The evaluation of an arbovirus infection begins with a medical history and physical examination.

Physical findings in those with an arbovirus infection may include:

• Rash
• Lymph node swelling
• Fever
• Brudzinski sign:
• Bending of the neck causes the hips and knees to bend
• Kernig sign:
• Extending the knees with the hips flexed causes pain and muscle spasms
• Papilledema:
• Increased pressure in the eyes
• Lethargy:
• Excessive sleepiness
• Confusion

Testing is necessary to determine the underlying cause for the arbovirus infection.

Tests that may be used to evaluate an arbovirus infection include:

• Spinal tap
• This is the most important test to diagnose meningitis or encephalitis
• Encephalitis or meningitis may cause the spinal fluid to become cloudy
• Blood cultures
• Complete blood count
• Blood serology:
• Blood test that identifies the virus.

Less commonly used tests that evaluate an arbovirus infection include:

• CT scan of the brain
• MRI scan of the brain