It didn’t take long this month for rumors of two cases of suspected tuberculosis present at an International school to spread like wild fire through the expat community in Bali. Fortunately the cases were not confirmed and further testing overseas revealed that the infection was indeed a kind on pneumonia and not TB. Tuberculosis is not an easy disease to diagnose and there is no one-step easy test that will give a definitive diagnosis. For this reason any person suspected of having TB should consult with a specialist in this field.
Tuberculosis (TB) is a disease caused by the bacteria Mycobacterium tuberculosis. It most commonly affects the lungs, although it can affect other parts of the body. Medications are available to treat TB, although the medications must be taken every day for at least six months. Worldwide, tuberculosis remains a leading cause of death and is very prevalent in Indonesia including Bali. TB can be fatal if not recognized and treated. However, tuberculosis is preventable. Identifying and treating those who are infected, but who have not yet developed active tuberculosis, can prevent the spread of TB in the community.
HOW DOES TUBERCULOSIS OCCUR?
The tuberculosis bacteria are spread through the air from a person who is ill with active tuberculosis. The bacteria are contained in small, airborne droplets created by coughing or sneezing. Anyone who inhales these droplets is called a “contact”. The contact person does not usually develop active TB immediately. In some cases, the person’s immune system is able to remove the bacteria and he/she does not develop the infection. In other cases, the person develops an immune response that controls the bacteria by “walling it off” inside the body. This causes the bacteria to become dormant. The person does not develop active TB or become ill at this time, but is said to have latent tuberculosis infection or LTBI. Up to one-third of the world’s population is infected with latent TB.
Latent TB - During this latent stage of tuberculosis, the person is well and cannot spread the infection to others. If the person is treated at this stage, active TB can usually be prevented. Treatment is recommended for all people with latent TB.
Active TB - Active tuberculosis may develop if latent infection is not fully treated. This is called reactivation tuberculosis, and it occurs in 5 to 10 percent of people with latent infection.
Reactivation tuberculosis may occur if the individual’s immune system becomes weakened and is no longer able to contain the dormant bacteria. The bacteria then become active and make the person sick with TB. The greatest risk for developing reactivation TB is within the first two years following the initial infection. Reactivation can also occur in people with HIV, diabetes mellitus, or those who take medications that weaken the immune system, such as steroids or cancer chemotherapy. Reactivation may also occur for other, unknown reasons.
HOW IS LATENT TUBERCULOSIS DIAGNOSED? Skin testing — The TB skin test (also called the purified protein derivative or PPD) is the most commonly used test for diagnosing TB. In a person who is newly infected, the skin test usually becomes positive within four to 10 weeks after exposure to a person with TB. TB skin tests are performed by injecting a small amount of a solution just beneath the surface of the skin, usually on the forearm. The solution contains an inactivated portion of the TB bacteria. Most individuals previously infected with TB develop a skin reaction (a red or swollen bump) at this site.
What does a positive TB skin test mean? — The TB skin test indicates that tuberculosis bacteria are in the body. It cannot determine if a person has active or latent TB. Further testing is needed to determine if the person has active or latent TB. People who have active TB usually have symptoms, such as a cough (usually persisting for several weeks), fevers, night sweats, and/or unexplained weight loss.
Skin testing after a positive test in the past — Anyone who has had a positive reaction to the TB skin test in the past will usually have a positive reaction in the future. Even after taking medication to treat tuberculosis, the reaction to the skin test will remain positive. Therefore, anyone who has a positive skin test should not have skin testing again. Repeat testing can rarely cause a large and painful skin reaction at the injection site.
Blood tests for TB — Blood tests are available in some areas to test for tuberculosis infection. The blood test may be offered instead of or in addition to the skin test. In addition, blood test results are easier to interpret for those who have received the BCG vaccine.
Further testing — If the TB test is read as positive, a healthcare provider will ask some specific questions, perform a physical examination, and obtain a chest x-ray to determine if person has active TB, either currently or in the past. In some cases, the person will be referred to a TB specialist for this evaluation. If these tests indicate that the person has active, rather than latent TB, the treatment regimen is different than that of someone with latent TB.
TREATMENT OF LATENT TUBERCULOSIS
Latent tuberculosis (LTBI) is treated with a medication to kill the dormant bacteria. Treating latent TB greatly reduces the risk of the infection progressing to active TB later in life. One of the most commonly used treatments for latent TB is isoniazid (INH). Isoniazid is taken daily for 9 months. It is important to take the medicine every day and to finish the entire course of treatment since missing days or discontinuing the medicine early may not prevent active TB. Another treatment option is a medication called rifampin. Rifampin is taken as two capsules every day for four months and these drugs are often prescribed in combination. While undergoing treatment for TB, it is important to avoid drinking alcohol and taking acetaminophen (Tylenol®). Both of these substances can make the liver work harder, potentially increasing the risk of liver injury.
ACTIVE TUBERCULOSIS
Active tuberculosis occurs when the TB bacteria become active and cause a person to become ill. This usually occurs in the lung, although TB can affect any part of the body, including the lymph nodes, brain, kidneys, or bones.) If there is evidence on a chest x-ray or other signs that active tuberculosis is present, sputum cultures will be performed to culture (grow) the bacteria in the laboratory. This usually involves coughing up a “deep” specimen of phlegm from the chest. The phlegm is then sent to a laboratory and cultured to determine if TB bacteria are present. Other tests, such as a bronchoscopy or biopsy, may also be needed. While waiting for the results of the sputum culture (it may take as long as two months for the bacteria to grow in the laboratory), treatment with several (usually four) TB drugs is usually recommended. It is important to use more than one medicine and to take the medicines exactly as prescribed to reduce the risk of the bacteria becoming resistant to one (or more) of the medicines.
Monitoring during treatment — People who are being treated for TB should be monitored by a healthcare provider at least once per month to monitor for any signs of medication toxicity, such as liver injury. Signs of liver injury may include: unexplained tiredness, loss of appetite, nausea, vomiting, dark-colored urine, jaundice (yellowing of the skin or the white portion of the eye), fatigue, abdominal pain, or rarely, unexplained bruises. Monthly monitoring may also include blood tests to monitor the function of the liver or blood counts.
THE VACCINE
A TB vaccine (called Bacillus Calmette-Guerin, or BCG) is given in many countries to prevent infection with TB. It usually is given to infants, although it may be given again at other times. Unfortunately this vaccine offers very little protection, if any, against tuberculosis beyond early childhood. This vaccine also may or may not cause a positive skin test making diagnosis of active TB difficult.
Kim Patra is a qualified registered nurse and midwife who has been living and working in Bali for almost 20 years. She now runs her own private practice and medical referral service from her Kuta office. Kim is happy to discuss any health concerns with you and she may be contacted via e-mail at info@chcbali.com or
