Limited airborne transmission of H7N9 influenza A virus between ferrets.
Wild waterfowl form the main reservoir of influenza A viruses, from which transmission occurs directly or indirectly to various secondary hosts, including humans. Direct avian-to-human transmission has been observed for viruses of subtypes A(H5N1), A(H7N2), A(H7N3), A(H7N7), A(H9N2) and A(H10N7) upon human exposure to poultry, but a lack of sustained human-to-human transmission has prevented these viruses from causing new pandemics. Recently, avian A(H7N9) viruses were transmitted to humans, causing severe respiratory disease and deaths in China. Because transmission via respiratory droplets and aerosols (hereafter referred to as airborne transmission) is the main route for efficient transmission between humans, it is important to gain an insight into airborne transmission of the A(H7N9) virus. Here we show that although the A/Anhui/1/2013 A(H7N9) virus harbours determinants associated with human adaptation and transmissibility between mammals, its airborne transmissibility in ferrets is limited, and it is intermediate between that of typical human and avian influenza viruses. Multiple A(H7N9) virus genetic variants were transmitted. Upon ferret passage, variants with higher avian receptor binding, higher pH of fusion, and lower thermostability were selected, potentially resulting in reduced transmissibility. This A(H7N9) virus outbreak highlights the need for increased understanding of the determinants of efficient airborne transmission of avian influenza viruses between mammals.
Department of Viroscience, Erasmus Medical Center, 3015GE Rotterdam, The Netherlands.
Mathilde
M
Richard
Eefje J A
EJ
Schrauwen
Miranda
M
de Graaf
Theo M
TM
Bestebroer
Monique I J
MI
Spronken
Sander
S
van Boheemen
Dennis
D
de Meulder
Pascal
P
Lexmond
Martin
M
Linster
Sander
S
Herfst
Derek J
DJ
Smith
Judith M
JM
van den Brand
David F
DF
Burke
Thijs
T
Kuiken
Guus F
GF
Rimmelzwaan
Albert D M E
AD
Osterhaus
Ron A M
RA
Fouchier
D000391:Air Microbiology; D000818:Animals; D001717:Birds / Q000821:virology; D002522:Chlorocebus aethiops; D004285:Dogs; D005289:Ferrets / Q000821:virology*; D016679:Genome, Viral / Q000235:genetics; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry; D006801:Humans; D009980:Influenza A virus / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000635:transmission / Q000821:virology; D007251:Influenza, Human / Q000635:transmission / Q000821:virology; D061985:Madin Darby Canine Kidney Cells; D008958:Models, Molecular; D009976:Orthomyxoviridae Infections / Q000635:transmission* / Q000821:virology*; D014709:Vero Cells
D019267:Hemagglutinin Glycoproteins, Influenza Virus