Findings of Chest Computed Tomography in Patients with Swine-Origin Influenza A (H1N1) Virus Infection

Abstract

In April 2009, an epidemic of acute febrile respiratory illness caused by a new virus – influenza A (H1N1) – broke out. The first cases occurred in Mexico and the infection rapidly propagated throughout the world. In August 2010, 214 countries had already been hit by the infection, with more than 18,000 confirmed deaths. This new virus is directly or indirectly transmitted from person to person by means of respiratory secretions from infected individuals (Amorim et al., 2013). The symptoms onset occurs in a period between 1 and 7 days following contact with the virus, and the transmission occurs mainly in indoor areas, even before the symptoms onset. The clinical manifestations of the infection are similar to those of the common influenza, and are many times self-limited. However, sometimes the respiratory symptoms may be exuberant, with respiratory failure and death (Amorim et al., 2013). Although the diagnosis of viral infection is based on the clinical signs and virus identification, familiarity with imaging findings of the disease may be useful in patients with atypical or baffling clinical signs, in whom the H1N1 infection has not been suspected (Amorim et al., 2013).