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7/26/2019 Perpetuation of influenza A viruses in Alaskan waterfowl reservoirs.pdf
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Arch Virol(1995) 140:1163-1172
_ A r c h i v e s
ro logy
© Spr inger Ver lag 1995
P r i n t e d i n
ust r ia
P e r p e t u a t i o n o f i n f l u e n z a A v i ru s e s in A l a s k a n w a t e r f o w l r e se r vo i rs
T. Ito 1 K. OkazakP Y. Kawaokaz A . Takada 1 R.G . W ebster2 and H. Kidax
~Department of V eterinaryHygieneand Microbiology,Schoolof V eterinary Medicine,
Hok kaido University,Sapporo, Japan
2Department of Virologyand Molecular Biology,St. Jude Children sResearch H ospital,
Mem phis, Tennessee, U.S.A.
Accepted Ma rch 31, 1995
S u m m a r y . T o p r o v i d e i n f o r m a t i o n o n t h e m e c h a n i s m o f p e r p e t u a t i o n o f i n fl u e n z a
viruses amo ng w ater fow l reservoir s in na ture , v i ro logica l surve i l lance was car r ied
ou t in A la s ka d u r ing the i r b r e e d ing s e a s on in s um m e r f r om 1991 to 1994. I n f lue nz a
v i r u se s we r e i s o la te d m a in ly f r om f e c al s a m ple s o f da bb l ing duc ks in the i r ne s t ing
p la c e s in c e n t r a l Ala s ka . The num be r s o f s ub type s o f 108 in f lue nz a v i ru s i s o la te s
w e r e 1 H 2 N 3 , 3 7 H 3 N 8 , 5 5 H 4 N 6 , 1 H 7 N 3 , 1 H S N 2 , 1 H 1 0 N 2 , 11 H 1 0 N 7 , a n d
H 10 N9. Inf luenza v iruses were a lso iso la ted f rom w ater sam ples of the lakes where
the y ne s t. Eve n in Se p te m be r o f 1994 wh e n the m os t duc ks ha d l e f t f o r m ig r a t io n
to s ou th , v i r u se s we r e s t il l i s o la te d f r om the l a ke w a te r. Phy loge n e t i c a na lys i s o f
the NP ge ne s o f the r e p r e s e n ta t ive i s o la te s s howe d tha t the y be long to the
N or t h Am e r ic a n l ine a ge o f a v ia n in f lue nz a v i ru s e s, s ugge s ting tha t the m a jo r i ty o f
t h e w a t e rf o w l s b r e ed i n g i n ce n t ra l A l a s k a m i g r a te t o N o r t h A m e r i c a a n d n o t t o
As ia . The p r e s e n t r e s u l t s s uppor t the no t ion tha t in f lue nz a v i r u s e s ha ve be e n
m a i n t a i n e d i n w a t er f o w l p o p u l a t i o n b y w a t e r - b o rn e t r a n sm i s s i o n a n d r e ve a le d t h e
me chan ism of year -by-y ear perpe tu a t ion of the v iruses in the lakes where they breed .
In tr od u c t i on
Since 1956 num erous inf luenza A viruses have been isolated from a var iety of
avian species [ 1]. All o f the different subtypes o f inf luenza A viruses (H 1 to H 14 an d N1
to N9) are circulating in aquatic birds , par ticular ly in migratory waterfowls [11] .
W aterfow ls are, therefore, ra ted as a majo r reservoir o f influenza A viruses in natu re [34].
I n f lue nz a A v i r u s e s o f a v ia n o r ig in ha ve be e n im p l ic a te d in ou tb r e a ks o f
inf lu enz a in ma m m als , such as seals [12, 32, 33] , wh ales [14] , pigs [25] , m ink s [20],
and horses [9] as wel l as in dom es t ic po ul t r ies [3 , 10]. These ev idences indica te tha t a
va s t in f lue nz a v i r u s ge ne poo l f o r f u tu r e m a m m a l ia n in f lue nz a e x i s t s in a v ia n
s ou rc e s . S inc e e a c h pa nde m ic o f hum a n in f lue nz a f i rs t a ppe a r e d in C h ina [ 34 ], the
pos s ib i l i ty ha s be e n r a i s e d tha t s ou the r n Ch ina i s a n in f lue nz a e p ic e n te r [27] . Ne w
hum a n pa nde m ic s t r a in s a r e be l i e ve d to a r i s e by ge ne t i c r e a s s o r tm e n t be twe e n
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1 1 6 4 T I t o e t a l
h u m a n a n d n o n - h u m a n v i r u se s [6, 2 1 ,3 1 ]. I t h as b e e n s h o w n t h a t H 2 N 2 A s i a n a n d
H 3 N 2 H o n g K o n g p a n d e m i c in f l u e n za v i ru s e s a r e g en e t ic r e a s s o r ta n t s b e t w e e n
s t r a in s o f h u m a n a n d a v i a n o r i g i n [1 6, 24 , 30 ]. A n t i g e n i c a n d g e n e t i c a n a l y s e s o f H 3
i n f l u e n z a v i r u s e s i s o l a t e d f r o m w i l d d u c k s c a p t u r e d o n t h e A s i a n P a c i f i c f l y w a y i n
J a p a n a n d d o m e s t i c d u c k s i n s o u t h e r n C h i n a h a v e s h o w n t h a t t h e h e m a g g l u t i n i n s
( H A s ) o f t h e s e v ir u s e s w e r e c l o s e l y r e l a t e d t o t h o s e o f t h e e a r l ie s t h u m a n H 3 v i r u se s
[1 8, 3 5]. T h e s e fi n d i ng s i n d i c a t e d t h a t t h e H A g e n e o f t h e h u m a n p a n d e m i c s t r ai n , A /
H o n g K o n g / 6 8 ( H 3 N 2 ) w a s d e r i v e d f r o m s u c h a n a v i a n v i r u s [ 1 9 ] . T h e r e f o r e ,
e p i d e m i o l o g i c a l su r v e il l an c e o f a v i a n i n f lu e n z a w o u l d p r o v i d e i n f o r m a t i o n o n t h e
n e x t e p i d e m i c s fo r o t h e r a n i m a l s p ec ie s, i n c l u d in g h u m a n p a n d e m i c s .
