J Gen Virol. 1978 Oct;41(1):115–27. Hinshaw VS, Webster RG, Turner B.
Novel influenza A viruses isolated from Canadian feral ducks: including strains antigenically related to swine influenza (Hsw1N1) viruses. - Twelve influenza A viruses, antigenically related to the Ho, H1 and Hsw1 subtypes, were isolated from cloacal samples of feral ducks in Canada. Antigenic comparisons showed that these viruses were most closely related to the recent HSW1N1 isolates from man and pigs, whereas in vivo pathogenicity tests revealed differences between the Hsw1N1 viruses from the ducks and those from humans and pigs. Antigenic characterization of 94 additional influenza A viruses from the ducks showed four haemagglutinin subtypes (Hav1, Hav4, Hav5 and Hav7), an unclassified haemagglutinin, and six neuraminidase subtypes (N1, N2, Neq2, Nav1, Nav2 and Nav5) in various combinations, some of which are novel and have not previously been reported. Three of these duck influenza viruses possessed a haemagglutinin antigenically related to that of classical fowl plaque virus. A much higher percentage of virus isolations were from juvenile ducks (18.5%) than from adults (5%). All of the ducks, from which viruses were isolated, appeared healthy at the time of sampling. Serological studies on a limited number of humans and domestic birds living in close proximity to the Canadian ducks revealed no evidence of interspecies transmission. Our findings suggest that these birds serve as a substantial reservoir of antigenically diverse influenza viruses, including isolates antigenically related to the current human and animal influenza viruses. This reservoir in nature may be perpetuated by a cycle involving annual infection of juvenile birds followed by transmission to the remaining susceptible birds until the next congregation during the breeding season.
Rev Can Biol. 1981 Mar;40(1):139–45. Boudreault A,Lecomte J.
Isolation of influenza viruses in different species of bird in Canada in 1978 [Article in French] - As part of the international program on the ecology of influenza virus in animals sponsored by W.H.O., 357 influenza A viruses isolated from 2 293 cloacal samples collected from ducks and other bird species in Eastern Canada during the 1978 season were characterized antigenically. Seven hemagglutinin (Hsw 1, H2, H3, Hav2, Hav4, Hav6, Hav7) and six neuraminidase subtypes (N1, N2, Neq2, Nav1, Nav5, Nav6) in 18 different combinations were found. A comparison with viruses isolated during previous seasons indicates that subtypes do change from year-to-year and from place-to-place. Isolation of few viruses from passerine birds requires additional studies to determine if these species are truly infected with influenza virus in nature. This large reservoir of influenza A viruses circulating at the same time in ducks may well be involved in the appearance of new viruses in other species, including humans. PMID: 6166031 [PubMed - indexed for MEDLINE]
Acta Virol. 1979 Sep;23(5):375–84. Yamane N, Odagiri T, Arikawa J, Ishida N.
Isolation and characterization of influenza A viruses from wild ducks in northern Japan: appearance of HSW1 antigens in the Japanese duck population.- Twenty-six influenza A viruses were isolated from cloacal and tracheal samples of 235 resident and 396 migratory ducks in Miyagi prefecture, Japan, in 1977-−78. Of these, twelve were antigenically related to the avian-origin HSW1 virus, A/duck/Alberta/35/76 (HSW1N1), but their neuraminidase antigens were characterized as Nav2–3, Nav4 or N2. These antigenic configuration have not previously been reported. In addition, one strain in which the neuraminidase antigen was identified as Nav4, was demonstrated to be a mixture of two haemagglutinins, HSW1 and Hav7. Two distinct strains were separated from the mixture and characterized as HSW1Nav4 and Hav7Nav4. The antigenic identification of an additional 13 influenza A viruses revealed the presence of six haemagglutinin subtypes (Hav1, Hav3, Hav4, Hav6, Hav7, and Hav8) and five neuaraminidase subtypes (Nav1, Nav2–3, Nav4, Neq2, and N2) in various combinations. The results suggest that the avian influenza A viruses among feral ducks may be isolated in various combinations of haemagglutinins and neuraminidase subtypes in Japan, and that feral ducks may be the site of genetic recombination occurring as a result of dual infection with different subtypes of influenza A virus. PMID: 42296 [PubMed - indexed for MEDLINE]
Acta Virol. 1983 Jan;27(1):75–9. Sinnecker R, Sinnecker H, Zilske E, Kohler D.
Surveillance of pelagic birds for influenza A viruses. - Within a 4-year surveillance period for influenza A virus in pelagic birds, 351 influenza A strains were isolated from the trachea or cloaca of 3344 apparently healthy ducks, gulls, swans, terns and geese. The isolated influenza A viruses represent 14 subtypes. Their haemagglutinins (HA) were mainly related to avian HA, but also to the human HA H2 and to the swine HA Hswl. The neuraminidases (NA) were identified as avian, equine and human NA. The isolated influenza A strains include fowl plague-like viruses Havl Neql, strains with the surface antigen Hswl Nav4 and the subtype Hav7 Navl isolated from unconcentrated water samples. A subtype unknown to date, with the antigen formula H2 Nav4, was isolated from ducks. 8.2% of pekin ducks showed dual infections. PMID: 6133434 [PubMed - indexed for MEDLINE]
Do these mean anything to anybody…its Double-Dutch to me…….do tell!
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