To avoid transmission between animals and humans, or even between humans, of influenza viruses linked to swine fluANSES recommends this Thursday “greater vigilance” in France, with several measures to reduce the risk. Swine flu represents “a threat to animal and human health“notes the health agency, which issued a report assessing the risks linked to transmission between species.
This viral respiratory disease, highly contagious and common in French pig farmsis generally benign but can be exacerbated or repeated in a breeding, “leading to health problems and significant economic losses“.
Pigs can be infected by porcine influenza viruses, but also by human or avian influenza viruses. This co-infection can facilitate the emergence of new viruses combining the genes of influenza viruses of different origins, at the risk of becoming more virulent or being transmitted more easily to other species. Cases of transmission of these viruses to humans have been demonstrated in several countries and for the first time in France. in 2021 at a breeder in Brittanyrecalls ANSES, requested by the government after this episode.
Screening and monitoring
In pig farms, “live pigs, particularly young sows, are the most important source of introduction” type A influenza virus, estimates the agency, which recommends screening of animals before their movements between farms, but also between regions and countries or continents. Because, “once influenza viruses are introduced into livestock production, they are particularly persistent, particularly given current models of intensive breeding”underlines Anses.
As “humans are also a very important source of introduction of influenza viruses”the agency recommends, among other things, following the recommendations of the High Authority of Health to vaccination against seasonal flu for people working on pig farms. Even if the risk of inter-human transmission of porcine viruses is considered “weak with the viruses currently circulating”ANSES calls for “strengthen surveillance of influenza viruses in pigs and humans”. This means in particular continuing and improve collaborations and exchanges of information between all stakeholders, scientists and professionals.
The agency still suggestsconsider a possible extension to swine flu of the active surveillance protocol for avian fluto early detect cases of animal-human transmission. “The establishment of a surveillance network is therefore necessary to identify as early as possible the emergence of new influenza type A viruses which could be transmitted to humans and their capacity to trigger inter-human transmission.“, according to ANSES.
