Totally drug-resistant TB emerges in India

http://www.nature.com/news/totally-drug-resistant-tb-emerges-in-india-1.9797

by pwg • 15 years ago

88 42 15 years ago

tomjen3• 15 years ago

That is to be expected when no new drugs are developed in half a century.

We really should focus more on doing what we did with smallpox -- destroy it outright, rather than merely give it a bloody nose or two.

JunkDNA• 15 years ago

The difference here is that smallpox is a virus that was eradicated with a vaccine. Antibiotics against bacteria are another matter. Vaccines allow your body to use its full nuclear arsenal. Antibiotics on the other hand are single points of failure that nature can route around.

drewblaisdell• 15 years ago

Not only that, when antibiotics fail, they often leave your body in a weaker state than before you took them (by destroying helpful gut flora and damaging your intestinal tract).

hesdeadjim• 15 years ago

It's not quite that simple.

This popped up on Reddit a few days back and in the comments a physician from India mentioned that a big part of the problem is that a) antibiotics are extremely over-used as they can be gotten over the counter and people do not understand that they do nothing for viral infections like the common cold, and b) his patients rarely finished an entire course even when they were directed to.

Both of these factors combine to create a great environment for disease resistant strains of bacteria to emerge.

Swizec• 15 years ago

As a person who usually doesn't finish the full course of antibiotics if they're feeling healthy: Why does it matter?

marvin2• 15 years ago

Unfortunately I'm a bit late to the party on this, but as a case in point, Norway has _very_ tight discipline on penicillin and antibiotics usage for this very reason. This has nothing to do with "medicines being outdated", it has to do with correct and disciplined usage of antibiotics.

Norwegian hospitals use forms of penicillin which simply do not work on patients from countries where antibiotics usage is more lax. Treating a patient from Spain with the same penicillin which is used for Norwegian patients would not have any effect and kill the patient. This is _solely_ because poor discipline in drug usage leads to antibiotics-risistant bacteria.

What needs to be done, and globally, is to

1) Stop treating livestock with prophylactic antibiotics 2) Stop prescribing antibiotics for conditions where it doesn't work (just because the patient has a cold and is complaining "can't you give me something?") 3) _Force_ patients to take their entire antibiotics course so even the small but drug-resistant minority of bacteria is killed off by the immune system and not transmitted further.

If the global community fails to do this, we will in the worst case end up with a world which looks the way it did in the 1800s - a simple bacterial infection will kill you, because it can't be treated.

This is a question of disciplined usage of medicines, not researching new and clever ways to kill bacteria. We can't eradicate every dangerous strain of bacteria on earth - it's simply not feasible.

tsotha4• 15 years ago

We will never, ever destroy TB. There are simply too many animal hosts for the disease. Hell, you can get it from your dog (http://www.petplace.com/dogs/tuberculosis-in-dogs/page1.aspx). The reason we could get rid of smallpox, the only reason, is that smallpox is a disease found only in human beings. There aren't a whole lot of diseases like this. Polio is one, I think.

But most communicable diseases that afflict humans can also be found in animals. Influenza, plague, leprosy... good luck on those.

dman• 15 years ago

Time to start vaccinating animals?

dodedo2• 15 years ago

Some of those would be easier to exterminate than others. Many animals carry influenza or plague, but isn't leprosy limited to humans and armadillos?

mcbaby• 15 years ago

Vaccines and antibiotics are not the only ways, and certainly not the most effective ways, to fight bacterial infections.

What we should be focusing on is developing bacteriophage technology (namely phage lysins).

As every human (a eukaryote) is prone to certain viruses (which can act only on eukaryotes), every bacteria (a prokaryote), this includes strep throat, TB, etc., is vulnerable to certain viruses (which can only work prokaryotes). These viruses are so specific that they only work on one type of bacteria, and they evolve at nearly the same rate as a bacteria evolves (which is how TB has become antibiotic resistant).

http://www.rockefeller.edu/vaf/phage.php

carbocation5• 15 years ago

People have been trying to use mycobacteriophages to treat TB since the 90s (at least) with no success: http://tbevidence.org/tbevidence_old_site_files/documents/re...

In contrast, vaccines for TB have made actual progress in animal studies: http://www.nature.com/nm/journal/v17/n10/full/nm.2420.html

boneheadmed2• 15 years ago

I think that what is termed "totally drug resistant TB" is more a matter of semantics as the article points out. I was in medical training in Southern California about 8 years ago and spent some time with a large county tuberculosis surveillance unit as part of a public health assignment. There were about five cases of then termed "multi-drug resistant TB" whereby the patients were either confined to their homes or an isolation unit in a hospital. They were under mandatory confinement and observation, enforceable by law. I had no idea that such cases existed at the time. I would refer people to this wikipedia article which has good information: http://en.wikipedia.org/wiki/Multi-drug-resistant_tuberculos...

carbocation5• 15 years ago

We've still got MDR-TB. But now we have XDR-TB (extensively drug-resistant TB) and TDR-TB (totally drug-resistant TB). Each less desirable to encounter than the last. TDR-TB seems to be the real deal: http://cid.oxfordjournals.org/content/early/2011/11/24/cid.c...

It's behind a paywall, but the gist is that some of these patients had TB resistant to ALL of the following:

isoniazid, rifampicin, ethambutol, pyrazinamide, and streptomycin (1st-line agents); as well as oﬂoxacin, moxiﬂoxacin, kanamycin, amikacin, capreomycin, para-aminosalicylic acid, and ethionamide (apparently 2nd-line agents).

Interestingly, the report doesn't discuss whether experimental/3rd-line treatments were tried (including my favorite from M2 year, linezolid). So it's possible that there's still something in our armamentarium that hasn't yet been tried (due, perhaps, to prohibitive cost). (And note that TB, and ID in general, is not my area of focus.)

dredmorbius• 15 years ago

I'm not up on my medical compounds, but how do the resistant strains respond to pre-penicillin compounds such as sulfa drugs and the like. Solfonamide: http://en.wikipedia.org/wiki/Sulfonamide_(medicine)

I've read, years ago, some speculation that these might be used to help beat down if not extinguish, an infection.

Seems that there was some work in this regards in the 1940s, but I don't see much since: http://chestjournal.chestpubs.org/content/8/6/166.abstract

tomwalker• 15 years ago

In the UK they use linezolid for drug resistant infections of all kinds. I think there have been a few cases of resistance already. In the dept I work they use tazocin as first line (it was considered second line til recently)

Without innovation we will have major problems within 20 years

boneheadmed2• 15 years ago

Ah, very good. Yes the term XDR-TB makes more sense in the absence of knowing if every potential antimicrobial therapy has been exhausted. Always found it interesting that the last line therapy is lobectomy or pneumonectomy. TB is a terrible disease for which we will hopefully always stay a few steps ahead.

Totally drug-resistant TB emerges in India

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