W a t e r f o w l s s u c h a s d u c k s a n d g e es e i n th e n o r t h e r n h e m i s p h e r e m i g r a t e t o
s o u t h i n a u t u m n , b a c k t o n o r t h i n s pr in g , a n d b r e e d i n s u m m e r i n th e n e s ti n g p la c es
i n n o r t h e r n t e r r i t o r i e s s u c h as A l a s k a , C a n a d a , o r S i b e r ia . E x t e n s i v e s u rv e i l l a n c e o f
i n f lu e n z a in m i g r a t o r y w a t e r f o w l s w a s c a r r i e d o u t i n m a r s h a l i n g a r e a s , w h e r e t h e y
w e r e g a t h e r i n g in p r e p a r a t i o n o f m i g r a t i o n t o s o u t h , i n C a n a d a f r o m 19 78 t o 1 98 3
[1 3] . H o w e v e r , l i t tl e is k n o w n a b o u t h o w i n f l u e n z a v i ru s e s a r e m a i n t a i n e d i n d u c k
p o p u l a t i o n i n t h e i r b r e e d i n g p la c e s .
I t w a s s u g g e s t e d t h a t s o m e d u c k s ( e .g . N o r t h e r n p i n ta i l) s h o u l d m i g r a t e f r o m
A l a s k a t h r o u g h A l e u t i a n I s la n d s t o A s i a, a l t h o u g h t h e m a j o r i t y o f m i g r a t o r y d u c k s
i n A s i a a r e f r o m S i b e r i a [ 36 ]. D i s t i n c t l i n e a g e s o f t h e g e n e s o f i n f l u e n z a v i r u s e s
i s o l a t e d f r o m a v i a n s p e c ie s i n d i f fe r e n t r e g i o n s o f t h e w o r l d ( e .g . N o r t h A m e r i c a a n d
Eu r a s i a ) w e r e d e m o n s t r a t e d [ 4 , 5 , 7 , 8 , 15 , 2 2] . P h y l o g e n e t i c a n a l y s i s o f t h e g e n e s o f
i n f l u e n z a v ir u s i s o la t e s, t h e r e f o r e , w o u l d m a k e i t p o s s i b l e to p r e s u m e t h e f l y w a y s o f
t h e h o s t b i r d s .
T o p r o v i d e i n f o r m a t i o n h o w i n f l u e n z a v i r u s e s a r e m a i n t a i n e d i n d u c k
p o p u l a t i o n i n th e i r b r e e d i n g a r e a s a n d t h e m e c h a n i s m o f p e r p e t u a t i o n o f t h e v ir u s es ,
v i r o l o g ic a l s ur v e i ll a n c e o f a v i a n i n f l u e n z a w a s m a d e i n A l a s k a f r o m 1 99 1 t o 1 99 4 a n d
p h y l o g e n e t i c a n a l y s e s o f th e g e n e s o f th e i s o l a t e s w e r e c a r r i e d o u t .
M a t e r i a l s a n d m e t h o d s
Sample collection
In ea ch July fro m 1991 to 1994, 3 120 fecal materials of birds, comprising 2 345 ducks, m ainly
mallards An as platyrhynchos) an d pintails Anas ac uta), 663 Can ada geese B ranta canadensis) 6
Tun dra swans
Cygnus columb ianus),
7 dunlins
Calidris alpina),
and 10 M ew gulls
Larus can us),
were collected at 15 different points in A laska o f the Un ited States (Fig. 1 and Table 1). In
1992-1994, 81 water sam ples were also collected from 11 different ponds and lakes were ducks an d
geese were nesting. In Septemb er 1994, after almost du cks migrated to south, 21 water samples of
Big Minto Lak e where the viruses were isolated from ducks in the sum mer w ere collected. Samples
were put into cryotubes, the lids sealed, and transp orted w ith dry ice to the D epartm ent of
Virology and Molecular Biology,St. Jude Children s R esearch Hospital, Mem phis, Tennessee and
then stored at- 80 °C until assayed.
