3rd November 2021

A 68-year-old gentleman presents to A+E with worsening confusion, lethargy and fever

A 68-year-old gentleman presents to A+E with worsening confusion, lethargy and fever. He had suffered a seizure at home. The patient has no known diagnosis of epilepsy. Prior to this episode, the patient had complained of a flu-like illness over the past couple of weeks. The patient undergoes a lumbar puncture and MRI following this. MRI shows areas of hyperintensity affecting the white matter and cortex. The doctor suspects a diagnosis of encephalitis. What is the most common viral cause of encephalitis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.