Typically, you can live with the bacteria that cause tuberculosis, Mycobacterium tuberculosis rather well and it doesn't cause disease except in very rare cases. The general scientific consensus is that over 1/3 of the worlds population is actually infected with TB, yet not many people will actually die of the disease. This particular curiosity is what my research is about, in that it's hypothesised that certain mutations in immune receptors or cells causes certain individuals to be more likely to get full blown disease than others. While that hasn't been fully established yet, where you do get an increased source of mortality as the link to the BBC story above illustrates, is in the areas that are worst hit by malaria and also AIDS.
HIV, malaria and tuberculosis have an almost synergistic relationship despite being very different kinds of pathogens. HIV is a virus that infects the immune system, malaria is caused a protozoan parasite (Plasmodium falciparum), which infects red blood cells and tb is caused by the previously mentioned Mycobacterium tuberculosis that is commonly found in the lungs. By themselves, someone infected with one of these organisms is going to have a pretty hard time but together they exacerbate the chances of dying. For example, someone infected with AIDS has a considerably lower life expectancy, but someone infected with both AIDS and tuberculosis will die even earlier.
This is because all three pathogens, as part of their survivial strategy interfere with the normal function of the human immune system. Get them together in the same person and the resulting chaos on the immune system essentially ensures an extremely rapid death. This is a confounding problem that makes the current HIV/Malaria/TB epidemics in Africa even harder to treat and manage, because managing one disease only isn't likely to actually help the local population that much: one of the others will step in.
There are also other unfortunate realities which the BBC article also highlights:
There have been no new tests or treatments for TB developed in decades and the ones that are available are difficult to administer.As I mentioned at the beginning, for the most part diseases like TB just aren't particularly prevelant in western societies. This means there really isn't much of a push from general medical establishments to come up with new treatments for diseases like tuberculosis: it's just not cost effective researching new treatments for an already 'cured' disease. This has made things difficult, because the current TB treatment is similar to the sort of thing you do for HIV: effectively bombard the organisms with a large amount of systemic antimycobacterial agents (like Isoniazad). This requires said individual to be carefully monitored however and generally dosed with fairly high concentrations of the drug on a regular basis.
You can probably picture that can be a problem in certain areas of Africa, where it can sometimes be difficult just reaching people let alone attempting to treat them. This doesn't mean that nobody is trying however, as there are moves to make an improved vaccine against the organism (using BCG, an attenuated form of Mycobacterium bovis, which is closely related to M. tuberculosis). It is just unfortunate that such improved vaccines are still a considerable period of time away and that the epidemic is still going to continue and probably increase.
