TB disease develops when the immune system cannot keep tuberculosis bacteria under control, and bacteria begin to rapidly multiply and destroy tissue in the body: the bacteria can actually create a cavity or hole in the lung. People with TB disease are sick, and usually have symptoms.
TB disease can develop very soon after infection, or may appear many years after infection. People with TB disease can spread TB to others.
People with TB Disease:
TB disease normally affects the lung and is known as pulmonary TB. When TB occurs outside the lung it is referred to as extra-pulmonary TB. TB in the lungs or throat can be infectious, meaning the bacteria can be spread to other people. People with TB disease are most likely to spread it to those they spend time with every day, including family members, friends, coworkers, classmates, commuters, etc. TB disease in other parts of the body – such as the kidney or spine – is usually not easily spread to others.
The likelihood that TB will be transmitted heavily depends on the following factors.
Tuberculosis (TB) is a bacterial disease of public health concern. It spreads through the air when a person with TB disease coughs, sneezes, laughs, sings, or even speaks. TB most often affects the lungs, but can spread to other parts of the body. If untreated, it can destroy lung tissue and make breathing difficult or impossible. If improperly treated or left untreated, TB can be fatal.
TB is spread through the air from one person to another. The TB bacteria are released into the air when a person with TB disease coughs, sneezes, speaks or sings. People nearby may inhale these bacteria and become infected. . Although anyone can be exposed to TB disease, certain groups are at higher risk for exposure, including health care professionals, the homeless, people in congregate settings and individuals from countries where TB is highly prevalent like Kenya.
TB is NOT spread by
The general symptoms of TB disease include
For Children below 10 years
Symptoms of TB disease occurring outside of the lungs depend on the area affected.
Note: Since symptoms of TB usually start gradually, often TB is not suspected, or is misdiagnosed as another illness.
TB disease can be treated by taking anti-tuberculosis drugs for 6 to 12 months or longer. It is very important that people who have TB disease finish this medicine, and take their drugs exactly as ordered. If they stop taking the drugs too soon, they can become sick again; if they do not take the drugs correctly, the germs that are still alive may become resistant to those drugs. TB that is resistant to drugs is harder and more expensive to treat.
Health Care Workers or trained community health volunteers meet regularly with patients who have TB to watch them take their medications. This is called directly observed therapy (DOT). DOT helps the patient complete treatment in the least amount of time.
Treatment is usually divided into two phases: the initial phase and the continuation phase. The initial phase begins with four drugs given daily for fourteen consecutive days. The remainder of the initial phase (usually about 2 months) may be daily or twice weekly depending on the patient’s drug tolerance and the extent of the disease or the patient’s other conditions. The continuation phase typically will last an additional 4 to 7 months with not less than 2 drugs. Laboratory testing is performed at regular intervals or as needed to monitor the patients progress and drug tolerance.
When a person is diagnosed with TB infection, it means that they have been exposed to someone with TB disease, have inhaled TB bacteria, and become infected with TB. About 5% of infected people progress to TB disease within the first two years after becoming infected. Another 5% will develop disease later. People who are infected:
People at greater risks of progressing to TB disease usually have a weakened immune system. Older people; children under the age of 5; people with chronic illness (especially diabetes), lung diseases, or certain cancers; those who smoke, abuse substances, or take immune suppressive medications; or those with HIV infection have much higher risk of developing TB disease if not treated.
Sometimes people are given treatment to prevent TB infection even if their TB test is negative. This is often done with infants, children and HIV-infected people who have recently spent time with someone who has infectious TB disease. These groups are at very high risk of developing serious TB disease soon after they are exposed to TB bacteria. If you are prescribed treatment for TB infection, it is important that you take all of your pills exactly as prescribed. You should follow-up regularly with your health care provider while on medication so they can monitor how you are doing.
