Molecular Epidemiology and Surveillance of Avian Influenza in Wild and Domestic Birds

Abstract

Surveillance of the existence of avian influenza virus in birds is essential in understanding its epidemiology and potential zoonosis. Point surveillance was made on December 2004 and May to August 2005 in wild birds, domestic poultry and environment. Seven out of 67 samples were positive for avian influenza infection resulting to a 10.4 % isolation rate during the winter. Partial sequencing revealed that all isolates were of H11N3 subtype. In the summer, a total of 584 tracheal, cloacal and environmental swabs were tested in the laboratory through virus isolation, real- time PCR and RT-PCR. All samples were negative. To understand the evolution and ecology of the isolated virus, further sequencing was done for all eight genes of H11N3 and each gene sequence was phylogenetically analyzed with available sequences in the Influenza Sequence Database. Replication and transmission of H11N3 were also investigated through experimental infection of chicken and quail.