European Journal of Radiology 61 (2007) 245–250 Radiological and clinical course of pneumonia in patients with avian influenza H5N1 Ali Bay a,∗ , ¨ Omer Etlik b , A. Faik ¨ Oner a , ¨ Ozkan ¨ Unal b , Halil Arslan b , Aydın Bora b , Ramazan Davran b , Sevil Arı Yuca a , Murat Dogan a a Yuzuncu Yil University, Faculty of Medicine, Department of Pediatrics, Van, Turkey b Yuzuncu Yil University, Faculty of Medicine, Department of Radiology, Van, Turkey Received 4 April 2006; received in revised form 4 September 2006; accepted 9 October 2006 Abstract Introduction: We evaluated chest X-ray and clinical findings of patients with lower respiratory tract infection due to influenza H5N1 and presented the radiological findings and clinical course of the infection. Materials and methods: Between December 2005 and February 2006, eight hospitalized patients (median age 10, 5–15 years) with avian-flu were evaluated in this study. All patients were evaluated with chest X-ray and four of them with CT scan. Post mortem pathological characterization were also available for three of the patients. Results: A rapidly progressive pneumonia with high mortality rate was observed especially for cases with late admission. The major radiologic abnormalities were extensive pneumonic infiltration with segmental and multifocal distribution, mostly located in lower zones of the lung. No pleural effusion and hilar lymphadenopathy was noted. Conclusion: Avian flu may be presented as rapidly progressive pneumonia. The chest radiography has an important role in diagnosis and should be obtained daily because of rapid change of the findings that may necessitate prompt action. © 2006 Elsevier Ireland Ltd. All rights reserved. Keywords: Avian-flu; Lower respiratory tract infection; Chest X-ray; Clinic 1. Introduction Influenza has been a significant and highly contagious disease of global importance and the virus infects a variety of animals, including humans and birds. Three subtypes are currently cir- culating among humans (H1N1, H1N2, and H3N2). During the past few years, several subtypes of avian influenza A have been shown to cross the species barrier and infect humans. The virus is mostly transmitted to humans directly through contact with infected birds or their secretions and presents as an influenza type illness with cough, sore throat, fever, malaise, and possible GI symptoms; which commonly results in a rapidly progressive pneumonic process and respiratory failure. During an outbreak of a highly pathogenic influenza A (H5N1) virus among poul- try in Hong Kong in 1997, 6 of 18 people with confirmed ∗ Corresponding author at: Arastirma Hastanesi Cocuk hst servisi, Van, Turkey. Tel.: +90 4322150470. E-mail address: bayalibay@yahoo.com (A. Bay). infection died. The first documented case of human infection with the influenza H5N1 virus occurred in Hong Kong in 1997 [1–3]. As the outbreak of avian flu has been relatively recent, radio- logic reports on this subject are limited. In this study, we aimed to evaluate chest X-rays (CXR) and clinical course of patients suffering from lower respiratory tract infection due to influenza H5N1. 2. Materials and methods Between December 2005 and February 2006, eight hospital- ized patients with avian-flu were evaluated in this study. There was history of close contact with diseased poultry in all patients. Suspicion of avian influenza infection was based on the patients presenting symptoms, i.e., temperature > 38 ◦ C associated with cough, sore throat or shortness of breath during the period with known avian influenza outbreak. In addition, a questionnaire was obtained from the parents of patients concerning the history of the child. The questions were: 0720-048X/$ – see front matter © 2006 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrad.2006.10.006