Extensively drug resistant tuberculosis. It's time to pay for our over-use of antibiotics.
Every time you use an antibiotic you run the risk of not killing the bacteria, especially if the course of the antibiotic is abandoned when the patient feels better. This gives evolution room to operate, the more resistant survive, and eventually the entire population of bacteria are resistant.
To date, new antibiotics have been found and we set off down the path towards resistance again.
Now it is the End Times. We have no more new antibiotics. Overuse of the antibiotics (even giving them to perfectly fine chickens so they will grow with no individual care) has lead to bacteria which resist multiple antibiotics.
XDR bacteria have simply been through enough evolution to be resistant to all antibiotics. Treatment has to return to the pre-Penicillin era. That's fine for some bacteria, they can be treated with old-fashioned sulphur drugs, although this is not as effective and weaker people will die. But there was no effective pre-Penicillin treatment for the common disease tuberculosis.
XDR TB is the new AIDS because is has the attributes that made our response to AIDS so poor.
Complicated by religion. Many religions forbid homosexuality and some forbid condoms. Understanding XDR TB requires accepting evolution, something many Christian religions cannot do. Many of these religions can command more resources than public health agencies. As with AIDS some may use these resources to undermine public health efforts, such as the Catholic Church's view that condoms are ineffective in controlling the spread of HIV via sex.
Long lead times. Politicans had to make unpopular decisions that would not have an immediate effect. The same is true of XDR TB. For exampple, doctors should be required to justify any use of the second-line antibiotics and be prepared to be audited for all their antibiotic use. That oversight does not sit well on doctors view of themsleves, and any government suggesting it will make itself unpopular with a influential community for no immediate effect.
Confounded traditional public health measures. This was probably more true of AIDS, where the paranoia and lack of honesty of closeted homosexuals made it difficult to make AIDS a notifiable disease and to do contact tracking. But our era has cheap global air travel, which was only in its infancy in the 1980s. We don't have effective means for tracking people across the globe. And, as with AIDS, overblown privacy concerns may well stymie and effective response until it is too late.
As with AIDS, government action is lacking. Last week my daughter bought home a pamphlet saying that you should not use antibiotics for a common cold. That pamphlet is twenty years too late. The horse has long bolted, and the issue is now one of damage control.
A vaccine for TB exists, Bacillus Calmette-Guérin, which is a weakened TB. As such it carries risks greater than other childhood injections and also results in positive diagnostic tests for TB. Western nations do not give the BCG vaccine to infants, because TB is not widespead and a simple test allows for better treatment of the occassional cluster of TB.
But worst of all, we don't know if BCG works anymore, and by how much. Measures of efficacy have wildly differing results, which appear to differ by geography, and we don't know why. BCG is a live bacteria, it is even possible that it has changed since it was widely used after WWII. We simply don't know yet.
There seems reasonable hope for new vaccines. Which is a relief after our ongoing failures with HIV. But if these do not appear within the next five years then we will have a public health disaster of the scale of AIDS.