THORACIC COMPUTERIZED TOMOGRAPHIC (CT) FINDINGS IN 2009 INFLUENZA A (H1N1) VIRUS INFECTION IN ISFAHAN, IRAN

Novel swine-origin influenza A (2009 H1N1) was first reported in Mexico in April 2009. 1 Since then, it has spread rapidly around the world. In June 2009, the World Health Organization (WHO) declared the emergence of a global pandemic, raising the alert level to phase 6 or pandemic phase. 2 This virus arrived at Isfahan in August 2009. The 2009 H1N1 virus is a subtype of the influenza A virus. Unfortunately, the most virulent influenza viruses are type A, and they mutate easily and quickly. 3,4 The symptoms of H1N1 infection may be similar to seasonal influenza, and hospitalization is not usually required. This virus causes a broad spectrum of clinical syndromes, ranging from mild to severe, and can infect the lower respiratory tract as well as cause rapidly progressive pneumonia, especially in children and younger adults. 5 The virus is still circulating in the world. The abnormal thoracic computrized tomography (CT) scan findings vary widely among the studies of 2009 H1N1 influenza. Differences in diagnostics, admission criteria and health care systems may all play roles in this regard. 6–8 In this study, we retrospectively evaluated the thoracic CT findings in patients with confirmed 2009 H1N1 virus infection. There has been no study about the thoracic CT findings in 2009 H1N1 in Iran in the literature. This study aimed to describe thoracic CT findings of the patients with confirmed pandemic 2009 influenza A (H1N1) infection compared to previously reported CT findings, and also to suggest patterns that may be suggestive of 2009 influenza A (H1N1) in the appropriate clinical setting.