Detection of mild to moderate influenza A/H7N9 infection by China's national sentinel surveillance system for influenza-like illness: case series

Abstract

Our findings support the existence of a "clinical iceberg" phenomenon in influenza A/H7N9 infections, and reinforce the need for vigilance to the diverse presentation that can be associated with A/H7N9 infection. At the public health level, indirect evidence suggests a substantial proportion of mild disease in A/H7N9 infections.