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Vet Microbiol. 2019 Dec;239:108477. doi: 10.1016/j.vetmic.2019.108477. Epub 2019 Nov 3. Virological and epidemiological patterns of swine influenza A virus infections in France: Cumulative data from the RESAVIP surveillance network, 2011-2018.
Herv? S1, Garin E2, Calavas D3, Lecarpentier L4, Ngwa-Mbot D5, Poliak S6, Wendling S7, Rose N8, Simon G9.
Author information
1 ANSES, French Agency for food, environmental and occupational health and safety, Ploufragan-Plouzan?-Niort Laboratory, Swine Virology Immunology Unit, National Reference Laboratory for Swine Influenza, Ploufragan, France; Bretagne Loire University, France. Electronic address: severine.herve@anses.fr. 2 Coop de France, Animal Health Service, Paris, France; Epidemiological Surveillance Platform for Animal Health (ESA Platform), Operational Team, Paris, France. 3 Epidemiological Surveillance Platform for Animal Health (ESA Platform), Operational Team, Paris, France; ANSES, French Agency for food, environmental and occupational health and safety, Lyon Laboratory, Epidemiological Surveillance Platform for animal health (ESA Platform), Lyon, France. 4 SNGTV, French National Society of Veterinary Technical Groups, Paris, France. 5 GDS France, French Federation of Health Protection Groups, Paris, France. 6 ADILVA, French Association of Directors and Executives of Public Veterinary Laboratories, Paris, France. 7 Epidemiological Surveillance Platform for Animal Health (ESA Platform), Operational Team, Paris, France; Ministry of Agriculture, DGAL, Directorate General for Food, Paris, France. 8 Bretagne Loire University, France; ANSES, French Agency for food, environmental and occupational health and safety, Ploufragan-Plouzan?-Niort Laboratory, Epidemiology, Health and Welfare Unit, Ploufragan, France. 9 ANSES, French Agency for food, environmental and occupational health and safety, Ploufragan-Plouzan?-Niort Laboratory, Swine Virology Immunology Unit, National Reference Laboratory for Swine Influenza, Ploufragan, France; Bretagne Loire University, France.
Abstract
Swine influenza A viruses (swIAVs) cause acute respiratory syndromes in pigs and may also infect humans. Following the 2009 pandemic, a network was established in France to reinforce swIAV monitoring. This study reports virological and epidemiological data accumulated through passive surveillance conducted during 1,825 herd visits from 2011 to 2018. Among them, 887 (48.6 %) tested swIAV-positive. The proportion of positive cases remained stable year-on-year and year-round. The European avian-like swine H1N1 (H1avN1) virus was the most frequently identified (69.6 %), and was widespread across the country. The European human-like reassortant swine H1N2 (H1huN2) virus accounted for 22.1 % and was only identified in the north-western quarter and recently in the far north. The 2009 pandemic H1N1 (H1N1pdm) virus (3.6 %) was detected throughout the country, without settling in areas of higher pig densities. Its proportion increased in winter, during the seasonal epidemics in humans. The European human-like reassortant swine H3N2 as well as H1avN2 viruses were identified sporadically. In up to 30 % of swIAV-positive cases, pigs exhibited clinical signs of high intensity, regardless of the viral subtype and vaccination program. The recurrent pattern of the disease, i.e., an endemic infection at the herd level, was reported in 41% of cases and mainly affected post-weaning piglets (OR = 5.11 [3.36-7.76]). Interestingly, the study also revealed a significant association between the recurrent pattern and sow vaccination (OR = 1.96 [1.37-2.80]). Although restricted to the studied pig population, these results bring new knowledge about swIAV dynamics and infection patterns in pig herds in France.
Copyright ? 2019 Elsevier B.V. All rights reserved.
KEYWORDS:
Epidemiological features; Pigs; RESAVIP; Surveillance; Swine influenza A virus
PMID: 31767089 DOI: 10.1016/j.vetmic.2019.108477