Tuberculosis – All you need to know

Overview

Tuberculosis or TB is an infectious disease that generally affects the lungs and is the second biggest killer worldwide compared to other diseases caused by a single infectious agent. As per the latest report on TB by the WHO, India leads the world in the burden of TB.

While the most commonly affected sites in humans are the lungs, TB can also occur in bones, especially in the spine and at the ends of the long bones. Other common sites of TB include the lymph nodes, brain and kidneys. In fact, there is virtually no organ that cannot be touched by TB.

However, frequently portrayed as a dreaded disease in books and movies, tuberculosis today is a highly treatable disease that needs better awareness.

TB and its Causes

Tuberculosis (TB) is a very common infection in India that is also very contagious. It is a highly infectious disease caused by bacteria (usually Mycobacterium tuberculosis) and most commonly affects the lungs.

When an infected person sneezes or coughs, air particles containing the TB bacteria can easily spread and each infected person can further infect up to another 10 people each year. Because it spreads through air, this infection is found in many humans. However, in most people it is latent and only 10% of these infections turn into an active disease.

Latent and Active TB

Doctors usually make a distinction between two kinds of tuberculosis infection – latent TB and active TB.

It is estimated that nearly one-third of the world is infected with Tuberculosis. However, the distribution of this number is not even throughout the world as almost 80 percent of those infected are from African and Asian countries.

The peculiar thing about the TB bacteria is that it can stay in the bloodstream of a person and not develop into active disease. The most frequent method of testing for TB is through a skin test called the Mantoux test or the tuberculin skin test. This test only determines whether the person being tested has the bacteria present in him or her, and not whether it has evolved into a full-fledged, active disease. Thus, it has less diagnostic value in countries like India and hold relevance in certain clinical situations only.

Latent TB is inactive, has no symptoms and is not contagious, while active TB makes a person sick and is highly contagious. It is not necessary that everyone infected with the TB bacteria develop active TB. In fact, most usually don’t.

Spread of TB

Tuberculosis is an airborne disease and spreads from person to person through tiny droplets discharged into the air. It spreads through very close contact when a person breathes the same air as the TB patient.

In a country like ours, where the TB bacteria are so prevalent, it is imperative to maintain hygiene to prevent the spread of the disease. Spitting in public or coughing or sneezing without covering the mouth

should be completely discouraged. It is also important to note that TB does not spread by touching the clothes, linen or utensils of an infected person.

TB can also be passed on from an infected pregnant woman to her child. Also, people with AIDS are very susceptible to TB as their immune systems are too weak to fight the bacteria.

Risk of Contracting TB

Anyone can contract TB, especially if they are in a closed space with the affected person. The unaffected person inhales droplets with bacteria and these bacteria reach the lungs. Here, the immune system puts up a fight against the bacteria. If successful, the bacteria will remain in a “latent” form. If the immune system is unsuccessful in containing the bacteria, then an active case of TB can develop. Once the bacteria invade the body and overwhelm the immune response of the body, they can also find their way to various organs through the blood stream.

Signs and Symptoms

People with a latent TB infection do not have any symptoms, do not feel sick and cannot infect others. They do, however, test positive to the Mantoux Skin Test. Treatment of latent TB is important as it may get activated, especially if the immune system is declining for some reason, including nutritional deficiencies or infection with HIV.

In the case of an active infection, symptoms may vary according to the organ that is affected.

In case the lungs are affected, the symptoms are:

• A cough persisting for 2 to 3 weeks and beyond, which is usually worse in the mornings
• Chest pain
• Blood in the sputum (the mucus and saliva produced when coughing or clearing throat)
• Breathlessness

Tuberculosis of the spine may cause back pain, and blood in the urine may be caused by tuberculosis in the kidneys.

TB in the brain can cause headaches, a stiff neck, confusion, vomiting, an altered mental state, seizures and other signs and symptoms related to the nerves.

Generally, a person with active TB in any organ may have the following symptoms:

• Weight loss
• Loss of appetite
• Chills
• Fever
• Sweating in the night time while sleeping, even if the weather is cold

If TB is suspected, what should you do?

If you or someone you know is experiencing any of these symptoms, or has reason to think they have been exposed to TB, then they should seek consultation from a physician and the public health authorities. A test on the skin and one of the sputum (mucus produced when coughing) will be performed.

Those who have had the BCG vaccine against TB, which is mandatory at birth in India, may have a “positive” skin test despite not being infected with TB. The skin test will need to be re-examined two days after it is given. If a sputum sample is provided, the results may take longer as they need to be sent for laboratory test.

Treatment for TB

Even though TB is largely treatable, TB is one of the leading causes of death in India with approximately two deaths occurring every three minutes.

TB infection can be treated with antibiotics and is nearly always curable with proper treatment. Proper treatment would be a regimen at least for six months. Too often, this routine is not followed.

Either due to lack of money or due to forgetfulness or carelessness, patients may stop the medication sooner than six months if they start to feel better. However, stopping treatment has serious consequences because the TB bacteria can better learn how to resist the standard medications when only a partial course is taken. The standard treatment for TB relies on the “first-line” drugs of Ethambutol, Isoniazid, Pyrazinamide, Rifampicin and Streptomycin. When these are no longer effective, it becomes necessary to rely on drugs that cost more, need to be taken for a longer time (up to 24 months) and are harsher on the body.

DOTS

The treatment for TB is often referred to as ‘DOTS’ that stands for Directly Observed Treatment, Short Course, which is the World Health Organization’s cornerstone of organizing TB treatment in countries around the world. India’s DOTS programme is undertaken by TB Control (TBC) within the central Ministry of Health and Family Welfare. “Directly observed therapy” refers to the fact that a medical provider or designated observer will be present when the patient takes his/her TB medication to ensure compliance. Treatment is referred to as ‘Short course’ as TB treatment used to last much longer than six months.

Conclusion

Fortunately, when treated properly, the vast majority of TB cases are curable and the risk of dying from it is very low. But, without proper treatment, up to two-thirds of people ill with tuberculosis will die.