Anonymous asked in HealthDiseases & ConditionsInfectious Diseases · 1 decade ago

How can you be TB (tuberculosis) positive but not infectious?

Can someone explain in layman terms what this means?

And for the future too? As in will/could it develop into full blown TB?

12 Answers

  • 1 decade ago
    Favorite Answer

    Ok, first, if you have a positive TB skin test you have definitely been infected with the bacteria. It is a common misconception that positive means exposure only. There is no way for your body to produce an immune response, and have a positive skin test, unless the bacteria comes in contact with your immune system. That means the bacteria is in your body, somewhere, most likely the lungs. BUT, let me repeat, BUT, that does not mean you have active disease now or maybe ever.

    This is the reason you can be TB positive without being infectious. Your immune system can do wonders in walling the organism off. A positive skin test, at least in the U.S. , means treatment with at least two antibiotics for a period of 3-6 months, maybe longer if you are immunocompromised. Treatment is necessary to hopefully prevent the infection from becoming active at a future point in time, even if you are not infectious.

    There is also the possibility that a positive skin test is due to active disease. In that case you will be potentially releasing tuberculosis bacteria when you cough and sneeze. This is a more urgent medical condition, for the patient and the people that have spent time with the person infected.

    By the way. Having a positive skin test does mean antibodies have been produced. There is no reliable scientific evidence that these antibodies prevent future re-infection.

    Hope this helps.

    Source(s): Microbiologist, Public Health Respiratory Diseases Medical Technologist University Microbiology Lab Instructor
  • 1 decade ago

    The best answer there is goshawk's.

    You can have whats called 'latent infection' - you are infected with TB, but are not showing symptoms (and I dont think you can pass it on at this precise point, although I am not sure about that).

    This latent TB can become 'active TB' , for reasons that are poorly understood. Then you have the disease, show symptoms and certainly can spread it to other people.

    There is no fixed treatment regime for latent TB, it very much depends on a) who you are, i.e. young or old, high risk person, immigrant etc etc and b) which doctor you go to.

    There is little agreement between chest physicians as to who exactly should be treated for latent TB - the ideal would be to treat everyone, but drugs, money and resources generally are limited, and this just would not be possible.

    According to the world health organisation, approx 1/3 of the worlds population are infected with latent TB. Very few people demonstrate the active form of the disease.

  • 1 decade ago

    Tuberculosis (also known as "TB") is a disease caused by a type of bacteria called Mycobacterium tuberculosis. TB mainly infects the lungs, although it can also affect other organs.

    When someone with untreated TB coughs or sneezes, the air is filled with droplets containing the bacteria. Inhaling these infected droplets is the usual way a person gets TB.

    One of the worst diseases of the 19th century, TB was the eighth leading cause of death in children 1 to 4 years of age in the 1920s. As the general standard of living and medical care got better in the United States, the incidence of TB decreased. By the 1960s, it wasn't even in the top 10 causes of death among children of any age group.

    But TB is making a comeback in the United States today — particularly among the homeless, those in prison, and people whose immune systems have been weakened because of HIV infection.

    Tuberculosis is contagious when it's airborne and can be inhaled by others. The incubation period (the time it takes for a person to become infected after being exposed) varies from weeks to years, depending on the individual and whether the infection is primary, progressive, or reactivation TB.

    Hope it helped

  • Anonymous
    4 years ago

    I am allergic to the skin test, so when I get my TB test I have to do the shot version, which comes up negative. If the person is allergic the result would be the same every time. There are other tests they can do. As far as the TB vaccinations I am not sure, you'd need to ask a doctor or look it up on a website by the Center for Disease Control.

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  • 1 decade ago

    TB positive as it refers to the TB skin test means you have had exposure to TB and that your body has reacted against it. It does not mean that you are infected or that TB is growing in your tissues. People who are exposed however do have a small risk of becoming infected with TB in the year following there exposure. As a result when your skin test converts to positive your doctor will commonly recommend a preventive treatment with the antibiotic INH for a period of several months as a precaution.

  • 1 decade ago

    I presume it means you carry the disease which can be passed on Gart but that you haven't got full blown TB. Best one to ask is Momof3 as she was a nurse and she would know.

  • randy
    Lv 7
    1 decade ago

    It just means that at some time in the past, you were exposed to it,( or received a live vacine for it) and your body developed anti bodies to fight it. Normally, once you have the anti bodies, you cannot contract the disease. UNLESS a new strain mutates and you are exposed to it, and even then you may have partial immunity to it.

  • 1 decade ago

    Haven't got a clue M...wish I could help you hun x

  • 1 decade ago

    it means you are a host. you can spread it but cant get it. read about it in my nursing book one time

  • 1 decade ago

    means u have your own immunity to it

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