Mink is a highly susceptible host species to circulating human and avian influenza viruses

Abstract

Pandemic influenza, typically caused by reassortment of human and avian influenza viruses, can result in severe or fatal infections in humans. Timely identification of potential pandemic viruses must be a priority in influenza virus surveillance. However, the range of host species responsible for the generation of novel pandemic influenza viruses remain unclear. In this study, we conducted serological surveys for avian and human influenza virus infections in farmed mink and determined the susceptibility of mink to prevailing avian and human virus subtypes. The results showed that farmed mink were commonly infected with human (H3N2 and H1N1/pdm) and avian (H7N9, H5N6, and H9N2) influenza A viruses. Correlational analysis indicated that transmission of human influenza viruses occurred from humans to mink, and that feed source was a probable route of avian influenza virus transmission to farmed mink. Animal experiments showed that mink were susceptible and permissive to circulating avian and human influenza viruses, and that human influenza viruses (H3N2 and H1N1/pdm), but not avian viruses, were capable of aerosol transmission among mink. These results indicate that farmed mink could be highly permissive "mixing vessels" for the reassortment of circulating human and avian influenza viruses. Therefore, to reduce the risk of emergence of novel pandemic viruses, feeding mink with raw poultry by-products should not be permitted, and epidemiological surveillance of influenza viruses in mink farms should be urgently implemented.

Influenza A Viruses and Zoonotic Events—Are We Creating Our Own Reservoirs?

“…Additionally, infections with HP H5N1 were reported [166]. As shown recently, the H1N1pdm virus was not only re-introduced into swine but was also introduced into farmed minks [164,165]. Sun and colleagues reported a 50% and 11% prevalence of H1N1pdm and human H3N2-specific antibodies, respectively, in nearly 2500 serum samples from 34 mink farms in the Chinese Shandong and Hebei provinces, where the majority of the fur farms are located.…”

“…Sun and colleagues reported a 50% and 11% prevalence of H1N1pdm and human H3N2-specific antibodies, respectively, in nearly 2500 serum samples from 34 mink farms in the Chinese Shandong and Hebei provinces, where the majority of the fur farms are located. Interestingly, antibodies against the AIV subtypes H5N6 (3%), H7N9 (3%), and H9N2 (20-50%), which have been endemic in poultry in this area at this time, were also detected in these mink-derived sera [160,161,164]. As 32% of the investigated sera contained antibodies to both human and avian strains, concerns arose that the minks could, similar to swine, serve as a mixing vessel [164].…”

“…An IAV of the H10 subtype was isolated from minks in the 1980s and it is believed to be the result of a direct transmission of an avian virus [158,159]. More recent studies have revealed a wider detection of several avian-, swine-, and human-derived IAV subtypes, such as H9N2 [160,161], H3N2 [162], H1N2 [163], and H1N1 [164,165] in minks. Additionally, infections with HP H5N1 were reported [166].…”

Airborne Transmission of Avian Origin H9N2 Influenza A Viruses in Mammals

“…Contact minks developed clinical signs consistent with H9N2 IAV infection whereas seroconversion, but no clinical signs were observed in foxes and raccoon dogs [116]. In another study, the airborne transmission of H9N2 IAV was evaluated in minks, but no positive results were obtained [51]. H9N2 IAV infection was also reported in experimentally infected cats and dogs but transmission through direct contact was only observed among cats but not dogs [137].…”

“…In addition, H9N2 IAVs are zoonotic viruses themselves and have also been reported in other mammalian species such as swine, dogs, horses, and mink. In humans, H9N2 IAV infections have presented with mild influenza-like symptoms such as respiratory symptoms, coughing, fever, nasal discharge, sore throat, and headache [48][49][50][51][52]. Only one fatality has been associated with H9N2 IAV infection in humans to date [53].…”