Pulmonary Manifestation of Novel Swine-Origin Influenza A (H1N1) Virus (S-OIV) Infection in Immunocompromised Patients: Initial Findings with Multidetector Computed Tomography

Abstract

Objective: To describe initial multidetector computed tomographic (MDCT) findings of novel swine-origin influenza A (H1N1) virus (S-OIV) infection in immunocompromised patients and to evaluate whether or not identification of certain abnormalities can help predict patients who are at risk for a severe clinical course. Subjects and Methods: This retrospective study included 13 patients with confirmed S-OIV infection suffering from an underlying immunodeficiency or who were receiving immunosuppressive therapy. All patients underwent MDCT of the thorax due to respiratory distress. All data were read by two independent radiologists who described the type and pattern of opacities, distribution and extent of the abnormalities observed. Adverse outcome measures were defined as acute respiratory distress syndrome with the need for mechanical ventilation, extracorporeal membrane oxygenation or death. Results: MDCT revealed pulmonary manifestations in 12 (92%) of 13 individuals. Six (50%) patients showed an adverse outcome with development of acute respiratory distress syndrome, 4 of these died. The most common findings were ground-glass opacities (10/12; 83%) and pulmonary consolidation (7/12; 58%) predominantly with a bilateral distribution. Reticular pattern and a tree-in-bud appearance were found in 3/12 (25%), respectively. Bilateral opacities with extensive involvement of the lung parenchyma were most predictive of a severe clinical course. Conclusion: The MDCT scan in immunocompromised patients with confirmed S-OIV infection frequently revealed pulmonary abnormalities, which included ground-glass opacities and consolidations. Therefore, prediction of an adverse clinical outcome could be made in patients with MDCT findings demonstrating bilateral extensive consolidations, often combined with ground-glass opacities.

Factors Associated with a Positive Severe Acute Respiratory Syndrome Coronavirus 2 Testing in Suspected Cases Presenting with Pneumonia: A Retrospective Cohort Study in a Single Medical Center

“…Patients with confirmed COVID-19 pneumonia have typical imaging features: ground-glass opacities (GGO) or mixed GGO, consolidation and vascular enlargement in the peripheral areas or lower lobe of the lung [7]. However, during a period of year, pneumonia caused by other pathogens is widespread [8], for example, the common imaging feature of pneumonia caused by influenza virus such as influenza A (H1N1) virus was also GGO [9, 10]. Real-time RT-PCR (rRT-PCR) on respiratory tract specimens has been the gold standard for the etiological diagnosis of SARS-CoV-2 infection [11].…”