A 34-year-old man presents with fever and confusion for four days. No other symptoms are present. He was diagnosed with schizophrenia a month ago and started on olanzapine. He is not on any other medications. His medical, surgical, and psychiatric histories are unremarkable otherwise.

A full blood count is significant for a leukocyte count of 12,000/mm3 (normal: < 11,000), with 65% neutrophils and 34% lymphocytes. A random capillary glucose and liver profile are within normal parameters.