What is Tuberculosis ?
Tuberculosis is an air-borne serious infection caused by a bacterium called Mycobacterium tuberculosis. This bacteria usually affects the lungs (pulmonary tuberculosis). It can also affect other parts of the body(extrapulmonary tuberculosis), such as the brain, lymph nodes, the kidneys, bones, and joints. If not treated properly, TB can cause fatality.
Mode of transmission: The bacteria that cause tuberculosis are transmitted from one person to another through tiny droplets released into the air via coughs and sneezes. When a person breathes in the bacteria , they can remain in the lungs (pulmonary tuberculosis) and grow. From there, they can spread through the blood to other parts of the body, such as the kidney, spine, and brain (extrapulmonary tuberculosis). TB in other parts of the body, such as the kidney or spine, is usually not infectious.People with TB disease tend to spread it to people they spend a lot of time with every day. This includes family members, friends, and coworkers or schoolmates forming a cluster.
Not everyone who is infected with TB develops TB disease. The body's immune system can "wall off" the bacteria, and there it lay dormant in the body. This is called latent TB infection. Individuals with latent TB infection do not have symptoms and are not infectious. They cannot spread the TB bacteria to others.TB disease develops in about 10% of those with latent TB infection.
Risk factors of developing Tb
Diagnosis of Tb
There are two kinds of tests that are used to detect TB bacteria in the body: the TB skin test (TST) and TB blood tests (QuantiFERON-TB Gold in-Tube test and T-Spot.TB test). A positive TB skin test or TB blood test only tells us that person has been infected with TB bacteria. It does not tell whether the person has latent TB infection (LTBI) or has progressed to infectious TB disease. Additional tests are chest x-ray and a sputum sample to determine if the person has active TB disease. Sputum tests can be used to test for drug-resistant strains of TB.
Mantoux Tb skin test : A small amount of a substance called PPD tuberculin is injected just below the skin of your inside forearm. Within 48 to 72 hours, a health care professional will check the size of swelling at the injection site. The size of the bump determines whether the test results are significant. A false-positive test may happen if you've been vaccinated recently with the bacillus Calmette-Guerin (BCG) vaccine. A false-negative result can also occur in people who've recently been infected with TB, HIV/AIDS patients, young children and in elderly.
A diagnosis of latent TB infection is made if a person has a positive TB test result BUTa medical evaluation does not indicate TB disease.
Treatment of Tuberculosis Tuberculosis can be treated with anti-TB drugs for 6-9 months. Incomplete treatment and non-compliance will result in resistance to the drugs and difficulty to treat. The World Health Organisation (WHO) has advocated Directly Observed Therapy (DOT) is the standard of care for TB patients. DOT is a process during which the patient takes each dose of medication under the direct observation of a health care worker usually a nurse to ensure that the correct dosage and combination of TB medications are taken for the entire course of the treatment. With DOT, the TB patients’ response and adherence to treatment is closely monitored, so that treatment failure, drug resistance and spread of the disease can be avoided.
Common Tb drugs are isoniazid, rifampin, ethambutol and Pyrazinamide. Each drug has certain side effects hence they should be monitored by respiratory physicians and blood tests need to be done routinely while on these medications.
Drug-resistant TB is caused by TB bacteria that are resistant to at least one of the first-line anti-TB drug. Multiple drug-resistant TB (MDR TB) is resistant to more than one anti-TB drug and at least isoniazid (INH) and rifampin (RIF). This is more difficult to treat.
Complications of TB
Without treatment of TB, it can cause serious complications and can be fatal. The TB bacteria can spread through blood and spread to other organs (miliary TB). It can spread to :
Controlling the spread of TB
Tb patients should complete their treatment so as to be cured and prevent the spread to others especially family members, friends and colleagues. Tb patients should stay at home during the first two weeks of treatment, cover your mouth when you sneeze or cough as Tb spreads through respiratory droplets and wear a surgical mask. Ventilate the room as Tb bacteria spread more easily in poorly ventilated enclosed small areas.
Contact tracing and tests will be done on close contacts of TB patient and treatment will be started if found positive.
Vaccinations
Infants often are vaccinated with bacillus Calmette-Guerin (BCG) vaccine because it can prevent severe tuberculosis in children. Please see BCG
Tuberculosis is an air-borne serious infection caused by a bacterium called Mycobacterium tuberculosis. This bacteria usually affects the lungs (pulmonary tuberculosis). It can also affect other parts of the body(extrapulmonary tuberculosis), such as the brain, lymph nodes, the kidneys, bones, and joints. If not treated properly, TB can cause fatality.
