6 ms·

Totally drug-resistant TB emerges in India

88 points by pwg 15y ago

tomjen3 15y 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 15y 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 15y 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 15y 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 15y ago
    As a person who usually doesn't finish the full course of antibiotics if they're feeling healthy: Why does it matter?
    - EliRivers 15y ago
      Because some of the bacteria remain. Not enough to make you feel unhealthy. Enough to breed and spread. These survivors are the ones that were most resistant to the antibiotics. Now they have less competition. They will breed more bacteria. More bacteria who inherit their improved resistance to antibiotics. Some of their children will be even more resistant. Some of their children will end up in someone else who, just like you, did not finish the course of antibiotics and, just like you, ended up being an incubator for a hardier, more antibiotic resistant strain. Eventually, the children are completely resistant and they laugh in the face of antibiotics, and then people start dying. People you never met. People who might be generations down the line from you infected with a super-resistant strain that can be traced back to you and others like you.
    - shiven 15y ago
      Because you are increasing the likelihood of giving rise to drug resistant variants of the life-form those antibiotics are directed towards. There is a whole field of investigation into this phenomenon. A good (technical) starting point if you are interested in more is: http://www.drug-resistance.org/ http://www.drug-resistance.org/ Please, for the sake of society at large, complete any and all antibiotic/antiviral drug courses you are prescribed by your physician.
    - dvdhsu 15y ago
      Just because you feel "healthy" doesn't mean that all the bacteria has been killed. If you stop taking the antibiotics before the bacteria is thoroughly eradicated, the bacteria may develop a resistance to the antibiotics you took. The antibiotics that you took are useless against this new bacteria. You will have to seek other antibiotics. Carry this on with multiple types of antibiotics, and you have a Big Problem. Edit: Amazing that there are four responses to this question, all within a minute of each other!
    - celoyd 15y ago
      Because you may have killed most of the bacteria but left a few with some resistance to that type of antibiotic. In classical evolutionary terms, you’ve thinned the herd to the strongest members. These surviving somewhat resistant bacteria, even if they aren’t making you noticeably sick, may then spread those genes into the general population. It’s important not to use antibiotics if you don’t need them, and to complete the course if you do need them. Otherwise you’re selecting for strains of disease that are hard to cure.
  - marvin 15y 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.
    - hartror 15y ago
      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. Wait what? The efficacy of an antibiotic is depended on the bacterial strain not the patient. The rest makes perfect sense however and I strongly agree.
      - carbocation 15y ago
        Dependent on the strain and its resistance profile. Staph aureus might be treated fine with some penicillins; or, it might have acquired methicillin resistance. Same staph aureus though, otherwise. On the other hand, yes, pseudomonas infection is quite different from staph infection. But that's not what GP is referring to.
- tsotha 15y 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 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 15y ago
    Time to start vaccinating animals?
    - OstiaAntica 15y ago
      We already do, especially for rabies.
      - tsotha 15y ago
        We do, but that's just to keep it one step away from us. We don't go out and vaccinate bats or rodents.
  - dodedo 15y 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?
    - tsotha 15y ago
      I don't know. But even if it's true, and even assuming we can develop a vaccine, how do you propose to go out and vaccinate every nine-banded armadillo, not missing even one population large enough to harbor the disease? This isn't an endangered species - they're all over the southeastern US.
mcbaby 15y 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 http://www.rockefeller.edu/vaf/phage.php
- carbocation 15y 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/rescentre/sop/studies/Bacteriophage-based%20assay/General/9.pdf 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 http://www.nature.com/nm/journal/v17/n10/full/nm.2420.html
boneheadmed 15y 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_tuberculosis http://en.wikipedia.org/wiki/Multi-drug-resistant_tuberculos...
- carbocation 15y 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.cir889 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 15y 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) 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 http://chestjournal.chestpubs.org/content/8/6/166.abstract
deleted 15y ago
[deleted]

88 points by pwg 15y 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 15y 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 15y 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 15y 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 15y ago
  As a person who usually doesn't finish the full course of antibiotics if they're feeling healthy: Why does it matter?
  - EliRivers 15y ago
    Because some of the bacteria remain. Not enough to make you feel unhealthy. Enough to breed and spread. These survivors are the ones that were most resistant to the antibiotics. Now they have less competition. They will breed more bacteria. More bacteria who inherit their improved resistance to antibiotics. Some of their children will be even more resistant. Some of their children will end up in someone else who, just like you, did not finish the course of antibiotics and, just like you, ended up being an incubator for a hardier, more antibiotic resistant strain. Eventually, the children are completely resistant and they laugh in the face of antibiotics, and then people start dying. People you never met. People who might be generations down the line from you infected with a super-resistant strain that can be traced back to you and others like you.
  - shiven 15y ago
    Because you are increasing the likelihood of giving rise to drug resistant variants of the life-form those antibiotics are directed towards. There is a whole field of investigation into this phenomenon. A good (technical) starting point if you are interested in more is: http://www.drug-resistance.org/ http://www.drug-resistance.org/ Please, for the sake of society at large, complete any and all antibiotic/antiviral drug courses you are prescribed by your physician.
  - dvdhsu 15y ago
    Just because you feel "healthy" doesn't mean that all the bacteria has been killed. If you stop taking the antibiotics before the bacteria is thoroughly eradicated, the bacteria may develop a resistance to the antibiotics you took. The antibiotics that you took are useless against this new bacteria. You will have to seek other antibiotics. Carry this on with multiple types of antibiotics, and you have a Big Problem. Edit: Amazing that there are four responses to this question, all within a minute of each other!
  - celoyd 15y ago
    Because you may have killed most of the bacteria but left a few with some resistance to that type of antibiotic. In classical evolutionary terms, you’ve thinned the herd to the strongest members. These surviving somewhat resistant bacteria, even if they aren’t making you noticeably sick, may then spread those genes into the general population. It’s important not to use antibiotics if you don’t need them, and to complete the course if you do need them. Otherwise you’re selecting for strains of disease that are hard to cure.
- marvin 15y 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.
  - hartror 15y ago
    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. Wait what? The efficacy of an antibiotic is depended on the bacterial strain not the patient. The rest makes perfect sense however and I strongly agree.
    - carbocation 15y ago
      Dependent on the strain and its resistance profile. Staph aureus might be treated fine with some penicillins; or, it might have acquired methicillin resistance. Same staph aureus though, otherwise. On the other hand, yes, pseudomonas infection is quite different from staph infection. But that's not what GP is referring to.
tsotha 15y 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 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 15y ago
  Time to start vaccinating animals?
  - OstiaAntica 15y ago
    We already do, especially for rabies.
    - tsotha 15y ago
      We do, but that's just to keep it one step away from us. We don't go out and vaccinate bats or rodents.
- dodedo 15y 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?
  - tsotha 15y ago
    I don't know. But even if it's true, and even assuming we can develop a vaccine, how do you propose to go out and vaccinate every nine-banded armadillo, not missing even one population large enough to harbor the disease? This isn't an endangered species - they're all over the southeastern US.

mcbaby 15y 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 http://www.rockefeller.edu/vaf/phage.php

carbocation 15y 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/rescentre/sop/studies/Bacteriophage-based%20assay/General/9.pdf 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 http://www.nature.com/nm/journal/v17/n10/full/nm.2420.html

boneheadmed 15y 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_tuberculosis http://en.wikipedia.org/wiki/Multi-drug-resistant_tuberculos...

carbocation 15y 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.cir889 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 15y 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) 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 http://chestjournal.chestpubs.org/content/8/6/166.abstract

deleted 15y ago

[deleted]