Natural History of West Nile Virus Infection
This study will examine how West Nile virus (WNV) infection affects the body. Some people infected with WNV have no symptoms. In others, symptoms may vary from fever and headache to a polio-like syndrome with paralysis, to coma and brain changes like those of a stroke. Many patients recover with no lasting effects, while a few can have long-lasting neurological damage or may die. This study will collect clinical, laboratory, diagnostic, and radiographic information on people thought to have WNV to better understand the disease.
Patients 18 years of age and older diagnosed with or suspected of having West Nile virus infection may be eligible for this study. Patients will be hospitalized until they are well enough to go home and will undergo the following tests and procedures:
- Medical history and physical examination: A thorough history and physical examination will be done on the first day of the study. Then, brief physical exams, including measures of blood pressure, heart rate, breathing rate, and temperature, will be done during each day of hospitalization and at every follow-up clinic visit (at 2 weeks and at 1, 3, and 6 months).
- Blood tests: Blood samples will be collected on the first day of the study, at day 7, at hospital discharge, and at follow-up visits to determine if virus remains in the blood and how it is affecting the body.
- Magnetic resonance imaging (MRI): MRI scans will be done within 72 hours of beginning the study and 1 month after that. This test uses a strong magnetic field and radio waves to produce images of the brain that might show abnormalities in the brains of patients with WNV and reveal whether the abnormalities can predict how an individual will recover. For the procedure, the patient lies on a table that is moved into the narrow tunnel-like scanner. During the procedure, a contrast agent that brightens the images is injected through a catheter placed in an arm vein.
- Neurological examination and neurological function tests: Participants will be tested to see if the West Nile virus has affected their thinking and ability to perform normal daily activities. These tests will be done at the start of the study, on days 3 and 7 (also days 2, 4, 5, and 6 if patients are still in the hospital), at discharge, and at follow-up visits. The tests involve answering a number of questions and performing simple tasks, such as squeezing a hand or lifting a foot.
Patients who develop weakness in their arms or legs will also have the following studies:
- Electromyography (EMG) to study the electrical activity of the muscle. For this test, needles are placed into a muscle to record the electrical activity at that site.
- Nerve conduction studies to measure how well the nerves are working. A small charge of electricity is delivered to a nerve in the affected limb, triggering a muscle to tighten or bend. Small wire electrodes are attached to the skin to measure the time is takes for the nerve to move the electrical current from one part of the limb to another.
- Spinal MRI to see if the virus is affecting the spinal cord.
Results of other tests done by the patient's local doctor (such as lumbar puncture, electroencephalogram, x-rays, etc.) will be requested. If a lumbar puncture is done, a small amount of cerebrospinal fluid will be requested for testing for WNV.
West Nile Virus
|Official Title:||Investigation of the Natural History of West Nile Virus Infection in Patients With Recently Acquired West Nile Fever or Neuroinvasive Disease|
|Study Start Date:||September 2003|
|Estimated Study Completion Date:||February 2011|
Please refer to this study by its ClinicalTrials.gov identifier: NCT00069303
|United States, Maryland|
|National Institutes of Health Clinical Center, 9000 Rockville Pike|
|Bethesda, Maryland, United States, 20892|