Virus isolation
Ea ch fecal sample was pu t in to phosphate-buffered saline (PBS; pH 7.2) containing antibiotics
(2 000 units of penicillin,400 ~ g o f streptomycin, 40 ~g o f gentamycin and 200 units ofpolymyxin B
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D u c k i n f l u e n z a v i r u s e s i n A l a s k a 1 1 6 5
~ CORVILLE DELTA
~ PRUDHOE BAY
MALLARD LAKE HEART LAKE
CANVASBACK
BIG M~NTO LAKE
~ '% LAKE
'o o
FAIRBANKS
NENANA o
o DELTA ]CT
DENALI NAT'L PARK o
ANCHORAGE
J
I
I
. i
I
LAKE HOOD/SPENARD
LAKE CHENEY
POTTERMARSH
WESTCHESTER LAGOON
F i g . 1 . L o c a t i o n o f 1 5 d i f f er e n t p o i n t s w h e r e f e c a l m a t e r i a l s o f w a t e r f o w l s w e r e c o l l e c t e d i n
A las ka . - - - - A r c t i c c i rc l e
p e r m l ) t o g i v e 1 0 - 2 0 s u s p e n s i o n . T h e s u s p e n s i o n w a s c e n t ri f u g e d a t 2 5 0 0 r p m f o r 2 0 m i n u t e s .
O n e t e n t h m l o f t h e s u p e r n a t a n t w a s i n o c u l a t e d i n t o a l l a n t o i c c a v i t ie s o f t w o 9 - 1 1 - d a y - o l d f e r ti l e
h e n ' s e g g s . T h e e g g s w e r e i n c u b a te d a t 3 5 ° C f o r 2 t o 3 d a y s u n l e s s d e a t h o f t h e e m b r y o w a s
d e t e c t e d . A t t h e e n d o f t h e i n c u b a t i o n p e r i o d o r u p o n e m b r y o d e a t h , t h e a l l a n t o i c f lu i d s w e r e
te s te d for h e ma gg lut ina t ing ac tiv ity .
W a t e r s a m p l e s w e r e c o n c e n t r a t e d u s i n g f o r m a l i n - tr e a t e d c h i c k e n e r y t h r o cy t e s a s f o ll o w s : t w o
m l o f 5 f o r m a l i n -t r e a te d c h i c k e n er y t h r o cy t e s in 3 0 x P B S w a s a d d e d t o e a c h 5 0 m l o f w a t e r
s a m p l e a n d m i x e d . A f t e r i n c u b a t i o n f o r 1 h a t 4 ° C , s a m p l e s w e r e ce n t r if u g e d a t 1 5 0 0 rp m f o r 5
m i n u t e s . A f t e r r e m o v i n g t h e s u p e r n a ta n t , 0 . 2 m l o f P B S c o n t a i n i n g a n t i b i o t i cs w e r e a d d e d a n d t h e
e r y t h ro c s ~ e s w e r e r es u s p e n d e d . O n e t e n t h m l o f t h e r e s u s p e n d e d e r y t h r o cy t e s w a s i n je c t ed i n t o
a l l a n t o i c c a v i ty o f 2 e g g s p e r s a m p l e . E a c h u n c o n c e n t r a t e d w a t e r s a m p l e w a s a l s o i n o c u l a t e d .
den t i f i ca t i on o f so l a t es
A l l h e m a g g I u t i n a t i n g a g e n t s w e r e id e n t i f ie d i n h e m a g g l u t i n a t i o n - i n h i b i t i o n a n d n e u r a m i n i d a s e -
i n h i b i t i o n t e s t s u s i n g s p e c i f ic a n t i s e r a t o t h e r e f e r e n c e s t r a in s o f i n f l u e n z a v i r u s e s [ 2 , 2 6 ] . T h e
a n t i s e r a w e r e u s e d a s p r e v i o u s l y p r e p a r e d a n d d e s c r i b e d [ 17 ].
Ph y t o g e n e t i c a n a l ysi s o f h e N P ge n es
P h y l o g e n e t i c a n a l y s is w a s b a s e d o n p a r t ia l n u c l e o t id e s e q u e n c e s o f th e N P g e n e s ( p o s i t i o n s
1 2 9 1 - 1 4 3 0 ) o f i n f l u e n z a v ir u s e s , d e t e r m i n e d b y r e v er s e t r a n s c r i p t io n a n d P C R d i r e c t s e q u e n c i n g
u s i n g v i ra l R N A a s a t e m p l a t e a n d o l i g o n u c t e o t i d e p r i m e r s . S e q u e n c e d a t a o f e a c h g e n e , t o g e th e r
w i t h s e q u e n c e s f r o m G e n B a n k , w e r e a n a l y ze d b y N e i g h b o r - j o in i n g m e t h o d [ 23 ] u s i n g a c o m p u t e r
s o f t w a r e , O D E N v e r s i o n 1 . 1 .1 ( Y a s u o I n a , N a t i o n a l I n s t i t u te o f G e n e t i c s, M i s h i m a , J a p an ).
