Tuberculosis or TB is one of those diseases that was once considered deadly but is now both curable and preventable – all thanks to the global effort that stopped it from claiming more lives. There is some comfort in knowing that fact; however, if you look at the numbers of daily TB casualties – with approximately four thousand people dying and almost 28,000 getting infected – you would understand why TB remains as one of the world’s most fatal diseases, despite every valiant effort to eradicate it. This is why TB screening in Singapore ( is carried out proactively by government and private health institutions. People who are diagnosed with active TB are treated immediately and placed on medical leave so that they can focus on recovery and help prevent further risk of exposure in the workplace or school. Read this article to learn more about TB –how it spreads, the signs and symptoms, diagnosis, treatment, and more.

First of all, what is tuberculosis or TB?

Tuberculosis is a disease caused by a specific type of bacteria called Mycobacterium tuberculosis. Although it commonly affects the lungs (known as pulmonary TB), it can also affect any tissue or organ in the body, including the lymph nodes, kidneys, bone, or brain. TB is infectious but not all people who is exposed to it develops the disease; the body’s immune system is capable of fighting the bacteria and rendering them inactive, thus effectively preventing them from growing and spreading. The bacteria, however, remains alive inside the body and this condition is known as latent TB infection.

In Singapore, TB had a high prevalence before 1960s and because of this, it is estimated that around 30% of the older population may have latent TB. A study was conducted in 2017 to prove this hypothesis and it showed that two-thirds of the new TB cases reported in Singapore were composed of people aged fifty years and above.

How does the disease spread?

Tb is considered an air-borne diseases and it can be passed through prolonged and close exposure to a carrier of the disease. When an untreated, actively infected person coughs or sneezes, TB can spread through tiny droplets in the air. When those droplets are inhaled, the bacteria will start to develop in the lungs of the unsuspecting individual. Later on, those who develop an active infection will start to experience the symptoms, while those who with latent TC will still carry the bacteria in their lungs but will not display any symptoms. According to studies, the latter will have a small chance – about five to ten percent – of developing active TB within the first two years of acquiring the infection. People with latent TB infection cannot spread TB to anyone else; the only way to know if they have the infection is through TB screening – either a blood test or a TB skin test.

What are the signs, symptoms, and risks?

Most healthy individuals who are exposed to the TB bacteria do not get infected as their bodies’ immune system are able to ward off the infection and prevent it from developing into active TB. On the other hand, those who have an active TB infection will experience the following symptoms: cough with phlegm that lasts for more than three weeks, low-grade fever, excessive sweating (especially at night) chest pain, breathing difficulty, fatigue, and unexplained loss of weight. Coughing up blood is also one of the most common signs that a person has TB.

A person may be at higher risk for TB if he or she:

  • Has been exposed to another individual who has an active TB infection.
  • Has a weak immune system
  • Resides or works in an area where TB infection is prevalent, e.g., correctional facilities, nursing homes, and shelters
  • Is a professional in the healthcare field who interacts with and cares for people.
  • Is a habitual user of intravenous drugs.
  • Has lived or been to a place or country where TB is endemic.

How is TB diagnosed?

Diagnosing TB is not an easy feat – it usually causes infection in the lungs, but not always, and it can be either asymptomatic or active. An individual who wants to get tested for TB will have to undergo a physical exam first, followed by (any or a combination of) these three common tests for TB:

  • Chest x-ray: this is done to determine if the infection has caused damage to the lungs
  • Tuberculin skin test (also called Mantoux test): this is performed by injecting a small amount of tuberculin fluid into the skin (on the lower part of the arm) and waiting for 48 to 72 hours for a reaction. A positive or negative result is determined based on the size of the swelling or raised, hard area on the injection site. This type of test is usually recommended for children below the age of five.
  • Blood test: this is used to measure the body’s response to TB antigens. If the result of the test is positive, you only need to visit the doctor once for the test.
  • Sputum test for the smear and culture analysis of TB germs

Additional tests such as chest CT scan, bronchoscopy, thoracentesis, and pleural biopsy may be required depending on the results of the tests above.

What are the treatment options for TB?

TB is treatable and there are anti-TB medications that a TB patient can take for at least six to nine months to resolve the symptoms. Some of the common drugs used to treat TB include rifampicin, isoniazid, ethambutol, streptomycin, and pyrazinamide. If the patient follows the treatment plan religiously over the prescribed time period, the possibility of recovering from TB fully goes as high as 95%. However, if the patient decided to stop taking the medication halfway (or less) through the prescribed period, a condition called TB relapse can occur, and this will trigger the emergence of a drug-resistant (aka harder to eliminate) strain of TB bacteria.

Last word of advice

Remember: completing treatment for TB is of utmost importance. After a few weeks of taking TB medication, the period of contagion will elapse, and you will start to feel better. But do not be too complacent, and more importantly, do not stop taking your TB drugs – make sure that you follow the treatment plan exactly as advised by your doctor.

IP Lung Clinic

Interventional Pulmonology & lung Clinic

Mount Elizabeth Medical Centre, 3 Mount Elizabeth, #12-03, Singapore 228510

+65 9023 0158