A person with TB infection needs to take anti-tuberculosis drugs in order to kill the TB germs and prevent TB disease from developing in the future. Some people are more likely than others to develop TB disease once they have TB infection. This includes people with HIV infection, people who were recently exposed to someone with TB disease, smokers, people with certain medical conditions such as diabetes and kidney problems, and persons taking immunosuppressive drugs.
The newest and best treatment for TB infection requires two drugs given in one directly observed dose per week for 12 weeks. Other single drug treatment options take from four to nine months to complete.
TB exposure occurs when a person shares air with someone who has active infectious TB disease. You may have been exposed to TB if you spent time near someone with TB disease of the lungs or throat. You can only get infected by breathing in TB germs that a person expels into the air.
You cannot get TB from someone’s clothes, drinking glass, eating utensils, handshake, toilet, or other surfaces where a TB patient has been. Most people are never exposed to a person with active infectious tuberculosis disease for a period long enough to become infected. People most likely to become infected are those that share air with a TB case for prolonged period of time, either in a single or group setting. Individuals more likely to be exposed to TB include health care workers, the homeless, persons living or working in congregate or long-term care facilities, and persons traveling to or living in countries with high TB prevalence. A TB Interferon Gamma Release Assay (blood test) will identify TB infection.
Untreated, TB infection can progress to TB disease. A person with TB infection does not feel sick and has no symptoms. Persons with TB infection cannot spread the infection to others. A skin test or blood test can detect the presence of TB infection. TB infection should be treated to prevent it from progressing to TB disease which can be spread to others.
You can get a sputum test, TB skin test or blood test in the nearest health facilities. The tests are quick and simple, and give results in only a few days. Sputum test is the preferred test and more specific than blood and a skin test. A skin test can require two to four visits whereas sputum and blood test can be performed with a single visit.
The GeneXpert test is a molecular test for TB. It is often the first test to be used in countries with a high rate of TB infection. The GeneXpert diagnoses TB by detecting the presence of TB bacteria, as well as testing for resistance to the drug Rifampicin.
Smear microscopy of sputum is often the second test to be used in countries with a high rate of TB infection. Sputum is a thick fluid that is produced in the lungs and the airways leading to the lungs. A sample of sputum is usually collected by the person coughing.
To do the test a very thin layer of the sample is placed on a glass slide, and this is called a smear. A series of special stains are then applied to the sample, and the stained slide is examined under a microscope for signs of the TB bacteria.
Sputum smear microscopy is inexpensive and simple, and people can be trained to do it relatively quickly and easily. In addition, the results are available within hours. The sensitivity though is only about 50-60%.
In countries with a high prevalence of both pulmonary TB and HIV infection, the detection rate can be even lower, as many people with HIV and TB co-infection have very low levels of TB bacteria in their sputum, and are therefore recorded as sputum negative
Sputum is mucous that you cough up from deep inside your lungs. It is usually thick, cloudy and sticky. Sputum is not saliva (spit). Saliva comes from your mouth and is thin, clear and watery. Do not collect saliva for this test.
Testing your sputum for TB bacteria is the best way to find out if you have TB.
If you are taking medicine for TB, testing your sputum is the best way to tell if the medicine is working.
It is very important that the results from your sputum test are accurate. Collecting multiple samples can improve the accuracy of your test results. Your health care provider will let you know if you can collect multiple samples on the same day or if you should collect the samples on separate days. Follow the instructions your health care provider gives you.
To collect sputum, follow these steps:
From infection to development of a positive TB test (the incubation period) can take 2 to 10 weeks. The risk for developing active disease is the highest in the first two years after infection. If not treated, a risk continues throughout your lifetime.
A TB contact is a person that has been exposed to TB. TB contacts are ranked from high priority to low. High priority means either the person has had prolonged exposure, or that the person is highly susceptible to becoming infected and progressing to TB disease — children under the age of 5 or persons infected with HIV or on immunosuppressive therapy. Contacts should be promptly tested once exposure is known, and tested again about 10 weeks after the last known exposure. If either test is positive, the person is considered infected and requires additional follow-up and treatment.
