Sputum Testing for Tuberculosis (TB)

HealthLinkBC File Number: 
51b
Last Updated: 
February 2021

What is TB?

TB is a serious disease caused by germs (bacteria) that spread through the air. A person with active TB disease in their lungs can spread TB disease to another person. When a person with active TB coughs, sneezes, sings or talks, they spread TB germs through the air.

TB usually affects the lungs, but can also affect other parts of the body like glands, bones, joints, kidneys, the brain and reproductive organs.

You can cure TB. In B.C., you can get medicines to prevent TB or to cure TB. The medicinces are free through Provincial TB Services and public health units.

For more information on TB, see: HealthLinkBC File #51a Tuberculosis (TB).

What is sputum?

Sputum (or phlegm) is mucous that you cough up from deep inside your lungs. It is usually thick, cloudy and sticky. Sputum is not saliva (spit) as saliva comes from your mouth and is thin, clear and watery. Do not collect saliva for this test.

Why should I do a sputum test for TB?

Testing your sputum for TB bacteria is the best way to find out if you have active TB disease.

If you are taking medicine for TB, testing your sputum is the best way to tell if the medicine is working.

Why do I have to give 3 sputum samples?

It is very important that the results from your sputum test are accurate. Collecting 3 sputum samples can improve the accuracy of your test results. Your health care provider will let you know if you can collect the 3 sputum samples on the same day or if you should collect the sputum on separate days. Follow the instructions your health care provider gives you.

How do I collect my sputum?

To collect sputum, follow these steps:

  1. Collect your sputum in the early morning unless your health care provider gives you different instructions
  2. Do not eat, drink, smoke, brush your teeth or use mouthwash before collecting your sputum
  3. Make sure your first name, last name and date of birth are on the label of the sputum bottles
  4. Collect your sputum away from other people. If possible, go outside or open a window while you collect your sputum
  5. Open a sputum bottle. Do not touch inside the sputum bottle or inside the cap
  6. Take a deep breath. Hold the air for a few seconds. Breathe out slowly. Take another deep breath. Cough hard until sputum comes up in your mouth
  7. Spit the sputum into the sputum bottle. Do this until there is enough sputum to cover the bottom of the bottle
  8. Screw the cap on the sputum bottle tightly so it does not leak
  9. Write the date and time you collected the sputum on the label of the sputum bottle
  10. Seal the sputum bottle in the plastic bag it came with. Do not put more than 1 sputum bottle in each plastic bag
  11. Make sure to put the paper lab form in the pouch on the outside of the plastic bag (not inside with the sputum bottle)
  12. After you finish collecting your sputum, wash your hands. For more information on proper hand washing, see: HealthLinkBC File #85 Hand Washing: Help Stop the Spread of Germs

What should I do with my sputum bottles?

Bring the sputum bottles to the lab or your health care provider as soon as possible. Store the sputum bottles in the fridge until you are able to bring them in. Do not store the sputum bottles at room temperature and do not freeze. If you are not sure where to return the sputum bottles, ask your health care provider.

What tests will be done on my sputum?

2 tests will be done on your sputum:

  • Smear
  • Culture

For the smear, lab staff will look at some of your sputum under a microscope. If they see bacteria in your sputum, the smear test result is positive.

For the culture, lab staff put some of your sputum into a special container to grow. If bacteria grow, your culture result is positive.

If the result from your smear test or your culture is positive, your health care provider will talk with you about what this result means.

When will I get the results from my sputum tests?

Smear test results are usually ready within 1 to 2 business days after it arrives at the lab. Culture results may take up to 8 weeks, depending on how quickly the bacteria grow.

The lab will notify your health care provider of your test results as soon as they are ready. If your test results are positive, your health care provider will let you know.

Be sure that your health care provider knows how to reach you to give you your test results. Check with your health care provider to make sure they have your current phone number and address.

If you have any questions or concerns, speak with your health care provider.

 

Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

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