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1 1 6 6 T I t o e t a l
R e s u l t s
Isolation o f influenza A viruses r om fec al samp les o f waterfowls
To assess if waterfowls harbor influenza A viruses at their breeding areas, we
collected 3 120 fresh fecal samples of birds in different areas in Alaska, USA during
their late breeding season from 1991 to 1994. From these samples, 205 hemag-
glutinating agents were isolated. Of these, 108 were serologically identified as
influenza viruses and the remainings as paramyxoviruses. Most of the influenza
virus isolates were obtained from fecal samples of ducks, while only 4 were isolated
from those of geese Table 1). These viruses were isolated mainly from the samples
collected in the central Alaska i.e., pond in Nenana, Big Minto Lake, and Mallard
Lake on the Yukon fiat), while the frequencies of influenza virus isolation were very
low in north and south Alaska. These results indicate that influenza viruses have
been maintained in duck population in the major breeding areas of central Alaska.
Antigen ic classi fication o f the influenza A virus isolates
As shown in Table 2, subtypes of the influenza virus isolates from ducks were H3N8,
H8N2, H10N2, H10N7, and H10N9 in 1991, H4N6 and H10N7 in 1992, H3NS,
H4N6, and H7N3 in 1993, and H2N3, H3NS, and H4N6 in 1994. In each of Big
Minto Lake and Heart Lake, influenza viruses of different subtypes were isolated at
the same time see footnote of Table 1). Additionally, different subtypes ofinfiuenza
viruses were isolated in different years in the same lake Big Minto Lake and
Mallard Lake). These results indicate that different subtypes of influenza A viruses
co-circulate in duck populat ion in their breeding areas.
Isolation of influenza A viruses rom take water
To investigate the mechanism of perpetuation of the viruses from year to year, virus
isolation was carried out from water samples of the lakes where ducks were nesting.
In 1992, two viruses were isolated from the samples from different lakes in Alaska,
where the same subtypes of influenza virus were isolated from ducks Table 3). In
the summer of 1994, 7 viruses were isolated from lake water and out of these, 2
samples contained 1018 and 10 2 8EIDs0 per ml of water samples. In the autumn of
1994, after most ducks left for migration to south, virus isolation was carried out
from the water samples of the Big Minto Lake where the viruses were isolated in the
summer. Three viruses were isolated from the water samples. These results suppor t
the notion that influenza viruses have been maintained in waterfowls by water-borne
transmission.
Phylogenetic a nalyses o f influenza virus isolates
To investigate the flyways of waterfowls carrying influenza viruses, phylogenetic
analyses of the NP genes of 18 representative strains which were isolated in different
years in the different lakes in Alaska was performed. Figure 2 shows an evolutionary
tree constructed on the basis of partial sequences of the NP genes together with
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Duck influenza viruses in Alaska
Table 1. Isolation of influenzaviruses from fecal samples ofwaterfowls
in Alaska in 1991-1994
1167
Location Species No. of samples with virus/
total no. of samples tested
t991 1992 1993
1994
Lake Hood/Spenard Duck 0/302 2d/317 0/26 0/15
Goose 4~/197 0/39 0/2
Gull 0/3
Lake Cheney Duck 0/293 0/133 0134
Goose 0/185 0/8 0/3
Potter Marsh Duck 0/1 0/18
Goose 0/130
Gull 0/4
Westchester Lagoon Duck 0/134
Goose 0/2
Lake Hanger Duck 0144
Fairbanks Duck 01156 0/116 0/54
Dunlin 0/7
Gull 0/3
Nenana Duck 14b/65 0/41 2h/2
Delta Junction Duck 0/27
Denali Nat'l Park Duck 0/6
BigMinto lake Duck 9~/149 14f1205 4i128
Goose 0/9
Mallard Lake Duck 46e/103 7g/53 0/24
Goose 013
Heart Lake Duck 0/29 6J/39
Canvasback Lake Duck 0/6
Corville Delta Duck 0/14
Goose 0/16
Swan 0/6
Prudhoe Bay Goose 0/69
Total 27/1585 481994 21/376 12/165
No. of each antigenic subtype of he isolates is as follows: 3 H10N7 and 1 H8N2, u 14 H3N8,
7 H 10 N7, 1 H 10N2, and 1 H 10Ng, a 1 H4 N6 and 1 H10N7, e46 H4N6, f7 H3N8, 6 H4N6, and
~ j
1 H7N3,g7H3N8, 2H3N8,4H3N8,and3H3N8,2H4N6, 1 H2N3
those from GenBank. Alth ough the sequence data o f the recent isolates in old world
was not available, the present approach is valid because distinct lineages between the
genes of isolates from avian species in North America and Eurasia have been
demon st ra ted previous ly in several reports [4, 5, 7, 8, 15, 22]. The results show ed
that the NP genes of the viruses isolated from ducks in Alaska belong to the Nor th
Ame ric an lineage of avian influenza viruses. These results suggest that waterfowls
carrying these viruses migrate thro ugh the Conti nent of Nort h America to south
and not through Aleutian Islands to Asia.
