Elevated IL-6 levels in CSF have not only been reported in nosocomial infections in patients with shunts and EVDs (Asi-Bautista et al., 1997; Schoch et al., 2008; Lenski et al., 2019, Skar et al., 2019b) but also in inflammation and vasospasm after subarachnoid haemorrhage (Lenski et al., 2017), all combining to make it a poor differentiator between nosocomial infection and sterile neuroinflammation. Here, IL6 is linked to subarachnoid hemorrhage.