Tuberculosis

I was a bit ill last week, hence the gap in my regular postings... Much better now.

I thought I would write a bit about tuberculosis this week. My major research project out here is looking at the spread of tuberculosis, and trying to assess the usefulness of various new tests for TB.

So... Tuberculosis (usually abbreviated to TB) is an ancient disease which has made a big recent comeback, and at present goes hand-in-hand with HIV/AIDS as a major killer in the developing world.

TB is a bacterial disease caused by the slow-growing Mycobacterium tuberculosis organism, which I've tried to put a microscope picture of below






This bacteria usually infects the lungs and is spread by coughing. The "classic" TB patient has a permanent cough, and sometimes coughs up blood ... Nicole Kidman in Moulin Rouge.

A typical chest x-ray (from a large pile of TB cases next to my desk!) looks like this :



TB is a strange disease in many ways: about 95% of the people who are infected with it will recover by themselves, though the disease may "reactivate" many years later. As well as affecting the lungs, it can also be in many other parts of the body: the spine, the skin, the brain, the heart.

My research is mainly based around finding out which people who were in contact with TB go on to develop the disease. I am working on a large study set up here at MRC in Gambia that is looking at about 2500 family members of people who had TB, and trying to find out which of these go on to have TB.

I'm also trying to evaluate some new blood tests that are being hailed as a new tool for TB. Basically, these tests count how many white blood cells a person has that are "targeted" towards TB, which should give an idea of whether the person has TB or is likely to develop it in the future.

Right, finally on TB is a bit I have shamelessly pinched from Wikpedia (the online encyclopedia) which I thought was quite interesting ...

"During the Industrial Revolution, tuberculosis was more commonly thought of as vampirism. When one member of a family died from it, the other members that were infected would lose their health slowly. People believed that the cause of this was the original victim was draining the life from his/her family members. To cure this, people would dig up the body of what they thought was the vampire, open the chest and burn the heart, sometimes with the rest of the body. Furthermore, people who had TB exhibited symptoms similar to what people considered vampire traits (and may be where much of the common mythology of the vampire comes from) . People with TB often had symptoms such as pale skin, thin stature, red, swollen eyes (which also creates a sensitivity to bright light) and would cough blood (which people often figured needed to be replenished because of the loss in this manner, i.e. sucking blood)."



Truth is stranger than fiction: in Malawi (in Southern Africa) in 2003 there was an outbreak of mob hysteria over fears that there were local vampires attacking children : http://news.bbc.co.uk/2/hi/africa/2602461.stm . Perhaps this was something to do with the rampant TB epidemic that Malawi was (and still is) experiencing ...