Zhang Y, et al. - Through a retrospectively study of 237 avian influenza virus (AIV) H7N9 subtype (AIV-H7N9, characterized by rapid progression and with a high fatality rate)-infected subjects from multiple centers from 2013 to 2015, the researchers investigated whether the neutrophil-to-lymphocyte ratio (NLR) taken within 24 h following admission could prognosticate disease severity and fatality in AIV-H7N9-infected subjects. Univariate and multivariate analyses were used in order to contrast clinical variables between the survival and fatal groups to assess the prognostic value. The NLR taken within 24 h following admission in the fatal group vs the survival group was significantly higher. NLR was independently correlated with fatality. The area under the curve of the NLR was 0.70, and further, when the NLR =19.94, the specificity and the sensitivity was 100% and 28.4%, respectively. In relation to the subjects with an NLR <19.94, the fatality in the NLR ≥19.94 group was significantly raised. Hence, in subjects infected with the AIV-H7N9 influenza virus, NLR was concluded to be a potential predictive prognostic biomarker.