Research Article Avian Influenza Surveillance in the Danube Delta Using Sentinel Geese and Ducks Alexandru Coman, 1 Daniel Narcis Maftei, 1 Razvan M. Chereches, 1 Elena Zavrotchi, 1 Paul Bria, 1 Claudiu Dragnea, 1 Pamela P. McKenzie, 2 Marissa A. Valentine, 3 and Gregory C. Gray 3 1 Center for Health Policy and Public Health, Institute for Social Research, Faculty of Political, Administrative and Communication Sciences, Babes-Bolyai University, 400132 Cluj-Napoca, Romania 2 Department of Infectious Diseases, St. Jude Children’s Research Hospital, Center of Excellence for Inluenza Research and Surveillance, Memphis, TN 38105, USA 3 College of Public Health and Health Professions, and Emerging Pathogens Institute, University of Florida, 101 S. Newell Dr., Suite 2150A, Gainesville, FL 32610, USA Correspondence should be addressed to Gregory C. Gray; gcgray@phhp.ul.edu Received 21 November 2013; Accepted 26 February 2014; Published 25 March 2014 Academic Editor: Daniel R. Perez Copyright © 2014 Alexandru Coman et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Highly pathogenic avian inluenza (HPAI) H5N1 virus incursions from migrating birds have occurred multiple times in Romania since 2005. Beginning in September 2008 through April 2013, seasonal sentinel surveillance for avian inluenza A viruses (AIVs) using domestic geese (Anser cygnoides) and ducks (Anas platyrhynchos) in the Danube Delta was established by placing 15 geese and 5 ducks at seven sites. Tracheal and cloacal swabs, and sera collections (starting in 2009) were taken monthly. We studied a total of 580 domestic birds and collected 5,520 cloacal and tracheal swabs from each and 2,760 sera samples. All swabs were studied with real-time reverse transcription polymerase chain reaction (rRT-PCR) for evidence of AIV. Serological samples were studied with hemagglutination inhibition assays against avian H5, H7, and H9 inluenza viruses. From 2009 to 2013, 47 swab specimens from Cot Candura, Enisala, and Saon screened positive for AIV; further subtyping demonstrated that 14 ducks and 20 geese had cloacal evidence of H5N3 carriage. Correspondingly, 4 to 12 weeks ater these molecular detections, sentinel bird sera revealed elevated HI titers against H5 virus antigens. We posit that domestic bird surveillance is an efective method to conduct AIV surveillance among migrating birds in delta areas. 1. Introduction Asian-lineage highly pathogenic avian inluenza (HPAI) H5N1 virus has infected poultry in many countries of the world and is thought to be highly endemic in certain delta areas due to frequent viral incursions from large populations of migrating birds [1, 2]. As of 2011, the Food and Animal Organization (FAO) considered HPAI H5N1 to be enzootic among aquatic birds in Bangladesh, China, Egypt, India, Indonesia, and Vietnam [3]. he latest report from the World Organization for Animal Health revealed outbreaks of HPAI H5N1 that have occurred in Bangladesh, Bhutan, Cambodia, China, India, Korea, Nepal, and Vietnam in 2013 and in China, Nepal, and Vietnam during early 2014 [4]. Large populations of aquatic migratory birds frequent delta areas in Romania and evidence to date strongly suggests that they have introduced HPAI strains into Romania’s poul- try. he irst Romanian HPAI H5N1 incursions were detected in backyard poultry farms in October 2005 [5, 6]. he virus rapidly spread throughout the country until aggressive control measures were taken; the epizootic halted in July 2006 [7]. Laboratory studies demonstrated that the epidemic virus was similar to H5N1 viruses previously detected in Southeast Asia and Turkey and that migrating birds were the Hindawi Publishing Corporation Influenza Research and Treatment Volume 2014, Article ID 965749, 6 pages http://dx.doi.org/10.1155/2014/965749