may limit the possibility to recognize the emergence of unusual virus strains evoking different immune responses. The use of a wider set of diagnostic methods should be encouraged. To guarantee a constant high quality level of RVF diagnosis in the region and to ensure the reliability of the diagnostic results conducting EQA studies on a regular basis is recommended.

20 Acknowledgments FAO and OIE subregional representations for North Africa CVOs of REMESA countries Central Veterinary Laboratory of Windhoek, Namibia

21 Thank you for your attention

Recent RVF outbreaks in North Western Africa Alessandro Ripani OIE Sub Regional Representation for North Africa Tunis, Tunisia

Inter-Regional Conference Rift Valley fever: new options for trade, prevention and control Djibouti City, Djibouti, 21-23 April 2015 Recent RVF outbreaks in North Western Africa Alessandro Ripani OIE Sub