Top
30
Doctor insights on: How Long Is A Tb Test Good For

Share
1

1
How long are TB test good for?

How long are TB test good for?

Until today: You tested negative today? Great. But maybe you will inhale the bug tonight? Then your TB test will change.

Once positive always positive. ...Read more

Dr. Scott Lindquist
615 Doctors shared insights

Mycobacterium Tuberculosis Infection (Definition)

Mycobacterium tuberculosis is an infectious organism that spreads by droplets coughed out by an infected person. Infection is established initially in lungs, but can spread within lungs & to other body parts, or can become latent, with reactivation occurring years to decades later. With effective treatment, it can be completely eliminated although drug resistant ...Read more


2

2
How long should you wait in order to repeat a TB test?

Generally 6 weeks: The need to repeat a TB test generally depends on each individual's previous test results, presence of symptoms & risk factors for exposure to tb. An interval of at least 6 weeks is generally recommended. Talk to an infectious disease specialist for proper interpretation of your testing. ...Read more

3

3
How long is TB test takes and what is the symptoms and causes of tb.

How long is TB test takes and what is the symptoms and causes of tb.

What test was done?: Skin test takes 48 hours and needs to be interpreted by a qualified professional, i.e.; whoever placed the test. Blood draws can give the answer in 1-2 days and may be indicative of past infections. Tb is an infection caused by a bacteria. It requires multiple antibiotics for months to eradicate. If there is an active infection of the lungs, it can be highly contagious. Symptoms are variable. ...Read more

4

4
How long would it take for TB test marks to go away? Mine came back neg but the mark went from unremarkable to large and red after 4 days now. Thx.

TB Test: There can be several reasons why a TB test takes longer to reactt. If you do have a large reaction as you describe you should go back to your doctors office to show it to them as theymay decide it is a delayed positive test ...Read more

5

5
TB test: neg >72 hrs but now large lump as time goes on? How long for mark to go away?

TB test: neg >72 hrs but now large lump as time goes on? How long for mark to go away?

Negative, give time: As long as there was no hardened lump at the infection site within that first 72 hours that was greater than 15mm (or less if you have risk factors), you are still considered negative. It can take some people up to a week or so for the redness and swelling to recede. Try ice several times a day to help with any swelling. ...Read more

6

6
Are there good ways to get a chest X-ray for positive TB test?

Are there good ways to get a chest X-ray for positive TB test?

Imaging center: Your doctor should have given you a referral slip for the chest xray. They may have a particular imaging place they want you to go to, but you can go to almost any imaging center or hospital. Most positive TB test chest x-rays will be normal so try not to worry too much until you have your results. ...Read more

8

8
Does a TB test hurt?

Does a TB test hurt?

Not really: It is a tiny needle, just within the layers of the skin to create a fluid bubble. Takes a few seconds to apply. ...Read more

9

9
What is a 2-part TB test?

Outdated?: May be tuberculosis skin testing?

Igra or quantiferon gold blood testing is at least as good or even better. Discuss with your doc.

The blood test is usually better than the skin test. ...Read more

11

11
What does a + TB test look like?

What does a + TB test look like?

Positive PPD test: A positive TB test should look like hard, raised bump with size >5to15 mm depending of the risk category you are in. It should be read in between 48 to72 hours. It is the hardness and not redness which is read. Thanks. ...Read more

12

12
Can I have a TB test with a cold?

Yes: The memory cells for TB are in the body and the test will still be valid if positive. The only problem are in people who have lower immune system but not quite bad enough to cause reactivation as they can develop anergy or false negative test. ...Read more

13

13
What does a positive TB test mean?

Chest X ray: It is possible to have active TB with very little symptoms especially early on. However, it is more than likely that you carry the germ for TB in a dormant form, this is called latent tb. No symptoms are expected with latent tb. ...Read more

14

14
What does a positive TB test look like?

What does a positive TB test look like?

