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Diagnosing Tuberculosis - Pulmonary and in the kidneys or bladder

Diagnosing pulmonary TB - how to collect sputum samples

Sputum test

XrayYour doctor has asked for an investigation to check if you have Tuberculosis (TB) in your lungs. The best way to diagnose this TB is to look for it in your sputum (phlegm). TB disease is caused by a bacterium (bug/germ) called Mycobacterium tuberculosis.

Three to 5 early morning samples of sputum, collected on consecutive days, are required. (If you can provide more than a teaspoon in each of the first 3 samples, this may be enough.)

Sample bottles

Clean universal containers are available from:

  • Pathology Reception, Noble's Hospital
  • Reception, Ramsey & District Cottage Hospital
  • Reception, local doctor's surgery.

If you are asked to provide a sample in the Outpatients Clinic, the nurse will give you the containers.

TB sputum sample bottle

Practical tips for collecting good sputum samples

  1. Use a clean universal container for each sample required.
  2. Clean and thoroughly rinse the mouth with water.
  3. Wash and dry your hands thoroughly.
  4. Breathe deeply 3 times - a tickly feeling should be felt at the end of a deep breath.
  5. After the third breath, cough hard and try to bring sputum up from deep in the lungs (saliva from the mouth will not help the doctor's diagnosis).
  6. Expectorate (spit) the sputum into a container, collecting at least one teaspoonful (5ml).
  7. Wipe the outside of the container with a tissue.
  8. Wash and dry your hands thoroughly.
  9. Arrange for delivery to the Pathology laboratory before lunchtime on the date of production of each sample. You can take it yourself, get a friend to take it or make arrangements with your local GP Practice.

Getting my sample to the laboratory safely

Please ensure that the container is labelled correctly. Please put the following details on the container:

  • your name
  • date of birth
  • date and time the sample was taken.

The lid should be screwed on tightly.

  1. Place the correctly-labelled container into an individual transparent plastic transport bag.
  2. Seal the bag.
  3. Then insert the yellow request form (which has already been completed by your Doctor or Nurse) - into the separate side pocket of this transport bag.

Examination of the sample

The laboratory staff will spread some of the sputum onto a glass slide and examine this under a microscope.

The results could be as follows:

  • If TB bug/germ is seen in one or more of the samples, you have TB and you will be classed as being infectious.
  • If TB bug/germ is not seen under the microscope on any of the samples, you still may have TB. The sample is sent to a specialist laboratory and is grown in the laboratory. Depending on other signs and symptoms, you may be treated for TB before the culture result is available, which may take up to 6 weeks.
  • After the culture result is available the consultant will decide if you have TB disease, whether or not the TB bug/germ is found.

Diagnosing Tuberculosis in the kidneys or bladder - how to collect three urine samples

Kidneys and bladder diagramUrine test

Your doctor suspects that you have tuberculosis (TB) in one of your kidneys or your bladder. The bacteria (bug/germ) that causes TB is called Mycobacterium tuberculosis. The laboratory needs to do special tests to identify this bug/germ. You cannot pass TB to any other person if it is in your kidney/bladder. The best way to diagnose TB is by testing your urine.

Sample bottles

Clean large containers are available from:

  • Pathology Reception, Noble's Hospital

Collecting urine samples for the TB test

  1. TB urine test sample bottlesUse three clean large containers.
  2. Collect the whole of your early morning urine on 3 consecutive days.
  3. Wash and dry your hands thoroughly.
  4. It is better that you collect your sample the first time you pass urine after rising from bed. Your urine will be more concentrated first thing in the morning and there will be a greater number of bacteria present for testing and there will be a greater chance of correct diagnosis.
  5. Use one bottle for each day and arrange delivery to the laboratory as soon as possible on the same day of collection of each sample.
  6. Ensure that the lid is screwed on tightly, the container has been dried and that your yellow request form accompanies the sample.
  7. Wash and dry your hands thoroughly.

Getting my sample to the laboratory safely

Please ensure that the container is labelled correctly.

Please put the following details on the container:

  • your name
  • date of birth
  • date and time the sample was taken

The lid should be screwed on tightly.

The correctly-labelled container with the specimen must be placed in an individual green plastic transportation bag.

A yellow request form (which has been completed by your doctor or nurse) must accompany each sample container.

Examination of the samples

The urine will be tested by the laboratory:

  • If the bug/germ is present in large numbers in the urine it will be possible to see them under the microscope. This means that the diagnosis can be made very quickly¬†- in a day or two.
  • If no TB bug/germ is seen in the urine, it does not mean that you do not have TB of the kidney/bladder. It may be the case that the numbers of bugs/germs are too small. The urine sample is then sent off for a further test¬†- the result of this is available in about 6 weeks. In a proportion of cases even this test does not show TB bugs/germs but the Consultant may feel that your condition is more likely to be TB and may treat you for this.

For further information and advice about TB please contact our Health Protection Nurses (Public Health Directorate) on +44 1624 642615 or +44 1624 642657.

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