Avian influenza virus monitoring in wintering waterbirds in Iran, 2003-2007

Sasan Fereidouni ,Ward Hagemeijer,Nicolas Gaidet,Anja Globig,Elke Starick,Ortrud Werner,Bernd Hoffmann,Martin Beer,Shirin Mousakhani,Mohammad E Sehati,Tim Dodman,Majid Kharrazian Moghaddam,Siamak Masoodi,Saliha Hammoumi,Giovanni Cattoli,Heydar Amini ,H Modirrousta ,M Aghakhan ,Mohammad Hassan Bozorghmehrifard ,M A Akhavizadegan ,Timm C Harder ,Scott H Newman ,Thomas C Mettenleiter

doi:10.1186/1743-422x-7-43

Abstract

BackgroundVirological, 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.ResultsOverall, 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%.ConclusionResults 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.

Highlights

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
Of positive samples were found in this portion of samples, though 78% of samples collected during this period originated from ducks
Avian influenza monitoring of wild birds in natural habitats and in areas at risk of transmission between domestic poultry and wild birds will increase the knowledge of epidemiology, ecology and genetic relationships of AIV infections

Summary

Introduction

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. Low pathogenic AIV (LPAIV) are widely distributed in wild avian species around the world. They have been most frequently identified in waterbirds of the orders Anseriformes (including ducks, geese and swans) and Charadriiformes ( gulls and terns). These viruses replicate in epithelial cells of the respiratory and intestinal tracts of birds, and are excreted in high.

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