P. K. Biswas
Professor
Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh
Nitish C. Debnath
Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh
Abu S.M.A. Hannan
Department of Livestock Services, Dhaka
Mohammad A. Habib
Department of Livestock Services, Dhaka
Himel Barua
Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh
M. H. Rahman
Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh
A. Das
Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh
J. P. Christensen
Copenhagen University, Copenhagen, Denmark
S. S. U. Ahmed
Chittagong Veterinary and Animal Sciences University, Chittagong, Bangladesh
Mohammed Giasuddin
Principal Scientific Officer
Animal Health Research Division, Bangladesh Livestock Research Institute, Savar, Dhaka-1341
Avian influenza virus, Bangladesh, HPAI, Backyards
Chittagong and Dhaka
Animal Health and Management
Study Population and Case Definition - Bangladesh is composed of 4,500 unions (local government units that comprise several villages) and 90,500 villages (10). Of the total poultry population in the country (≈222 million birds), 50% are backyard poultry, predominantly indigenous (nondescriptive) chickens and mostly reared in free-range systems on the homesteads in these villages (10). In Bangladesh, villagers sometime rear Fayoumi and Sonali (a cross-bred F1 generation of Fayoumi [female] and Rhode Island Red [male]) chickens in a semi-scavenging system (11–13) and occasionally in intensive systems. All 25 HPAI outbreaks recorded in indigenous (n = 20 farms), Fayoumi (n = 2), and Sonali (n = 5) chickens in village areas in Bangladesh by November 17, 2007, were considered outbreaks in backyard chickens, and the farms were enrolled in our study as case backyard farms. By date of onset of clinical signs, the first outbreak of HPAI in backyard chickens was recorded on March 22, 2007, the date on which Bangladesh was officially declared HPAI (H5N1) virus infected. In 2007, the numbers of backyard farms infected were 1 farm in March, 3 in April, 7 in May, 7 in June, 2 in July, 1 in September, 3 in October, and 1 in November.Global positioning system coordinates from the case and control farms were collected during farm visits and entered into a digitized map of Bangladesh. A geographic information system program (Arc View 9.1; Environmental System Research Institute, Redlands, CA, USA) was used.
Data Collection and Survey Method - A questionnaire designed for this study was pretested at 5 case farms. The questionnaire was then modified according to new variables encountered during pretesting. In the final questionnaire, 59 variables were surveyed (spreadsheet available from P.K.B.).
Statistical Analysis -The collected data were entered into a spread sheet program (Excel; Microsoft, Redmond, WA, USA) and transferred into Epi Info 2000 (Centers for Disease Control and Prevention, Atlanta, GA, USA) for analysis.
Emerging Infectious Diseases, Volume 15, Number 12–December 2009, DOI: 10.3201/eid1512.090643
Journal