The virus induced in both mild and severe patients a systemic elevation of three chemokines that have been shown to be expressed early during viral infections, CXCL-10 (IP-10), CCL-2 (MCP-1) and CCL-4 (MIP-1β), with no differences in the levels of these mediators between them (data on immune mediators profiling are shown in Figure 2 and Additional file 1). Here, CCL2 is linked to viral infectious disease.