Avian influenza virus monitoring in wintering waterbirds in Iran, 2003-2007.
BACKGROUND
Virological, molecular and serological studies were carried out to determine the status of infections with avian influenza viruses (AIV) in different species of wild waterbirds in Iran during 2003-2007. Samples were collected from 1146 birds representing 45 different species with the majority of samples originating from ducks, coots and shorebirds. Samples originated from 6 different provinces representative for the 15 most important wintering sites of migratory waterbirds in Iran.


RESULTS
Overall, AIV were detected in approximately 3.4% of the samples. However, prevalence was higher (up to 8.3%) at selected locations and for certain species. No highly pathogenic avian influenza, including H5N1 was detected. A total of 35 AIVs were detected from cloacal or oropharyngeal swab samples. These positive samples originated mainly from Mallards and Common Teals.Of 711 serum samples tested for AIV antibodies, 345 (48.5%) were positive by using a nucleoprotein-specific competitive ELISA (NP-C-ELISA). Ducks including Mallard, Common Teal, Common Pochard, Northern Shoveler and Eurasian Wigeon revealed the highest antibody prevalence ranging from 44 to 75%.


CONCLUSIONS
Results of these investigations provide important information about the prevalence of LPAIV in wild birds in Iran, especially wetlands around the Caspian Sea which represent an important wintering site for migratory water birds. Mallard and Common Teal exhibited the highest number of positives in virological and serological investigations: 43% and 26% virological positive cases and 24% and 46% serological positive reactions, respectively. These two species may play an important role in the ecology and perpetuation of influenza viruses in this region. In addition, it could be shown that both oropharyngeal and cloacal swab samples contribute to the detection of positive birds, and neither should be neglected.
Fereidouni
Sasan R
SR
Friedrich-Loeffler-Institut, Insel Riems, Germany. sasan.fereidouni@fli.bund.de
Werner
Ortrud
O
Starick
Elke
E
Beer
Martin
M
Harder
Timm C
TC
Aghakhan
Mehdi
M
Modirrousta
Hossein
H
Amini
Hamid
H
Moghaddam
Majid Kharrazian
MK
Bozorghmehrifard
Mohammad H
MH
Akhavizadegan
Mohammad A
MA
Gaidet
Nicolas
N
Newman
Scott H
SH
Hammoumi
Saliha
S
Cattoli
Giovanni
G
Globig
Anja
A
Hoffmann
Bernd
B
Sehati
Mohammad E
ME
Masoodi
Siamak
S
Dodman
Tim
T
Hagemeijer
Ward
W
Mousakhani
Shirin
S
Mettenleiter
Thomas C
TC
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001717:Birds; D002988:Cloaca / Q000821:virology; D005838:Genotype; D009980:Influenza A virus / Q000145:classification* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000453:epidemiology* / Q000821:virology; D007492:Iran / Q000453:epidemiology; D009960:Oropharynx / Q000821:virology; D010802:Phylogeny; D015995:Prevalence; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA
D000914:Antibodies, Viral; D012367:RNA, Viral