Re: India: H5 avian influenza reported in poultry in Kottayam and Alappuzha, Kerala
Re: India: H5 avian influenza reported in poultry in Kottayam and Alappuzha, Kerala
High Security Animal Disease Laboratory (HSADL), Bhopal, confirmed that the virus spreading
the flu among the ducks was H5N1.
http://timesofindia.indiatimes.com/...team-plays-down-fear/articleshow/45291221.cms
what kind of ducks were these ?
http://malayalam.oneindia.com/img/2014/11/26-dead-ducks.jpg
http://www.thehindu.com/multimedia/dynamic/02221/duck_2221124f.jpg
mallards ? Baikal teals ? Common teals ?
I thought that usually ducks won't die from H5N1,
it mat depend on the strain
wild mallards should rarely get H5N1 ?!
too distant from the index (for waterborne transmission)
5 sorts of mallards in China
Kuttanad Duck (Anas platyrhynchos domestics)
http://en.wikipedia.org/wiki/Indian_Runner_duck
Kerala = Kuttanad region
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domestic ducks presumably have no prior exposure to influenza ?!
on exposure to HPAIV H5N1 in mallards with homosubtypic immunity induced by LPAIV H5N2
infection, clinical disease was absent and shedding of HPAIV from respiratory and intestinal
tracts was grossly reduced compared to the heterosubtypic and control groups
(mean GEC/100 µl at 3 dpi: 3.0×102 vs. 2.3×104 vs. 8.7×104; p<0.05).
Heterosubtypic immunity induced by an H4N6 infection mediated a similar but less pronounced effect
A/mallard/Foehr (Germany)/Wv1806-09K/03(H4N6)
A/duck/Potsdam/1402/86(H5N2)
A/duck/Vietnam/TG24-01/05(H5N1) [RERRKKR]
1-2 mallards out of 8 died
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006706
A/duck/Potsdam/1402-6/86(H5N2) is at genbank, cleavage site is RETR
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http://www.tandfonline.com/doi/pdf/10.1080/03079450903349147
Characterization of duck H5N1 influenza viruses with
differing pathogenicity in mallard (Anas platyrhynchos)
ducks
In order to investigate the variations in virulence of
H5N1 viruses to mallard ducks (Anas platyrhynchos) in
China, four H5N1 influenza viruses
A/mallard/Huadong/Y/2003 (Y) - RERRRKKR , lp
A/mallard/Huadong/hn/2005 (hn) - REGRRKKR , lp
A/mallard/Huadong/S/2005 (S) - RERRRKR , hp
A/mallard/Huadong/lk/2005 (lk) - RERRRKR , hp
isolated from [domestic] mallard ducks were studied.
Biological characterization showed that the S and lk
isolates were highly pathogenic in mallard ducks, while
the Yand hn isolates were of low pathogenicity in ducks.
An intravenous pathogenicity index (IVPI) test in the
mallard model, which can distinguish differences in the
pathogenicity of H5N1 viruses, is described.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2749972/
...Qinghai...controversial
domestic grazing ducks in Thailand, 2004 infected with H5N1 HPAI viruses were asymptomatic
While all duck species tested to date are susceptible to lethal infection with H5N1 HPAI viruses,
some species, including the mallard and Pintail ducks, are less susceptible and many survive.
mallard ducks continue to shed virus for up to 17 days
absence of morbidity in highly susceptible geese and chickens is surprising.
chickens previously infected with H9N2 virus and then inoculated with H5N1 HPAI virus become
infected and shed virus but do not show disease signs [51]
34
50
34. Keawcharoen J, van Riel D, van Amerongen G, et al. Wild ducks as long-distance vectors
of highly pathogenic avian influenza virus (H5NI) Emerging Infectious Diseases. 2008;14:600–607.
[PMC free article] [PubMed]
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2570914/
By experimentally infecting wild ducks, we found that tufted ducks, Eurasian pochards,
and mallards excreted significantly more virus than common teals, Eurasian wigeons,
and gadwalls; yet only tufted ducks and, to a lesser degree, pochards became ill or died.
A/turkey/Turkey/1/2005 (H5N1)
50. Brown JD, Stallknecht DE, Beck JR, Suarez DL, Swayne DE. Susceptibility of North
American ducks and gulls to H5N1 highly pathogenic avian influenza viruses. Emerging
Infectious Diseases. 2006;12:1663–1670. [PMC free article] [PubMed]
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3372354/
only wood ducks (Aix sponsa) and laughing gulls exhibited illness or died.
mallard,northern pintail,blue-winged teal not
A/Whooper Swan/Mongolia/244/05 (H5N1) (Mongolia/05)
A/Duck Meat/Anyang/01 (H5N1) (Anyang/01).
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http://jvi.asm.org/content/84/3/1527.full
A/chicken/Vietnam/C58/04 (H5N1) i
Wild-type virus had a calculated environmental persistence of 62 days and
caused extensive morbidity, mortality, shedding, and transmission in mallards.
An N114K mutation that increased the pH of HA activation by 0.5 unit resulted
in decreased replication, genetic stability, and environmental stability. Changes
of +0.4 and −0.5 unit in the pH of activation by Y23H and K58I mutations,
respectively, reduced weight loss, mortality, shedding, and transmission in mallards.
An H24Q mutation that decreased the pH of activation by 0.3 unit resulted in weight
loss, mortality, clinical symptoms, and shedding similar to those of the wild type.
However, the HA-H241Q virus was shed more extensively into drinking water and
persisted longer in the environment.
[hopefully the Kerala sequences will be released ...]