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1168 T. Ito et al.
Table 2. Antigenic characterization ofinfluenzaA virus isolates from fecal samples
of waterfowls in Alaska from 1991 to 1994
Antigenic
subtype
Number of influenza A viruses
isolated in the following year
1~1 1~2 1~3 1~4
o t a l
H2N3 1 1
H3N8 14 14 9 37
H4N6 47 6 2 55
HTN3 1 1
H8N2 1 1
H10N2 1 1
H10N7 10 1 11
H10N9 1 1
Total 27 48 21 12 108
Table 3 Isolation ofinfluenzaviruses from water samples of lakes in Alaska
in 1992-1994
Location
No. of samples with virus/
total no. of samples tested
1992 1993 1994 1994
summer summer summer antumn
Lake Hood/Spenard 1~/4 0/2
Lake Cheney 0/3 0/3
Potter Marsh 0/4
Westchester Lagoon 0/1
Lake Hanger 0/4
Fairbanks 0/5
Big Minto Lake 0/10
Mallard Lake 1b/2 0/5
Heart Lake 0/5
Canvasback Lake 0/3
Corville Delta 0/t
7o/13 3d/21
0/17
Total 2/23 0/28 7/30 3/21
No. of each antigenic subtype of the isolates is as follows: ~1 H4N6 b 1 H4N6 c4 H3N8 and 3
H4N6 2 H3N8 and 1 H7N3
D i s c u s s i o n
Hins haw et al . [13] demon stra ted high incidence of infection of ducks in the
marsh aling areas for their migra tory flyway in Cana da at the end of breeding season.
They suggested that i t was probabl y due to large numbers of susceptible juvenile
birds in the areas. The present surveillance study of waterfowls in Alaska reveals
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D u c k i n f l u e n z a v i r u s e s i n A la s k a 1 1 69
r D I d E g / 6 2 ( H 4 N 6 )
n / S A / 6 1 ( H S N 3 )
C k / G r / 4 9 ( H 1 0 N 7 )
I D I d E g / 5 6 ( H 1 1 N 6 )
= l i i ,,,,, D k / U / 6 3 ( H 3 N e )
I I ~ . . . . . . . F P V /D b /2 7 ( H 7 N 7 )
I I= I " F P V / R t / 3 4 ( H 7 N)
I l e D k / C z / f 6 1 , H 4 : )d / H q 7 7 ( H 4 N 6 )
W
' = D k / M r r v 7 4 ( H 3 N 8 )
I I D k , , A k / ~ O , , S l ( H 3 N e i ]
o n d i n N e n a n a
I D k / A k / 9 2 4 / 9 1 ( H 3 N S i t P o n d i n N e n a n a
I D W A k / 9 0 7 / g l (H 3 N e ) , ,] P o n d i n N e n a n a
M I / N Y / 7 8 ( H 2 N 2 )
D k / P n / 6 9 ( H S N 1 )
T y / O t / 6 8 ( H 8 N 4 )
T y / M n / 8 1 ( H 1 N 1 )
= " • I D k / A k / 2 6 9 5 / 9 2 ( H 4 N 6 ) , ,J M a l la r d L a k e
[ D k / A W 2 6 0 4 / 9 2 H 4 N 6 1 , ,, ,
M a l l a r d L a k e
T y / M n / 8 0 ( H 4 N 2 )
R t / N J / 8 5 ( H 4 N 6 )
t
o O O l / s i t e
~ , ~
' - " J A k / 3 1 0 7 / 9 3 ( H 3 N 8 ) [ B i g M i n to L a k e
I D k / A k / 3 1 1 1 / 9 3 ( H 7 N 3 ) '1 B i g M i n to L a k e
. I D I d A t d 3 2 4 2 " / 9 3 I H 3 N S i
B i g M i n t o
a k e
• I D k / A k / 3 2 4 5 '~ 3 ~ H 4 N 6 ) I B i g M i n to L a k e
" [ D k / A I d 3 2 1 0 / 9 3 ( H 4 N 6 ) ] B i g M i n to L a k e
• = , n • I D k / A k / 3 0 0 1 / 9 3 ( H 3 N e ) I M a l la r d L a k e
I D I d A I d 3 0 4 0 /9 3 1 H 3 N e ) I M a l la r d L a k e
I D I d A I d 2 3 3 3 / 9 2 /H 4 N 6 ) I L a k e S p e n a r d
I D k / A W 2 0 1 2 / 9 2 /H 1 0 N T ) I L a k e H o o d
i • [ D I d A k / 6 5 8 / 9 1 ( H 1 0 N 2 ) [ B i g M in t o L a k e
I D I d A I d S S 3 / 9 1 ( H 1 0 N 7 i , ]
B i g M i n to a k e
I D k / A k / 7 1 2 / 9 , , (H 1 0 N 9 ) ] B i g M in t o L a k e
I D k / A k / 7 0 2 / 9 1 ( H s N 2 ) I B i g a i n t o L a k e
C I d P n / 8 3 ( H 5 N 3 )
N
F ig . 2. P h y to g e n e t i c t r e e f o r a v i a n i n f l u e n z a A v i r u s N P g e n e s . H o r i z o n t a l d i s t a n c e s a r e
p r o p o r t i o n a l t o t h e m i n i m u m n u m b e r o f n u c l e o t i d e d i f fe r e nc e s r e q u i r e d t o j o i n n o d e s a n d
s e q u e n c e s . D o t s r e p r e s e n t t h a t t h e s e q u e n c e s a r e i d e n t i c a l w i th t h e n o d e s . V e r t i c a l li n e s a r e f o r
s p a c in g b r a n c h e s a n d l a b el s . V i r u s e s i s o l at e d f r o m w a te r f o w l s a t t h e i r n e s t i n g p o in t s i n A la s k a a r e
in b o x e s , t o g e th e r w i th t h e n a m e o f th e l a k e w h e r e t h e y w e r e i s o la t e d . A b b r e v i a t i o n s f o r v i ru s e s a r e
