Evaluation of dried blood spots for serological surveys of myxoma and rabbit hemorrhagic disease viruses in their wild reservoir

Abstract

5 Pág.Myxoma (MYXV) and rabbit hemorrhagic disease (RHDV) viruses are pathogens of economic relevance for cuniculture and conservation concern for wild European rabbits (Oryctolagus cuniculus), recently classified as 'Endangered' in its native range. Large-scale serological surveys, facilitated by sample collection using dried blood spots (DBS), allow monitoring seroprevalence in the wild reservoir but require evaluating the technique for the host and pathogen of interest. This study aimed to evaluate Protein Saver 903 DBS for MYXV and RHDV (genotype GI.2) serological surveys in European rabbits. Paired serum and DBS collected from 172 rabbits harvested or found dead in the Iberian Peninsula were tested for IgG antibodies specific against MYXV and RHDV GI.2 using indirect ELISA. We found an almost perfect agreement between serum and DBS for MYXV (Cohen's κ=0.914, CI95 0.847 - 0.981) and a strong agreement for RHDV GI.2 (Cohen's κ=0.808, CI95=0.722 - 0.893). The diagnostic sensitivity of DBS was 95.4 % (CI95 90.3 - 97.9 %) for MYXV and 82.1 % (CI95 73.2 - 88.5 %) for RHDV GI.2. The diagnostic specificity and positive predictive value were 100 % for both pathogens. This study supports DBS as a suitable sampling strategy for serological surveys of antibodies specific to MYXV and RHDV GI.2 in European rabbits, which generally agrees with results from other hosts and pathogens where this technique was evaluated.This work was supported by Fundação para a Ciência e Tecnologia (FCT) [grant SFRH/BPD/116596/2016 to N.S., CEECIND/01388/2017 to A.M.L. and CEECIND/00078/2017 to J.A.] and co-funded by the project NORTE-01–0246-FEDER-000063, supported by Norte Portugal Regional Operational Programme (NORTE2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This study was partially funded by project LAGMED (www.lagmed.eu), supported by FCT (PRIMA/0003/2018), the Spanish Ministry of Science, Innovation and University (PRIMA S2–11-PCI2019–103732 to E.B.) and PRIMA programme, an Art. 185 initiative supported and funded under Horizon 2020, the European Union’s Framework Programme for Research and Innovation. This work benefited from research grants funded by the Spanish Ministry of Science and Innovation (projects Iber-Lagohealth; PID2023–151954NB-100 and LagoHealth; PID2019–111080RB-C21). It was also partially funded by the Sub-modality 2.4. "UCOLIDERA" of the "Enrique Aguilar Benítez de Lugo" Research Plan of the University of Cordoba and CIBER -Consorcio Centro de Investigación Biomédica en Red- (CB 2021), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and European Union – NextGenerationEU. S.J.R. is supported by a ‘Juan de la Cierva’ contract (JDC2022–048850-I) funded by the MCIN/AEI/10.13039/501100011033 and by the European Union “NextGenerationEU”/PRTR. S.C.S. is supported by an FPU grant from the Spanish Ministry of Universities (FPU19/06026). This work was supported by Life Iberconejo (LIFE20-GIE ES000731).Peer reviewe