Extensively drug resistant TB (XDR-TB) is a relatively rare type of MDR-TB. XDR-TB is defined as TB which is resistant to isoniazid and rifampin, plus resistant to any fluoroquinolone and at least one of three injectable second-line drugs (i.e., amikacin, kanamycin, or capreomycin). Because XDR-TB is resistant to first-line and second-line drugs, patients are left with treatment options that are much less effective and may require prolonged treatment.
Multi-drug resistant TB (MDR-TB) is tuberculosis disease in which the TB bacterium is resistant to both isoniazid and rifampin, the two strongest anti-tuberculosis medications. TB can become resistant to antibiotics when the drugs are misused or mismanaged, when patients do not complete their full course of treatment, when healthcare providers prescribe the wrong treatment, the wrong dose, or length of time for taking the drugs; or when the drugs are of poor quality. Treating MDR-TB is complicated and involves the use of second-line medications that carry greater risk of side effects and adverse reactions. Patients taking these drugs must be monitored closely throughout the course of treatment. The regimen usually requires at least 18-24 months and must be individualized based upon the patient’s medical history. Treatment for patients co-infected with HIV can be more complicated, usually further lengthening treatment time.
You should get a TB test if:
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 laboratory 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.
Two tests will be done on your sputum:
If the result from tests above are positive, your health care provider will talk with you about what this result means.
Bring the sample bottles to the lab or your health care provider as soon as possible. Store the sample bottles in the fridge until you are able to bring them in. Do not store the sample bottles at room temperature and do not let the sample bottles freeze.
If you are not sure where to return the sample bottles to, ask your health care provider.
Clinicians should ask about the patient’s history of TB exposure, infection, or disease. It is also important to consider demographic factors (e.g., country of origin, age, ethnic or racial group, occupation) that may increase the patient’s risk for exposure to TB or to drug-resistant TB. Also, clinicians should determine whether the patient has medical conditions, especially HIV infection, that increase the risk of latent TB infection progressing to TB disease.
A physical exam can provide valuable information about the patient’s overall condition and other factors that may affect how TB is treated, such as HIV infection or other illnesses.
The Mantoux tuberculin skin test (TST) or the TB blood test can be used to test for M. tuberculosis infection. Additional tests are required to confirm TB disease. The Mantoux tuberculin skin test is performed by injecting a small amount of fluid called tuberculin into the skin in the lower part of the arm. The test is read within 48 to 72 hours by a trained health care worker, who looks for a reaction (induration) on the arm.
The TB blood test measures the patient’s immune system reaction to M. tuberculosis.
A posterior-anterior chest radiograph is used to detect chest abnormalities. Lesions may appear anywhere in the lungs and may differ in size, shape, density, and cavitation. These abnormalities may suggest TB, but cannot be used to definitively diagnose TB. However, a chest radiograph may be used to rule out the possibility of pulmonary TB in a person who has had a positive reaction to a TST or TB blood test and no symptoms of disease.
The presence of acid-fast-bacilli (AFB) on a sputum smear or other specimen often indicates TB disease. Acid-fast microscopy is easy and quick, but it does not confirm a diagnosis of TB because some acid-fast-bacilli are not M. tuberculosis. Therefore, a culture is done on all initial samples to confirm the diagnosis. (However, a positive culture is not always necessary to begin or continue treatment for TB.) A positive culture for M. tuberculosis confirms the diagnosis of TB disease. Culture examinations should be completed on all specimens, regardless of AFB smear results.
For all patients, the initial M. tuberculosis isolate should be tested for drug resistance. It is crucial to identify drug resistance as early as possible to ensure effective treatment. Drug susceptibility patterns should be repeated for patients who do not respond adequately to treatment or who have positive culture results despite 3 months of therapy. Susceptibility results from laboratories should be promptly reported to the primary health care provider and the state or local TB control program.