Iraqi Journal of Veterinary Sciences, Vol. 35, Supplement III, 2021 (47-52) Proceedings of the 13th (2nd International) Scientific Conference, College of Veterinary Medicine, University of Baghdad 47 Iraqi Journal of Veterinary Sciences www.vetmedmosul.com First serodetection and molecular phylogenetic documentation of Coxiella burnetii isolates from female camels in Wasit governorate, Iraq M.A. Al-Graibawi 1 , A.A. Yousif 1 , H.A. Gharban 2 , and J. Zinsstag 3 1 Department of Internal and Preventive Veterinary Medicine, College of Veterinary Medicine, University of Baghdad, 2 Department of Internal and Preventive Veterinary Medicine, College of Veterinary Medicine, Wasit University, Wasit, Iraq, 3 Departments of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland Article information Abstract Article history: Received May 18, 2020 Accepted October 10, 2020 Available online December 1, 2021 This study aims to detect Coxiella burnetii in one-humped female camels (Camelus dromedarius) using ELISA and confirmation of infection by PCR with the phylogenetic analysis of local isolates. The 91 adult female camels were selected for clinical examination and blood sampling from different areas in Badra and Al-Numaniyah districts in Wasit governorate, Iraq, from February to April 2019. The prevalence of Coxiella (C.) burnetii was 19.8% and 4.4% by ELISA and PCR, respectively. Targeting 16S rRNA genes from three positive samples were documented in the Genbank-NCBI under accession numbers of MN900579.1, MN900580.1, and MN900581.1. Clinical evaluation revealed insignificant variation in temperature, pulse, respiratory rates, and lymph node enlargement among the positive and negative animals. The findings also showed that camels of the Badra regions have positive signs. burnetii compared to other regions, and the infection was increased significantly in April and March. In conclusion, our findings confirmed the prevalence of C. burneth among Iraqi female camels, suggesting that these animals might be a source of the pathogen for humans and other animal species. Therefore, further studies are necessary to provide more detailed data about the prevalence of C. burnetiito to improve effective control measures. Keywords: Q fever Camelus dromedarius PCR Sequence ELISA Correspondence: A.A. Yousif afaf.a@covm.uobaghdad.edu.iq DOI: 10.33899/ijvs.2021.130888.1890, ©Authors, 2021, College of Veterinary Medicine, University of Mosul. This is an open access article under the CC BY 4.0 license (http://creativecommons.org/licenses/by/4.0/). Introduction The Coxiella (C.) burnetii is an obligate intracellular, Gram-negative, non-motile bacterium belonging to the Coxiellaceae family of Legionellales order, which causes a highly contagious neglected zoonotic disease known as Q (Query) fever (1). Many studies reported that this pathogen is considered a potential agent for bioterrorism due to its highly high infectivity (one bacterium may produce disease) in humans and a wide range of domestic and wild animals and its survival under harsh environmental conditions (2). C. burnetii is an occupational pathogen of farmers, slaughterhouse workers, and veterinarians and can be transmitted by inhaling aerosolized contaminated dust, direct contact with infected tissues and fluids, as well as by arthropod bites (3). Multiple hosts can serve as the main reservoir for infection, particularly the infected females that shed vast numbers of highly stable bacteria into their birth products (amniotic fluids and placenta) and smaller amounts in milk, feces, and urine which may continue over several months (4-6). Worldwide, numerous studies investigate the prevalence of Coxiella in camels such as the United Arab Emirates (7), Egypt (8), Algeria (9), Saudi Arabia (10), and Iran (11). These studies showed that the prevalence of C. burnetii varies widely by geographical location, type of management, and flock numbers. ELISA is the most recommended and preferred diagnostic technique for Q fever and other diseases for screening assays and epidemiological studies because of its high specificity and sensitivity, relatively low cost, and easier to use (11,12). For confirmation, the isolation of C. burnetii by inoculation of the yolk sac of 5-7 old chick embryos or in vitro tissue