A 68-year-old man presented to the emergency department of our hospital because of high fever, tachycardia, consciousness disturbance, and generalized muscle rigidity. According to his caregiver’s statement, he was found groaning and shivering on the bed with rapid and shallow respirations before he was sent to the hospital.
The patient had a depressive disorder and had been followed up regularly at a local psychiatric center for 6 years. Moreover, he had chronic hepatitis B and had received a diagnosis of pneumoconiosis. Ten days before this hospital admission, he was brought to the psychiatric clinic of our hospital because of deteriorating depressed mood. Venlafaxine, amantadine, clonazepam, and zopiclone were prescribed, and he had good compliance to these drugs. The patient had also received an influenza vaccination 8 h prior to this emergency visit.