Tuberculosis is serious shit. I don’t resort to that kind of language unless I have to, but for TB, it’s warranted. Over a third of the world’s population is expected to carrying the bacteria responsible for disease, it kills approximately 3 million people every year and 2 million of those deaths come from the developing world. I told you it’s serious shit.
History of TB
TB has one of those really interesting histories that I could write as a separate article. However, I will limit myself as Thomas whines when my articles are long (so all the time) and his whine is so high-pitched it hurts my ears. I bet it pisses dogs off too.
Cool fact about TB # 1: Up till the early 18th century, Scrofula (a form of TB affecting the skin and lymph nodes) was also called the King’s Evil due to the widely held belief that a monarch (although the ‘power’ only appears to have been wielded by English and French Kings) could cure it with merely a touch due to their divine power. They would also present a coin to the newly ‘healed’ called an Angel with was worth up to 10 shillings (assuming 10 shillings is worth the same now as it was then, that’s about 70 cents). In fact, King Henry IV would apparently heal up to 1500 people at a time. I’d like to think he lined up them all up in single file then ran along the line, giving them each a high five.
Cool fact about TB # 2: TB has been linked to vampires. Its not hard to see the connection but it is awesome nonetheless. An example, Grandma dies of a TB infection. She’s living in a house with her children and grandchildren and she manages to spread it to her family, some of whom get sick and die. What explanation could there be. Grandma has come back as a vampire of course. A common symptom of TB (or the consumption as it was also called) was coughing up blood and of course anyone with blood in their mouth is feeding off the living…
But why is only Grandmas family dying? Well vampire Grandma might be undead but she knows which of her ex-family are the most vulnerable and where they keep the spare keys. How do the townspeople protect the family?, foster the children out (spreading TB throughout the whole town…) and dig up the dead family members. Everyone knows the best way to kill a vampire is to cut out and burn its heart (or otherwise destroy it – including impaling it on a stake), remove the skull from the spinal column then place it on the vampires chest and create a crucifix from an arm and leg bone to be placed under the skull.
It’s thought that the arm bone was in some cases replaced by the other femur bone and the crucifix was tilted into what we now known as the skull and crossbones. That’s one of the reasons I like writing about TB, how often do you get to connect vampires to pirates?
Cool fact about TB # 3: The bacteria responsible was first identified by Robert Koch. Who is he? Scroll up and look at the header (he’s on the left). Also check this out.
That’s Pretty Cool But What Actually Happens?
Yea I should probably mention that stuff huh? TB is caused by a bacterium called Mycobacterium tuberculosis infecting and destroying lung tissue (typically, I’ll come to that). Most commonly TB is a respiratory disease and the bacteria is spread in aerosol as you would expect. Following inhalation, the bacteria are introduced in to the terminal surfaces of the lungs called the alveoli. Once detected in the alveoli the bodies defences’ kick into gear. The bacteria are taken up into a cell called a macrophage and transported to the nearest lymph node. Where 1 of 3 fates await the bacteria (1) killed by the immune system, (2) multiply and cause primary TB, (3) become dormant and remain asymptomatic.
Macrophages are like the eager-to-please younger siblings of other cells in the immune system. They float around the body collecting up all sorts of stuff then coming to lymph nodes to say “Look at me!!!! Look at what I found!!!!”. Lymph nodes are kind of like the common room for the older siblings. All the macrophages run around showing off what they found, while other cells like T- and B- cells hang out smoking and listening to The Cure. Macrophages not only want to show off what they find but they are normally able to break up what they find into lots of smaller pieces, that way there is more to show off. When something doesn’t look ‘right’ (i.e. not from the body) the T- and B- cells respond.
While all this is happening other macrophages as well as other cells of the immune system flood into the lungs looking the bacteria. The lungs are used for breathing so when they fill up with stuff you tend to cough a bit. At this stage you are experiencing primary TB. Generally this feels like a mild flu and most people ignore it. Unfortunately this is the best time to try to treat TB, but it is extraordinarily hard to diagnose at this point.
Inside your lungs the shit is hitting the fan. It turns out M. tuberculosis confuses the immune system (kind of – don’t nitpick) and instead of dealing with bacteria the way it does any other bacteria it forms tubercules. Tubercules are characterised by large clumps of cells surrounding the bacteria that lack a blood supply and therefore die. The bacteria then are stuck within necrotic or dead tissue and are, in every sense of the term, walled off from the rest of the body. These tubercules are visible on chest x-rays as they are so dense and can sometimes be seen throughout the lungs giving a ‘speckled egg’ appearance.
Sometimes a primary stage of disease is not seen but eventually a latent stage of disease is established. The tubercules do not actually kill the bacteria so (somehow and we don’t know how) the bacteria wait it out. Eventually the tubercule breaks down and the bacteria escape. Primary disease repeats until the patients lungs are so full of tubercules they cannot function and the patient dies.
I mentioned Scrofula earlier. This occurs when the bacteria are transported to lymph nodes that then burst spewing bacteria into area outside the lungs. This is also called non-pulmonary TB. The lymph nodes can burst and relase the bacteria anywhere including the skin (Scrofula) and the blood. If its in you blood your in trouble. Tubercules forming in your joints gives you a painful kind of arthritis, in your muscles can impair movement and in you, brain equals death.
The Sad Truth About TB
Possibly the worst thong about TB is that it shouldn’t exist. I’m not suggesting that the CIA is responsible for TB or anything but we had it under control and were beating it into submission. M. tuberculosis is known to only infect humans which means if we are diligent we can eradicate it (like we effectively did with polio). By the 1950’s we could cheaply detect and treat TB infections so an effort was made to try and wipe out the bacteria. We adopted some pretty extreme measures (such as making it illegal to refuse treatment for TB) and we just about achieved our goal but for two main reasons we fell short. Firstly, the treatment sucked. In order to make sure the disease was treated properly, sufferers were treated as outpatients in hospitals requiring them to visit regularly to pick up the medication. He medication included a handful of pills (literally 3-5 different pills in some cases) to be taken every day for 6 months. As you can imagine few people made it the full 6 months which meant that some retained bacteria despite the treatment.
The other problem was we were too successful to quickly. In the 20 years following the establishment of anti-TB programs the rates of disease dropped significantly, so we stopped funding the programs. Without the subsidisation of the medication and continued support of public health warnings we completely undid all the good work we have done. By the 1980’s TB was on the rise again worldwide after being reduced to undetectable levels in many places all over the world.
As for the future
The future is looking good for TB treatment. On Dec 8th the World Health Organisation released a report stating that over the last 15 years more than 36 million people have been cured of TB infection. They also reported that the majority of countries involved in programs reported 85% or better cure to treatment percentages with the worldwide average being 87%. While this news is good an important point was made by Dr Mario Raviglione, Director of WHO’s Stop TB Department:
“It is a disease that destroys lives, damages families and stifles development … Without help to fill the US$2 billion funding gap for TB care and control in 2010, the most vulnerable people will continue to miss the benefits so many others have seen.”