f o u n d in G o r m a n e t a l. [8 ]. E a c h t r e e w a s b r a n c h e d i n t o O l d W o r l d O W ) a n d N o r t h A m e r i c a n
N A ) s n b l i n e a g e s
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1 1 7 0 T I t o e t a l
that high incidence of virus infection of ducks has already occurred in the breeding
places of ducks. Cont inuous surveillance of influenza viruses in migratory birds in
Canada and USA showed that the frequency of virus isolation from migratory
ducks coming from northern territories in autumn was high (more than 20 of
juveniles), whereas those from south in spring was extremely low (less than 0.25 )
[34], suggesting that viruses are mainly supplied when they migrate to south. The
present results suggest that first amplification of the virus by juvenile birds has
already occurred in the breeding areas of waterfowls and the viruses were brought to
southern area by their migration.
The mechanism of perpetuation of influenza viruses in avian species year by year
has no t been well understood. Influenza viruses were isolated from unconcentrated
lake water when migratory ducks are present [11]. In the present study, high titers of
the viruses were isolated from water samples of different lakes in the breeding areas
of ducks in northern high latitudes in summer (Lake Hood, Mallard lake and Big
Minto Lake). Furthermore , the viruses remained viable in the lake water after that
almost ducks left for migration to south. I t is possible that influenza viruses are
preserved in frozen lake water during winter when ducks are absent and that ducks
coming back from south are infected with these viruses in spring. Survival of
influenza viruses in water is dependent on the virus strain and the salinity, pH, and
temperature o f the water; at 17 °C some strains remain infectious for up to 207 days,
and at 4 °C they remain infectious for longer period [28, 29]. The major breeding
areas of ducks in Alaska located in high latitudes, 65-68 degrees north, near the
arctic regions. The take water in this area is cold enough for viruses to survive for
longer period in autumn when ducks leave for migration to south. Therefore,
influenza viruses could be preserved in the frozen lake water while ducks are absent.
The phylogenetic analysis of the NP genes of influenza virus isolates from ducks
in Alaska showed that all of those analyzed belonged to the North American lineage
(Fig. 2). Therefore, these viruses were not supposed to be the gene sources of Hong
Kong pandemic strains. Alternatively, Bean et al. [4] suggested that A/duck/
Hokkaido/21/82 (H3N8) which was isolated from a migratory duck captured on the
Asian Pacific flyway in Japan bore the North American type HA gene. There are
other major breeding areas of waterfowls in west and south Alaska such as Yuk on
Delta, Seward Peninsula, and St. Lawrence Island. The possibility that waterfowls
in these areas migrate to Asia through Aleutian Islands was retained. Phylogenetic
analysis of various virus isolates from waterfowls may make it possible to presume
the migratory flyways of host birds carrying influenza viruses.
A c k n o w l e d g e m e n t s
This studywas supportedby Grants-in-Aid or ScientificResearch03041013 and 05044117 from
the Ministry of Education, Scienceand Culture, Japan and in part by Public Health Service
Research Gran~s AI-29680 and AI-33898 from the National Institute of Allergyand Infectious
Disease, by Cancer Center Support (CORE) Grant CA-21765, and by the AmericanLebanese
Syrian AssociatedCharities. We are grateful o R. M. Oates, R. King, S. McLean, and T. Heuer
(theU.S. Fish and WildlifeService),J. M. Wright,and C. A. Smith theAlaskaDepartmentoffish
and Game) for their kind cooperation for the present surveillance study. We thank Hiroki
Takakuwa and AyakoShimizu or technicalassistance.
