IL6 and infection: Overall IL-1α levels were higher in the infection subgroup compared to CHI or febrile risk factor subgroups; overall IL-6 levels were higher in the CHI subgroup compared to the febrile subgroup; and overall MIP-1β levels were higher in the mCHI subgroup compared to the developmental, infection, febrile, or lesional risk factor subgroups (Additional file 2: Figure S4B).