I keep hearing more and more about tuberculosis or TB lately in the news. It is always about this and that person unexpectedly getting it. Is TB on the rise?
Luckily, despite what you hear, TB is not on the rise globally, according to the World Health Organization (WHO).
In 2017, there were 10 million people worldwide diagnosed with TB, and 1.6 million people died from it.
This includes 300,000 people who had both HIV (human immunodeficiency virus) and TB.
Of these 10 million people, 10% of them were children.
TB incidence worldwide seems to be falling by 2% every year.
This is good, but not good enough, according to WHO’s mission. It needs to fall by 5% every year to reach their 2030 health target.
Nevertheless, TB remains one of the top 10 causes of death worldwide and is a leading cause of death for HIV-positive people.
It is definitely the number one cause of death by infectious disease worldwide.
Most of the deaths occur in developing countries like India, many parts of China, Indonesia, Pakistan and the Philippines.
TB is an infection of the lungs, right?
TB is an infectious disease, but not just necessarily of the lungs.
TB is caused by a type of bacteria called Mycobacterium tuberculosis.
It is spread primarily from person to person through droplets in the air when someone with untreated TB coughs, talks, sneezes, spits or opens his or her mouth in any capacity at all.
It is generally a disease of the lungs, but can affect other parts of your body like the liver, spine, brain and bone marrow.
Is TB easy to catch?
It is contagious. But it is surprisingly not easy to catch.
For example, you won’t catch TB easily if you happen to be in a train with someone who has it and is coughing next to you.
But you are likely to get it from someone you have close contact with over a period of time, such as someone you live or work with.
Even so, if these people with TB have been successfully treated, they are no longer contagious.
Why do I keep reading about how much TB used to kill people in the past? On TV, if I am watching a period drama, a cough with bloody sputum in a main character usually indicates TB and the person is about to die soon!
TB used to be called consumption. It was first described around 460 BC as “phthisis” by Hippocrates, who associated it with dry seasons.
An interesting thing that most people don’t know about TB is that it used to be associated with people who were very artistic or poetic. Hence, it was called the “romantic disease”.
I do however think that those who suffered and died of TB did not find it all that romantic!
Poets John Keats and Percy Shelley had TB. So did authors Kafka, George Orwell, Robert Louis Stevenson, Katherine Mansfield, Charlotte Bronte, (Fyodor) Doestoevsky, Somerset Maugham and (Anton) Chekov.
It used to be believed that the fever and illness associated with TB helped these people write or create better!
In the past, there was a lot of overcrowding and malnutrition. Therefore, a lot of people were likely to get TB due to the close living proximity and low immune systems.
Poets, authors, and painters in history were usually not very rich, so they would be subject to such living conditions.
Am I at risk of getting TB today?
It depends on where you live and your circumstances.
In the past, as mentioned, there used to be overcrowding and malnutrition, making TB a disease of poverty.
Today, the highest risk factor is having HIV/AIDS. About 13% of all people who have TB today also have HIV, especially those in Africa.
Of course, poverty and overcrowding are still major risk factors, such as those who live in shelters, refugee camps and prisons, and those who work in such places.
Other risk factors include:
• Injecting drugs
• Being unvaccinated or having no access to good medical treatment
• Chronic lung disease, e.g. silicosis
• Medications like steroids and chemotherapy
• Kidney disease
• Being very young or very old
I have been vaccinated with the BCG vaccine. Does that prevent me from getting TB?
BCG stands for Bacilli Calmette-Guerin.
In Malaysia, which is considered a high endemic population for TB, all babies receive the BCG vaccination at birth, and again during Year One of primary school if they do not have a scar from the first vaccination. (The scar is visual evidence that the vaccine has done its job.)
In many Western countries, including the United States, people are not routinely vaccinated with the BCG because of the low incidence rate of TB.
In these countries, you will be vaccinated only if you are among the populations at high risk of getting TB.
The BCG is effective up to 70-80% of the time against the most severe forms of TB, like TB meningitis in children.
It is unfortunately less effective against the more common lung or pulmonary TB.
So you can still get TB even if you have been vacinated with the BCG, although your chances of it are far less than someone who is unvaccinated.