Findings in children severely infected with a novel influenza A virus of swine origin: pulmonary imaging

BACKGROUND: This article reviews the chest radiography of children with severe infection caused by a novel influenza A (H1N1) virus of swine origin (S-OIV). We analyzed the role of their pulmonary images in predicting the severity and diagnosis of the disease. METHODS: Among 97 patients with confirmed novel H1N1 infection, 42 patients treated with mechanical ventilation formed group 1, and the remaining 55 patients constituted group 2. The initial and subsequent radiograhic findings in groups 1 and 2 were compared with respect to the pattern, distribution, and extent of the abnormality. RESULTS: In group 1, 24 patients presented with three or more lung zone diseases, whereas only 5 patients in group 2 demonstrated these findings (P<0.001). A pneumomediastinum or pneumothorax was observed in 24/42 patients in group 1 and in 18/55 patients in group 2 (P=0.019). Twelve patients in group 1 and 5 in group 2 developed a ground-glass opacity cyst with a honeycomb appearance (P=0.007). CONCLUSIONS: The most common radiographic and computed tomography findings in children who were severely infected with S-OIV included unilateral or bilateral ground-glass opacities with or without associated focal or multifocal areas of consolidation. Children with bilateral involvement or with greater opacity on the chest radiographs were more likely to worsen and require the mechanical ventilation.