TB can occur when you inhale the Mycobacterium tuberculosis (M. tuberculosis) bacteria. The condition is most contagious when it affects the lungs as compared to when it affects the outer surface of the lungs, or brain, or bones. This is because all of us breathe air in and out of our lungs.

Hence if our lungs contain TB germ, we can breathe it out in the environment with our breath. In most cases, a person will only become sick if they have had close contact with someone with this type of TB. About 1300 people are diagnosed with TB in Singapore every year.

It is possible for a person to have TB bacteria in their body and not develop any symptoms. In most people, their immune system is strong enough to be able to effectively contain the bacteria.

As a result, the bacteria does not replicate and cause disease. In such cases, a person will not have an active disease but a TB infection. Your body has seen the TB germ but you are not sick from it because your immune system is keeping it in check.

This condition is commonly referred to as latent TB infection (LTBI). There is no risk of passing on latent TB to another person. However, latent TB will still require treatment if you are at risk of getting sick or develop TB disease from it. In the United States alone, CDC estimates as many as 13 million people have latent TB. It also said that 1/3^rd of the world population has LTBI.

The risk of developing active TB is a lot higher in:

• People with a weakened immune system
• People who first developed the infection in the past 2-5 years
• Young children and older adults
• People who inject recreational drugs
• People who were not given proper TB treatment in the past

Early Warning Signs of Active TB

It is recommended that you see your doctor right away if you experience the following symptoms:

• Persistent cough (lasts at least 3 weeks)
• Phlegm (can contain blood)
• General feeling of being unwell and fatigue
• Weight loss
• Loss of appetite
• Fever
• Chest pain
• Night sweats
• Swelling in the neck

Latent TB

Individuals with latent TB will not exhibit any symptoms. No damage will also appear on a chest X-ray. However, a skin prick or blood test can indicate if they have TB infection.

Active TB

Individuals with TB disease can experience cough with phlegm, fever, chills, fatigue, weight loss, and loss of appetite. Typically, symptoms will worsen overtime. However, it is also possible for the symptoms to go away spontaneously and then return.

While TB often affects the lungs, symptoms can also develop in other parts of the body. This is prevalent among individuals with a weakened immune system.

TB may also cause:

• Abdominal pain
• Bone or joint pain
• Confusion
• Seizures
• Persistent headache

It would be wise to ask for a TB test if:

• You have spent time with someone who has TB or is at risk of TB
• Have been in a country with high rates of TB
• Have worked in an environment where TB may be present

For the diagnosis to be accurate, the doctor will ask about the symptoms and the person’s medical history. A physical examination may also be conducted (may involve checking for swelling in the lymph node, listening to the lung, etc.)

Two tests can show if TB bacteria are present:

• The TB skin test
• The TB blood test

However, the test can’t indicate if TB is latent or active. To test for active TB disease, a chest X-ray and a sputum test may be recommended.

When detected early and given proper treatment, TB is curable. The length of treatment and the antibiotic given will depend on the following factors:

• The person’s overall health and age
• Whether they have active or latent TB
• The location of the infection
• Whether the TB strain is drug resistant

Latent TB treatment can vary. It can involve taking antibiotics every day for 9 months or 4 months. Completing the full course of treatment is essential, even if the symptoms have disappeared.

If a person stops the medication prematurely, some bacteria can survive and will become resistant to the antibiotics. In similar cases, the person can develop drug resistant TB. Depending on the parts of the body affected, corticosteroids may be prescribed.

Below are some of the ways you can prevent TB from infecting other:

• Getting a diagnosis and treatment early
• Staying away from individuals until the risk of infection is no longer there
• Ventilating rooms, covering the mouth, and wearing a mask

People with weakened immune systems are likely to develop active TB. The following are other factors that can weaken the immune system.

For those with HIV, TB is considered an opportunistic infection. In other words, a person with HIV has a higher risk of developing TB. They are also likely to experience severe symptoms compared to someone with a healthy immune system.

Treatment can be complex in someone with HIV but doctors can come up with a comprehensive plan to address both issues.

Secondhand smoke and tobacco use have also been known to increase the risk of developing TB. These factors can make the condition hard to treat. It can also make the condition more likely to return after treatment. Avoiding contact with those who smoke and quitting smoking can significantly reduce the risk of developing TB.

Other health conditions that can weaken the immune system and increase the risk of developing TB include:

• Diabetes
• Silicosis
• Head and neck cancer
• Severe kidney disease
• Low body weight
• Substance abuse disorders
• Use of immunosuppressive drugs like chemotherapy

Left untreated, TB can be fatal. Once it spreads throughout the body, the infection can cause cardiovascular and metabolic problems. TB may also lead to sepsis, a form of life-threatening infection.