Assessment of Influenza D Virus in Domestic Pigs and Wild Boars in France: Apparent Limited Spread within Swine Populations Despite Serological Evidence of Breeding Sow Exposure

Viruses

Nicolas Rose¹  Christelle Fablet¹  Frédéric Paboeuf²  Stéphane Gorin³  Nicolas Barbier³  Gaëlle Simon³  Stéphane Quéguiner³  Séverine Hervé³ 

[1] Epidemiology, Health and Welfare Unit, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 22440 Ploufragan, France;SPF Pig Production and Experimentation, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 22440 Ploufragan, France;Swine Virology Immunology Unit, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 22440 Ploufragan, France;

关键词: influenza d virus;    swine;    pig;    wild boar;    epidemiology;    serology;    pb1-gene rt-qpcr;    porcine respiratory disease complex;    influenza-like illness;   

DOI  :  10.3390/v12010025

来源: DOAJ

【 摘 要 】

In order to assess influenza D virus (IDV) infections in swine in France, reference reagents were produced in specific pathogen free pigs to ensure serological and virological analyses. Hemagglutination inhibition (HI) assays were carried out on 2090 domestic pig sera collected in 2012−2018 in 102 farms. Only 31 sera from breeding sows sampled in 2014−2015 in six farrow-to-finish herds with respiratory disorders contained IDV-specific antibodies. In two of them, within-herd percentage of positive samples (73.3% and 13.3%, respectively) and HI titers (20−160) suggested IDV infections, but virus persistence was not confirmed following new sampling in 2017. All growing pigs tested seronegative, whatever their age and the sampling year. Moreover, PB1-gene RT-qPCR performed on 452 nasal swabs taken in 2015−2018 on pigs with acute respiratory syndrome (137 farms) gave negative results. In Corse, a Mediterranean island where pigs are mainly bred free-range, 2.3% of sera (n = 177) sampled on adult pigs in 2013−2014 obtained low HI titers. Finally, 0.5% of sera from wild boars hunted in 2009−2016 (n = 644) tested positive with low HI titers. These results provide the first serological evidence that sows were exposed to IDV in France but with a limited spread within the swine population.

【 授权许可】

Unknown