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Sputum Culture Test



  • A sputum culture tests a sample of mucus coughed up from your child’s lungs. It can help diagnose infections caused by bacteria or fungus.
  • Your child will be asked to cough and spit some mucus into a sterile cup. The sample will then be sent to the lab.
  • Talk to your healthcare provider about what the test results mean and ask any questions you have.


What is a sputum culture test?

A sputum culture tests a sample of mucus coughed up from your child’s lungs. The test checks for bacteria, viruses, or fungus in the mucus.

Why is this test done?

This test may be done to see what is causing an infection of your child’s airways. It can help your child’s healthcare provider know how to treat the infection.

How do I prepare my child for this test?

  • Your child may need to avoid taking certain medicines before the test because they might affect the test result. Make sure your child’s healthcare provider knows about any medicines, herbs, or supplements that your child is taking. Ask your provider before stopping any of your child’s regular medicines.
  • Your child may need to brush his teeth and rinse his mouth before the sample is collected. He may also need to avoid food for 1 or 2 hours before the test.
  • Talk to your healthcare provider if you have any questions about the test.

How is the test done?

There are several ways to get a sputum sample. Your child may be asked to breathe a mist that will make him start coughing. If your child is able to cough up a sample, he will be asked to cough and spit some mucus into a sterile cup. It’s important that your child take several deep breaths first and try to cough up a sample from deep in his lungs. The saliva from your child’s mouth will not be helpful. Keep the lid on the cup until your child is ready to spit out the sample. Try not to touch the inside of the container. Put the lid back on the container as soon as you are done. The sample will then be sent to the lab.

A bronchoscopy is another way to get a mucus sample. For a bronchoscopy, a healthcare provider uses a flexible, lighted tube to look at the airways in your child’s lungs and get fluid (mucus) and tissue samples. Your child will be given a numbing medicine to keep him from gagging and medicine to relax him before the procedure.

Ask your healthcare provider when and how you will get the result of your child’s test.

What does the test result mean?

A negative test result means no bacteria or fungus grew in the culture. A negative test result is considered a normal test result.

A positive test result usually means your child has a lung infection, like bronchitis or pneumonia. However, the result could be positive when your child doesn’t have an infection if too many bacteria from your child’s mouth got in the sample.

What if my child’s test result is not normal?

Test results are only one part of a larger picture that takes into account your child’s medical history and current health. Sometimes a test needs to be repeated to check the first result. Talk to your healthcare provider about the result and ask questions, such as:

  • If your child needs more tests
  • What kind of treatment your child might need
  • What lifestyle, diet, or other changes your child might need to make
Developed by RelayHealth.
Pediatric Advisor 2015.3 published by RelayHealth.
Last modified: 2015-03-25
Last reviewed: 2015-03-24
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright ©1986-2015 McKesson Corporation and/or one of its subsidiaries. All rights reserved.
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