Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 12 5 2020 10 31 404 410 Fereshteh Ansari Evidence-Based Medicine Research Center, Health Management and Safety Promotion Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran AND Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran Saied Bokaie Department of Food Hygiene, School of Veterinary Medicine, University of Tehran, Tehran, Iran Seyed Mostafa Peighambari Department of Avian Diseases, School of Veterinary Medicine, University of Tehran, Tehran, Iran Mohammad Hosein Fallah Department of Poultry Diseases, Razi Vaccine and Serum Research Institute, Karaj, Iran Farshad Tehrani Iranian Veterinary Organization, Tehran, Iran Abolfazl Rajab Iranian Veterinary Organization, Tehran, Iran Seyed Ali Ghafouri Iranian Veterinary Organization, Tehran, Iran Maryam Shabani Iranian Veterinary Organization, Tehran, Iran Hadi Pourjafar Department of Food Sciences and Nutrition, Maragheh University of Medical Sciences, Maragheh, Iran AND Dietary Supplements and Probiotic Research Center, Alborz University of Medical Sciences, Karaj, Iran 2019 02 12 2020 08 10 Background and Objectives: The aim of this study was to determine the prevalence of Salmonella at broiler breeder farms of Iran and investigate the factors underlying salmonellosis in these farms. This is a cross-sectional investigation conducted in 23 provinces of Iran. Materials and Methods: Fecal samples were collected from 139 broiler breeder farms in the country and standard bacteriological tests were carried out on the samples for the isolation of Salmonella. The serological tests were then applied for the samples that were positive in the bacteriological test. The information on the sampled farms extracted from the Iran GIS-VET Monitoring and Surveillance System was used for the analysis of the risk factors. Results: A total of 11 farms out of the 139 sampled farms were infected with Salmonella with the largest number of infected cases related to Tehran and Fars Provinces. Conclusion: The statistical analysis results showed that flocks with older ages and farms with larger number of houses are at greater risk of Salmonella infection. https://ijm.tums.ac.ir/index.php/ijm/article/view/2036 https://ijm.tums.ac.ir/index.php/ijm/article/download/2036/1273