A previously healthy 45-year-old man presents with a fever of 39˚C (102.2 ˚F) for two days. He also experienced nausea, photophobia, and a continuous generalized headache for one day. There is no history of weakness, vomiting, loss of consciousness, or seizures.
He returned from Vietnam three days prior to the onset of symptoms. He had spent two weeks there as a tourist. He was bitten by insects multiple times, ingested seafood, and drank unboiled fresh water.
There is no history of allergies. He only drinks socially, and does not smoke or use ilicit drugs. A complete blood count, liver and renal profiles, urinalysis, ECG, and chest x-ray are all unremarkable.