Mode of transmission: The bacteria that cause tuberculosis are transmitted from one person to another through tiny droplets released into the air via coughs and sneezes. When a person breathes in the bacteria , they can remain in the lungs (pulmonary tuberculosis) and grow. From there, they can spread through the blood to other parts of the body, such as the kidney, spine, and brain (extrapulmonary tuberculosis). TB in other parts of the body, such as the kidney or spine, is usually not infectious.People with TB disease tend to spread it to people they spend a lot of time with every day. This includes family members, friends, and coworkers or schoolmates forming a cluster.
Not everyone who is infected with TB develops TB disease. The body's immune system can "wall off" the bacteria, and there it lay dormant in the body. This is called latent TB infection. Individuals with latent TB infection do not have symptoms and are not infectious. They cannot spread the TB bacteria to others.TB disease develops in about 10% of those with latent TB infection.
Risk factors of developing Tb
- Close contacts of a person with infectious TB disease
- Persons who have immigrated from areas of the world with high rates of TB
- People with high rates of TB transmission are homeless persons, injection drug users, and persons with HIV infection
- Persons who work or reside with people who are at high risk for TB in facilities or institutions such as hospitals, homeless shelters, correctional facilities, nursing homes, and residential homes for those with HIV
- People with weakened immune system such as HIV infection, AIDS, drug/substance abuse, Silicosis, Diabetes mellitus , Chronic kidney disease, people with Organ transplants , Cancer patients on chemotherapy, immuno-suppressant medications.
- cough that lasts 3 weeks or longer
- pain in the chest due to cough (pleuritic chest pain)
- coughing up blood or sputum (hemoptysis)
- weakness or fatigue
- weight loss
- fever and chills
- night sweats
- loss of appetite
Diagnosis of Tb
There are two kinds of tests that are used to detect TB bacteria in the body: the TB skin test (TST) and TB blood tests (QuantiFERON-TB Gold in-Tube test and T-Spot.TB test). A positive TB skin test or TB blood test only tells us that person has been infected with TB bacteria. It does not tell whether the person has latent TB infection (LTBI) or has progressed to infectious TB disease. Additional tests are chest x-ray and a sputum sample to determine if the person has active TB disease. Sputum tests can be used to test for drug-resistant strains of TB.
Mantoux Tb skin test : A small amount of a substance called PPD tuberculin is injected just below the skin of your inside forearm. Within 48 to 72 hours, a health care professional will check the size of swelling at the injection site. The size of the bump determines whether the test results are significant. A false-positive test may happen if you've been vaccinated recently with the bacillus Calmette-Guerin (BCG) vaccine. A false-negative result can also occur in people who've recently been infected with TB, HIV/AIDS patients, young children and in elderly.
A diagnosis of latent TB infection is made if a person has a positive TB test result BUTa medical evaluation does not indicate TB disease.
Treatment of Tuberculosis Tuberculosis can be treated with anti-TB drugs for 6-9 months. Incomplete treatment and non-compliance will result in resistance to the drugs and difficulty to treat. The World Health Organisation (WHO) has advocated Directly Observed Therapy (DOT) is the standard of care for TB patients. DOT is a process during which the patient takes each dose of medication under the direct observation of a health care worker usually a nurse to ensure that the correct dosage and combination of TB medications are taken for the entire course of the treatment. With DOT, the TB patients’ response and adherence to treatment is closely monitored, so that treatment failure, drug resistance and spread of the disease can be avoided.
Common Tb drugs are isoniazid, rifampin, ethambutol and Pyrazinamide. Each drug has certain side effects hence they should be monitored by respiratory physicians and blood tests need to be done routinely while on these medications.
Drug-resistant TB is caused by TB bacteria that are resistant to at least one of the first-line anti-TB drug. Multiple drug-resistant TB (MDR TB) is resistant to more than one anti-TB drug and at least isoniazid (INH) and rifampin (RIF). This is more difficult to treat.
Complications of TB
Without treatment of TB, it can cause serious complications and can be fatal. The TB bacteria can spread through blood and spread to other organs (miliary TB). It can spread to :
- Spinal cord: causing back pain and stiffness
- Tuberculosis arthritis : causing joint damage at hips and knees for example
- Meningitis: infection of the membrane of the brain causing fever, headache and rash
- Liver and kidney damage
- Heart disorder: Very rarely TB bacteria spread to the heart leading to inflammation and fluid collection around the heart (Cardiac Tamponade) which can be fatal.
Controlling the spread of TB
Tb patients should complete their treatment so as to be cured and prevent the spread to others especially family members, friends and colleagues. Tb patients should stay at home during the first two weeks of treatment, cover your mouth when you sneeze or cough as Tb spreads through respiratory droplets and wear a surgical mask. Ventilate the room as Tb bacteria spread more easily in poorly ventilated enclosed small areas.
Contact tracing and tests will be done on close contacts of TB patient and treatment will be started if found positive.
Vaccinations
Infants often are vaccinated with bacillus Calmette-Guerin (BCG) vaccine because it can prevent severe tuberculosis in children. Please see BCG