Skin test: If you had a PPD skin test and you have no risk factors, a positive test is when after 48 to 72 hoursyou have swelling in the site and redness that measures more than 15 mm, it is considered a positive tb. Test. ...Read more

15

15
What does a negative TB test look like?

Doc: Either your blood test igra is negative or your skin testing does not show any "bump". This should always be checked by a professional since even health care workers report false results. Best to check with a doc and not pa or np or nurse. ...Read more

16

16
What is the best TB test and does it hurt?

What is the best TB test and does it hurt?

Sputum: To check for active pulmonary tb, sputum stain and culture is an easy and painless way to test. Sometimes a blood test or a skin test are needed. They involve a needle stick. In certain cases a bronchoscopy, and/or a biopsy are needed. ...Read more

17

17
How often should you safely take a TB test?

CDC says.: According to the cdc "there is no contraindication to repeating the tst, unless a previous tst was associated with a severe reaction." tst = tuberculin skin test. ...Read more

18

18
How do I know if I have a positive TB test?

If there is a bump: When TB infects the body the infection gets walled off by antibodies. The medical person injects a manufactured antibody under your skin that reacts to the TB antibody. If a bump appears at the injection site after 48 hours it means you have the antibody to TB already in your body and therefore have TB infection. It does not mean that you have active disease or are contagious. ...Read more

19

19
What do a positive and negative TB test look like?

TB Tests: I bet you could google image that question. A positive reaction is read after 48 hours from the test. It would be a raised redness greater than 5 mm in circumference. ...Read more

20

20
When after taking a TB test can I take another one?

Readministration: If it is noted that first PPD was administered incorrectly, the PPD can be repeated at that time using a site that is several centimeters away from the original injection. ...Read more

21

21
Do you think I should be scared of getting a TB test?

It is not painful: & it is important to know the results.
In the words of NIKE - "Just do it! " ...Read more

22

22
Where do you go to get a quick and inexpensive TB test?

Clinic/public health: Since TB infection is a public health issue, your local public health department website may have a list of clinics. The clinic will perform a standard skin test called a ppd and they will ask you to return to have it read.
...Read more

23

23
How quickly will you know if you have a positive TB test?

48-72 hours: Tb test is meant to be interpreted in 48-72 hours after being administered on the forearm. Make sure that the induration (not redness) is measured in that time frame & results documented by a health care provider. Further testing may be determined based on your results from the TB test. ...Read more

24

24
How would I be able to tell if I have a positive TB test?

Size of induration: After the TB test, the skin at the site can develop swelling (induration). The size of this swelling (measured in millimeters by a health care provider within 48-72 hours) determines whether you have a positive result or not. It is important to not measure the area of redness but the actual size of the swelling around the test site. The cut off value for positive test is based on yr risk factors. ...Read more

25

25
Does the TB test commonly appear positive on the first day?

Yes: The TB test can become positive within the first day in someone that has been exposed to TB in the recent past. ...Read more

26

26
Could you tell me what happens if I have a positive TB test?

Latent vs active TB: If you have a + PPD then you will be screened to determine if you have TB infection or TB disease. The physician will obtain a medical history, physical examination, chest x-ray, & any other pertinent lab tests. ...Read more

27

27
What does a positive TB test look like? How is this treated?

What does a positive TB test look like? How is this treated?

What is important: Is what it feels like - not how it looks. Induration is palpated & measured. Treatment (such as INH) is determined once it is established where this is latent or active TB and the type. ...Read more

28

28
I need to get a TB test soon. Is there anything I shouldn't do?

Avoid steroids: Corticosteroid medications can mask skin testing results of the TB screening test ("PPD"). They should not effect the blood test (Quantiferon TB). Steroid medications include pills and inhalers. Topical (applied to skin) should not affect the TB screening test result. ...Read more

29

29
How difficult must an induration be to be considered positive TB test?

PPD: It is not about hardness of the induration it is about the size of the area of induration. It is harder than surrounding skin. ...Read more

30

30
For what length of time can I wait before getting my TB test looked at?

48 to 72 hours.: 48 to 72 hours is when the PPD is read. The induration will be maximal at that time. ...Read more

Dr. Klaus d Lessnau
1,215 Doctors shared insights

Tuberculosis (Definition)

A potentially serious infectious bacterial disease that ...Read more