Japanese encephalitis virus (JEV) RNA PCR, CSF
Quick answer: This test looks for the genetic material of Japanese encephalitis virus in the spinal fluid. Doctors order it when they suspect brain infection (encephalitis) caused by Japanese encephalitis virus.
- SampleCSF (spinal fluid)
- TakesAbout 20 to 30 minutes, plus a short rest afterwards
- Before the testThe sample is collected by a doctor through a lumbar puncture, and staff will explain the steps.
How the test is done
- 1You lie on your side with knees drawn up, or sit leaning forward
- 2A doctor cleans and numbs a small area of your lower back
- 3A thin needle is placed between the spine bones to collect a few drops of fluid
- 4The fluid is sent for PCR to look for Japanese encephalitis virus
What your results can mean
Reading your report
Results are reported as detected or not detected; a negative result does not always rule out the infection.
If the result is outside the usual range
A detected result can confirm Japanese encephalitis virus in the nervous system. A negative result does not rule it out, because the virus is often cleared from the fluid quickly, so antibody tests are also used.
Who usually has this test
Children and adults with fever, confusion, seizures or reduced consciousness in areas where Japanese encephalitis occurs.
Risks and aftercare
You may have a headache or back soreness for a day or two; lying flat and drinking fluids can help.
Names and options
Also called: JE PCR, JEV PCR, Japanese encephalitis test
Listed by the hospital as
- JEV RNA PCR, CSF
Questions about this test
Is a lumbar puncture dangerous?
It is a common procedure and serious problems are uncommon. The most frequent side effect is a headache, and doctors check that it is safe for you before doing it.
Why test spinal fluid instead of blood for JEV?
Japanese encephalitis mainly affects the brain, so the virus or antibodies are more likely to show in spinal fluid.
Is there a vaccine for Japanese encephalitis?
Yes. It is given to children in many affected districts of India under the national programme, and to some travellers.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
Reception
Waiting area
IVF lab
This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.