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D uck inf luenza vi ruses in Alask a 1171
References
1. Alexa nder D J (1986) Av ian diseases-his tor ica l aspec ts . In: Proceedin gs of the 2nd Inte r -
na t iona l Sy m po s ium on a v i a n I n flue nza , R ic hm o nd , V a , 1986. U .S . Anim a l He a l th Asso-
c ia tion, p p 4- 13
2 . A y m a r d - H e n r y M , C o l e m a n M T , D o w d le W R , L a v e r W G , S ch il d G C , W e b s t e r R G (1 97 3)
Inf luenza vi rus neuraminidase and neuraminidase- inhibi t ion tes t procedures . Bul l Wor ld
He a l th Or ga n 48 :199- 202
3 . Be a n W J , Ka w a ok a Y , Wo od JM , Pe a r son JE , W e bs t e r R G ( 1985) Cha r a c t e ri z a t ion o f
vi rulent and avi rulent A/Chicken/Pennsylvania /83 inf luenza A vi ruses : potent ia l role of
defec t ive inte r fe r ing R N A s in na ture . J Viro154:151 -160
4 . Be a n W J , Schel l M , Ka tz J , Ka w a ok a Y , Ne a ve C , Gor m a n O , We bs t e r R G ( 1992) E vo lu t ion
of the H3 in f lue nz a v ir us he m a gglu tin in f r om hum a n a nd no nhum a n hos t s. J V i r o l 66 :
1129 1138
5 . Don i s RO , Be a n WJ , K a w a ok a Y , We bs t e r RG ( 1989) D i s t inc t li ne age s o f in f lue nz a v i rus H4
hemagglut inin genes in di fferent regions of the wor ld. Virology 1 69:408 -417
6. Eas te rday B C, Cou ch RB (1975) Anim al inf luenza : i t s s ignif icance in hu ma n infe c t ion-
sum mary of inf luenza wo rksh op VI . J Infec t Dis 131: 602-612
7 . Go r m a n OT , Be a nW J, Ka w a ok a Y , We b s t e r R G ( 1990) E vo lu t ion o f the nuc l e opro t e in ge ne
of influenza A virus. J Viro1 64:14 8 149 7
8 . Go r m a n OT , Doni s RO , Ka w a oka Y , W e bs t e r R G ( 1990) E vo lu t ion o f i nf luenz a A v i rus PB2
ge ne s: im pl i c a t ions f o r e vo lu t ion o f t he r ibonuc le opr o t e in c om ple x a nd o r ig in o f hum a n
influenza A vi rus . J Viro164:4 893-4 902
9 . G u o Y , W a n g M , K a w a o k a Y , G o r m a n O T , I to T , S ai to T , W e b s t e r R G ( t 9 9 2 ) C h a r ac t er -
iza t ion of a new avian- l ike influenza A vi rus f rom horses in China . V irology 18 8:245-255
10. Ha lv or son D , Ka r un a kr a n D , Se nne D , Ke l le he r C , Ba i le y C , Abr a ha m A , H insha w VS,
Ne w ma n J (1993) Ep izoo tiolog y o f avian inf luenza-simultaneous mo nitoring o f sentinel duck s
a nd tu r ke ys i n M inne so ta . Avia n D i s 27 :77- 85
11. H insh a w VS, We bs t e r RG , T ur ne r B (1980) T he pe r pe tua t ion o f o r thom yxovi r use s a nd
pa r a m yxovi r use s i n Ca na d ia n wa te rf owl . Ca n J M ic r ob io126 :622- 629
12. H insha w VS, Be a n WJ , W e bs t e r RG , Re h g JE , F io r e ll i P , E a r ly JR , Ge r a c i JR , S t Au bin DJ
(1984) Are seals f requent ly infec ted wi th avian influenza vi ruses ? J V irol 51:8 63-86 5
13 . H insh a w VS, Wo od JM , W e bs t e r RG , De ibe l R , T ur ne r B (1985) C i r c u l a ti on o f i n flue nz a
v i ruse s a nd pa r a m yxo vi r use s i n wa te r f owl o r ig ina t ing f r om tw o d i f fe r e n t a r e a s o f No r th
Amer ica . B ul l W or ld Hea l th Organ 63:711-719
14. Hinsh aw VS, Bean W J, Gerac i JR , Fiore l liP , Ear ly G, Webster RG (1986) Charac te r iza t ion o f
two inf luenza A vi ruses f rom a pi lot whale . J Viro158: 65 5 - 656
15 . I t o T , Gor m a n OT , K a w a ok a Y , Be a n W J , W e bs t e r R G ( 1991) E vo lu t iona r y a nalys is o f t he
inf luenza A vi rus M gene wi th comp ar ison o f the M 1 and M 2 prote ins . J Viro165:549 1-5498
16 . Ka wa ok a Y , K r a uss S , W e bs t e r R G ( 1989) Avia n- to - hum a n t r ansm iss ion o f t he PB 1 gene o f
influenza A vi rus in the 1957 and 1968 pandem ics . J Viro163: 460 3-4 608
17. Kid a H, Yan aga wa R (1979) I sola t ion and charac te r iza t ion of inf luenza A vi ruses f rom wi ld
f ree-f lying ducks H okk aido , Japan. Zent ra lbl Bakter iol Mik robiol H yg I Ab t Or ig A 244:
135-143
