A 27-year-old nurse has been complaining of a terrible headache for the last 24 hours. The pain is all over his cranium, which gradually worsened. Over the last couple of hours, he finds it difficulty turning his head and prefers to be in a dark room. He generally appears unwell and irritable. On examination, he is pyrexic, photophobic and has marked neck stiffness. Fundoscopy did not reveal any evidence of papilloedema. No. skin rashes were visualised. Kernig’s sign is positive. A lumbar puncture (LP) reveals high protein and low glucose. What is the most likely diagnosis?