Probable reverse zoonosis of influenza A(H1N1)pdm 09 in a striped skunk (Mephitis mephitis)

Abstract

Striped skunks (skunks) are susceptible to respiratory infection by influenza A viruses (IAV). As they are common synanthropes, maintenance of IAV in skunks could provide a source of infection for humans. We previously studied the nasal turbinates, lungs and faeces of 50 free-ranging skunks for the presence of IAV and identified two individuals with influenza A(H1N1)pdm09 infection during the 2009/2010 and 2013/2014 flu seasons. Subsequent to publication of that study, ferrets were shown to preferentially replicate and harbour A(H1N1)pdm09 in the soft palate, a site which had not been investigated in the skunks. From March 2015 to May 2016, we surveyed a convenience sample of 80 free-ranging urban skunks for IAV in soft palate, nasal turbinates and lungs. The newly emergent influenza A(H1N1)pdm09 clade 6B.1 was detected at all three sites in one skunk with acute rhinitis in February 2016. Clade 6B.1 was the dominant clade in circulation during the 2015/2016 flu season.As the skunk was detected at the height of flu season, reverse zoonosis was considered the most probable source of infection. K E Y W O R D SA(H1N1)pdm09, influenza A virus, reverse zoonosis, skunks

Spillback in the Anthropocene: the risk of human-to-wildlife pathogen transmission for conservation and public health

“…At macroscopic scales, time-structuring or geographic expansions are occasionally sufficient to assume zooanthroponosis (see vector-borne examples above). For example, newly emergent strains of Influenza A (H1N1) were detected in striped skunks (Mephitis mephitis) at the height of flu season, which was deemed highly unlikely unless humans were sourcing the disease (Britton et al 2019). Similarly, Zika virus was discovered in New World primates following introduction of the virus to the Americas (Favoretto et al 2019), implying that humans were responsible for transporting it.…”

“…There is some documented evidence for spillback of human pathogens into wildlife populations (e.g. (Osterhaus et al 2000;Nizeyi et al 2001;Goldberg et al 2007;Kaur et al 2008;Rwego et al 2008;Obanda et al 2013;Terzian et al 2018;Britton et al 2019;Favoretto et al 2019), but there has been little critical analysis concerning the magnitude of the threat, limiting our understanding of its realised and potential impacts on conservation and public health (Ryan & Walsh 2011), particularly compared to our advancing understanding of its inverse (i.e., the more classical animal-to-human spillover, or zoonosis). This research gap leaves three intertwined questions unanswered.…”

Reverse Zoonosis of COVID-19: Lessons From the 2009 Influenza Pandemic

“…Histopathological changes ranged from moderate, acute, suppurative rhinitis to severe bronchopneumonia. 4,5…”

Avian Influenza A Virus Associations in Wild, Terrestrial Mammals: A Review of Potential Synanthropic Vectors to Poultry Facilities

“…Although not avian-origin, striped skunks (Mephitis mephitis) have exhibited tissues positive for the pandemic (H1N1) 2009 IAV [63]. More recently, a possible reverse zoonosis was suspected in striped skunks shown to be infected with A(H1N1)pdm09 clade 6B.1 [64]. Although the source of this virus was likely humans, these natural exposures, coupled with the successful experimental infections of striped skunks with viruses of avian-origin suggests that skunks are possibly naturally exposed to avian viruses when conditions are conducive for transmission [5,71].…”