18. K ida H , Ka w a ok a Y , Ne a ve CW, W e bs t e r R G ( 1987) Ant ige n ic a nd ge ne ti c c onse r va t ion o f
H3 influenza vi rus in wi ld ducks . Virology 159:109 -119
19. Kid a H (1993) Av ian inf luenza virus as the origin ofh um an p and em ic strains. In: Proceed ings
of the Third Inte rna t iona l Sym posium on A vian Influenza, Ma dison, W is, 1992. Univers i ty of
Wisconsin-Madison, pp 85-97
20. Kl ingebo rne B, Englun d R R , Junt t i N, R ock bo rn G (1985) An avian inf luenza A vi rus ki ll ing
a mam mal ian sp ec ies- the mink. Arch Viro186: 34 351
7/26/2019 Perpetuation of influenza A viruses in Alaskan waterfowl reservoirs.pdf
http://slidepdf.com/reader/full/perpetuation-of-influenza-a-viruses-in-alaskan-waterfowl-reservoirspdf 10/10
1172 T. I to et al . : Du ck influenza viruses in Alas ka
21. L e ve r W G, W e bs t e r R G ( 1973) S tud i es on t he o r ig in o f pa nde m ic i n f luenz a I II . E v ide nc e
implicating duc k and equine influenza viruses as possible proge nitors o f the Ho ng K on g strain
of hum an influenza . Virology 51:383 -391
22. Saito T, Ka w ao ka Y, W ebster R G (I 993) Phylogenetic analysis of th e N8 neuraminindase gene
of inf luenza A viruses. Virolo gy 19 3:86 8-8 76
23. Sa i t ou M , Ne i M ( 1987) T he ne ighbour - jo in ing m e thod : a ne w m e tho d f o r r e c ons t ruc t i ng
phylogenic trees . Mo l Biol Evol 4:406 - 425
24. Sc ho l t is se k C , R o M e W , yon Hoy ninge n V , Ro t t R ( 1978) On the o r ig in o f t he hum a n
inf lue nz a v i rus sub type s H2 N2 a nd H3N 2. V i r o logy 87 :13- 20
25 . Sc ho l t i s se k C , Bur ge r H , Ba c hm a nn PA, Honnoun C ( 1983) Ge ne t i c r e l a t e dne ss o f
hemagglutinin of the H 1 subtyp e of inf luenza A viruses isolated from swine and birds. V irology
129:521-523
26. Sever JL (1962) Ap plication o f a microtechniq ue to viral serological investigations. J lmm un ol
88:320-329
27. Sho rtr idge KF , Stua rt-Ha rr is C H (1982) A n influenza epicentre? Lanc et i i: 812-81 3
28. S t a ll kne c h t DE , Ke a r ne y M D, Sha ne SM , Z wa nk P J (1990) E ff ec ts o f p H , t e m pe r a tu r e , a nd
sa linity on pers is tence of avian inf luenza vi ruses in water . Av ian D is 34:4 12-413
29. S t a ll kne c h t DE , Sha ne SM , Ke a r ne y M D, Z wa n k PJ ( t 990) Pe r s is t e nce o f a v i a n in f lue nz a
viruses in water . Avia n Dis 34:4 06 - 411
30. W e bs t e r RG , L a ve r W G ( 1972) S tud i e s on t he o r ig in o f pa nde m ic i n f lue nz a I. Ant ige n ic
a na lysi s o f A2 in f lue nz a v i ruse s iso l a t e d be f or e a nd a f t e r the a ppe a r a nc e o f Ho ng Ko ng
influenza using antisera to the isolated hemagglutinin subu nits. Virology 48:43 3 - 444
31. W ebster RG , Lav er RG (1975) Ant igenic var ia t ion of inf luenza viruses . In: Ki lbourne ED (ed)
The inf luenza vi ruses and inf luenza . Acad emic Press, N ew Yo rk, pp 2 69-3 14
32. W e bs t e r RG , Ge r a c i JR , Pe tu r s son G , Sk i r ns son K ( 1981) Conjuc ti v i ti s i n hum a n be ings
caus ed by inf luenza A vi rus o f seals. N ew En gl J M ed 304:911
33. W e bs t e r RG, H insha w VS, Be a n W J , Va n Wyk e KL , Ge r a c i JR , S t Aubin D J, Pe tu r s son G
(1981) Cha racter ization of an inf luenza A virus from seals. Virolo gy 113:712--724
3 4. W e b s t e r R G , B e a n W J , G o r m a n O T , C h a m b e r s T M , K a w a o k a Y ( 19 92 ) E v o l u t io n a n d
ecology of influenza A vi ruses . M icrobiol Re v 56:152 -179
35. Yasu da J , Shor t r idge KF , Shimizu Y, Kida H (1991) M olecular evidence for a role of domest ic
ducks in the int roduct ion of avian H3 inf luenza vi ruses to pigs in southern China, where the A/
Ho ng Kon g/68(H3 N2) s t ra in emerged. J G en Viro172:2007-2010
36. Yoshi i M, K anou chi T (1979) M igra tory bi rds . Tok ai Univers i ty Press , Tok yo, Japan, p 38 (in
Japanese)
Au thors address: D r . H. Kida , Depar tm ent o f Veter inary Hygiene and M icrobiology, School
of Veter inary Medic ine , Hok kaid o Un ivers ity , Sapporo 060, Japa n
Received Feb ruary 16, 1995