Patient education: Viral culture (The Basics)

What is a viral culture? — This is a lab test that checks a sample of fluid or cells for certain viruses.

The sample could come from different sources, including:

●Fluid from inside the nose or throat

●Saliva (spit)

●Mucus that is coughed up

●Fluid from a rash or blister

●Fluid from around the spinal cord

The sample is sent to a lab. In the lab, they add a special substance that causes germs to grow. If there are viruses in the fluid or cells, these will usually show up within a few days to a week. Some viruses might take longer.

There are other, newer tests doctors can also use to check for specific viruses. These are called "nucleic acid tests" or "antigen tests." These are often used instead of a viral culture because the results come back faster. In some cases, they are also better able to identify the virus.

Why might I get a viral culture? — Your doctor might order a viral culture to:

●Help figure out the cause if you have symptoms of an infection

●Figure out which specific virus is causing your symptoms

●Help decide the best treatment for a viral illness

How do I prepare for a viral culture? — You do not have to do anything special to prepare.

What happens during a viral culture? — To do a viral culture:

●Your doctor or nurse will need to take a sample of fluid. The way they do this depends on where they need to take the sample from. For example:

•If they need a sample from the nose or throat, they will use a swab. This can be uncomfortable, but it is quick.

•They can also use a swab to take some fluid and cells from a blister or sore.

•If your doctor needs to take a sample of fluid from around the spinal cord, they will do a procedure called a "lumbar puncture." This is also called a "spinal tap." It is done by inserting a needle into the back.

●They will send the sample to a lab for testing.

What do my results mean? — Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

●If your viral culture is "positive," this means that a virus was found in your sample. Your doctor or nurse will talk to you about what to do next and whether you need treatment.

●If your viral culture is "negative," this means that a virus was not found in your sample. If you have symptoms of infection but your viral culture is negative, your doctor or nurse might want to do other tests to try to figure out the cause.

More on this topic

Patient education: Cold sores (oral herpes) (The Basics)
Patient education: Viral meningitis (The Basics)
Patient education: Chickenpox (The Basics)
Patient education: Shingles (The Basics)
Patient education: Encephalitis (The Basics)
Patient education: Genital herpes (The Basics)

Patient education: Chickenpox prevention and treatment (Beyond the Basics)
Patient education: Shingles (Beyond the Basics)